WO2024207433A1 - 二次电池和用电装置 - Google Patents

二次电池和用电装置 Download PDF

Info

Publication number
WO2024207433A1
WO2024207433A1 PCT/CN2023/086923 CN2023086923W WO2024207433A1 WO 2024207433 A1 WO2024207433 A1 WO 2024207433A1 CN 2023086923 W CN2023086923 W CN 2023086923W WO 2024207433 A1 WO2024207433 A1 WO 2024207433A1
Authority
WO
WIPO (PCT)
Prior art keywords
positive electrode
electrode material
particle size
secondary battery
quasi
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/CN2023/086923
Other languages
English (en)
French (fr)
Inventor
桓书星
沈重亨
陈强
吴昌栩
柳娜
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Contemporary Amperex Technology Co Ltd
Original Assignee
Contemporary Amperex Technology Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Contemporary Amperex Technology Co Ltd filed Critical Contemporary Amperex Technology Co Ltd
Priority to PCT/CN2023/086923 priority Critical patent/WO2024207433A1/zh
Priority to CN202380016621.6A priority patent/CN119111003B/zh
Priority to EP23931494.1A priority patent/EP4664556A4/en
Publication of WO2024207433A1 publication Critical patent/WO2024207433A1/zh
Priority to US19/268,114 priority patent/US20250343232A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H01M4/364—Composites as mixtures
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L50/00—Electric propulsion with power supplied within the vehicle
    • B60L50/50—Electric propulsion with power supplied within the vehicle using propulsion power supplied by batteries or fuel cells
    • B60L50/60—Electric propulsion with power supplied within the vehicle using propulsion power supplied by batteries or fuel cells using power supplied by batteries
    • B60L50/64—Constructional details of batteries specially adapted for electric vehicles
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/021—Physical characteristics, e.g. porosity, surface area
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/028—Positive electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2220/00—Batteries for particular applications
    • H01M2220/20—Batteries in motive systems, e.g. vehicle, ship, plane
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present application relates to the technical field of secondary batteries, and in particular to a secondary battery and an electrical device.
  • secondary batteries are widely used in energy storage power supply systems such as hydropower, thermal power, wind power and solar power stations, as well as in many fields such as electric tools, electric bicycles, electric motorcycles and electric vehicles.
  • Secondary batteries with high energy density and long cycle life have very high requirements for positive electrode plates.
  • the positive electrode plates of secondary batteries with high energy density and long cycle life should have a higher compaction density and a longer service life.
  • the present application is made in view of the above-mentioned problems, and one of its purposes is to provide a secondary battery having a higher energy density and a better cycle life.
  • the first aspect of the present application provides a secondary battery, including a positive electrode plate, on which a positive electrode active material is provided, wherein the positive electrode active material includes an aggregate-type positive electrode material and a quasi-single-crystal positive electrode material;
  • the volume average particle size Dv50 of the agglomerate type positive electrode material is 8 ⁇ m to 15 ⁇ m, and the primary particle size of the agglomerate type positive electrode material is 0.1 ⁇ m to 0.6 ⁇ m;
  • the volume average particle size Dv50 of the quasi-single-crystal positive electrode material is 2.5 ⁇ m to 4 ⁇ m, and the primary particle size of the quasi-single-crystal positive electrode material is 0.8 ⁇ m to 2 ⁇ m;
  • the mass ratio of the agglomerate-type positive electrode material to the quasi-single-crystal positive electrode material is greater than or equal to 1.
  • the present invention adopts a Dv50 of 2.5 ⁇ m to 4 ⁇ m and a primary particle size of 0.8 ⁇ m to 2 ⁇ m.
  • the quasi-single-crystal positive electrode material is graded with the agglomerate-type positive electrode material with a Dv50 of 8 ⁇ m to 15 ⁇ m and a primary particle size of 0.1 ⁇ m to 0.6 ⁇ m in a mass ratio greater than or equal to 1. While ensuring the high pressure density of the positive electrode plate, the positive electrode plate can obtain a better life and capacity, so that the secondary battery using the positive electrode plate has a higher energy density and a longer cycle life.
  • the mass ratio of the agglomerate-type positive electrode material to the quasi-single-crystal positive electrode material is 1 to 9:1.
  • the mass ratio of the agglomerate type positive electrode material to the quasi-single crystal type positive electrode material is 2.3 to 3: 1. In this way, the energy density and cycle life of the secondary battery can be further improved.
  • the volume average particle size Dv50 of the quasi-monocrystalline positive electrode material is 3 ⁇ m to 3.5 ⁇ m, and/or the primary particle size of the quasi-monocrystalline positive electrode material is 1.2 ⁇ m to 1.5 ⁇ m. In this way, the energy density of the secondary battery can be further improved.
  • the primary particle size of the aggregate-type positive electrode material is 0.2 ⁇ m to 0.4 ⁇ m. In this way, the energy density of the secondary battery can be further improved.
  • the chemical formula of the agglomerate-type positive electrode material is Li x1 Ni y1 Co z1 M 1-y1-z1 O 2 , wherein 0.9 ⁇ x1 ⁇ 1, 0.9 ⁇ y1 ⁇ 0.98, 0.05 ⁇ z1 ⁇ 0.1, and M includes one or more of Mn, Al, B, Zr, Sr, Y, Sb, W, Ti, Mg and Nb.
  • M includes one or more of Mn, Al, B, Zr, Sr, Y, Sb, W, Ti, Mg and Nb.
  • 0.9 ⁇ y1 ⁇ 0.96 the nickel content of the aggregate-type positive electrode material is appropriately reduced while ensuring that the positive electrode sheet has a high capacity.
  • the chemical formula of the quasi-monocrystalline positive electrode material is Li x2 Ni y2 Co z2 M′ 1-y2-z2 O 2 , wherein 0.9 ⁇ x2 ⁇ 1, 0.9 ⁇ y2 ⁇ 0.98, 0.05 ⁇ z2 ⁇ 0.1, and M′ includes one or more of Mn, Al, B, Zr, Sr, Y, Sb, W, Ti, Mg and Nb.
  • M′ includes one or more of Mn, Al, B, Zr, Sr, Y, Sb, W, Ti, Mg and Nb.
  • y2 >y1. In this way, the capacity of the positive electrode sheet can be better improved, thereby improving the energy density of the secondary battery, when the overall nickel content of the positive electrode active material is relatively not very high.
  • the particle size distribution span of the agglomerate-type positive electrode material is (Dv90-Dv10)/Dv50 ⁇ 1.5. In this way, sufficient filling space and gram capacity can be provided for the positive electrode sheet, thereby increasing the capacity of the positive electrode sheet and further increasing the energy density of the secondary battery.
  • the particle size distribution span (Dv90-Dv10)/Dv50 of the agglomerate-type positive electrode material is 0.7 to 1.4. In this way, sufficient filling space can be provided for the positive electrode sheet, the capacity of the positive electrode sheet can be better improved, and the energy density of the secondary battery can be improved.
  • the BET specific surface area of the agglomerate positive electrode material is 0.2 m 2 / g to 0.8 m 2 /g. This can prevent excessive active surface of the agglomerate positive electrode material from contacting the electrolyte and avoid excessive corrosion of the agglomerate positive electrode material by the electrolyte, thereby increasing the life of the positive electrode sheet and the cycle life of the secondary battery.
  • the BET specific surface area of the agglomerate-type positive electrode material is 0.3 m 2 / g to 0.6 m 2 /g. In this way, the life of the positive electrode sheet can be better improved, thereby improving the cycle life of the secondary battery.
  • the particle size distribution span of the quasi-single crystal positive electrode material is (Dv90-Dv10)/Dv50 ⁇ 1.2. In this way, the compressive performance of the positive electrode sheet can be improved, thereby increasing the life of the positive electrode sheet and the cycle life of the secondary battery.
  • the particle size distribution span of the quasi-monocrystalline positive electrode material (Dv90-Dv10)/Dv50 is 1.3 to 1.5. In this way, the compressive performance of the positive electrode sheet can be better improved, the life of the positive electrode sheet can be better improved, and the cycle life of the secondary battery can be improved.
  • the BET specific surface area of the quasi-single-crystal positive electrode material is 0.8 m 2 /g to 1.3 m 2 /g. In this way, a highly dispersed morphology can be achieved, which is beneficial to improving the space utilization of the positive electrode sheet.
  • the BET specific surface area of the quasi-single-crystal positive electrode material is 0.85 m 2 /g to 1.15 m 2 /g. In this way, the space utilization of the positive electrode sheet can be further improved.
  • the particle size distribution span of the positive electrode active material (Dv90-Dv10)/Dv50 is 1.5-2.1. In this way, the positive electrode sheet can obtain a higher compaction density and processing performance at a higher film loading.
  • the BET specific surface area of the positive electrode active material is 0.5 m 2 /g to 0.7 m 2 /g. In this way, the positive electrode sheet can also obtain a higher surface area at a higher film loading. Compacting density and processing performance to improve the energy density of secondary batteries.
  • the mass percentage of the positive electrode active material in the positive electrode sheet to the positive electrode film layer is 95% to 99.5%, so that the gram capacity of the positive electrode active material in the secondary battery can be guaranteed, the capacity of the positive electrode sheet can be increased, and the energy density of the secondary battery can be increased.
  • the coating area density of the positive active material in the positive electrode sheet is 21.5 mg/cm 2 to 32.5 mg/cm 2 .
  • thick positive electrode coating combined with high compaction density can further increase the capacity of the positive electrode sheet and improve the energy density of the secondary battery.
  • a second aspect of the present application provides an electrical device, which includes the secondary battery of the first aspect of the present application.
  • the positive electrode plate of the secondary battery of the present application adopts a quasi-single-crystal positive electrode material with a Dv50 of 2.5 ⁇ m to 4 ⁇ m and a primary particle size of 0.8 ⁇ m to 2 ⁇ m, and a graded with an agglomerate-type positive electrode material with a Dv50 of 8 ⁇ m to 15 ⁇ m and a primary particle size of 0.1 ⁇ m to 0.6 ⁇ m in a mass ratio greater than or equal to 1. While ensuring the high pressure density of the positive electrode plate, the positive electrode plate can obtain a better life and capacity, thereby making the secondary battery have a higher energy density and a longer cycle life.
  • FIG1 is a schematic diagram of a secondary battery according to an embodiment of the present application.
  • FIG2 is an exploded view of the secondary battery of one embodiment of the present application shown in FIG1 ;
  • FIG. 3 is a schematic diagram of an electric device using a secondary battery as a power source according to an embodiment of the present application.
  • Secondary battery 51. Casing; 52. Electrode assembly; 53. Cover plate; 6. Electrical device.
  • range disclosed in the present application is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of the particular range.
  • the range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 60 to 120 and 80 to 110 is listed for a particular parameter, it is understood that a range of 60 to 110 and 80 to 120 is also expected.
  • the numerical range "a to b" represents an abbreviation of any real number combination between a and b, where a and b are both real numbers.
  • the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations.
  • a parameter is expressed as an integer ⁇ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.
  • the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially.
  • the method may further include step (c), which means that step (c) may be added to the method in any order.
  • the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.
  • the “include” and “comprising” mentioned in this application are open-ended or closed-ended.
  • the “include” and “comprising” may mean that other components not listed may also be included or only the listed components may be included or only the listed components may be included.
  • the term "or” is inclusive.
  • the phrase “A or B” means “A, B, or both A and B”. More specifically, any of the following conditions satisfies the condition "A or B”: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).
  • the weight described in this application specification may be ⁇ g, mg, g, kg or other weight units known in the chemical industry.
  • the present application provides a secondary battery, which mainly through the selection and ratio of the positive electrode active material in the positive electrode plate, can make the positive electrode plate have a higher compaction density and service life, and at the same time have a higher capacity, so that the secondary battery has a higher energy density and a longer cycle life.
  • a secondary battery comprising a positive electrode plate having a positive electrode active material thereon, the positive electrode active material comprising an agglomerate-type positive electrode material and a quasi-single-crystal positive electrode material; wherein the volume average particle size Dv50 of the agglomerate-type positive electrode material is 8 ⁇ m to 15 ⁇ m, and the primary particle size of the agglomerate-type positive electrode material is 0.1 ⁇ m to 0.6 ⁇ m; the volume average particle size Dv50 of the quasi-single-crystal positive electrode material is 2.5 ⁇ m to 4 ⁇ m, and the primary particle size of the quasi-single-crystal positive electrode material is 0.8 ⁇ m to 2 ⁇ m; and the mass ratio of the agglomerate-type positive electrode material to the quasi-single-crystal positive electrode material is greater than or equal to 1.
  • the secondary battery In order to make the secondary battery reach a high energy density of 360Wh/kg to 500Wh/kg, the secondary battery needs to use a positive high nickel active material in design and a high coating surface density.
  • the negative electrode uses graphite + high content silicon-based materials as the negative electrode active material.
  • the thick coating design of the positive electrode plate will lead to the following two problems for the secondary battery: On the one hand, when the coating surface density (CW) of the currently used positive electrode material is large, the compaction density of the positive electrode plate is limited, generally ⁇ 3.3g/ cm3 , and the low compaction of the positive electrode plate will reduce the energy density of the battery; On the other hand, when the positive electrode active material uses polycrystalline material, the specific surface area is large, the side reactions increase, and the cycle performance of the high energy density lithium-ion battery is reduced.
  • CW coating surface density
  • the positive electrode active material uses polycrystalline material
  • the specific surface area is large, the side reactions increase, and the cycle performance of the high energy density lithium-ion battery is reduced.
  • the positive electrode active material in the positive electrode sheet includes agglomerate type Positive electrode material and quasi-single crystal positive electrode material; wherein, the volume average particle size Dv50 of the agglomerate positive electrode material is controlled within 8 ⁇ m to 15 ⁇ m, and the primary particle size of the agglomerate positive electrode material is 0.1 ⁇ m to 0.6 ⁇ m; the volume average particle size Dv50 of the quasi-single crystal positive electrode material is controlled within 2.5 ⁇ m to 4 ⁇ m, and the primary particle size of the quasi-single crystal positive electrode material is 0.8 ⁇ m to 2 ⁇ m; and the mass ratio of the agglomerate positive electrode material to the quasi-single crystal positive electrode material is controlled to be greater than or equal to 1.
  • agglomerate-type positive electrode materials with a specific volume average particle size Dv50 and a specific primary particle size and quasi-single crystal positive electrode materials with a specific volume average particle size Dv50 and a specific primary particle size they are mixed in a specific mass ratio; wherein the agglomerate-type positive electrode material has a larger particle size, plays a skeleton role, and can increase the capacity of the electrode sheet; the quasi-single crystal positive electrode material has a smaller particle size, which can fill the gaps between the particles of the agglomerate-type positive electrode material, thereby increasing the compaction density of the positive electrode sheet; and the quasi-single crystal positive electrode material has a longer life, which can extend the service life of the electrode sheet.
  • Agglomerate-type positive electrode materials with a Dv50 of 8 ⁇ m to 15 ⁇ m can be used as the framework of the positive electrode sheet. If the particle size is too large, cracks are likely to appear on the edge of the particles and the gram capacity is limited. If the particle size is too small, there is no skeleton effect.
  • Single-crystal-like positive electrode materials with a Dv50 of 2.5 ⁇ m to 4 ⁇ m can be used as secondary fillers for agglomerate-type positive electrode materials to improve space utilization. Because of their high dispersibility and compressive resistance, they can be fully filled in the pores between the particles of agglomerate-type positive electrode materials.
  • the mass ratio of the two to be greater than or equal to 1 can maximize the compatibility of gram capacity and compaction density, and such dense stacking is not prone to particle displacement/slip under high pressure, thereby avoiding large elongation of the electrode and increased brittleness.
  • the Dv50 of the quasi-single-crystal positive electrode material is 2.5 ⁇ m ⁇ 4 ⁇ m, and its primary particle size is 0.8 ⁇ m ⁇ 2 ⁇ m, which ensures the positive electrode capacity and life while achieving high positive electrode density.
  • the Dv50 of the quasi-single-crystal positive electrode material is too large, the compaction density of the electrode sheet will decrease; when the primary particle size of the quasi-single-crystal positive electrode material is less than 0.8 ⁇ m, the number of primary particles required to form the quasi-single-crystal positive electrode material is too large, and its morphology will be closer to agglomerates.
  • the active specific surface of the quasi-single-crystal positive electrode material is too exposed, and it is easily corroded by the electrolyte, resulting in a decrease in the life of the positive electrode sheet and a decrease in compressive resistance; when the primary particle size of the quasi-single-crystal positive electrode material is greater than 2 ⁇ m, the quasi-single-crystal positive electrode The number of primary particles required for the material is too small. Perhaps only 2 to 3 primary particles are needed to form a quasi-single-crystal positive electrode material.
  • the active surface of the quasi-single-crystal positive electrode material is too little exposed, the lithium ion transmission path is limited, and the kinetic performance is deteriorated, which affects the capacity and life of the positive electrode.
  • This application adopts a quasi-single crystal positive electrode material with a Dv50 of 2.5 ⁇ m to 4 ⁇ m and a primary particle size of 0.8 ⁇ m to 2 ⁇ m, and a gradation of agglomerate positive electrode material with a Dv50 of 8 ⁇ m to 15 ⁇ m and a primary particle size of 0.1 ⁇ m to 0.6 ⁇ m according to a mass ratio of 1 to 9:1, while ensuring the high pressure density of the positive electrode plate, the positive electrode plate has a better life and capacity, thereby improving the energy density and cycle life of the secondary battery.
  • the gram capacity range of the positive electrode material in the secondary battery of this application can reach 215mAh/g to 230mAh/g, 0.33C.
  • the quasi-single crystal positive electrode material is an irregular structure formed by several primary particles stacked together; the agglomerate positive electrode material is a regular small sphere formed by a larger number of spherical primary particles with smaller particle sizes.
  • the volume average particle size Dv50 of the quasi-single crystal positive electrode material can be but is not limited to 2.5 ⁇ m, 2.6 ⁇ m, 2.7 ⁇ m, 2.8 ⁇ m, 2.9 ⁇ m, 3.0 ⁇ m, 3.1 ⁇ m, 3.2 ⁇ m, 3.3 ⁇ m, 3.4 ⁇ m, 3.5 ⁇ m, 3.6 ⁇ m, 3.7 ⁇ m, 3.8 ⁇ m, 3.9 ⁇ m, 4 ⁇ m.
  • the primary particle size of the quasi-single crystal positive electrode material may be, but is not limited to, 0.8 ⁇ m, 0.9 ⁇ m, 1.0 ⁇ m, 1.1 ⁇ m, 1.2 ⁇ m, 1.3 ⁇ m, 1.4 ⁇ m, 1.5 ⁇ m, 1.6 ⁇ m, 1.7 ⁇ m, 1.8 ⁇ m, 1.9 ⁇ m, 2 ⁇ m.
  • the volume average particle size Dv50 of the agglomerate positive electrode material may be, but is not limited to, 8 ⁇ m, 8.5 ⁇ m, 9 ⁇ m, 9.5 ⁇ m, 10 ⁇ m, 10.5 ⁇ m, 11 ⁇ m, 11.5 ⁇ m, 12 ⁇ m, 12.5 ⁇ m, 13 ⁇ m, 13.5 ⁇ m, 14 ⁇ m, 14.5 ⁇ m, 15 ⁇ m.
  • the primary particle size of the agglomerate positive electrode material may be, but is not limited to, 0.1 ⁇ m, 0.2 ⁇ m, 0.3 ⁇ m, 0.4 ⁇ m, 0.5 ⁇ m, 0.6 ⁇ m.
  • the mass ratio of the agglomerate-type positive electrode material to the quasi-single-crystal positive electrode material may be, but is not limited to, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, or 9:1.
  • the mass ratio of the agglomerate-type positive electrode material to the quasi-single-crystal positive electrode material is 1 to 9: 1. In this way, the energy density and cycle life of the secondary battery can be further improved.
  • the mass ratio of the agglomerate type positive electrode material to the quasi-single crystal type positive electrode material is 2.3 to 3: 1. With such a particle mass ratio gradation, the energy density and cycle life of the secondary battery can be further improved.
  • the volume average particle size Dv50 of the quasi-single-crystal positive electrode material is 3 ⁇ m to 3.5 ⁇ m, and the primary particle size of the quasi-single-crystal positive electrode material is 1.2 ⁇ m to 1.5 ⁇ m. It is more conducive to improving the energy density of the secondary battery using the positive electrode plate.
  • the primary particle size of the aggregate-type positive electrode material is 0.2 ⁇ m to 0.4 ⁇ m, which is more conducive to improving the energy density and cycle life of the secondary battery.
  • the chemical formula of the agglomerate-type positive electrode material is Li x1 Ni y1 Co z1 M 1-y1- z1 O 2 , wherein 0.9 ⁇ x1 ⁇ 1, 0.9 ⁇ y1 ⁇ 0.98, 0.05 ⁇ z1 ⁇ 0.1, and M includes one or more of Mn, Al, B, Zr, Sr, Y, Sb, W, Ti, Mg, and Nb.
  • M includes one or more of Mn, Al, B, Zr, Sr, Y, Sb, W, Ti, Mg, and Nb.
  • the chemical formula of the agglomerate-type positive electrode material is 0.9 ⁇ y1 ⁇ 0.96. Since the primary particle size of the agglomerate-type positive electrode material is relatively small, there are more grain boundaries inside the agglomerate, which is more conducive to the transmission of lithium ions, so high capacity can be obtained even when the nickel content is not very high.
  • the chemical formula of the quasi-monocrystalline positive electrode material is Li x2 Ni y2 Co z2 M′ 1-y2- z2 O 2 , wherein 0.9 ⁇ x2 ⁇ 1, 0.9 ⁇ y2 ⁇ 0.98, 0.05 ⁇ z2 ⁇ 0.1, and M′ includes one or more of Mn, Al, B, Zr, Sr, Y, Sb, W, Ti, Mg, and Nb.
  • M′ includes one or more of Mn, Al, B, Zr, Sr, Y, Sb, W, Ti, Mg, and Nb.
  • the quasi-monocrystalline positive electrode material also uses high-nickel active materials, which can further increase the capacity of the positive electrode sheet and improve the energy density of the secondary battery.
  • 0.92 ⁇ y2 ⁇ 0.98 0.92 ⁇ y2 ⁇ 0.98. This is because the primary particle size of the quasi-single-crystal positive electrode material is relatively larger, and the particle size of the secondary sphere of the quasi-single-crystal positive electrode material is larger than that of the agglomerated positive electrode material. The particle size of the secondary spheres is small, and there is no interface for rapid lithium ion transmission inside the single-crystal-like positive electrode material. Therefore, setting the nickel content y2 of the single-crystal-like positive electrode material to 0.92-0.98 can further increase the capacity of the positive electrode sheet and improve the energy density of the secondary battery.
  • y2 >y1. That is, the nickel content of the quasi-monocrystalline positive electrode material is greater than the nickel content of the agglomerate positive electrode material. In this way, the capacity of the positive electrode sheet can be better improved when the overall nickel content of the positive electrode active material is relatively not very high, thereby improving the energy density of the secondary battery.
  • the element types of M in the chemical formula of the quasi-single crystal positive electrode material and M' in the chemical formula of the agglomerate positive electrode material are different, and their roles in the synthesis process of the positive electrode material are also different accordingly.
  • M and M' are high-priced elements such as Sb and Nb, they can play a role in refining the grains, making the primary particle size of the positive electrode material smaller, and further improving the capacity and power performance of the positive electrode material
  • M and M' are Sr, they can be used as a co-solvent, so that the positive electrode material does not require too high a temperature during the sintering process of the positive electrode material to obtain the positive electrode material of the corresponding particle size, reduce the formation of the rock salt phase, and improve the capacity and cycle life of the positive electrode sheet to a certain extent.
  • the element types of M and M' in the chemical formula of the positive electrode material can be determined according to actual needs.
  • the particle size distribution span of the agglomerate-type positive electrode material is (Dv90-Dv10)/Dv50 ⁇ 1.5. Controlling the particle size distribution span of the agglomerate-type positive electrode material (Dv90-Dv10)/Dv50 to ⁇ 1.5 can provide sufficient filling space and gram capacity for the positive electrode sheet.
  • the particle size distribution span (Dv90-Dv10)/Dv50 of the agglomerate-type positive electrode material can be but is not limited to 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, and 1.5.
  • the particle size distribution span (Dv90-Dv10)/Dv50 of the agglomerated positive electrode material is 0.7 to 1.4, which can better provide sufficient filling space for the positive electrode sheet, better improve the gram capacity of the positive electrode sheet, and improve the energy density of the secondary battery.
  • the BET specific surface area of the agglomerate positive electrode material is 0.2 m 2 /g to 0.8 m 2 /g. Controlling the BET specific surface area of the agglomerate positive electrode material between 0.2 m 2 / g and 0.8 m 2 /g can prevent excessive active surface of the agglomerate positive electrode material from contacting with the electrolyte, and avoid excessive corrosion of the agglomerate positive electrode material by the electrolyte, thereby increasing the life of the positive electrode sheet and the cycle life of the secondary battery.
  • the BET specific surface area of the agglomerate type positive electrode material may be, but is not limited to, 0.2 m 2 /g, 0.3 m 2 /g, 0.4 m 2 /g, 0.5 m 2 /g, 0.6 m 2 /g, 0.7 m 2 /g, or 0.8 m 2 /g.
  • the BET specific surface area of the aggregate-type positive electrode material is 0.3 m 2 /g to 0.6 m 2 /g. In this way, the life of the positive electrode sheet can be better improved, and the cycle life of the secondary battery can be improved.
  • the particle size distribution span (Dv90-Dv10)/Dv50 of the quasi-monocrystalline positive electrode material is ⁇ 1.2. Controlling the particle size distribution span (Dv90-Dv10)/Dv50 of the quasi-monocrystalline positive electrode material to ⁇ 1.2 can improve the compressive performance of the positive electrode sheet, thereby increasing the life of the positive electrode sheet and the cycle life of the secondary battery. It can be understood that the particle size distribution span (Dv90-Dv10)/Dv50 of the quasi-monocrystalline positive electrode material can be, but is not limited to, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0.
  • the particle size distribution span of the quasi-single crystal positive electrode material (Dv90-Dv10)/Dv50 is 1.3 to 1.5. In this way, the compressive performance of the positive electrode sheet can be better improved, the life of the positive electrode sheet can be better improved, and the cycle life of the secondary battery can be improved.
  • the BET specific surface area of the quasi-single-crystal positive electrode material is 0.8 m 2 /g to 1.3 m 2 /g.
  • the BET specific surface area of the quasi-single-crystal positive electrode material can be, but is not limited to, 0.8 m 2 /g, 0.9 m 2 /g, 1.0 m 2 /g, 1.1 m 2 /g , 1.2 m 2 /g, and 1.3 m 2 /g.
  • the BET specific surface area of the quasi-single-crystal positive electrode material is 0.85 m 2 /g to 1.15 m 2 /g. In this way, the space utilization of the positive electrode sheet can be further improved.
  • the particle size distribution span (Dv90-Dv10)/Dv50 of the positive electrode active material is 1.5 to 2.1. In this way, the positive electrode sheet can obtain a higher compaction density and processing performance at a higher membrane load, thereby improving the energy density of the secondary battery. It is understood that the particle size distribution span (Dv90-Dv10)/Dv50 of the mixed positive electrode active material can be, but is not limited to, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1.
  • volume average particle size Dv10, Dv50, and Dv90 of the positive electrode material are well-known concepts in the art. Specifically, Dv10 is the particle size that reaches 10% of the volume from the small particle size side in the particle size distribution based on volume, and the unit is usually ⁇ m. Dv50 is the particle size that reaches 50% of the volume from the small particle size side in the particle size distribution based on volume. Dv90 is the particle size at which 90% of the volume is accumulated from the smallest particle size in the volume-based particle size distribution of the powder particles.
  • the BET specific surface area of the positive electrode active material is 0.5m2/ g to 0.7m2 /g.
  • the positive electrode sheet can also obtain a higher compaction density and processing performance at a higher film loading, thereby improving the energy density of the secondary battery.
  • the BET specific surface area of the mixed positive electrode active material can be, but is not limited to, 0.5m2 / g, 0.55m2/ g, 0.6m2 /g, 0.65m2 /g, and 0.7m2 /g.
  • the mass percentage of the positive electrode active material in the positive electrode sheet to the positive electrode film layer is 95% to 99.5%. Controlling the mass percentage of the positive electrode active material in the positive electrode sheet to the positive electrode film layer at 95% to 99.5% can ensure the gram capacity of the positive electrode active material in the secondary battery and improve the energy density of the secondary battery. It is understandable that the mass percentage of the positive electrode active material in the positive electrode sheet to the positive electrode film layer can be but not limited to 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, 99.5%.
  • the coating area density of the positive active material in the positive electrode sheet is 21.5 mg/cm 2 to 32.5 mg/cm 2 .
  • the positive electrode sheet of the present application can achieve a high compaction density of the positive electrode sheet at a higher coating area density of the positive active material, and the compaction density of the positive electrode sheet can reach more than 3.7 g/cm 3 , and the elongation of the sheet after cold pressing is small, and the positive electrode sheet is not prone to breakage and other problems during later use.
  • the coating area density of the positive electrode active material in the positive electrode sheet can be, but is not limited to , 21.5 mg/cm 2 , 22 mg/cm 2 , 22.5 mg/cm 2 , 23 mg/cm 2 , 23.5 mg/cm 2 , 24 mg/cm 2 , 24.5 mg/cm 2 , 25 mg/cm 2 , 25.5 mg/cm 2 , 26 mg/cm 2 , 26.5 mg/cm 2 , 27 mg/cm 2 , 27.5 mg/cm 2 , 28 mg/cm 2 , 28.5 mg/cm 2 , 29 mg/cm 2 , 29.5 mg/cm 2 , 30 mg/cm 2 , 30.5 mg/cm 2 , 31 mg/cm 2 , 31.5 mg/cm 2 , 32 mg/cm 2 , 32.5mg/ cm2 .
  • the positive electrode plate includes a positive electrode current collector, which may be a metal foil or a composite current collector, wherein the metal foil may be an aluminum foil, and the composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer.
  • a method for preparing a positive electrode sheet in a secondary battery comprises the following steps:
  • the slurry is coated on the positive electrode current collector, dried and pressed to obtain a positive electrode sheet.
  • the mass ratio of the positive electrode active material, the conductive agent and the binder in the slurry is (90-96): (2-5): (2-5), and the solid content of the slurry is 70%-99.5%.
  • the size grading of the aggregated positive electrode material and the quasi-single crystal positive electrode material in the positive electrode active material the positive electrode active material, the conductive agent and the binder are mixed in a specific mass ratio, and the slurry is adjusted to a specific solid content by a solvent; by combining the particle grading of the positive electrode active material with the specific positive electrode slurry formula, it can be ensured that the performance of the positive electrode active material is fully exerted, and the compaction density of the positive electrode sheet can be better improved.
  • the agglomerate-type positive electrode material and the quasi-single crystal positive electrode material are put into a stirring tank according to a mass ratio, a conductive agent and a binder are added for premixing, and a solvent is added for rapid stirring under a vacuum environment to form a positive electrode slurry; the positive electrode slurry is evenly coated on both sides of the positive electrode collector aluminum foil, the electrode sheet coated with the slurry is dried at 100°C to 130°C, taken out and cold pressed to obtain a positive electrode sheet.
  • a lithium source, a high-nickel ternary precursor, and an additive are placed in a mixer according to a proportion, mixed evenly, and sintered at 550°C to 800°C in an oxygen atmosphere for 5h to 20h to obtain an agglomerate-type positive electrode material; a lithium source, a high-nickel ternary precursor, and an additive are placed in a mixer according to a proportion, mixed evenly, and sintered at 600°C to 900°C in an oxygen atmosphere for 5h to 20h to obtain a single-crystal-like positive electrode material.
  • the conductive agent includes one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.
  • the binder includes one or more of polyvinylidene fluoride, polytetrafluoroethylene, vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorine-containing acrylate resin.
  • the secondary battery also includes a negative electrode plate, which has a negative electrode active material, and the mass percentage of the silicon-based material in the negative electrode active material is 20% to 100%.
  • the positive electrode plate of the first aspect of the present application and the negative electrode plate with a high silicon content form a secondary battery, which can enable the secondary battery to achieve a higher energy density.
  • the mass percentage of the silicon-based material in the negative electrode active material can be but is not limited to 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%.
  • an electrical device comprising the secondary battery of the first aspect of the present application.
  • the components, material types or contents of the batteries mentioned are applicable to both lithium-ion secondary batteries and sodium-ion secondary batteries.
  • a secondary battery is provided.
  • a secondary battery includes a positive electrode sheet, a negative electrode sheet, an electrolyte and a separator.
  • active ions are embedded and released back and forth between the positive electrode sheet and the negative electrode sheet.
  • the electrolyte plays the role of conducting ions between the positive electrode sheet and the negative electrode sheet.
  • the separator is set between the positive electrode sheet and the negative electrode sheet, mainly to prevent the positive and negative electrodes from short-circuiting, while allowing ions to pass through.
  • the positive electrode plate includes a positive electrode current collector and a positive electrode film layer arranged on at least one surface of the positive electrode current collector.
  • the positive electrode current collector has two surfaces opposite to each other in its thickness direction, and the positive electrode film layer is disposed on any one or both of the two opposite surfaces of the positive electrode current collector.
  • the positive electrode current collector may be a metal foil or a composite current collector.
  • aluminum foil may be used as the metal foil.
  • the composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer.
  • the composite current collector may be formed by forming a metal material on a polymer material substrate.
  • the metal material includes but is not limited to aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.
  • Polymer material substrate such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.
  • the positive electrode active material may include a positive electrode active material for a battery known in the art.
  • the positive electrode active material of the lithium ion secondary battery may include at least one of the following materials: olivine-structured lithium-containing phosphates, lithium transition metal oxides and their respective modified compounds.
  • the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more.
  • lithium transition metal oxides may include, but are not limited to, lithium cobalt oxide (such as LiCoO 2 ), lithium nickel oxide (such as LiNiO 2 ), lithium manganese oxide (such as LiMnO 2 , LiMn 2 O 4 ), At least one of lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1/3 Co 1/3 Mn 1/3 O 2 (also referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O 2 (also referred to as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O 2 (also referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O 2 (also referred to as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O 2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O 2
  • lithium-containing phosphates having an olivine structure may include, but are not limited to, lithium iron phosphate (such as LiFePO 4 (may also be referred to as LFP)), at least one of a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO 4 ), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.
  • lithium iron phosphate such as LiFePO 4 (may also be referred to as LFP)
  • LiMnPO 4 lithium manganese phosphate
  • the positive electrode active material of the sodium ion secondary battery may include at least one of the following materials: at least one of a sodium transition metal oxide, a polyanionic compound, and a Prussian blue compound.
  • the present application is not limited to these materials, and other conventionally known materials that can be used as positive electrode active materials for sodium ion batteries may also be used.
  • the transition metal in the sodium transition metal oxide, may be at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr and Ce.
  • the sodium transition metal oxide is, for example, Na x MO 2 , wherein M is one or more of Ti, V, Mn, Co, Ni, Fe, Cr and Cu, and 0 ⁇ x ⁇ 1.
  • the polyanionic compound can be a class of compounds having sodium ions, transition metal ions and tetrahedral (YO 4 ) n- anion units.
  • the transition metal can be at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr and Ce;
  • Y can be at least one of P, S and Si;
  • n represents the valence state of (YO 4 ) n- .
  • the polyanionic compound may also be a compound having sodium ions, transition metal ions, tetrahedral (YO 4 ) n- anion units and halogen anions.
  • the transition metal may be at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr and Ce;
  • Y may be at least one of P, S and Si, and n represents the valence state of (YO 4 ) n- ;
  • the halogen may be at least one of F, Cl and Br.
  • the polyanionic compound may also be a compound having sodium ions, tetrahedral (YO 4 ) n- anion units, polyhedral units (ZO y ) m+ and optional halogen anions.
  • Y may be at least one of P, S and Si
  • n represents the valence state of (YO 4 ) n-
  • Z represents a transition metal, which may be Mn, Fe, At least one of Ni, Co, Cr, Cu, Ti, Zn, V, Zr and Ce
  • m represents the valence state of (ZO y ) m+
  • the halogen may be at least one of F, Cl and Br.
  • the polyanionic compound is, for example, at least one of NaFePO4 , Na3V2 (PO4) 3 (sodium vanadium phosphate , abbreviated as NVP), Na4Fe3 ( PO4 ) 2 ( P2O7 ), NaM'PO4F (M' is one or more of V , Fe, Mn and Ni) and Na3 ( VOy ) 2 ( PO4 ) 2F3-2y ( 0 ⁇ y ⁇ 1).
  • the Prussian blue compound may be a compound having sodium ions, transition metal ions and cyanide ions (CN - ).
  • the transition metal may be at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr and Ce.
  • the Prussian blue compound is, for example, Na a Me b Me' c (CN) 6 , wherein Me and Me' are each independently at least one of Ni, Cu, Fe, Mn, Co and Zn, 0 ⁇ a ⁇ 2, 0 ⁇ b ⁇ 1, 0 ⁇ c ⁇ 1.
  • the weight ratio of the positive electrode active material in the positive electrode film layer is 80 to 100 weight %, based on the total weight of the positive electrode film layer.
  • the positive electrode film layer may also optionally include a binder.
  • the binder may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer and fluorine-containing acrylate resin.
  • PVDF polyvinylidene fluoride
  • PTFE polytetrafluoroethylene
  • PTFE polytetrafluoroethylene
  • the weight ratio of the binder in the positive electrode film layer is 0 to 20 weight%, based on the total weight of the positive electrode film layer.
  • the positive electrode film layer may further include a conductive agent.
  • the conductive agent may include at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.
  • the weight ratio of the conductive agent in the positive electrode film layer is 0-20% by weight, based on the total weight of the positive electrode film layer.
  • the positive electrode sheet can be prepared in the following manner: the components for preparing the positive electrode sheet, such as the positive electrode active material, the conductive agent, the binder and any other components are dispersed in a solvent (such as N-methylpyrrolidone) to form a positive electrode slurry, wherein the positive electrode slurry has a solid content of 40 mass percent (wt%) to 80wt%, and the viscosity at room temperature is adjusted to 5000 millipascals ⁇ seconds (mPa ⁇ s) to 25000 mPa ⁇ s, the positive electrode slurry is coated on the surface of the positive electrode collector, and after drying, it is cold-pressed by a cold rolling mill to form a positive electrode sheet.
  • a solvent such as N-methylpyrrolidone
  • the thickness T of the positive electrode film can be measured by using a micrometer, for example, a micrometer of model Mitutoyo293-100 with an accuracy of 0.1 ⁇ m.
  • the thickness of the positive electrode diaphragm mentioned here refers to the thickness of the positive electrode diaphragm in the positive electrode sheet used to assemble the battery after cold pressing.
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector, wherein the negative electrode film layer includes a negative electrode active material.
  • the negative electrode current collector has two surfaces opposite to each other in its thickness direction, and the negative electrode film layer is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.
  • the negative electrode current collector may be a metal foil or a composite current collector.
  • copper foil may be used as the metal foil.
  • the composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material substrate.
  • the composite current collector may be formed by forming a metal material on a polymer material substrate.
  • the metal material includes but is not limited to copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.
  • the polymer material substrate includes but is not limited to polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE) and other substrates.
  • the negative electrode active material may be a negative electrode active material for a battery known in the art.
  • the negative electrode active material of the lithium ion secondary battery may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc.
  • the silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys.
  • the tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys.
  • the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.
  • the negative electrode active material of the sodium ion secondary battery is generally a hard carbon material, a two-dimensional metal carbide or a nitride.
  • the negative electrode active material of the sodium ion secondary battery is generally a hard carbon material.
  • the weight ratio of the negative electrode active material in the negative electrode film layer is 70 to 100 weight %, based on the total weight of the negative electrode film layer.
  • the negative electrode film layer may further include a binder.
  • the binder may be selected from styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide At least one of polyvinyl alcohol (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA) and carboxymethyl chitosan (CMCS).
  • SBR styrene-butadiene rubber
  • PAA polyacrylic acid
  • PAAS sodium polyacrylate
  • PAM polyacrylamide
  • PAM polyvinyl alcohol
  • PVA polyvinyl alcohol
  • SA sodium alginate
  • PMAA polymethacrylic acid
  • CMCS carboxymethyl chitosan
  • the weight ratio of the binder in the negative electrode film layer is 0 to 30 weight %, based on the total weight of the negative electrode film layer.
  • the negative electrode film layer may further include a conductive agent.
  • the conductive agent may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.
  • the weight ratio of the conductive agent in the negative electrode film layer is 0 to 20 weight %, based on the total weight of the negative electrode film layer.
  • the negative electrode film layer may further include other additives, such as a thickener (such as sodium carboxymethyl cellulose (CMC-Na)), etc.
  • a thickener such as sodium carboxymethyl cellulose (CMC-Na)
  • the weight ratio of the other additives in the negative electrode film layer is 0 to 15 weight %, based on the total weight of the negative electrode film layer.
  • the negative electrode sheet can be prepared by the following method: the components for preparing the negative electrode sheet, such as the negative electrode active material, the conductive agent, the binder and any other components are dispersed in a solvent (such as deionized water) to form a negative electrode slurry, wherein the solid content of the negative electrode slurry is 30wt% to 70wt%, and the viscosity at room temperature is adjusted to 2000mPa ⁇ s to 10000mPa ⁇ s; the obtained negative electrode slurry is coated on the negative electrode collector, and after a drying process, cold pressing such as a roller is performed to obtain a negative electrode sheet.
  • the negative electrode powder coating unit area density is 75mg/ m2 to 220mg/ m2
  • the negative electrode sheet compaction density is 1.2 grams/cubic meter (g/ m3 ) to 2.0g/ m3 .
  • the mass M of the negative electrode active material per unit area of the negative electrode film can be obtained by weighing using a standard balance.
  • the thickness T of the negative electrode film can be measured by using a micrometer, for example, a Mitutoyo 293-100 micrometer with an accuracy of 0.1 ⁇ m. It should be noted that the thickness of the negative electrode film described in this application refers to the thickness of the negative electrode film in the negative electrode sheet used for assembling the battery after cold pressing.
  • the electrolyte plays the role of conducting ions between the positive electrode and the negative electrode.
  • the present application has no specific restrictions on the type of electrolyte, which can be selected according to needs.
  • the electrolyte can be liquid, gel or all-solid.
  • the electrolyte is an electrolyte solution, which includes an electrolyte salt and a solvent.
  • the electrolyte salt of the lithium ion secondary battery can be selected from one or more of lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate (LiBF 4 ), lithium perchlorate (LiClO 4 ), lithium hexafluoroarsenate (LiAsF 6 ), lithium bisfluorosulfonyl imide (LiFSI), lithium bistrifluoromethanesulfonyl imide (LiTFSI), lithium trifluoromethanesulfonate (LiTFS), lithium difluorooxalatoborate (LiDFOB), lithium bisoxalatoborate (LiBOB), lithium difluorophosphate (LiPO 2 F 2 ), lithium difluorobisoxalatophosphate (LiDFOP) and lithium tetrafluorooxalatophosphate (LiTFOP).
  • LiPF 6 lithium hexafluorophosphate
  • the electrolyte salt of the sodium ion secondary battery can be selected from one or more of sodium hexafluorophosphate, sodium bis(fluorosulfonyl)imide, sodium bis(trifluoromethanesulfonyl)imide, sodium trifluoromethanesulfonate, sodium tetrafluoroborate, sodium difluorophosphate, sodium perchlorate, and sodium chloride.
  • the concentration of the electrolyte salt is generally 0.5 mol/L to 5 mol/L.
  • the solvent can be selected from one or more of fluoroethylene carbonate (FEC), ethylene carbonate (EC), propylene carbonate (PC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), butylene carbonate (BC), methyl formate (MF), methyl acetate (MA), ethyl acetate (EA), propyl acetate (PA), methyl propionate (MP), ethyl propionate (EP), propyl propionate (PP), methyl butyrate (MB), ethyl butyrate (EB), 1,4-butyrolactone (GBL), sulfolane (SF), dimethyl sulfone (MSM), ethyl methyl sulfone (EMS) and diethyl sulfone (FEC),
  • the electrolyte may further include additives, such as negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain battery properties, such as additives that improve battery overcharge performance, additives that improve battery high or low temperature performance, etc.
  • additives such as negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain battery properties, such as additives that improve battery overcharge performance, additives that improve battery high or low temperature performance, etc.
  • the secondary battery further includes a separator.
  • the present application has no particular limitation on the type of separator, and any known porous separator with good chemical stability and mechanical stability can be selected.
  • the material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.
  • the isolation membrane can be a single-layer film or a multi-layer composite film, without particular limitation.
  • the materials of each layer can be The same or different, there is no particular limitation.
  • the isolation film has a thickness of 6 ⁇ m to 40 ⁇ m, and may be 12 ⁇ m to 20 ⁇ m.
  • the positive electrode sheet, the negative electrode sheet, and the separator may be formed into an electrode assembly by a winding process or a lamination process.
  • the secondary battery may include an outer package, which may be used to encapsulate the electrode assembly and the electrolyte.
  • the outer packaging of the secondary battery may be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc.
  • the outer packaging of the secondary battery may also be a soft package, such as a bag-type soft package.
  • the material of the soft package may be plastic, and examples of the plastic include polypropylene, polybutylene terephthalate, and polybutylene succinate.
  • FIG1 is a secondary battery 5 of a square structure as an example.
  • the outer package may include a shell 51 and a cover plate 53.
  • the shell 51 may include a bottom plate and a side plate connected to the bottom plate, and the bottom plate and the side plate enclose a receiving cavity.
  • the shell 51 has an opening connected to the receiving cavity, and the cover plate 53 can be covered on the opening to close the receiving cavity.
  • the positive electrode sheet, the negative electrode sheet and the isolation film can form an electrode assembly 52 through a winding process or a lamination process.
  • the electrode assembly 52 is encapsulated in the receiving cavity.
  • the electrolyte is infiltrated in the electrode assembly 52.
  • the number of electrode assemblies 52 contained in the secondary battery 5 can be one or more, and those skilled in the art can select according to specific actual needs.
  • the secondary batteries 5 can be assembled into a battery module.
  • the number of secondary batteries 5 contained in the battery module can be one or more, and the specific number can be selected by those skilled in the art according to the application and capacity of the battery module.
  • the plurality of secondary batteries 5 may be arranged in sequence along the length direction of the battery module. Of course, they may also be arranged in any other manner. Further, the plurality of secondary batteries 5 may be fixed by fasteners.
  • the battery module may further include a housing having a receiving space, and the plurality of secondary batteries 5 are received in the receiving space.
  • the battery modules can also be assembled into a battery pack.
  • the number of battery modules can be one or more, and the specific number can be selected by those skilled in the art according to the application and capacity of the battery pack.
  • the battery pack may include a battery box and a plurality of battery modules disposed in the battery box.
  • the battery box includes an upper box body and a lower box body, and the upper box body can be covered on the lower box body to form a closed space for accommodating the battery modules.
  • the plurality of battery modules can be arranged in the battery box in any manner.
  • the present application also provides an electrical device, which includes at least one of the secondary battery, battery module, or battery pack provided in the present application.
  • the secondary battery, battery module, or battery pack can be used as a power source for the electrical device, and can also be used as an energy storage unit for the electrical device.
  • the electrical device may include mobile devices (such as mobile phones, laptops, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc., but are not limited to these.
  • a secondary battery, a battery module or a battery pack may be selected according to its usage requirements.
  • FIG3 is an example of an electric device.
  • the electric device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc.
  • a battery pack or a battery module may be used.
  • the device may be a mobile phone, a tablet computer, a notebook computer, etc.
  • a device is usually required to be light and thin, and a secondary battery may be used as a power source.
  • Embodiment 1 is a diagrammatic representation of Embodiment 1:
  • the positive electrode active material is a mixture of an agglomerate-type positive electrode material (primary particle size of 0.4 ⁇ m) with a Dv50 of 12 ⁇ m and a quasi-single-crystal positive electrode material (primary particle size of 1.2 ⁇ m) with a Dv50 of 3 ⁇ m in a mass ratio of 7:3.
  • the chemical formula of the agglomerate type positive electrode material is Li x1 Ni y1 Co z1 M 1-y1-z1 O 2 ;
  • the chemical formula of the quasi-single crystal type positive electrode material is Li x2 Ni y2 Co z2 M′ 1-y2-z2 O 2 .
  • the particle size distribution span (Dv90-Dv10)/Dv50 of the agglomerate type positive electrode material is 1.25, and the particle size distribution span (Dv90-Dv10)/Dv50 of the quasi-single crystal type positive electrode material is 1.35;
  • the BET specific surface area of the agglomerate type positive electrode material is 0.56m 2 /g, and the BET specific surface area of the quasi-single crystal type positive electrode material is 1.05m 2 /g;
  • the particle size distribution span (Dv90-Dv10)/Dv50 of the mixed positive electrode active material is 1.78, and the BET specific surface area is 0.66m 2 /g.
  • the above positive electrode active material was put into a 5L stirring tank, and then the conductive agent acetylene black (SP) and the binder polyvinylidene fluoride (PVDF) were added for premixing for 30 minutes, and then the solvent N-methylpyrrolidone (NMP) was added and stirred rapidly under vacuum to form a positive electrode slurry.
  • SP conductive agent
  • PVDF binder polyvinylidene fluoride
  • NMP solvent N-methylpyrrolidone
  • the positive electrode slurry was evenly coated on both sides of the positive electrode current collector aluminum foil with a thickness of 12 ⁇ m.
  • the coated electrode was dried in an oven at 100°C to 130°C for half an hour, then taken out and cold-pressed by rollers to prepare the positive electrode electrode.
  • the active material loading of the positive electrode film on the electrode was 21.5 mg/cm 2 .
  • the negative electrode active materials graphite + silicon carbon material, carbon black (SP), styrene butadiene rubber (SBR), and carboxymethyl fiber (CMC) are dissolved in solvent deionized water at a weight ratio of 95:2:2:1, and stirred to obtain a uniformly dispersed negative electrode slurry, which is evenly coated on the surface of the negative electrode current collector copper foil, and then dried, cold pressed, and cut to obtain a negative electrode sheet.
  • the mass proportion of silicon carbon material in the negative electrode active material is 30%.
  • a polyethylene (PE) porous polymer film is used as the isolation membrane.
  • lithium hexafluorophosphate LiPF 6
  • VC vinylene carbonate
  • HDI hexamethylene diisocyanate
  • EC 25% ethylene carbonate
  • DMC dimethyl carbonate
  • EMC ethyl methyl carbonate
  • the positive electrode sheet, the separator, and the negative electrode sheet are sequentially stacked and wound to form a bare cell, the bare cell is placed in a battery casing, an electrolyte is injected, and the secondary battery is obtained.
  • Embodiment 2 is a diagrammatic representation of Embodiment 1:
  • This embodiment is basically the same as the embodiment 1, except that the Dv50 of the agglomerate type positive electrode material in the positive electrode active material is different.
  • the Dv50 of the agglomerate type positive electrode material in this embodiment is 8.2 ⁇ m.
  • Embodiment 3 is a diagrammatic representation of Embodiment 3
  • This embodiment is basically the same as the embodiment 1, except that the particle size of the primary particles of the agglomerate type positive electrode material in the positive electrode active material is different.
  • the particle size of the primary particles of the agglomerate type positive electrode material in this embodiment is 0.2 ⁇ m.
  • Embodiment 4 is a diagrammatic representation of Embodiment 4:
  • This embodiment is basically the same as embodiment 1, except that the particle size distribution span (Dv90-Dv10)/Dv50 (i.e., SPAN) of the agglomerate-type positive electrode material in the positive electrode active material is different.
  • the particle size distribution span SPAN of the agglomerate-type positive electrode material is 1.39.
  • Embodiment 5 is a diagrammatic representation of Embodiment 5:
  • This embodiment is basically the same as the embodiment 1, except that the molecular formula of the agglomerate-type positive electrode material in the positive electrode active material is different.
  • y1 is 0.98 and z1 is 0.01.
  • Embodiment 6 is a diagrammatic representation of Embodiment 6
  • This embodiment is basically the same as the embodiment 1, except that the BET specific surface area of the agglomerate type positive electrode material in the positive electrode active material is different.
  • the BET specific surface area of the agglomerate type positive electrode material in this embodiment is 0.78 m 2 /g.
  • Embodiment 7 is a diagrammatic representation of Embodiment 7:
  • This embodiment is basically the same as the embodiment 1, except that the Dv50 of the quasi-single-crystal positive electrode material in the positive electrode active material is different.
  • the Dv50 of the quasi-single-crystal positive electrode material in this embodiment is 3.8 ⁇ m.
  • Embodiment 8 is a diagrammatic representation of Embodiment 8
  • This embodiment is basically the same as the embodiment 1, except that the particle size of the primary particles of the quasi-single-crystal positive electrode material in the positive electrode active material is different.
  • the particle size of the primary particles of the quasi-single-crystal positive electrode material in this embodiment is 0.9 ⁇ m.
  • Embodiment 9 is a diagrammatic representation of Embodiment 9:
  • This embodiment is basically the same as embodiment 1, except that the particle size distribution span (Dv90-Dv10)/Dv50 (i.e., SPAN) of the quasi-single-crystal positive electrode material in the positive electrode active material is different.
  • the particle size distribution span SPAN of the quasi-single-crystal positive electrode material is 1.47.
  • Embodiment 10 is a diagrammatic representation of Embodiment 10:
  • This embodiment is basically the same as the embodiment 1, except that the molecular formula of the quasi-single-crystal positive electrode material in the positive electrode active material is different.
  • y2 is 0.97 and z2 is 0.02.
  • Embodiment 11 is a diagrammatic representation of Embodiment 11:
  • This embodiment is basically the same as the embodiment 1, except that the BET specific surface area of the quasi-single-crystal positive electrode material in the positive electrode active material is different.
  • the BET specific surface area of the quasi-single-crystal positive electrode material in this embodiment is 0.85 m 2 /g.
  • Embodiment 12 is a diagrammatic representation of Embodiment 12
  • This embodiment is basically the same as embodiment 1, except that the mass ratio of the agglomerate positive electrode material to the quasi-single crystal positive electrode material in the positive electrode active material is different.
  • the mass ratio of the agglomerate positive electrode material to the quasi-single crystal positive electrode material is 8:2.
  • Embodiment 13 is a diagrammatic representation of Embodiment 13:
  • This embodiment is basically the same as embodiment 1, except that the particle size distribution span (Dv90-Dv10)/Dv50 (ie, SPAN) of the mixed positive electrode active material is different.
  • the particle size distribution span SPAN of the positive electrode active material is 2.03.
  • Embodiment 14 is a diagrammatic representation of Embodiment 14:
  • This embodiment is basically the same as the embodiment 1, except that the BET specific surface area of the mixed positive electrode active material is different.
  • the BET specific surface area of the positive electrode active material in this embodiment is 0.52 m 2 /g.
  • Embodiment 15 is a diagrammatic representation of Embodiment 15:
  • This embodiment is basically the same as the embodiment 1, and the only difference is that the content of the silicon-based material in the negative electrode active material of the negative electrode plate is different. In this embodiment, the mass content of the silicon-based material in the negative electrode active material is 90%.
  • Embodiment 16 is a diagrammatic representation of Embodiment 16:
  • the Dv50 of the agglomerate type positive electrode material is 14.9 ⁇ m
  • the particle size of the primary particles of the agglomerate type positive electrode material is 0.3 ⁇ m
  • the particle size distribution span SPAN of the agglomerate type positive electrode material is 0.72
  • y1 in the molecular formula of the agglomerate type positive electrode material is 0.94
  • z1 is 0.05
  • the BET specific surface area of the agglomerate type positive electrode material is 0.3 m 2 /g
  • the Dv50 of the quasi-single crystal type positive electrode material is 3.5 ⁇ m
  • the particle size of the primary particles of the quasi-single crystal type positive electrode material is 1.5 ⁇ m
  • the particle size distribution span SPAN of the quasi-single crystal type positive electrode material is 1.44
  • y2 in the molecular formula of the quasi-single crystal type positive electrode material is 0.92
  • z2 is 0.06
  • Embodiment 17 is a diagrammatic representation of Embodiment 17:
  • the Dv50 of the agglomerate type positive electrode material is 9.5 ⁇ m
  • the particle size of the primary particles of the agglomerate type positive electrode material is 0.13 ⁇ m
  • the particle size distribution span SPAN of the agglomerate type positive electrode material is 1.33
  • y1 in the molecular formula of the agglomerate type positive electrode material is 0.94
  • z1 is 0.05
  • the BET specific surface area of the agglomerate type positive electrode material is 0.2 m 2 /g
  • the Dv50 of the quasi-single crystal type positive electrode material is 3.5 ⁇ m
  • the particle size of the primary particles of the quasi-single crystal type positive electrode material is 1.5 ⁇ m
  • the particle size distribution span SPAN of the quasi-single crystal type positive electrode material is 1.44
  • y2 in the molecular formula of the quasi-single crystal type positive electrode material is 0.92
  • z2 is 0.06
  • Embodiment 18 is a diagrammatic representation of Embodiment 18:
  • the Dv50 of the agglomerate type positive electrode material is 9.5 ⁇ m
  • the particle size of the primary particles of the agglomerate type positive electrode material is 0.3 ⁇ m
  • the particle size distribution span SPAN of the agglomerate type positive electrode material is 1.33
  • y1 in the molecular formula of the agglomerate type positive electrode material is 0.94
  • z1 is 0.05
  • the agglomerate type positive electrode material is The BET specific surface area is 0.45m 2 /g
  • the Dv50 of the quasi-single-crystal positive electrode material is 3.5 ⁇ m
  • the particle size of the primary particles of the quasi-single-crystal positive electrode material is 1.5 ⁇ m
  • the particle size distribution span SPAN of the quasi-single-crystal positive electrode material is 1.44
  • y2 in the molecular formula of the quasi-single-crystal positive electrode material is 0.92
  • z2 is 0.06
  • Embodiment 19 is a diagrammatic representation of Embodiment 19:
  • the Dv50 of the agglomerate type positive electrode material is 9.5 ⁇ m
  • the particle size of the primary particles of the agglomerate type positive electrode material is 0.56 ⁇ m
  • the particle size distribution span SPAN of the agglomerate type positive electrode material is 1.33
  • y1 in the molecular formula of the agglomerate type positive electrode material is 0.94
  • z1 is 0.05
  • the BET specific surface area of the agglomerate type positive electrode material is 0.45 m 2 /g
  • the Dv50 of the quasi-single crystal type positive electrode material is 3.5 ⁇ m
  • the particle size of the primary particles of the quasi-single crystal type positive electrode material is 1.9 ⁇ m
  • the particle size distribution span SPAN of the quasi-single crystal type positive electrode material is 1.44
  • y2 in the molecular formula of the quasi-single crystal type positive electrode material is 0.92
  • z2 is 0.06
  • Embodiment 20 is a diagrammatic representation of Embodiment 20.
  • the Dv50 of the agglomerate type positive electrode material is 9.5 ⁇ m
  • the particle size of the primary particles of the agglomerate type positive electrode material is 0.3 ⁇ m
  • the particle size distribution span SPAN of the agglomerate type positive electrode material is 1.33
  • y1 in the molecular formula of the agglomerate type positive electrode material is 0.94
  • z1 is 0.05
  • the BET specific surface area of the agglomerate type positive electrode material is 0.45 m 2 /g
  • the Dv50 of the quasi-single crystal type positive electrode material is 2.6 ⁇ m
  • the particle size of the primary particles of the quasi-single crystal type positive electrode material is 1.5 ⁇ m
  • the particle size distribution span SPAN of the quasi-single crystal type positive electrode material is 1.44
  • y2 in the molecular formula of the quasi-single crystal type positive electrode material is 0.92
  • z2 is 0.06
  • the Dv50 of the agglomerate-type positive electrode material is 9 ⁇ m
  • the particle size of the primary particles of the agglomerate-type positive electrode material is 0.2 ⁇ m
  • the particle size distribution span SPAN of the agglomerate-type positive electrode material is 1.2
  • y1 in the molecular formula of the agglomerate-type positive electrode material is 0.94
  • z1 is 0.05
  • the BET specific surface area of the agglomerate-type positive electrode material is 0.45 m 2 / g
  • the Dv50 of the quasi-single-crystal positive electrode material is 3.3 ⁇ m
  • the particle size of the primary particles of the quasi-single-crystal positive electrode material is 0.7 ⁇ m
  • the particle size distribution span SPAN of the quasi-single-crystal positive electrode material is 1.4
  • y2 in the molecular formula of the quasi-single-crystal positive electrode material is 0.93
  • z2 is 0.06
  • This comparative example is basically the same as comparative example 1, except that: the positive electrode active material uses only agglomerate-type positive electrode material, and does not use quasi-single crystal positive electrode material, the total amount of positive electrode active material remains unchanged; and the compaction density of the positive electrode sheet is different.
  • This comparative example is basically the same as comparative example 1, with the only difference being that: the positive electrode active material only uses a quasi-single crystal positive electrode material, and does not use an agglomerate positive electrode material, and the primary particle size of the quasi-single crystal positive electrode material is 1.2 ⁇ m, and the total amount of the positive electrode active material remains unchanged; the compaction density of the positive electrode sheet is different.
  • the test method for the volume average particle size Dv10, Dv50, and Dv90 of the particles can be tested by methods known in the art.
  • the BET specific surface area of the particles can be tested by a method known in the art.
  • GB/T 19587-2017 “Determination of the specific surface area of solid substances by gas adsorption BET method”
  • the measurement can be performed using the TriStar II 3020 device.
  • the scanning electron microscope measures the length of each particle in the longest direction (the diameter of a regular sphere is measured, and the length of an irregular particle is measured in the opposite direction of its longest length). Approximately 300 particles are measured, and the average value is calculated to obtain the primary particle size.
  • Capacity test of battery cells let the battery cells stand at 25°C for 2h, and ensure that the temperature of the battery cells is 25°C. At 25°C, charge the battery cells at 0.1C to the charge cut-off voltage, and then continue to charge at the charge cut-off voltage until the current reaches 0.05C and the charge is cut off (where C represents the rated capacity of the battery cells). Let the battery cells stand at 25°C for 1h, and discharge the battery cells at 0.1C to the discharge cut-off voltage at 25°C, and record the total discharge capacity C0 of the battery cells, and the total discharge energy is E0.
  • Battery cell weight measurement Place the battery cell on an electronic balance until the weight is stable, and read the battery cell weight value M0.
  • discharge energy E0 of battery cell/weight M0 of battery cell is the energy density of battery cell.
  • the secondary batteries of Examples 1 to 20 of the present application have high energy density, good cycle performance, and excellent comprehensive performance.
  • the primary particle size of the single-crystal-like positive electrode material in the positive electrode active material in Comparative Example 1 is not within the scope of the present application; the positive electrode active material in Comparative Example 2 only uses agglomerate-type positive electrode material, and does not use single-crystal-like positive electrode material; The positive electrode active material only uses a quasi-single crystal positive electrode material, and does not use an aggregate positive electrode material.
  • the comprehensive performance of the secondary batteries of Examples 1 to 20 of the present application is significantly better than that of Comparative Examples 1, 2 and 3.
  • Example 7 of the present application The main difference between the secondary battery of Example 7 of the present application and Example 1 is that the Dv50 of the quasi-single crystal positive electrode material is different.
  • the Dv50 of the quasi-single crystal positive electrode material in Example 7 is 3.8, and the Dv50 of the quasi-single crystal positive electrode material in Example 1 is 3.
  • the cycle performance of the secondary batteries is equivalent, but the energy density of Example 1 is higher.
  • the main difference between the secondary battery of Example 8 of the present application and Example 1 is that the primary particle size of the quasi-single crystal positive electrode material is different.
  • the primary particle size of the quasi-single crystal positive electrode material in Example 8 is 0.9, and the primary particle size of the quasi-single crystal positive electrode material in Example 1 is 1.2.
  • the energy density and cycle performance of the secondary battery of Example 1 are significantly improved compared with those of Example 8.
  • the main difference between the secondary battery of Example 12 of the present application and Example 1 is that the mixing ratio of the agglomerate positive electrode material and the quasi-single crystal positive electrode material is different.
  • the mixing ratio of the agglomerate positive electrode material and the quasi-single crystal positive electrode material in Example 12 is 8:2, and the mixing ratio of the agglomerate positive electrode material and the quasi-single crystal positive electrode material in Example 1 is 7:3.
  • the energy density and cycle performance of the secondary battery of Example 1 are significantly improved compared with those of Example 12.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Inorganic Chemistry (AREA)
  • Composite Materials (AREA)
  • Battery Electrode And Active Subsutance (AREA)

Abstract

本申请提供了一种二次电池，包括正极极片，正极极片上具有正极活性材料，正极活性材料包括团聚体型正极材料和类单晶型正极材料；团聚体型正极材料的体积平均粒径Dv50为8μm～15μm，团聚体型正极材料的一次颗粒粒径为0.1μm～0.6μm；类单晶型正极材料的体积平均粒径Dv50为2.5μm～4μm，类单晶型正极材料的一次颗粒粒径为0.8μm～2μm；团聚体型正极材料和类单晶型正极材料的质量比大于或等于1；并涉及相应的用电装置。该二次电池具有较高的能量密度和较好的循环寿命。

Description

二次电池和用电装置 技术领域
本申请涉及二次电池技术领域，特别是涉及一种二次电池和用电装置。
背景技术
近年来，随着二次电池的应用范围越来越广泛，二次电池广泛应用于水力、火力、风力和太阳能电站等储能电源系统，以及电动工具、电动自行车、电动摩托车和电动汽车等多个领域。
由于二次电池取得了极大的发展，因此对其电池性能也提出了更高的要求。高能量密度、长循环寿命的二次电池对于正极极片具有很高的要求。例如，高能量密度、长循环寿命的二次电池的正极极片应该具有较高的压实密度，同时应该具有较长的使用寿命。
因此，寻求一种能量密度较高、循环寿命较好的二次电池是本领域技术人员重点关注的方向之一。
发明内容
本申请是鉴于上述课题而进行的，其目的之一在于，提供一种二次电池，其具有较高的能量密度和较好的循环寿命。
为了达到上述目的，本申请的第一方面提供了一种二次电池，包括正极极片，所述正极极片上具有正极活性材料，所述正极活性材料包括团聚体型正极材料和类单晶型正极材料；
所述团聚体型正极材料的体积平均粒径Dv50为8μm～15μm，所述团聚体型正极材料的一次颗粒粒径为0.1μm～0.6μm；
所述类单晶型正极材料的体积平均粒径Dv50为2.5μm～4μm，所述类单晶型正极材料的一次颗粒粒径为0.8μm～2μm；
所述团聚体型正极材料和所述类单晶型正极材料的质量比大于或等于1。
本申请通过采用Dv50为2.5μm～4μm、一次颗粒粒径为0.8μm～2μm 的类单晶型正极材料，与Dv50为8μm～15μm、一次颗粒粒径为0.1μm～0.6μm的团聚体型正极材料按照质量比大于或等于1进行级配，在保证正极极片高压密的同时，可使正极极片获得较好的寿命和容量，使得采用该正极极片的二次电池具有较高的能量密度和较长的循环寿命。
在任意的实施方式中，所述团聚体型正极材料和所述类单晶型正极材料的质量比为1～9:1。
在任意的实施方式中，所述团聚体型正极材料和所述类单晶型正极材料的质量比为2.3～3:1。如此，可以进一步提高二次电池的能量密度和循环寿命。
在任意的实施方式中，所述类单晶型正极材料的体积平均粒径Dv50为3μm～3.5μm，和/或所述类单晶型正极材料的一次颗粒粒径为1.2μm～1.5μm。如此，可以进一步提高二次电池的能量密度。
在任意的实施方式中，所述团聚体型正极材料的一次颗粒粒径为0.2μm～0.4μm。如此，可以进一步提高二次电池的能量密度。
在任意的实施方式中，所述团聚体型正极材料的化学式为Lix1Niy1Coz1M1-y1-z1O2，其中0.9≤x1≤1，0.9≤y1≤0.98，0.05≤z1≤0.1，M包括Mn、Al、B、Zr、Sr、Y、Sb、W、Ti、Mg和Nb中的一种或多种。如此，可以进一步提高正极极片的容量，进而提高二次电池的能量密度。
在任意的实施方式中，0.9≤y1≤0.96。如此，在保证正极极片具有较高容量的情况下，适当降低团聚体型正极材料的镍含量。
在任意的实施方式中，所述类单晶型正极材料的化学式为Lix2Niy2Coz2M′1-y2-z2O2，其中0.9≤x2≤1，0.9≤y2≤0.98，0.05≤z2≤0.1，M′包括Mn、Al、B、Zr、Sr、Y、Sb、W、Ti、Mg和Nb中的一种或多种。如此，可以进一步提高正极极片的容量，提高二次电池的能量密度。
在任意的实施方式中，0.92≤y2≤0.98。如此，可以进一步提升正极极片的容量，进而提高二次电池的能量密度。
在任意的实施方式中，y2>y1。如此，可以在正极活性材料的整体镍含量相对不是非常高的情况下，更好地提高正极极片的容量，进而提高二次电池的能量密度。
在任意的实施方式中，所述团聚体型正极材料的粒径分布跨度(Dv90-Dv10)/Dv50≤1.5。如此，可以为正极极片提供充分的填充空间和克容量发挥，提高正极极片的容量，进而提高二次电池的能量密度。
在任意的实施方式中，所述团聚体型正极材料的粒径分布跨度(Dv90-Dv10)/Dv50为0.7～1.4。如此，可以更好地为正极极片提供充分的填充空间，更好地提高正极极片的容量，进而提高二次电池的能量密度。
在任意的实施方式中，所述团聚体型正极材料的BET比表面积为0.2m2/g～0.8m2/g。如此，可以防止团聚体型正极材料过多的活性表面与电解液接触，避免团聚体型正极材料过多的被电解液腐蚀，从而可以提高正极极片的寿命，提高二次电池的循环寿命。
在任意的实施方式中，所述团聚体型正极材料的BET比表面积为0.3m2/g～0.6m2/g。如此，可以更好地提高正极极片的寿命，进而提高二次电池的循环寿命。
在任意的实施方式中，所述类单晶型正极材料的粒径分布跨度(Dv90-Dv10)/Dv50≥1.2。如此，可以提高正极极片的抗压性能，进而提高正极极片的寿命，提高二次电池的循环寿命。
在任意的实施方式中，所述类单晶型正极材料的粒径分布跨度(Dv90-Dv10)/Dv50为1.3～1.5。如此，可以更好地提高正极极片的抗压性能，更好地提高正极极片的寿命，提高二次电池的循环寿命。
在任意的实施方式中，所述类单晶型正极材料的BET比表面积为0.8m2/g～1.3m2/g。如此，可以实现分散性较高的形貌，有利于提高正极极片的空间利用率。
在任意的实施方式中，所述类单晶型正极材料的BET比表面积为0.85m2/g～1.15m2/g。如此，可以进一步提高正极极片的空间利用率。
在任意的实施方式中，所述正极活性材料的粒径分布跨度(Dv90-Dv10)/Dv50为1.5～2.1。如此，可以使正极极片在较高的膜片载量下获得较高的压实密度和加工性能。
在任意的实施方式中，所述正极活性材料的BET比表面积为0.5m2/g～0.7m2/g。如此，同样可以使正极极片在较高的膜片载量下获得较高的 压实密度和加工性能，提高二次电池的能量密度。
在任意的实施方式中，所述正极极片中所述正极活性材料占正极膜层的质量百分比为95％～99.5％。如此，可以保证正极活性材料在二次电池中的克容量发挥，提高正极极片的容量，提高二次电池的能量密度。
在任意的实施方式中，所述正极极片中所述正极活性材料的涂布面密度为21.5mg/cm2～32.5mg/cm2。如此，采用正极厚涂布并且结合高的压实密度，可以进一步提高正极极片的容量，提高二次电池的能量密度。
本申请的第二方面提供了一种用电装置，该用电装置包括本申请第一方面的二次电池。
本申请的二次电池的正极极片通过采用Dv50为2.5μm～4μm、一次颗粒粒径为0.8μm～2μm的类单晶型正极材料，与Dv50为8μm～15μm、一次颗粒粒径为0.1μm～0.6μm的团聚体型正极材料按照质量比大于或等于1进行级配，在保证正极极片高压密的同时，可使正极极片获得较好的寿命和容量，进而使二次电池具有较高的能量密度和较长的循环寿命。
附图说明
为了更好地描述和说明本申请的实施例和/或示例，可以参考一幅或多幅附图。用于描述附图的附加细节或示例不应当被认为是对所公开的申请、目前描述的实施例和/或示例以及目前理解的这些申请的最佳模式中的任何一者的范围的限制。
图1是本申请一实施方式的二次电池的示意图；
图2是图1所示的本申请一实施方式的二次电池的分解图；
图3是本申请一实施方式的二次电池用作电源的用电装置的示意图。
附图标记说明：
5、二次电池；51、壳体；52、电极组件；53、盖板；6、用电装置。
具体实施方式
以下，适当地参照附图详细说明具体公开了本申请的正极极片及其制备方法、二次电池和用电装置的实施方式。但是会有省略不必要的详细说明 的情况。例如，有省略对已众所周知的事项的详细说明、实际相同结构的重复说明的情况。这是为了避免以下的说明不必要地变得冗长，便于本领域技术人员的理解。此外，附图及以下说明是为了本领域技术人员充分理解本申请而提供的，并不旨在限定权利要求书所记载的主题。
本申请所公开的“范围”以下限和上限的形式来限定，给定范围是通过选定一个下限和一个上限进行限定的，选定的下限和上限限定了特别范围的边界。这种方式进行限定的范围可以是包括端值或不包括端值的，并且可以进行任意地组合，即任何下限可以与任何上限组合形成一个范围。例如，如果针对特定参数列出了60～120和80～110的范围，理解为60～110和80～120的范围也是预料到的。此外，如果列出的最小范围值1和2，和如果列出了最大范围值3，4和5，则下面的范围可全部预料到：1～3、1～4、1～5、2～3、2～4和2～5。在本申请中，除非有其他说明，数值范围“a～b”表示a到b之间的任意实数组合的缩略表示，其中a和b都是实数。例如数值范围“0～5”表示本文中已经全部列出了“0～5”之间的全部实数，“0～5”只是这些数值组合的缩略表示。另外，当表述某个参数为≥2的整数，则相当于公开了该参数为例如整数2、3、4、5、6、7、8、9、10、11、12等。
如果没有特别的说明，本申请的所有实施方式以及可选实施方式可以相互组合形成新的技术方案。
如果没有特别的说明，本申请的所有技术特征以及可选技术特征可以相互组合形成新的技术方案。
如果没有特别的说明，本申请的所有步骤可以顺序进行，也可以随机进行，优选是顺序进行的。例如，所述方法包括步骤(a)和(b)，表示所述方法可包括顺序进行的步骤(a)和(b)，也可以包括顺序进行的步骤(b)和(a)。例如，所述提到所述方法还可包括步骤(c)，表示步骤(c)可以任意顺序加入到所述方法，例如，所述方法可以包括步骤(a)、(b)和(c)，也可包括步骤(a)、(c)和(b)，也可以包括步骤(c)、(a)和(b)等。
如果没有特别的说明，本申请所提到的“包括”和“包含”表示开放式，也可以是封闭式。例如，所述“包括”和“包含”可以表示还可以包括或包含没有列出的其他组分，也可以仅包括或包含列出的组分。
如果没有特别的说明，在本申请中，术语“或”是包括性的。举例来说，短语“A或B”表示“A，B，或A和B两者”。更具体地，以下任一条件均满足条件“A或B”：A为真(或存在)并且B为假(或不存在)；A为假(或不存在)而B为真(或存在)；或A和B都为真(或存在)。
本申请说明书中所述的重量可以是μg、mg、g、kg等化工领域公知的重量单位。
目前，随着二次电池的应用范围越来越广泛，对二次电池的性能也提出了更高的要求。其中，能量密度和循环寿命是二次电池的两个非常重要的性能指标。传统的二次电池的能量密度和循环寿命有待提高。因此，如何提供一种能量密度较高且循环寿命较好的二次电池成为本领域的重要研究方向之一。对此，本申请提供了一种二次电池，其主要通过对正极极片中的正极活性材料的选择和配比，可使正极极片具有较高的压实密度和使用寿命，同时具有较高的容量，从而使得二次电池具有较高的能量密度和较长的循环寿命。
本申请的一个方面，提供了一种二次电池，包括正极极片，正极极片上具有正极活性材料，正极活性材料包括团聚体型正极材料和类单晶型正极材料；其中，团聚体型正极材料的体积平均粒径Dv50为8μm～15μm，团聚体型正极材料的一次颗粒粒径为0.1μm～0.6μm；类单晶型正极材料的体积平均粒径Dv50为2.5μm～4μm，类单晶型正极材料的一次颗粒粒径为0.8μm～2μm；团聚体型正极材料和类单晶型正极材料的质量比大于或等于1。
为了使二次电池能够达到360Wh/kg～500Wh/kg的高能量密度，二次电池在设计上需要采用正极高镍活性材料，且需要采用较高的涂布面密度，相应地负极采用石墨+高含量硅基材料作为负极活性材料。然而，由于正极极片的厚涂布设计会导致二次电池面临以下两个问题：一方面，目前所用的正极材料在涂布面密度(CW)较大时，正极极片的压实密度受到限制，一般＜3.3g/cm3，而正极极片的压密小会降低电池的能量密度；另一方面，正极活性材料采用多晶材料时比表面积大，副反应增加，导致高能量密度锂离子电池的循环性能下降。
本申请上述的二次电池，其正极极片中的正极活性材料包括团聚体型 正极材料和类单晶型正极材料；其中，将团聚体型正极材料的体积平均粒径Dv50控制在8μm～15μm，团聚体型正极材料的一次颗粒粒径为0.1μm～0.6μm；将类单晶型正极材料的体积平均粒径Dv50控制在2.5μm～4μm，类单晶型正极材料的一次颗粒粒径为0.8μm～2μm；并且将团聚体型正极材料和类单晶型正极材料的质量比控制在大于或等于1。
如此，通过采用特定体积平均粒径Dv50和特定一次颗粒粒径的团聚体型正极材料和特定体积平均粒径Dv50和特定一次颗粒粒径的类单晶型正极材料，按照特定质量比混合；其中团聚体型正极材料的粒径较大，起到骨架作用，且可提高极片容量；类单晶型正极材料的粒径较小，可以填充团聚体型正极材料颗粒之间的缝隙，提升正极极片的压实密度，且类单晶型正极材料的寿命更长，可以延长极片的使用寿命。
将上述的两种不同类型和粒径的正极材料活性物质进行组合，能够充分地提高颗粒间的孔隙与体积利用率，提高正极极片的抗压能力。Dv50为8μm～15μm的团聚体型正极材料可以作为正极极片的框架，粒径过大容易出现颗粒边缘的裂纹同时限制克容量的发挥，粒径过小则没有骨架的作用。Dv50为2.5μm～4μm的类单晶型正极材料作为团聚体型正极材料的次级填充物，可提高空间利用率，因为其较高的分散性和抗压性，可以充分填充在团聚体型正极材料颗粒之间的孔隙内。
由于高镍类单晶型正极材料的克容量发挥较团聚体型正极材料低，而团聚体型正极材料本身不耐压，因此将两者的质量比控制在大于或等于1可以最大化地兼容克容量与压实密度，并且这样的密实堆积不容易产生高压下的颗粒位移/滑移，从而避免极片产生较大的延展而使脆性提高。
另外，类单晶型正极材料的Dv50为2.5μm～4μm，其一次颗粒粒径为0.8μm～2μm，在实现正极高压密的同时保证了正极容量和寿命。当类单晶型正极材料的Dv50过大时极片的压实密度会下降；当类单晶型正极材料的一次颗粒粒径小于0.8μm时，组成类单晶型正极材料所需的一次颗粒数量过多，其形貌方面会更加接近团聚体，类单晶型正极材料的活性比表面暴露过多，容易受到电解液的腐蚀，导致正极极片的寿命下降，同时抗压性也下降；当类单晶型正极材料的一次颗粒粒径大于2μm时，组成类单晶型正极 材料所需的一次颗粒数量过少，可能只需要2～3颗一次颗粒就能组成类单晶型正极材料，类单晶型正极材料的活性比表界面暴露太少，锂离子传输路径有限，动力学性能变差，影响正极极片的容量和寿命。
本申请通过采用Dv50为2.5μm～4μm、一次颗粒粒径为0.8μm～2μm的类单晶型正极材料，与Dv50为8μm～15μm、一次颗粒粒径为0.1μm～0.6μm的团聚体型正极材料按照质量比1～9:1进行级配，在保证正极极片高压密的同时，使正极极片获得较好的寿命和容量，从而可以提高二次电池的能量密度和循环寿命。本申请的二次电池中正极材料的克容量范围可以达到215mAh/g～230mAh/g，0.33C。
需要说明的是，类单晶型正极材料是由数个一次颗粒堆积在一起形成的不规则结构；团聚体型正极材料是由数量更多的，且粒径更小的一次颗粒球形颗粒形成的规则小圆球。可以理解，类单晶型正极材料的体积平均粒径Dv50可以为但不限于2.5μm、2.6μm、2.7μm、2.8μm、2.9μm、3.0μm、3.1μm、3.2μm、3.3μm、3.4μm、3.5μm、3.6μm、3.7μm、3.8μm、3.9μm、4μm。类单晶型正极材料的一次颗粒粒径可以为但不限于0.8μm、0.9μm、1.0μm、1.1μm、1.2μm、1.3μm、1.4μm、1.5μm、1.6μm、1.7μm、1.8μm、1.9μm、2μm。团聚体型正极材料的体积平均粒径Dv50可以为但不限于8μm、8.5μm、9μm、9.5μm、10μm、10.5μm、11μm、11.5μm、12μm、12.5μm、13μm、13.5μm、14μm、14.5μm、15μm。团聚体型正极材料的一次颗粒粒径可以为但不限于0.1μm、0.2μm、0.3μm、0.4μm、0.5μm、0.6μm。团聚体型正极材料和类单晶型正极材料的质量比可以为但不限于1:1、2:1、3:1、4:1、5:1、6:1、7:1、8:1、9:1。
在一些实施方式中，团聚体型正极材料和类单晶型正极材料的质量比为1～9:1。如此，可以进一步提高二次电池的能量密度和循环寿命。
在一些实施方式中，团聚体型正极材料和类单晶型正极材料的质量比为2.3～3:1。采用这样的颗粒质量比级配，可以进一步提高二次电池的能量密度和循环寿命。
在一些实施方式中，类单晶型正极材料的体积平均粒径Dv50为3μm～3.5μm，类单晶型正极材料的一次颗粒粒径为1.2μm～1.5μm。如此， 更加有利于提高采用该正极极片的二次电池的能量密度。
在一些实施方式中，团聚体型正极材料的一次颗粒粒径为0.2μm～0.4μm。如此，更加有利于提高二次电池的能量密度和循环寿命。
在一些实施方式中，团聚体型正极材料的化学式为Lix1Niy1Coz1M1-y1- z1O2，其中0.9≤x1≤1，0.9≤y1≤0.98，0.05≤z1≤0.1，M包括Mn、Al、B、Zr、Sr、Y、Sb、W、Ti、Mg和Nb中的一种或多种。如此，团聚体型正极材料采用高镍活性材料，可以提高正极极片的容量，进而提高二次电池的能量密度。
可以理解，团聚体型正极材料的化学式中x1可以为但不限于0.9、0.91、0.92、0.93、0.94、0.95、0.96、0.97、0.98、0.99、1；团聚体型正极材料的化学式中y1可以为但不限于0.9、0.91、0.92、0.93、0.94、0.95、0.96、0.97、0.98；团聚体型正极材料的化学式中z1可以为但不限于0.05、0.06、0.07、0.08、0.09、0.1。
在一些实施方式中，团聚体型正极材料的化学式中0.9≤y1≤0.96。由于团聚体型正极材料的一次颗粒粒径相对较小，团聚体内部晶界较多，更加有利于锂离子的传输，因此在镍含量不是非常高的情况下也可以获得高容量。
在一些实施方式中，类单晶型正极材料的化学式为Lix2Niy2Coz2M′1-y2- z2O2，其中0.9≤x2≤1，0.9≤y2≤0.98，0.05≤z2≤0.1，M′包括Mn、Al、B、Zr、Sr、Y、Sb、W、Ti、Mg和Nb中的一种或多种。如此，类单晶型正极材料也采用高镍活性材料，可以进一步提高正极极片的容量，提高二次电池的能量密度。
可以理解，类单晶型正极材料的化学式中x2可以为但不限于0.9、0.91、0.92、0.93、0.94、0.95、0.96、0.97、0.98、0.99、1；类单晶型正极材料的化学式中y2可以为但不限于0.9、0.91、0.92、0.93、0.94、0.95、0.96、0.97、0.98；类单晶型正极材料的化学式中z2可以为但不限于0.05、0.06、0.07、0.08、0.09、0.1。
在一些实施方式中，0.92≤y2≤0.98。因为类单晶型正极材料的一次颗粒粒径相对更大，且类单晶型正极材料二次球的粒径比团聚体型正极材料 二次球的粒径小，类单晶型正极材料内部没有锂离子快速传输的界面，因此将类单晶型正极材料的镍含量y2设为0.92～0.98，可以进一步提升正极极片的容量，提高二次电池的能量密度。
在一些实施方式中，y2>y1。即类单晶型正极材料的镍含量大于团聚体型正极材料的镍含量。如此设置，可以在正极活性材料的整体镍含量相对不是非常高的情况下，更好地提高正极极片的容量，从而提高二次电池的能量密度。
需要说明的是，类单晶型正极材料的化学式中的M和团聚体型正极材料的化学式中的M′的元素种类不同，其在正极材料合成过程中所起到的作用也相应地有所不同。例如：当M、M′为高价元素Sb、Nb等时，可以起到细化晶粒的作用，使正极材料的一次粒径更加细小，进一步提升正极材料的容量和功率性能；当M、M′为Sr时，其可作为助溶剂，使得正极材料烧结过程中不需要太高的温度也可以获得相应粒径的正极材料，减少岩盐相的生成，使得正极极片的容量和循环寿命都有一定提升。可以根据实际需要确定正极材料化学式中M、M′的元素种类。
在一些实施方式中，团聚体型正极材料的粒径分布跨度(Dv90-Dv10)/Dv50≤1.5。将团聚体型正极材料的粒径分布跨度(Dv90-Dv10)/Dv50控制在≤1.5，可以为正极极片提供充分的填充空间和克容量发挥。
可理解，团聚体型正极材料的粒径分布跨度(Dv90-Dv10)/Dv50可以为但不限于0.1、0.2、0.3、0.4、0.5、0.6、0.7、0.8、0.9、1.0、1.1、1.2、1.3、1.4、1.5。
在一些实施方式中，团聚体型正极材料的粒径分布跨度(Dv90-Dv10)/Dv50为0.7～1.4。如此，可以更好地为正极极片提供充分的填充空间，更好地提高正极极片的克容量，提高二次电池的能量密度。
在一些实施方式中，团聚体型正极材料的BET比表面积为0.2m2/g～0.8m2/g。将团聚体型正极材料的BET比表面积控制在0.2m2/g～0.8m2/g之间，可以防止团聚体型正极材料过多的活性表面与电解液接触，避免团聚体型正极材料过多的被电解液腐蚀，从而可以提高正极极片的寿命，提高二次电池的循环寿命。
可理解，团聚体型正极材料的BET比表面积可以为但不限于0.2m2/g、0.3m2/g、0.4m2/g、0.5m2/g、0.6m2/g、0.7m2/g、0.8m2/g。
在一些实施方式中，团聚体型正极材料的BET比表面积为0.3m2/g～0.6m2/g。如此，可以更好地提高正极极片的寿命，提高二次电池的循环寿命。
在一些实施方式中，类单晶型正极材料的粒径分布跨度(Dv90-Dv10)/Dv50≥1.2。将类单晶型正极材料的粒径分布跨度(Dv90-Dv10)/Dv50控制为≥1.2，可以提高正极极片的抗压性能，进而提高正极极片的寿命，提高二次电池的循环寿命。可以理解，类单晶型正极材料的粒径分布跨度(Dv90-Dv10)/Dv50可以为但不限于1.2、1.3、1.4、1.5、1.6、1.7、1.8、1.9、2.0。
在一些实施方式中，类单晶型正极材料的粒径分布跨度(Dv90-Dv10)/Dv50为1.3～1.5。如此，可以更好地提高正极极片的抗压性能，更好地提高正极极片的寿命，提高二次电池的循环寿命。
在一些实施方式中，类单晶型正极材料的BET比表面积为0.8m2/g～1.3m2/g。将类单晶型正极材料的BET比表面积控制在0.8m2/g～1.3m2/g范围之内，可以实现分散性较高的形貌，有利于提高正极极片的空间利用率。可理解，类单晶型正极材料的BET比表面积可以为但不限于0.8m2/g、0.9m2/g、1.0m2/g、1.1m2/g、1.2m2/g、1.3m2/g。
在一些实施方式中，类单晶型正极材料的BET比表面积为0.85m2/g～1.15m2/g。如此，可以进一步提高正极极片的空间利用率。
在一些实施方式中，正极活性材料的粒径分布跨度(Dv90-Dv10)/Dv50为1.5～2.1。如此，可以使正极极片在较高的膜片载量下获得较高的压实密度和加工性能，提高二次电池的能量密度。可理解，混合后的正极活性材料的粒径分布跨度(Dv90-Dv10)/Dv50可以为但不限于1.5、1.6、1.7、1.8、1.9、2.0、2.1。
需要说明的是，正极材料的颗粒体积平均粒径Dv10、Dv50、Dv90为本领域的公知概念。具体地，Dv10为粉体颗粒以体积为基准的粒度分布中，从小粒径侧起、达到体积累计10％的粒径，单位通常为μm。Dv50为粉体颗粒以体积为基准的粒度分布中，从小粒径侧起、达到体积累计50％的粒 径。Dv90为粉体颗粒以体积为基准的粒度分布中，从小粒径侧起、达到体积累计90％的粒径。
在一些实施方式中，正极活性材料的BET比表面积为0.5m2/g～0.7m2/g。如此，同样可以使正极极片在较高的膜片载量下获得较高的压实密度和加工性能，提高二次电池的能量密度。可理解，混合后的正极活性材料的BET比表面积可以为但不限于0.5m2/g、0.55m2/g、0.6m2/g、0.65m2/g、0.7m2/g。通过采用上述的混合后正极活性材料粒径分布跨度和BET比表面积，可以使正极极片的冷压后延展率≤0.8％。
在一些实施方式中，正极极片中正极活性材料占正极膜层的质量百分比为95％～99.5％。将正极极片中正极活性材料占正极膜层的质量百分比控制在95％～99.5％，可以保证正极活性材料在二次电池中的克容量发挥，提高二次电池的能量密度。可理解，正极极片中正极活性材料占正极膜层的质量百分比可以为但不限于95％、95.5％、96％、96.5％、97％、97.5％、98％、98.5％、99％、99.5％。
在一些实施方式中，正极极片中正极活性材料的涂布面密度为21.5mg/cm2～32.5mg/cm2。本申请的正极极片，可以在较高的正极活性材料涂布面密度下实现正极极片的高压实密度，其正极极片的压实密度可以达到3.7g/cm3以上，且冷压后极片的延展率较小，在后期使用过程中正极极片不易出现断裂等问题。可以理解，正极极片中正极活性材料的涂布面密度可以为但不限于21.5mg/cm2、22mg/cm2、22.5mg/cm2、23mg/cm2、23.5mg/cm2、24mg/cm2、24.5mg/cm2、25mg/cm2、25.5mg/cm2、26mg/cm2、26.5mg/cm2、27mg/cm2、27.5mg/cm2、28mg/cm2、28.5mg/cm2、29mg/cm2、29.5mg/cm2、30mg/cm2、30.5mg/cm2、31mg/cm2、31.5mg/cm2、32mg/cm2、32.5mg/cm2。
在一些实施方式中，正极极片包括正极集流体，正极集流体可采用金属箔片或复合集流体。其中，金属箔片可采用铝箔，复合集流体可包括高分子材料基层和形成于高分子材料基层至少一个表面上的金属层。
在一些实施方式中，二次电池中正极极片的制备方法，包括以下步骤：
将正极活性材料与导电剂、粘结剂和溶剂混合形成浆料；以及
将浆料涂覆在正极集流体上，干燥后压制，得到正极极片。
在一些实施方式中，浆料中正极活性材料、导电剂和粘结剂的质量比为(90～96)：(2～5)：(2～5)，浆料的固含量为70％～99.5％。如此，通过正极活性材料中团聚体型正极材料和类单晶型正极材料的大小颗粒级配，将正极活性材料、导电剂和粘结剂按照特定的质量比混合，并通过溶剂调节浆料至特定的固含量；通过正极活性材料的颗粒级配与特定的正极浆料配方相结合，可以保证正极活性材料性能得到充分发挥，且能够更好地提高正极极片的压实密度。
在一些实施方式中，将团聚体型正极材料和类单晶型正极材料按照质量比投入搅拌罐中，加入导电剂和粘结剂进行预混合，加入溶剂在抽真空环境下进行快速搅拌，形成正极浆料；将正极浆料均匀、双面涂覆在正极集流体铝箔上，将涂覆浆料后的极片在100℃～130℃下进行干燥，取出后进行冷压，得到正极极片。
在一些实施方式中，将锂源、高镍三元前驱体、添加剂按配比置于混料机中混合均匀并在氧气气氛中550℃～800℃温度下烧结5h～20h，得到团聚体型正极材料；将锂源、高镍三元前驱体、添加剂按配比置于混料机中混合均匀并在氧气气氛中600℃～900℃温度下烧结5h～20h，得到类单晶型正极材料。
在一些实施方式中，导电剂包括超导碳、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨烯和碳纳米纤维中的一种或多种。
在一些实施方式中，粘结剂包括聚偏氟乙烯、聚四氟乙烯、偏氟乙烯-四氟乙烯-丙烯三元共聚物、偏氟乙烯-六氟丙烯-四氟乙烯三元共聚物、四氟乙烯-六氟丙烯共聚物和含氟丙烯酸酯树脂中的一种或多种。
在一些实施方式中，二次电池还包括负极极片，负极极片中具有负极活性材料，负极活性材料中硅基材料的质量百分比为20％～100％。如此，将本申请第一方面的正极极片与高硅含量的负极极片组成二次电池，可使二次电池达到更高的能量密度。可理解，负极活性材料中硅基材料的质量百分比可以为但不限于20％、30％、40％、50％、60％、70％、80％、90％、100％。
本申请的第二方面，提供了一种用电装置，包括本申请第一方面的二次电池。
以下适当参照附图对本申请的二次电池和用电装置进行说明。
除非特别说明，否则提及的电池的组件、材料种类或含量同时适用于锂离子二次电池和钠离子二次电池。
本申请的一个实施方式中，提供一种二次电池。
通常情况下，二次电池包括正极极片、负极极片、电解质和隔离膜。在电池充放电过程中，活性离子在正极极片和负极极片之间往返嵌入和脱出。电解质在正极极片和负极极片之间起到传导离子的作用。隔离膜设置在正极极片和负极极片之间，主要起到防止正负极短路的作用，同时可以使离子通过。
【正极极片】
正极极片包括正极集流体以及设置在正极集流体至少一个表面的正极膜层。
作为示例，正极集流体具有在其自身厚度方向相对的两个表面，正极膜层设置在正极集流体相对的两个表面的其中任意一者或两者上。
在一些实施方式中，所述正极集流体可采用金属箔片或复合集流体。例如，作为金属箔片，可采用铝箔。复合集流体可包括高分子材料基层和形成于高分子材料基层至少一个表面上的金属层。复合集流体可通过将金属材料形成在高分子材料基材上而形成。其中，金属材料包括但不限于铝、铝合金、镍、镍合金、钛、钛合金、银及银合金等。高分子材料基材(如聚丙烯(PP)、聚对苯二甲酸乙二醇酯(PET)、聚对苯二甲酸丁二醇酯(PBT)、聚苯乙烯(PS)、聚乙烯(PE)等的基材)
在一些实施方式中，正极活性材料可包含本领域公知的用于电池的正极活性材料。
作为示例，锂离子二次电池的正极活性材料可包括以下材料中的至少一种：橄榄石结构的含锂磷酸盐、锂过渡金属氧化物及其各自的改性化合物。但本申请并不限定于这些材料，还可以使用其他可被用作电池正极活性材料的传统材料。这些正极活性材料可以仅单独使用一种，也可以将两种以上组合使用。其中，锂过渡金属氧化物的示例可包括但不限于锂钴氧化物(如LiCoO2)、锂镍氧化物(如LiNiO2)、锂锰氧化物(如LiMnO2、LiMn2O4)、 锂镍钴氧化物、锂锰钴氧化物、锂镍锰氧化物、锂镍钴锰氧化物(如LiNi1/3Co1/3Mn1/3O2(也可以简称为NCM333)、LiNi0.5Co0.2Mn0.3O2(也可以简称为NCM523)、LiNi0.5Co0.25Mn0.25O2(也可以简称为NCM211)、LiNi0.6Co0.2Mn0.2O2(也可以简称为NCM622)、LiNi0.8Co0.1Mn0.1O2(也可以简称为NCM811)、锂镍钴铝氧化物(如LiNi0.85Co0.15Al0.05O2)及其改性化合物等中的至少一种。橄榄石结构的含锂磷酸盐的示例可包括但不限于磷酸铁锂(如LiFePO4(也可以简称为LFP))、磷酸铁锂与碳的复合材料、磷酸锰锂(如LiMnPO4)、磷酸锰锂与碳的复合材料、磷酸锰铁锂、磷酸锰铁锂与碳的复合材料中的至少一种。
作为示例，钠离子二次电池的正极活性材料可包括以下材料中的至少一种：钠过渡金属氧化物、聚阴离子型化合物和普鲁士蓝类化合物中的至少一种。但本申请并不限定于这些材料，还可以使用其他可被用作钠离子电池正极活性材料的传统公知的材料。
作为本申请可选的技术方案，钠过渡金属氧化物中，过渡金属可以是Mn、Fe、Ni、Co、Cr、Cu、Ti、Zn、V、Zr及Ce中的至少一种。钠过渡金属氧化物例如为NaxMO2，其中M为Ti、V、Mn、Co、Ni、Fe、Cr及Cu中的一种或几种，0＜x≤1。
作为本申请可选的技术方案，聚阴离子型化合物可以是具有钠离子、过渡金属离子及四面体型(YO4)n-阴离子单元的一类化合物。过渡金属可以是Mn、Fe、Ni、Co、Cr、Cu、Ti、Zn、V、Zr及Ce中的至少一种；Y可以是P、S及Si中的至少一种；n表示(YO4)n-的价态。
聚阴离子型化合物还可以是具有钠离子、过渡金属离子、四面体型(YO4)n-阴离子单元及卤素阴离子的一类化合物。过渡金属可以是Mn、Fe、Ni、Co、Cr、Cu、Ti、Zn、V、Zr及Ce中的至少一种；Y可以是P、S及Si中的至少一种，n表示(YO4)n-的价态；卤素可以是F、Cl及Br中的至少一种。
聚阴离子型化合物还可以是具有钠离子、四面体型(YO4)n-阴离子单元、多面体单元(ZOy)m+及可选的卤素阴离子的一类化合物。Y可以是P、S及Si中的至少一种，n表示(YO4)n-的价态；Z表示过渡金属，可以是Mn、Fe、 Ni、Co、Cr、Cu、Ti、Zn、V、Zr及Ce中的至少一种，m表示(ZOy)m+的价态；卤素可以是F、Cl及Br中的至少一种。
聚阴离子型化合物例如是NaFePO4、Na3V2(PO4)3(磷酸钒钠，简称NVP)、Na4Fe3(PO4)2(P2O7)、NaM’PO4F(M’为V、Fe、Mn及Ni中的一种或几种)及Na3(VOy)2(PO4)2F3-2y(0≤y≤1)中的至少一种。
普鲁士蓝类化合物可以是具有钠离子、过渡金属离子及氰根离子(CN-)的一类化合物。过渡金属可以是Mn、Fe、Ni、Co、Cr、Cu、Ti、Zn、V、Zr及Ce中的至少一种。普鲁士蓝类化合物例如为NaaMebMe’c(CN)6，其中Me及Me’各自独立地为Ni、Cu、Fe、Mn、Co及Zn中的至少一种，0＜a≤2，0＜b＜1，0＜c＜1。
所述正极活性材料在正极膜层中的重量比为80～100重量％，基于正极膜层的总重量计。
在一些实施方式中，正极膜层还可选地包括粘结剂。作为示例，所述粘结剂可以包括聚偏氟乙烯(PVDF)、聚四氟乙烯(PTFE)、偏氟乙烯-四氟乙烯-丙烯三元共聚物、偏氟乙烯-六氟丙烯-四氟乙烯三元共聚物、四氟乙烯-六氟丙烯共聚物及含氟丙烯酸酯树脂中的至少一种。所述粘结剂在正极膜层中的重量比为0～20重量％，基于正极膜层的总重量计。
在一些实施方式中，正极膜层还可选地包括导电剂。作为示例，所述导电剂可以包括超导碳、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨烯及碳纳米纤维中的至少一种。所述导电剂在正极膜层中的重量比为0-20重量％，基于正极膜层的总重量计。
在一些实施方式中，可以通过以下方式制备正极极片：将上述用于制备正极极片的组分，例如正极活性材料、导电剂、粘结剂和任意其他的组分分散于溶剂(例如N-甲基吡咯烷酮)中，形成正极浆料，其中所述正极浆料固含量为40质量百分比(wt％)～80wt％，室温下的粘度调整到5000毫帕·秒(mPa·s)～25000mPa·s，将正极浆料涂覆在正极集流体的表面，烘干后经过冷轧机冷压后形成正极极片。
所述正极膜片的厚度T可采用万分尺测量得到，例如可使用型号为Mitutoyo293-100、精度为0.1μm的万分尺测量得到。需要说明的是，本申 请所述的正极膜片厚度是指经冷压压实后并用于组装电池的正极极片中的正极膜片的厚度。
【负极极片】
负极极片包括负极集流体以及设置在负极集流体至少一个表面上的负极膜层，所述负极膜层包括负极活性材料。
作为示例，负极集流体具有在其自身厚度方向相对的两个表面，负极膜层设置在负极集流体相对的两个表面中的任意一者或两者上。
在一些实施方式中，所述负极集流体可采用金属箔片或复合集流体。例如，作为金属箔片，可以采用铜箔。复合集流体可包括高分子材料基层和形成于高分子材料基材至少一个表面上的金属层。复合集流体可通过将金属材料形成在高分子材料基材上而形成。其中，金属材料包括但不限于铜、铜合金、镍、镍合金、钛、钛合金、银及银合金等，高分子材料基材包括但不限于聚丙烯(PP)、聚对苯二甲酸乙二醇酯(PET)、聚对苯二甲酸丁二醇酯(PBT)、聚苯乙烯(PS)、聚乙烯(PE)等基材。
在一些实施方式中，负极活性材料可采用本领域公知的用于电池的负极活性材料。
作为示例，锂离子二次电池的负极活性材料可包括以下材料中的至少一种：人造石墨、天然石墨、软炭、硬炭、硅基材料、锡基材料和钛酸锂等。所述硅基材料可选自单质硅、硅氧化合物、硅碳复合物、硅氮复合物以及硅合金中的至少一种。所述锡基材料可选自单质锡、锡氧化合物以及锡合金中的至少一种。但本申请并不限定于这些材料，还可以使用其他可被用作电池负极活性材料的传统材料。这些负极活性材料可以仅单独使用一种，也可以将两种以上组合使用。
作为示例，钠离子二次电池的负极活性材料通常为硬碳材料，二维金属碳化物或氮化物。优选钠离子二次电池的负极活性材料通常为硬碳材料。
所述负极活性材料在负极膜层中的重量比为70～100重量％，基于负极膜层的总重量计。
在一些实施方式中，负极膜层还可选地包括粘结剂。所述粘结剂可选自丁苯橡胶(SBR)、聚丙烯酸(PAA)、聚丙烯酸钠(PAAS)、聚丙烯酰胺 (PAM)、聚乙烯醇(PVA)、海藻酸钠(SA)、聚甲基丙烯酸(PMAA)及羧甲基壳聚糖(CMCS)中的至少一种。所述粘结剂在负极膜层中的重量比为0～30重量％，基于负极膜层的总重量计。
在一些实施方式中，负极膜层还可选地包括导电剂。导电剂可选自超导碳、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨烯及碳纳米纤维中的至少一种。所述导电剂在负极膜层中的重量比为0～20重量％，基于负极膜层的总重量计。
在一些实施方式中，负极膜层还可选地包括其他助剂，例如增稠剂(如羧甲基纤维素钠(CMC-Na))等。所述其他助剂在负极膜层中的重量比为0～15重量％，基于负极膜层的总重量计。
在一些实施方式中，可以通过以下方式制备负极极片：将上述用于制备负极极片的组分，例如负极活性材料、导电剂、粘结剂和任意其他组分分散于溶剂(例如去离子水)中，形成负极浆料，其中所述负极浆料固含量为30wt％～70wt％，室温下的粘度调整到2000mPa·s～10000mPa·s；将所得到的负极浆料涂覆在负极集流体上，经过干燥工序，冷压例如对辊，得到负极极片。负极粉末涂布单位面密度为75mg/m2～220mg/m2，负极极片压实密度1.2克/立方米(g/m3)～2.0g/m3。
单位面积负极膜片中负极活性物质的质量M的可使用标准天平称量得到。
所述负极膜片的厚度T可采用万分尺测量得到，例如可使用型号为Mitutoyo293-100、精度为0.1μm的万分尺测量得到。需要说明的是，本申请所述的负极膜片厚度是指经冷压压实后并用于组装电池的负极极片中的负极膜片的厚度。
【电解质】
电解质在正极极片和负极极片之间起到传导离子的作用。本申请对电解质的种类没有具体的限制，可根据需求进行选择。例如，电解质可以是液态的、凝胶态的或全固态的。
在一些实施方式中，所述电解质采用电解液。所述电解液包括电解质盐和溶剂。
在一些实施方式中，锂离子二次电池的电解质盐可选自六氟磷酸锂(LiPF6)、四氟硼酸锂(LiBF4)、高氯酸锂(LiClO4)、六氟砷酸锂(LiAsF6)、双氟磺酰亚胺锂(LiFSI)、双三氟甲磺酰亚胺锂(LiTFSI)、三氟甲磺酸锂(LiTFS)、二氟草酸硼酸锂(LiDFOB)、二草酸硼酸锂(LiBOB)、二氟磷酸锂(LiPO2F2)、二氟二草酸磷酸锂(LiDFOP)及四氟草酸磷酸锂(LiTFOP)中的一种或几种。
钠离子二次电池的电解质盐可选自六氟磷酸钠、双氟磺酰亚胺钠、双三氟甲烷磺酰亚胺钠、三氟甲磺酸钠、四氟硼酸钠、二氟磷酸钠、高氯酸钠、氯化钠中的一种或几种。
所述电解质盐的浓度通常为0.5摩尔/升(mol/L)～5mol/L。
在一些实施方式中，溶剂可选自氟代碳酸乙烯酯(FEC)、碳酸亚乙酯(EC)、碳酸亚丙基酯(PC)、碳酸甲乙酯(EMC)、碳酸二乙酯(DEC)、碳酸二甲酯(DMC)、碳酸二丙酯(DPC)、碳酸甲丙酯(MPC)、碳酸乙丙酯(EPC)、碳酸亚丁酯(BC)、甲酸甲酯(MF)、乙酸甲酯(MA)、乙酸乙酯(EA)、乙酸丙酯(PA)、丙酸甲酯(MP)、丙酸乙酯(EP)、丙酸丙酯(PP)、丁酸甲酯(MB)、丁酸乙酯(EB)、1,4-丁内酯(GBL)、环丁砜(SF)、二甲砜(MSM)、甲乙砜(EMS)及二乙砜(ESE)中的一种或几种。
在一些实施方式中，所述电解液还可选地包括添加剂。例如添加剂可以包括负极成膜添加剂、正极成膜添加剂，还可以包括能够改善电池某些性能的添加剂，例如改善电池过充性能的添加剂、改善电池高温或低温性能的添加剂等。
【隔离膜】
在一些实施方式中，二次电池中还包括隔离膜。本申请对隔离膜的种类没有特别的限制，可以选用任意公知的具有良好的化学稳定性和机械稳定性的多孔结构隔离膜。
在一些实施方式中，隔离膜的材质可选自玻璃纤维、无纺布、聚乙烯、聚丙烯及聚偏二氟乙烯中的至少一种。隔离膜可以是单层薄膜，也可以是多层复合薄膜，没有特别限制。在隔离膜为多层复合薄膜时，各层的材料可以 相同或不同，没有特别限制。
在一些实施方式中，所述隔离膜的厚度为6μm～40μm，可选为12μm～20μm。
在一些实施方式中，正极极片、负极极片和隔离膜可通过卷绕工艺或叠片工艺制成电极组件。
在一些实施方式中，二次电池可包括外包装。该外包装可用于封装上述电极组件及电解质。
在一些实施方式中，二次电池的外包装可以是硬壳，例如硬塑料壳、铝壳、钢壳等。二次电池的外包装也可以是软包，例如袋式软包。软包的材质可以是塑料，作为塑料，可列举出聚丙烯、聚对苯二甲酸丁二醇酯以及聚丁二酸丁二醇酯等。
本申请对二次电池的形状没有特别的限制，其可以是圆柱形、方形或其他任意的形状。例如，图1是作为一个示例的方形结构的二次电池5。
在一些实施方式中，参照图2，外包装可包括壳体51和盖板53。其中，壳体51可包括底板和连接于底板上的侧板，底板和侧板围合形成容纳腔。壳体51具有与容纳腔连通的开口，盖板53能够盖设于所述开口，以封闭所述容纳腔。正极极片、负极极片和隔离膜可经卷绕工艺或叠片工艺形成电极组件52。电极组件52封装于所述容纳腔内。电解液浸润于电极组件52中。二次电池5所含电极组件52的数量可以为一个或多个，本领域技术人员可根据具体实际需求进行选择。
在一些实施方式中，二次电池5可以组装成电池模块，电池模块所含二次电池5的数量可以为一个或多个，具体数量本领域技术人员可根据电池模块的应用和容量进行选择。
在电池模块中，多个二次电池5可以是沿电池模块的长度方向依次排列设置。当然，也可以按照其他任意的方式进行排布。进一步可以通过紧固件将该多个二次电池5进行固定。
可选地，电池模块还可以包括具有容纳空间的外壳，多个二次电池5容纳于该容纳空间。
在一些实施方式中，上述电池模块还可以组装成电池包，电池包所含电 池模块的数量可以为一个或多个，具体数量本领域技术人员可根据电池包的应用和容量进行选择。
在电池包中可以包括电池箱和设置于电池箱中的多个电池模块。电池箱包括上箱体和下箱体，上箱体能够盖设于下箱体，并形成用于容纳电池模块的封闭空间。多个电池模块可以按照任意的方式排布于电池箱中。
另外，本申请还提供一种用电装置，所述用电装置包括本申请提供的二次电池、电池模块、或电池包中的至少一种。所述二次电池、电池模块、或电池包可以用作所述用电装置的电源，也可以用作所述用电装置的能量存储单元。所述用电装置可以包括移动设备(例如手机、笔记本电脑等)、电动车辆(例如纯电动车、混合动力电动车、插电式混合动力电动车、电动自行车、电动踏板车、电动高尔夫球车、电动卡车等)、电气列车、船舶及卫星、储能系统等，但不限于此。
作为所述用电装置，可以根据其使用需求来选择二次电池、电池模块或电池包。
图3是作为一个示例的用电装置。该用电装置为纯电动车、混合动力电动车、或插电式混合动力电动车等。为了满足该用电装置对二次电池的高功率和高能量密度的需求，可以采用电池包或电池模块。
作为另一个示例的装置可以是手机、平板电脑、笔记本电脑等。该装置通常要求轻薄化，可以采用二次电池作为电源。
以下为一些实施例。
为了使本申请所解决的技术问题、技术方案及有益效果更加清楚，以下将结合实施例和附图对本申请进行进一步详细说明。显然，所描述的实施例仅仅是本申请一部分实施例，而不是全部的实施例。以下对至少一个示例性实施例的描述实际上仅仅是说明性的，决不作为对本申请及其应用的任何限制。基于本申请中的实施例，本领域普通技术人员在没有付出创造性劳动前提下所获得的所有其他实施例都属于本申请保护的范围。
实施例中未注明具体技术或条件的，按照本领域内的文献所描述的技术或条件或者按照产品说明书进行。所用试剂或仪器未注明生产厂商者，均为可以通过市购获得的常规产品。
一、实施例
实施例1：
1)正极极片
正极活性材料为Dv50为12μm的团聚体型正极材料(一次颗粒粒径为0.4μm)、Dv50为3μm的类单晶型正极材料(一次颗粒粒径为1.2μm)按照质量比7:3形成的混合物。
其中，团聚体型正极材料的化学式为Lix1Niy1Coz1M1-y1-z1O2；类单晶型正极材料的化学式为Lix2Niy2Coz2M′1-y2-z2O2。x1为1，y1为0.93，z1为0.05，x2为1，y2为0.91，z2为0.07；团聚体型正极材料的粒径分布跨度(Dv90-Dv10)/Dv50为1.25，类单晶型正极材料的粒径分布跨度(Dv90-Dv10)/Dv50为1.35；团聚体型正极材料的BET比表面积为0.56m2/g，类单晶型正极材料的BET比表面积为1.05m2/g；混合后的正极活性材料的粒径分布跨度(Dv90-Dv10)/Dv50为1.78、BET比表面积为0.66m2/g。
将上述正极活性材料投入5L搅拌罐中，然后加入导电剂乙炔黑(SP)和粘结剂聚偏氟乙烯(PVDF)进行30min的预混合，再加入溶剂N-甲基吡咯烷酮(NMP)在抽真空环境下进行快速搅拌，形成正极浆料。其中，正极活性材料：乙炔黑：聚偏氟乙烯的质量比＝96：2：2，浆料的固含量为70％。
将正极浆料均匀、双面涂覆于厚度为12μm的正极集流体铝箔上，涂覆后的极片经过100℃～130℃烘箱干燥半小时后取出，过辊冷压后制备得到正极极片。其中，极片上正极膜层的活性物质载量为21.5mg/cm2。
2)负极极片
将负极活性材料石墨+硅碳材料、炭黑(SP)、丁苯橡胶(SBR)、羧甲基纤维(CMC)按照重量比为95:2:2:1溶于溶剂去离子水中，经搅拌得到分散均匀的负极浆料，将负极浆料均匀地涂在负极集流体铜箔的表面，经过干燥、冷压、裁切，得到负极极片。负极活性材料中硅碳材料的质量占比为30％。
3)隔离膜
采用聚乙烯(PE)多孔聚合薄膜作为隔离膜。
4)电解液
在氩气气氛手套箱中，以电解液质量％计，将8％六氟磷酸锂(LiPF6)、2％碳酸亚乙烯酯(VC)、0.5％六亚甲基二异氰酸酯(HDI)、25％碳酸乙烯酯(EC)、10％碳酸二甲酯(DMC)、20％碳酸甲乙酯(EMC)、剩余的用碳酸二乙酯(DEC)补充至100％，混合得到相应的电解液。
5)电池组装
将正极极片、隔离膜、负极极片依次层叠卷绕组装成裸电芯，将裸电芯置于电池壳体中，注入电解液，化成，得到二次电池。
实施例2：
该实施例与实施例1基本相同，区别仅在于：正极活性材料中团聚体型正极材料的Dv50不同。本实施例中团聚体型正极材料的Dv50为8.2μm。
实施例3：
该实施例与实施例1基本相同，区别仅在于：正极活性材料中团聚体型正极材料的一次颗粒的粒径不同。本实施例中团聚体型正极材料的一次颗粒的粒径为0.2μm。
实施例4：
该实施例与实施例1基本相同，区别仅在于：正极活性材料中团聚体型正极材料的粒径分布跨度(Dv90-Dv10)/Dv50(即SPAN)不同。本实施例中团聚体型正极材料的粒径分布跨度SPAN为1.39。
实施例5：
该实施例与实施例1基本相同，区别仅在于：正极活性材料中团聚体型正极材料的分子式不同。本实施例中团聚体型正极材料的分子式中y1为0.98，z1为0.01。
实施例6：
该实施例与实施例1基本相同，区别仅在于：正极活性材料中团聚体型正极材料的BET比表面积不同。本实施例中团聚体型正极材料的BET比表面积为0.78m2/g。
实施例7：
该实施例与实施例1基本相同，区别仅在于：正极活性材料中类单晶型正极材料的Dv50不同。本实施例中类单晶型正极材料的Dv50为3.8μm。
实施例8：
该实施例与实施例1基本相同，区别仅在于：正极活性材料中类单晶型正极材料的一次颗粒的粒径不同。本实施例中类单晶型正极材料的一次颗粒的粒径为0.9μm。
实施例9：
该实施例与实施例1基本相同，区别仅在于：正极活性材料中类单晶型正极材料的粒径分布跨度(Dv90-Dv10)/Dv50(即SPAN)不同。本实施例中类单晶型正极材料的粒径分布跨度SPAN为1.47。
实施例10：
该实施例与实施例1基本相同，区别仅在于：正极活性材料中类单晶型正极材料的分子式不同。本实施例中类单晶型正极材料的分子式中y2为0.97，z2为0.02。
实施例11：
该实施例与实施例1基本相同，区别仅在于：正极活性材料中类单晶型正极材料的BET比表面积不同。本实施例中类单晶型正极材料的BET比表面积为0.85m2/g。
实施例12：
该实施例与实施例1基本相同，区别仅在于：正极活性材料中团聚体型正极材料与类单晶型正极材料的质量比不同。本实施例中团聚体型正极材料与类单晶型正极材料的质量比为8：2。
实施例13：
该实施例与实施例1基本相同，区别仅在于：混合后的正极活性材料的粒径分布跨度(Dv90-Dv10)/Dv50(即SPAN)不同。本实施例中正极活性材料的粒径分布跨度SPAN为2.03。
实施例14：
该实施例与实施例1基本相同，区别仅在于：混合后的正极活性材料的BET比表面积不同。本实施例中正极活性材料的BET比表面积为0.52m2/g。
实施例15：
该实施例与实施例1基本相同，区别仅在于：负极极片的负极活性材料中硅基材料的含量不同。本实施例中负极活性材料中硅基材料的质量含量为90％。
实施例16：
本实施例中团聚体型正极材料的Dv50为14.9μm，团聚体型正极材料的一次颗粒的粒径为0.3μm，团聚体型正极材料的粒径分布跨度SPAN为0.72，团聚体型正极材料的分子式中y1为0.94，z1为0.05，团聚体型正极材料的BET比表面积为0.3m2/g；类单晶型正极材料的Dv50为3.5μm，类单晶型正极材料的一次颗粒的粒径为1.5μm，类单晶型正极材料的粒径分布跨度SPAN为1.44，类单晶型正极材料的分子式中y2为0.92，z2为0.06，类单晶型正极材料的BET比表面积为0.9m2/g；团聚体型正极材料与类单晶型正极材料的质量比为65:35，正极活性材料的粒径分布跨度SPAN为1.55，正极活性材料的BET比表面积为0.53m2/g，负极活性材料中硅基材料的质量含量为50％，其余与实施例1相同。
实施例17：
本实施例中团聚体型正极材料的Dv50为9.5μm，团聚体型正极材料的一次颗粒的粒径为0.13μm，团聚体型正极材料的粒径分布跨度SPAN为1.33，团聚体型正极材料的分子式中y1为0.94，z1为0.05，团聚体型正极材料的BET比表面积为0.2m2/g；类单晶型正极材料的Dv50为3.5μm，类单晶型正极材料的一次颗粒的粒径为1.5μm，类单晶型正极材料的粒径分布跨度SPAN为1.44，类单晶型正极材料的分子式中y2为0.92，z2为0.06，类单晶型正极材料的BET比表面积为0.83m2/g；团聚体型正极材料与类单晶型正极材料的质量比为75:25，正极活性材料的粒径分布跨度SPAN为1.9，正极活性材料的BET比表面积为0.53m2/g，负极活性材料中硅基材料的质量含量为50％，其余与实施例1相同。
实施例18：
本实施例中团聚体型正极材料的Dv50为9.5μm，团聚体型正极材料的一次颗粒的粒径为0.3μm，团聚体型正极材料的粒径分布跨度SPAN为1.33，团聚体型正极材料的分子式中y1为0.94，z1为0.05，团聚体型正极材料的 BET比表面积为0.45m2/g；类单晶型正极材料的Dv50为3.5μm，类单晶型正极材料的一次颗粒的粒径为1.5μm，类单晶型正极材料的粒径分布跨度SPAN为1.44，类单晶型正极材料的分子式中y2为0.92，z2为0.06，类单晶型正极材料的BET比表面积为1.14m2/g；团聚体型正极材料与类单晶型正极材料的质量比为7:3，正极活性材料的粒径分布跨度SPAN为1.9，正极活性材料的BET比表面积为0.68m2/g，负极活性材料中硅基材料的质量含量为50％，其余与实施例1相同。
实施例19：
本实施例中团聚体型正极材料的Dv50为9.5μm，团聚体型正极材料的一次颗粒的粒径为0.56μm，团聚体型正极材料的粒径分布跨度SPAN为1.33，团聚体型正极材料的分子式中y1为0.94，z1为0.05，团聚体型正极材料的BET比表面积为0.45m2/g；类单晶型正极材料的Dv50为3.5μm，类单晶型正极材料的一次颗粒的粒径为1.9μm，类单晶型正极材料的粒径分布跨度SPAN为1.44，类单晶型正极材料的分子式中y2为0.92，z2为0.06，类单晶型正极材料的BET比表面积为0.9m2/g；团聚体型正极材料与类单晶型正极材料的质量比为8:2，正极活性材料的粒径分布跨度SPAN为1.9，正极活性材料的BET比表面积为0.53m2/g，负极活性材料中硅基材料的质量含量为50％，其余与实施例1相同。
实施例20：
本实施例中团聚体型正极材料的Dv50为9.5μm，团聚体型正极材料的一次颗粒的粒径为0.3μm，团聚体型正极材料的粒径分布跨度SPAN为1.33，团聚体型正极材料的分子式中y1为0.94，z1为0.05，团聚体型正极材料的BET比表面积为0.45m2/g，类单晶型正极材料的Dv50为2.6μm，类单晶型正极材料的一次颗粒的粒径为1.5μm，类单晶型正极材料的粒径分布跨度SPAN为1.44；类单晶型正极材料的分子式中y2为0.92，z2为0.06，类单晶型正极材料的BET比表面积为1.26m2/g，团聚体型正极材料与类单晶型正极材料的质量比为7:3，正极活性材料的粒径分布跨度SPAN为2.07，正极活性材料的BET比表面积为0.53m2/g，负极活性材料中硅基材料的质量含量为50％，其余与实施例1相同。
对比例1：
本对比例中团聚体型正极材料的Dv50为9μm，团聚体型正极材料的一次颗粒的粒径为0.2μm，团聚体型正极材料的粒径分布跨度SPAN为1.2，团聚体型正极材料的分子式中y1为0.94，z1为0.05，团聚体型正极材料的BET比表面积为0.45m2/g；类单晶型正极材料的Dv50为3.3μm，类单晶型正极材料的一次颗粒的粒径为0.7μm，类单晶型正极材料的粒径分布跨度SPAN为1.4；类单晶型正极材料的分子式中y2为0.93，z2为0.06，类单晶型正极材料的BET比表面积为0.95m2/g；团聚体型正极材料与类单晶型正极材料的质量比为8:2，正极活性材料的粒径分布跨度SPAN为1.94，正极活性材料的BET比表面积为0.61m2/g，负极活性材料中硅基材料的质量含量为40％，其余与实施例1相同。
对比例2：
本对比例与对比例1基本相同，区别仅在于：正极活性材料仅采用团聚体型正极材料，不采用类单晶型正极材料，正极活性材料的总量不变；正极极片的压实密度不同。
对比例3：
本对比例与对比例1基本相同，区别仅在于：正极活性材料仅采用类单晶型正极材料，不采用团聚体型正极材料，且类单晶型正极材料的一次颗粒粒径为1.2μm，正极活性材料的总量不变；正极极片的压实密度不同。
二、测试方法
1)Dv10、Dv50、Dv90测试
颗粒的体积平均粒径Dv10、Dv50、Dv90的测试方法可以采用本领域中公知的方法进行测试。作为示例，可以参考GB/T 19077-2016/ISO 13320:2009粒度分布激光衍射法，采用设备马尔文3000进行测定。
2)BET比表面积测试
颗粒的BET比表面积的测试方法可以采用本领域中公知的方法进行测试。作为示例，可以参考GB/T 19587-2017《气体吸附BET法测定固态物质比表面积》，采用设备TriStar II 3020进行测定。
3)一次颗粒粒径测试
扫描电镜在3000倍放大的照片中，一粒粒地测量颗粒最长方向的长度(规则球形测量直径即可，不规则颗粒测量长度最长的反向)，大约测量300个，求平均值，即可得到一次粒径大小。
4)压实密度计算
正极极片压实密度可以通过公式PD＝M/(d×A)计算得到，上式中M为直径40mm小圆片的质量，可通过10次称重取平均值得到；d为冷压后的正极极片厚度，数值可以通过裁成40mm小圆片分别测厚取平均值得到；A为40mm小圆片的面积。
5)长度方向延展率测试
正极极片冷压后长度方向延展率可以通过公式ΔEL％＝(L2-L1)/L1×100％计算得到，上式中L1为冷压前标记长度，一般固定为100mm；L2为冷压后L1标记长度的距离。
6)能量密度测试
电池单体的容量测试：将电池单体在25℃静置2h，确保电池单体的温度为25℃。在25℃下，以0.1C将电池单体充电至充电截止电压后，继续以该充电截止电压进行恒压充电，直至电流为0.05C，充电截止(其中，C表示电池单体额定容量)。将电池单体在25℃静置1h，在25℃下，以0.1C将电池单体放电至放电截止电压，记录电池单体放出的总放电容量C0，总放电能量为E0。
电池单体重量测量：将电池单体放置在电子天平上至重量稳定，读取电池单体重量数值M0。
能量密度计算：电池单体的放电能量E0/电池单体重量M0，即为电池单体的能量密度。
7)循环圈数测试
(1)将全电池放进恒温箱中45℃下静置30min，0.33C恒流放电至2.8V；(2)静置5min，0.33C恒流充电至4.25V而后0.05C恒压至4.25V，静置5min；(3)0.33C恒流放电至2.8V，此时读取容量值记为初始容量C0。重复步骤(2)～(3)得到第二圈容量数据C1，C1/C0即可得到 循环保持率。测试至循环保持率为80％时的测试圈数即为循环圈数。
以上各个实施例和对比例中的正极极片和二次电池的参数和性能测试结果如以下表1、表2和表3所示。以下各表中的A表示团聚体型正极材料，B表示类单晶型正极材料。
需要说明的是，由于同一种材料的多次粒径测试结果可能存在一定的波动，因此本申请各实施例中粒径的小幅波动(例如±0.1μm)属于正常的误差范围内。同样地，同一种正极材料的BET比表面积的小幅波动(例如±0.01m2/g)也属于正常的误差范围。
表1

表2

表3
由以上各表中的数据可知：
本申请实施例1至实施例20的二次电池具有较高的能量密度，同时具有良好的循环性能，具有优异的综合性能。对比例1中正极活性材料中类单晶型正极材料的一次颗粒粒径不在本申请范围之内；对比例2中正极活性材料只采用团聚体型正极材料，不采用类单晶型正极材料；对比例3中 正极活性材料只采用类单晶型正极材料，不采用团聚体型正极材料。本申请实施例1至实施例20的二次电池的综合性能明显优于对比例1、对比例2和对比例3。
本申请实施例7的二次电池与实施例1相比，主要区别在于类单晶型正极材料的Dv50不同。实施例7中类单晶型正极材料的Dv50为3.8，实施例1中类单晶型正极材料的Dv50为3，其二次电池的循环性能相当，但实施例1的能量密度更高。
本申请实施例8的二次电池与实施例1相比，主要区别在于类单晶型正极材料的一次颗粒粒径不同。实施例8中类单晶型正极材料的一次颗粒粒径为0.9，实施例1中类单晶型正极材料的一次颗粒粒径为1.2，实施例1的二次电池的能量密度和循环性能相比于实施例8均明显提升。
本申请实施例12的二次电池与实施例1相比，主要区别在于团聚体型正极材料与类单晶型正极材料的混合比不同。实施例12中团聚体型正极材料与类单晶型正极材料的混合比为8:2，实施例1中团聚体型正极材料与类单晶型正极材料的混合比为7:3，实施例1的二次电池的能量密度和循环性能均比实施例12明显提升。
需要说明的是，本申请不限定于上述实施方式。上述实施方式仅为示例，在本申请的技术方案范围内具有与技术思想实质相同的构成、发挥相同作用效果的实施方式均包含在本申请的技术范围内。此外，在不脱离本申请主旨的范围内，对实施方式施加本领域技术人员能够想到的各种变形、将实施方式中的一部分构成要素加以组合而构筑的其它方式也包含在本申请的范围内。

Claims (17)

  1. 一种二次电池，包括正极极片，所述正极极片上具有正极活性材料，所述正极活性材料包括团聚体型正极材料和类单晶型正极材料；
    所述团聚体型正极材料的体积平均粒径Dv50为8μm～15μm，所述团聚体型正极材料的一次颗粒粒径为0.1μm～0.6μm；
    所述类单晶型正极材料的体积平均粒径Dv50为2.5μm～4μm，所述类单晶型正极材料的一次颗粒粒径为0.8μm～2μm；
    所述团聚体型正极材料和所述类单晶型正极材料的质量比大于或等于1。
  2. 根据权利要求1所述的二次电池，其特征在于，所述团聚体型正极材料和所述类单晶型正极材料的质量比为1～9:1；可选为2.3～3:1。
  3. 根据权利要求1或2所述的二次电池，其特征在于，所述类单晶型正极材料的体积平均粒径Dv50为3μm～3.5μm，和/或所述类单晶型正极材料的一次颗粒粒径为1.2μm～1.5μm。
  4. 根据权利要求1至3中任一项所述的二次电池，其特征在于，所述团聚体型正极材料的一次颗粒粒径为0.2μm～0.4μm。
  5. 根据权利要求1至4中任一项所述的二次电池，其特征在于，所述团聚体型正极材料的化学式为Lix1Niy1Coz1M1-y1-z1O2，其中0.9≤x1≤1，0.9≤y1≤0.98，0.05≤z1≤0.1，M包括Mn、Al、B、Zr、Sr、Y、Sb、W、Ti、Mg和Nb中的一种或多种；
    可选地，0.9≤y1≤0.96。
  6. 根据权利要求5所述的二次电池，其特征在于，所述类单晶型正极材料的化学式为Lix2Niy2Coz2M′1-y2-z2O2，其中0.9≤x2≤1，0.9≤y2≤0.98，0.05≤z2≤0.1，M′包括Mn、Al、B、Zr、Sr、Y、Sb、W、Ti、Mg和Nb中的一种或多种；
    可选地，0.92≤y2≤0.98。
  7. 根据权利要求6所述的二次电池，其特征在于，y2>y1。
  8. 根据权利要求1至7中任一项所述的二次电池，其特征在于，所述团 聚体型正极材料的粒径分布跨度(Dv90-Dv10)/Dv50≤1.5；可选为0.7～1.4。
  9. 根据权利要求1至8中任一项所述的二次电池，其特征在于，所述团聚体型正极材料的BET比表面积为0.2m2/g～0.8m2/g；可选为0.3m2/g～0.6m2/g。
  10. 根据权利要求1至9中任一项所述的二次电池，其特征在于，所述类单晶型正极材料的粒径分布跨度(Dv90-Dv10)/Dv50≥1.2；可选为1.3～1.5。
  11. 根据权利要求1至10中任一项所述的二次电池，其特征在于，所述类单晶型正极材料的BET比表面积为0.8m2/g～1.3m2/g；可选为0.85m2/g～1.15m2/g。
  12. 根据权利要求1至11中任一项所述的二次电池，其特征在于，所述正极活性材料的粒径分布跨度(Dv90-Dv10)/Dv50为1.5～2.1。
  13. 根据权利要求1至12中任一项所述的二次电池，其特征在于，所述正极活性材料的BET比表面积为0.5m2/g～0.7m2/g。
  14. 根据权利要求1至13中任一项所述的二次电池，其特征在于，所述正极极片中所述正极活性材料占正极膜层的质量百分比为95％～99.5％。
  15. 根据权利要求1至14中任一项所述的二次电池，其特征在于，所述正极极片中所述正极活性材料的涂布面密度为21.5mg/cm2～32.5mg/cm2。
  16. 根据权利要求1至15中任一项所述的二次电池，其特征在于，还包括负极极片，所述负极极片上具有负极活性材料，所述负极活性材料中硅基材料的质量百分比为20％～100％。
  17. 一种用电装置，包括权利要求1至16中任一项所述的二次电池。
PCT/CN2023/086923 2023-04-07 2023-04-07 二次电池和用电装置 Ceased WO2024207433A1 (zh)

Priority Applications (4)

Application Number Priority Date Filing Date Title
PCT/CN2023/086923 WO2024207433A1 (zh) 2023-04-07 2023-04-07 二次电池和用电装置
CN202380016621.6A CN119111003B (zh) 2023-04-07 2023-04-07 二次电池和用电装置
EP23931494.1A EP4664556A4 (en) 2023-04-07 2023-04-07 SECONDARY BATTERY AND ELECTRICAL DEVICE
US19/268,114 US20250343232A1 (en) 2023-04-07 2025-07-14 Secondary battery and electrical device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2023/086923 WO2024207433A1 (zh) 2023-04-07 2023-04-07 二次电池和用电装置

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US19/268,114 Continuation US20250343232A1 (en) 2023-04-07 2025-07-14 Secondary battery and electrical device

Publications (1)

Publication Number Publication Date
WO2024207433A1 true WO2024207433A1 (zh) 2024-10-10

Family

ID=92970889

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2023/086923 Ceased WO2024207433A1 (zh) 2023-04-07 2023-04-07 二次电池和用电装置

Country Status (4)

Country Link
US (1) US20250343232A1 (zh)
EP (1) EP4664556A4 (zh)
CN (1) CN119111003B (zh)
WO (1) WO2024207433A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN119890415A (zh) * 2025-03-28 2025-04-25 宁德时代新能源科技股份有限公司 锂离子二次电池、制备方法与用电装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108134069A (zh) * 2017-12-26 2018-06-08 深圳市贝特瑞纳米科技有限公司 一种锂离子电池正极材料的复合改性方法
CN109888368A (zh) * 2019-03-05 2019-06-14 深圳鸿鹏新能源科技有限公司 低温锂离子电池
CN109962221A (zh) * 2019-02-20 2019-07-02 江西星盈科技有限公司 复合正极材料及正极片及正极片制备方法及锂离子电池
CN114204016A (zh) * 2020-09-18 2022-03-18 比亚迪股份有限公司 正极材料、正极浆料、正极片及电池
WO2022080108A1 (ja) * 2020-10-13 2022-04-21 国立大学法人信州大学 リチウムイオン二次電池およびその正極
CN114430027A (zh) * 2020-10-28 2022-05-03 比亚迪股份有限公司 正极复合材料及其制备方法和锂离子电池

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111384372B (zh) * 2018-12-29 2021-03-23 宁德时代新能源科技股份有限公司 一种高压实密度正极材料及电化学储能装置
CN113166329B (zh) * 2019-03-04 2023-02-21 国立大学法人大阪大学 电化学器件用粘结剂、电极合剂、电极、电化学器件和二次电池
CN112151775B (zh) * 2019-06-28 2021-11-23 宁德时代新能源科技股份有限公司 一种低产气高容量的三元正极材料
WO2021217576A1 (zh) * 2020-04-30 2021-11-04 宁德时代新能源科技股份有限公司 二次电池、其制备方法及含有该二次电池的装置
CN116072816A (zh) * 2020-09-22 2023-05-05 宁德时代新能源科技股份有限公司 一种用于二次电池的正极极片、二次电池、电池模块、电池包和装置
DE112022004427T5 (de) * 2021-11-18 2024-07-04 Murata Manufacturing Co., Ltd. Sekundärbatterie, Batteriepack, elektronische Geräte, elektrisches Werkzeug, elektrisches Luftfahrzeug und elektrisches Fahrzeug
CN115832183A (zh) * 2022-05-05 2023-03-21 宁德时代新能源科技股份有限公司 正极极片及其制备方法、二次电池、电池模块、电池包及用电装置
CN115000407B (zh) * 2022-06-13 2023-06-09 万向一二三股份公司 一种硅基负极极片及其制备方法和应用

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108134069A (zh) * 2017-12-26 2018-06-08 深圳市贝特瑞纳米科技有限公司 一种锂离子电池正极材料的复合改性方法
CN109962221A (zh) * 2019-02-20 2019-07-02 江西星盈科技有限公司 复合正极材料及正极片及正极片制备方法及锂离子电池
CN109888368A (zh) * 2019-03-05 2019-06-14 深圳鸿鹏新能源科技有限公司 低温锂离子电池
CN114204016A (zh) * 2020-09-18 2022-03-18 比亚迪股份有限公司 正极材料、正极浆料、正极片及电池
WO2022080108A1 (ja) * 2020-10-13 2022-04-21 国立大学法人信州大学 リチウムイオン二次電池およびその正極
CN114430027A (zh) * 2020-10-28 2022-05-03 比亚迪股份有限公司 正极复合材料及其制备方法和锂离子电池

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP4664556A4 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN119890415A (zh) * 2025-03-28 2025-04-25 宁德时代新能源科技股份有限公司 锂离子二次电池、制备方法与用电装置

Also Published As

Publication number Publication date
US20250343232A1 (en) 2025-11-06
CN119111003A (zh) 2024-12-10
CN119111003B (zh) 2026-02-03
EP4664556A1 (en) 2025-12-17
EP4664556A4 (en) 2026-04-15

Similar Documents

Publication Publication Date Title
US12119486B2 (en) Anode material and electrochemical device and electronic device including the same
JP7657216B2 (ja) 二次電池及び当該二次電池を備える装置
CN116231091B (zh) 锂二次电池用电解液、二次电池和用电装置
JP7713033B2 (ja) リチウムイオン電池の正極板、それを含むリチウムイオン電池及び電力利用装置
WO2023108352A1 (zh) 一种正极活性材料及其相关的极片、二次电池、电池模块、电池包和装置
WO2020135110A1 (zh) 负极活性材料、电池及装置
WO2021217628A1 (zh) 二次电池、其制备方法及含有该二次电池的装置
CN117133861B (zh) 负极极片、电池单体和用电装置
JP7739566B2 (ja) 負極板、二次電池、電池モジュール、電池パック及び電力消費装置
CN115832290A (zh) 负极活性材料及其制备方法、负极极片、二次电池、电池模块、电池包和用电装置
CN116053469B (zh) 正极活性材料、正极极片、二次电池和用电装置
US20250343232A1 (en) Secondary battery and electrical device
US20250364547A1 (en) Secondary battery and electric apparatus
CN116210097A (zh) 硅基材料、其制备方法及其相关的二次电池、电池模块、电池包和装置
CN118676358B (zh) 正极活性材料、正极极片、电池及管理方法和应用
WO2024178675A1 (zh) 正极活性物质、正极极片、二次电池、用电装置和制备方法
WO2024092501A1 (zh) 正极极片、制法、二次电池和用电装置
CN118511299A (zh) 负极活性材料的制备方法、负极活性材料、二次电池和用电装置
CN119208507B (zh) 阴极极片及其制备方法、以及包含该阴极极片的电池和用电设备
US20250391837A1 (en) Positive electrode plate, secondary battery, and electric apparatus
WO2024221320A1 (zh) 二次电池和用电装置
CN116646471A (zh) 负极极片及其制备方法、二次电池和用电装置
CN118511296A (zh) 负极组合物及制备方法、负极浆料及制备方法、负极极片及制备方法、二次电池、用电装置以及噻蒽类化合物的应用
WO2025010988A1 (zh) 负极极片、二次电池和用电装置
WO2025107539A1 (zh) 正极活性材料及其制备方法、电池和用电装置

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 202380016621.6

Country of ref document: CN

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23931494

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

WWP Wipo information: published in national office

Ref document number: 2023931494

Country of ref document: EP