WO2023070600A1 - 二次电池、电池模组、电池包以及用电装置 - Google Patents

二次电池、电池模组、电池包以及用电装置 Download PDF

Info

Publication number
WO2023070600A1
WO2023070600A1 PCT/CN2021/127721 CN2021127721W WO2023070600A1 WO 2023070600 A1 WO2023070600 A1 WO 2023070600A1 CN 2021127721 W CN2021127721 W CN 2021127721W WO 2023070600 A1 WO2023070600 A1 WO 2023070600A1
Authority
WO
WIPO (PCT)
Prior art keywords
active material
material layer
electrode active
secondary battery
positive electrode
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/CN2021/127721
Other languages
English (en)
French (fr)
Inventor
李全国
叶永煌
刘倩
何建福
黄发军
林晨辉
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 EP21961952.5A priority Critical patent/EP4287331A4/en
Priority to PCT/CN2021/127721 priority patent/WO2023070600A1/zh
Priority to CN202180093127.0A priority patent/CN116868398A/zh
Publication of WO2023070600A1 publication Critical patent/WO2023070600A1/zh
Priority to US18/366,342 priority patent/US12218311B2/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Images

Classifications

    • 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
    • H01M10/058—Construction or manufacture
    • H01M10/0585—Construction or manufacture of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
    • 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
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • H01M4/381—Alkaline or alkaline earth metals elements
    • 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
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • 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
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/5825—Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
    • 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
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/621—Binders
    • H01M4/622—Binders being polymers
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/621—Binders
    • H01M4/622—Binders being polymers
    • H01M4/623—Binders being polymers fluorinated polymers
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • 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
    • H01M2004/027—Negative electrodes
    • 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 a secondary battery, in particular to a secondary battery, such as a lithium ion battery, and a battery module, a battery pack, and an electrical device including the secondary battery.
  • a secondary battery such as a lithium ion battery
  • a battery module such as a lithium ion battery
  • a battery pack such as a battery pack
  • an electrical device including the secondary battery.
  • the most energy storage batteries used in new energy electric vehicles are mainly lithium-ion secondary batteries, mainly including chemical systems such as lithium iron phosphate, lithium manganese oxide, lithium cobalt oxide, and ternary materials containing nickel, cobalt, and manganese.
  • the cycle life of secondary batteries generally decays to about 80% of the initial capacity after 1000-2000 times of charging and discharging. Generally, the battery will be eliminated. This not only causes a great waste of batteries, but also brings a series of problems such as environmental pollution.
  • the present application achieves the purpose of reducing battery attenuation and prolonging service life by pre-living active ions (such as lithium ions) in the positive electrode sheet and making them slowly released during use to supplement the consumption of active ions. question.
  • a secondary battery includes a positive electrode sheet and a negative electrode sheet, wherein the positive electrode sheet includes a positive electrode current collector distributed on one side of the positive electrode current collector The first positive electrode active material layer, and the second positive electrode active material layer distributed on the other side of the positive electrode current collector;
  • the negative electrode sheet includes a negative electrode current collector, a first negative electrode active material layer distributed on one side of the negative electrode current collector and opposite to the second positive electrode active material layer, and a first negative electrode active material layer distributed on the other side of the negative electrode current collector. the second negative electrode active material layer,
  • the resistance of the first positive active material layer is R1
  • the resistance of the second positive active material layer is R2
  • the resistance of the first negative active material layer is R3
  • the resistance of the second negative active material layer is R4 and satisfies the following relationship:
  • A is 0.95-1.05.
  • R1 is 0.1 ⁇ -20 ⁇
  • R2 is 0.15 ⁇ -22 ⁇
  • R3 is 0.7m ⁇ -40m ⁇
  • R4 is 0.5m ⁇ -35m ⁇
  • R1 is 0.5 ⁇ -10 ⁇
  • R2 is 0.55 ⁇ - 12 ⁇
  • R3 is 1m ⁇ -30m ⁇
  • R4 is 1.1m ⁇ -30m ⁇ .
  • the coating weight per unit area of the first positive electrode active material layer is CW1
  • the coating weight per unit area of the second positive electrode active material layer is a positive electrode active material of CW2, and satisfy 0.5 ⁇ CW1/CW2 ⁇ 1.
  • the coating weight per unit area of the first negative electrode active material layer is CW3
  • the coating weight per unit area of the second negative electrode active material layer is CW4, and satisfy 1 ⁇ CW3/CW4 ⁇ 1.5.
  • the capacity per unit area of the second positive electrode active material layer is CapA
  • the capacity per unit area of the first negative electrode active material layer is CapB
  • optional Ground 0.468 ⁇ CapA/CapB ⁇ 0.870.
  • the thickness of the first positive electrode active material layer is T1
  • the thickness of the second positive electrode active material layer is T2
  • T1 ⁇ T2 is satisfied.
  • the thickness of the first negative electrode active material layer is T3
  • the thickness of the second negative electrode active material layer is T4, and T4 ⁇ T3 is satisfied.
  • the compacted density of the first positive electrode active material layer and/or the second positive electrode active material layer is 2.0g/cm 3 -3.6g/cm 3
  • the first negative electrode active material layer The compacted density of the material layer and/or the second negative electrode active material layer is 0.5g/cm 3 -2g/cm 3 ; or the compaction of the first positive electrode active material layer and/or the second positive electrode active material layer
  • the density is 2.3g/cm 3 -3.5g/cm 3
  • the compacted density of the first negative electrode active material layer and/or the second negative electrode active material layer is 1.0g/cm 3 -1.8g/cm 3 .
  • the first positive electrode active material layer and/or the second positive electrode active material layer independently contain NCM ternary material, NCA ternary material, lithium iron phosphate, lithium manganate, cobalt acid Lithium and at least one of an oxide containing active sodium ions, a polyanion material, or a Prussian blue-like material.
  • the first positive electrode active material layer and/or the second positive electrode active material layer independently contain conductive materials such as graphite, carbon black, acetylene black, graphene, carbon nanotubes, and combinations of the above materials. agent, and a binder selected from polyvinylidene fluoride, polyacrylic acid, polytetrafluoroethylene, polyimide, and combinations thereof.
  • the first negative electrode active material layer and/or the second negative electrode active material layer independently contain natural graphite, artificial graphite, graphene, carbon nanotubes, soft carbon, hard carbon and their A combination of two or more.
  • a battery module including the secondary battery described in the present application.
  • a battery pack which includes the secondary battery or battery module described in the present application.
  • an electric device which includes the secondary battery, the battery module or the battery pack described in the present application, and the secondary battery or the battery module or the battery pack is used for Serve as the power source of the electric device or the energy storage unit of the electric device.
  • Fig. 1 is a schematic diagram of a positive pole piece and a negative pole piece of a secondary battery in some embodiments of the present application.
  • FIG. 2 is the battery cycle life curves of specific embodiments and comparative embodiments of the present application.
  • FIG. 3 is a schematic diagram of an embodiment of the secondary battery of the present application.
  • FIG. 4 is an exploded view of the secondary battery shown in FIG. 3 .
  • FIG. 5 is a schematic diagram of an embodiment of a battery module of the present application.
  • Fig. 6 is a schematic diagram of an embodiment of the battery pack of the present application.
  • FIG. 7 is an exploded view of the battery pack shown in FIG. 6 .
  • FIG. 8 is a schematic diagram of an embodiment of a device using the secondary battery of the present application as a power source.
  • ranges disclosed herein are defined in terms of lower and upper limits, and a given range is defined by selecting a lower limit and an upper limit that define the boundaries of the particular range. Ranges defined in this manner may be inclusive or exclusive and may be combined arbitrarily, ie any lower limit may be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a particular parameter, it is understood that ranges of 60-110 and 80-120 are contemplated. Additionally, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are listed, the following ranges are all expected: 1-3, 1-4, 1-5, 2- 3, 2-4 and 2-5.
  • the numerical range "a-b” represents an abbreviated representation of any combination of real numbers between a and b, where a and b are both real numbers.
  • the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article, and "0-5" is only an abbreviated representation of the combination of these values.
  • a certain parameter is an integer ⁇ 2
  • the "comprising” and “comprising” mentioned herein mean an open type or a closed type.
  • the “comprising” and “comprising” may mean that other components not listed may be included or included, or only listed components may be included or included.
  • the term "or” is inclusive.
  • the phrase “A or B” means “A, B, or both A and B.” More specifically, the condition “A or B” is satisfied by either of the following: 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 resistance of the first positive active material layer is R1
  • the resistance of the second positive active material layer is R2
  • the resistance of the first negative active material layer is R3
  • the active material layers on both sides of the positive electrode current collector simultaneously start to extract active lithium ions from the positive electrode material, pass through the separator, and embed in the negative electrode graphite, while electrons are transferred to the negative electrode through the positive electrode current collector and the external circuit. , at this time, the potential difference of the active material layers on both sides of the positive current collector is equal.
  • the resistance of the active material layer on both sides of the positive electrode current collector is set as R2>R1. The rate of ion extraction is relatively slow.
  • A may be within a numerical range formed by any two of the following numerical values as endpoints: 0.80, 0.85, 0.90, 0.95, 1.00, 1.05, 1.10, 1.15, 1.20. It should be emphasized that although the above numerical values are listed side by side, it does not mean that a numerical range composed of any two of the above numerical values as endpoints can obtain equivalent or similar performance. This also applies to the numerical ranges mentioned below. With regard to the preferred embodiments of the present application, the selection is only based on the specific discussion below and specific experimental data. In an optional embodiment of the present application, A is 0.95-1.05.
  • R1 can be within the numerical range formed by any two of the following numerical values as end values: 0.1 ⁇ , 0.5 ⁇ , 1 ⁇ , 5 ⁇ , 10 ⁇ , 15 ⁇ , 20 ⁇ ; R2 can be within the value range formed by any two of the following values as end values: 0.15 ⁇ , 0.55 ⁇ , 1 ⁇ , 3 ⁇ , 6 ⁇ , 9 ⁇ , 12 ⁇ . Any two of the values listed below are within the value range formed by the end values: 0.5m ⁇ , 1.1m ⁇ , 5m ⁇ , 10m ⁇ , 20m ⁇ , 30m ⁇ , 35m ⁇ .
  • the R1, R2, R3 and R4 can ensure that when the two sides of the positive electrode sheet in the secondary battery are discharged at the same time, the side with more transferable active materials will remain, and as the secondary battery cycles and ages, the remaining The transferable active substances will be released gradually, delaying battery aging and increasing cycle life.
  • R1 is 0.1 ⁇ -20 ⁇
  • R2 is 0.15 ⁇ -22 ⁇
  • R3 is 0.7m ⁇ -40m ⁇
  • R4 is 0.5m ⁇ -35m ⁇
  • R1 is 0.5 ⁇ -10 ⁇
  • R2 is 0.55 ⁇ -12 ⁇
  • R3 is 1m ⁇ -30m ⁇
  • R4 is 1.1m ⁇ -30m ⁇ .
  • the first positive electrode active material layer contains active ionic compounds in an amount of CW1
  • the second positive electrode active material layer contains active ionic compounds in an amount of CW2, and satisfy 0.5 ⁇ CW1/CW2 ⁇ 1.
  • CW1/CW2 may be within a numerical range formed by any two of the following numerical values as endpoints: 0.5, 0.6, 0.7, 0.8, 0.9, 0.95, 0.99.
  • CW2 the side with more transferable active substances (CW2) will remain. As the secondary battery cycles and ages, the remaining transferable active substances will be gradually released, delaying battery aging and increasing cycle life.
  • CW1 can be a numerical range formed by any two of the following numerical values as end values Within: 6.5mg/cm 2 , 9.5mg/cm 2 , 13.0mg/cm 2 , 18.5mg/cm 2 , 26.0mg/cm 2 , 32.5mg/cm 2 ;
  • CW2 can be any two of the values listed below Within the range of values constituted as end values: 6.5 mg/cm 2 , 9.5 mg/cm 2 , 13.0 mg/cm 2 , 18.5 mg/cm 2 , 26.0 mg/cm 2 , 32.5 mg/cm 2 .
  • the first negative electrode active material layer contains active ion vacancy materials in an amount of CW3
  • the second negative electrode active material layer contains active ion vacancy materials in an amount of CW4, and satisfies 1 ⁇ CW3/CW4 ⁇ 1.5 .
  • CW3/CW4 can be within the numerical range formed by any two of the following numerical values as end values: 1.0, 1.05, 1.10, 1.15, 1.20, 1.25, 1.30, 13.5, 1.40, 1.45, 1.50 .
  • the energy density of the secondary battery of the present application can be improved.
  • CW3 on the basis of satisfying 1 ⁇ CW3/CW4 ⁇ 1.5, based on the weight of the active ion vacancy material per unit area, CW3 can be composed of any two of the values listed below as end values Within the range of values: 5.2mg/cm 2 , 8.4mg/cm 2 , 12.0mg/cm 2 , 14.6mg/cm 2 , 16.9mg/cm 2 , 19.5mg/cm 2 ; CW4 can be any of the values listed below Within the numerical range constituted by two end values: 5.2 mg/cm 2 , 8.4 mg/cm 2 , 12.0 mg/cm 2 , 14.6 mg/cm 2 , 16.9 mg/cm 2 , 19.5 mg/cm 2 .
  • the capacity per unit area of the first positive electrode active material layer and the second positive electrode active material layer is CapA
  • the capacity per unit area of the first negative electrode active material layer and the second negative electrode active material layer is CapB
  • CapA/CapB may be within a numerical range formed by any two of the following listed numerical values as end values: 0.300, 0.368, 0.400, 0.450, 0.500, 0.550, 0.670, 0.933.
  • the secondary battery of the present application can avoid too much positive electrode active material (for example, lithium), which will cause the negative electrode to be unable to accommodate and lead to the phenomenon of "lithium precipitation", thereby deteriorating the cycle life of the secondary battery.
  • positive electrode active material for example, lithium
  • the first positive electrode active material layer includes an active ionic compound layer with a thickness of T1
  • the second positive electrode active material layer includes an active ionic compound layer with a thickness of T2
  • T1 ⁇ T2 is satisfied.
  • the coating thickness of the active ionic compound in the second positive electrode active material layer may be greater than the coating thickness of the active ionic compound in the first positive electrode active material layer, thus, the second positive electrode active material layer (also referred to as R2
  • the transferable active material for example, lithium) on the surface
  • the first negative electrode active material layer includes an active ion vacancy material layer with a thickness of T3
  • the second negative electrode active material layer includes an active ion vacancy material layer with a thickness of T4, and T4 ⁇ T3 is satisfied.
  • the coating thickness of the active ion vacancy material in the first negative electrode active material layer (also known as the R3 surface) opposite to the R2 surface can be greater than that of the second negative electrode active material layer (also known as the R3 surface) facing the R1 surface.
  • the coating thickness of the active ion vacancy material in the R4 surface is to provide enough vacancies for the negative electrode to accommodate lithium ions.
  • 0 ⁇ (T1+T4)/(T2+T3) ⁇ 1 thereby ensuring that the positive electrode sheet is coated with less transferable active material/the corresponding negative electrode sheet has less active ion vacancy material
  • the total resistance of one side of the pole piece is small, and the polarization is small, which can preferentially transfer the transferable active material (for example, lithium), and finally ensure that the transferable active material can remain on the side with a large coating amount.
  • the compaction density of the first positive electrode active material layer and the second positive electrode active material layer of the secondary battery is controlled, which can reduce the ion transmission path, so as to improve the cycle life of the secondary battery, while not Due to the high compaction density, the particles of the active material are broken, and the specific surface area (BET) increases, which leads to side reactions and deteriorates the cycle life of the secondary battery to a certain extent.
  • BET specific surface area
  • the compacted density of the first positive electrode active material layer and/or the second positive electrode active material layer may be within a numerical range formed by any two of the values listed below as end values : 2.0g/cm 3 , 2.3g/cm 3 , 2.6g/cm 3 , 2.9g/cm 3 , 3.2g/cm 3 , 3.5g/cm 3 , 3.6g/cm 3 .
  • the compacted density of the first negative electrode active material layer and/or the second negative electrode active material layer may be within a numerical range formed by any two of the following listed values as end values: 0.5g/cm 3 , 0.8g /cm 3 , 1.0g/cm 3 , 1.3g/cm 3 , 1.5g/cm 3 , 1.8g/cm 3 , 2.0g/cm 3 .
  • the compacted density of the first positive electrode active material layer and/or the second positive electrode active material layer is 2.0 g/cm 3 -3.6 g/cm 3 or 2.3 g/cm 3 - 3.5g/cm 3 ; the compacted density of the first negative electrode active material layer and/or the second negative electrode active material layer is 0.5g/cm 3 -2g/cm 3 or 1.0g/cm 3 -1.8g/cm 3 .
  • the performance improvements brought by coating different amounts of transferable active materials on both sides of the positive electrode sheet of the present application will be characterized, but here it is necessary It is particularly emphasized that the differential coating design on both sides of the positive electrode sheet of the present application can be used for any electrical device including carbon-based electrodes, and allow the electrical device to benefit from it.
  • a secondary battery in one embodiment of the present application, can be a lithium-ion secondary battery, a potassium-ion secondary battery, a sodium-ion secondary battery, a lithium-sulfur battery, etc., and is particularly preferably a lithium-ion secondary battery. ion secondary battery.
  • the secondary battery of the present application includes a positive electrode (pole sheet), a negative electrode (pole sheet), a separator, an electrolyte/liquid, and the like.
  • active ions are intercalated and extracted back and forth between the positive electrode and the negative electrode.
  • the electrolyte plays the role of conducting ions between the positive pole piece and the negative pole piece.
  • the positive electrode sheet includes a positive electrode collector and a positive electrode film layer (or called a positive electrode active material layer) disposed on at least one surface of the positive electrode collector and including a positive electrode active material.
  • the positive current collector has two opposite surfaces 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 current collector.
  • the positive current collector may be a metal foil or a composite current collector, for example, the metal foil may be an aluminum foil, and the composite current collector may include a polymer material base layer and a base layer formed on the high polymer material. A metallic layer on at least one surface of the molecular material base layer.
  • the composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as polypropylene PP, polyethylene terephthalic acid It is formed on substrates such as ethylene glycol ester PET, polybutylene terephthalate PBT, polystyrene PS, polyethylene PE and its copolymers).
  • a metal material aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.
  • a polymer material substrate such as polypropylene PP, polyethylene terephthalic acid It is formed on substrates such as ethylene glycol ester PET, polybutylene terephthalate PBT, polystyrene PS, polyethylene PE and its copolymers.
  • the positive electrode active material may be a positive electrode active material known in the art for secondary batteries.
  • the positive electrode active material may include one or more of the following: olivine-structured lithium-containing phosphate, lithium transition metal oxides, and their respective modified compounds.
  • the present application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for secondary batteries can 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 oxides (such as LiCoO 2 ), lithium nickel oxides (such as LiNiO 2 ), lithium manganese oxides (such as LiMnO 2 , LiMn 2 O 4 ), 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 (NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM523), LiNi 0.5 Co 0.25 Mn 0.25 O 2 (NCM211), LiNi 0.6 Co 0.2 Mn 0.2 O 2 (NCM622), LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811)), lithium nickel cobalt aluminum oxide (such as One or more of LiNi 0.85 Co 0.15 Al 0.05 O 2 ) and its modified compounds.
  • lithium cobalt oxides such as LiCoO 2
  • lithium nickel oxides such as Li
  • olivine-structured lithium-containing phosphates may include, but are not limited to, lithium iron phosphate (such as LiFePO 4 (LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO 4 ), lithium manganese phosphate and carbon One or more of composite materials, lithium manganese iron phosphate, lithium manganese iron phosphate and carbon composite materials.
  • the second positive electrode active material and the third positive electrode active material are the same or different, and are selected from lithium iron phosphate (LFP), lithium manganese oxide (LMO), nickel cobalt lithium manganese oxide (NCM), Lithium cobalt oxide (LCO), lithium nickel cobalt aluminate (NCA) and oxides containing active sodium ions, polyanionic materials or Prussian blue-like materials.
  • LFP lithium iron phosphate
  • LMO lithium manganese oxide
  • NCM nickel cobalt lithium manganese oxide
  • LCO Lithium cobalt oxide
  • NCA lithium nickel cobalt aluminate
  • oxides containing active sodium ions polyanionic materials or Prussian blue-like materials.
  • the positive electrode film layer may further optionally include a binder.
  • the non-limiting example that can be used for the binding agent of anode film layer can include following one or more: polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene meta-copolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer and fluorine-containing acrylate resin.
  • the first positive electrode active material layer and/or the second positive electrode active material layer each independently contain polyvinylidene fluoride, polyacrylic acid, polytetrafluoroethylene, polyimide and binders for their combination.
  • the positive electrode film layer may further optionally contain a conductive agent.
  • the conductive agent used in the positive film layer may include one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.
  • the first positive electrode active material layer and/or the second positive electrode active material layer independently contain conductive materials such as graphite, carbon black, acetylene black, graphene, carbon nanotubes, and combinations of the above materials. agent.
  • the positive electrode can be prepared in the following manner: the above-mentioned components for preparing the positive electrode, such as positive electrode active material, conductive agent, binder and any other components, are dispersed in a solvent (such as N- Methylpyrrolidone) to form a uniform positive electrode slurry; the positive electrode slurry is coated on the positive electrode current collector, and after drying, cold pressing and other processes, the positive electrode sheet can be obtained.
  • a solvent such as N- Methylpyrrolidone
  • the secondary battery of the present application includes a negative electrode sheet, and the negative electrode sheet includes a negative electrode current collector and a negative electrode film layer (or called a negative electrode active material layer) arranged on at least one surface of the negative electrode current collector.
  • the first negative electrode active material and the second negative electrode active material are the same or different, each independently containing natural graphite, artificial graphite, graphene, carbon nanotubes, soft carbon, hard carbon and two or more of them combination of species.
  • the negative electrode film layer can also include a certain amount of other commonly used negative electrode active materials, such as natural graphite, other artificial graphite, soft carbon, hard carbon, One or more of silicon-based materials, tin-based materials, and lithium titanate.
  • the silicon-based material can be selected from one or more of elemental silicon, silicon oxide, and silicon-carbon composites.
  • the tin-based material may be selected from one or more of simple tin, tin oxide compounds, and tin alloys.
  • the negative electrode membrane includes negative electrode active materials, optional binders, optional conductive agents and other optional additives, and is usually formed by coating and drying negative electrode slurry.
  • the negative electrode slurry coating is usually formed by dispersing the negative electrode active material and optional conductive agent and binder in a solvent and stirring them evenly.
  • the solvent can be N-methylpyrrolidone (NMP) or deionized water.
  • the conductive agent may include one or more of superconducting carbon, carbon black (such as acetylene black, ketjen black), carbon dots, carbon nanotubes, graphene, and carbon nanofibers.
  • carbon black such as acetylene black, ketjen black
  • carbon dots carbon nanotubes, graphene, and carbon nanofibers.
  • the binder may include styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA) , sodium alginate (SA) and carboxymethyl chitosan (CMCS) in one or more.
  • the binder may include one of styrene-butadiene rubber (SBR), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS) or several.
  • Other optional additives are, for example, thickeners (such as sodium carboxymethylcellulose CMC-Na), PTC thermistor materials, and the like.
  • the negative electrode sheet does not exclude other additional functional layers other than the negative electrode film layer.
  • the negative electrode sheet of the present application can also include a conductive primer layer (for example, made of a conductive agent and a bonding agent composition).
  • the negative electrode sheet of the present application may further include a covering protective layer covering the surface of the second negative electrode film layer.
  • the negative electrode current collector may be a metal foil or a composite current collector, for example, the metal foil may be copper foil, silver foil, iron foil, or a foil composed of an alloy of the above metals.
  • the composite current collector can include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer, and can be made by adding metal materials (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) ) formed on the base layer of polymer materials (such as polypropylene PP, polyethylene terephthalate PET, polybutylene terephthalate PBT, polystyrene PS, polyethylene PE and its copolymers and other materials) Formed on the base layer).
  • polymer materials such as polypropylene PP, polyethylene terephthalate PET, polybutylene terephthalate PBT, polystyrene PS, polyethylene PE and its copolymers and other materials
  • the electrolyte plays the role of conducting ions between the positive pole piece and the negative pole piece.
  • the electrolyte may be selected from at least one of solid electrolytes and liquid electrolytes (ie, electrolytic solutions).
  • the electrolyte is an electrolytic solution.
  • the electrolyte solution includes an electrolyte salt and a solvent.
  • the electrolyte salt may be selected from LiPF 6 (lithium hexafluorophosphate), LiBF 4 (lithium tetrafluoroborate), LiClO 4 (lithium perchlorate), LiAsF 6 (lithium hexafluoroarsenate), LiFSI (difluorosulfonate Lithium imide), LiTFSI (lithium bistrifluoromethanesulfonyl imide), LiTFS (lithium trifluoromethanesulfonate), LiDFOB (lithium difluorooxalate borate), LiBOB (lithium dioxalate borate), LiPO 2 F 2 One or more of (lithium difluorophosphate), LiDFOP (lithium difluorooxalatephosphate) and LiTFOP (lithium tetrafluorooxalatephosphate).
  • LiPF 6 lithium hexafluorophosphate
  • LiBF 4 lithium tetrafluoroborate
  • the solvent can be selected from one or more of the following: 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), Fluoroethylene Carbonate (FEC ), 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), methyl ethyl sulfone (EMS) and two E
  • the content of the solvent is 60-99% by weight, such as 65-95% by weight, or 70-90% by weight, or 75- 89% by weight, or 80-85% by weight. In one embodiment of the present application, based on the total weight of the electrolyte, the content of the electrolyte is 1-40% by weight, such as 5-35% by weight, or 10-30% by weight, or 11- 25% by weight, or 15-20% by weight.
  • additives may optionally be included in the electrolyte.
  • additives can include one or more of the following: negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain performances of the battery, such as additives that improve battery overcharge performance, additives that improve battery high-temperature performance, Additives to improve low-temperature performance of batteries, etc.
  • the secondary battery further includes a separator, which separates the anode side and the cathode side of the secondary battery, and provides selective permeation for substances of different types, sizes and charges in the system.
  • a separator which separates the anode side and the cathode side of the secondary battery, and provides selective permeation for substances of different types, sizes and charges in the system.
  • barrier for example, the separator can insulate the electrons, physically separate the positive and negative active materials of the secondary battery, prevent internal short circuit and form an electric field in a certain direction, and at the same time allow the ions in the battery to pass through the separator to the positive and negative electrodes to move between.
  • the material used to prepare the isolation film may include one or more of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.
  • the isolation film can be a single-layer film or a multi-layer composite film.
  • the materials of each layer may be the same or different.
  • the isolation film is selected from polyolefin isolation films, polyester isolation films, polyimide isolation films, polyamide isolation films and cellulose isolation films.
  • the above-mentioned positive pole piece, negative pole piece and separator can be made into an electrode assembly/bare cell through a winding process or a lamination process.
  • the secondary battery may include an outer package for encapsulating the above-mentioned electrode assembly and electrolyte.
  • the outer packaging of the secondary battery may be a hard case, such as a hard plastic case, aluminum case, steel case, and the like.
  • the outer package of the secondary battery may be a soft bag, such as a pouch-type soft bag.
  • the material of soft bag can be plastics, as one or more in polypropylene (PP), polybutylene terephthalate (PBT), polybutylene succinate (PBS) etc.
  • the positive pole piece and the negative pole piece are arranged on the opposite side; wherein, the R1 surface of the positive pole piece has more active materials that can be transferred, or the thickness of the coated active material layer is relatively high ; while the R2 surface of the positive electrode sheet has less transferable active material, or the thickness of the coated active material layer is smaller.
  • the R3 surface facing the R1 surface of the positive electrode sheet similarly has more active ion vacancy substances, or the thickness of the coated active ion vacancy substance layer is relatively high.
  • the R4 surface of the negative electrode sheet has less active ion vacancy material, or the thickness of the coated active ion vacancy material layer is relatively small.
  • FIG. 3 shows a secondary battery 5 having a square structure as an example.
  • FIG. 4 shows an exploded view of the secondary battery 5 of FIG. 3, the outer package may include a housing 51 and a cover plate 53, the housing 51 may include a bottom plate and side plates connected to the bottom plate, the bottom plate and the side plates Enclosed to form an accommodation chamber.
  • the housing 51 has an opening communicating with the accommodating cavity, and the cover plate 53 can cover the opening to close the accommodating cavity.
  • the positive pole piece, the negative pole piece and the separator can form the electrode assembly 52 through a winding process or a lamination process.
  • the number of electrode assemblies 52 included in the secondary battery 5 may be one or more.
  • FIG. 5 is a battery module 4 as an example.
  • a plurality of secondary batteries 5 may be arranged in sequence along the length direction of the battery module 4 .
  • the plurality of secondary batteries 5 may be fixed by fasteners.
  • the battery module 4 may also include a case having a housing space in which a plurality of secondary batteries 5 are accommodated.
  • two or more of the above-mentioned battery modules can be assembled into a battery pack, and the number of battery modules contained in the battery pack depends on the application of the battery pack and the parameters of a single battery module.
  • the battery pack can include a battery box and a plurality of battery modules arranged in the battery box.
  • the battery box includes an upper box and a lower box.
  • the upper box can be covered on the lower box and well matched with it to form a battery for accommodating The enclosed space of the module.
  • Two or more battery modules can be arranged in the battery box in a desired manner.
  • the battery pack 1 may include a battery box and a plurality of battery modules 4 disposed in the battery box.
  • the battery box includes an upper box body 2 and a lower box body 3 , the upper box body 2 is used to cover the lower box body 3 and forms a closed space for accommodating the battery module 4 .
  • Multiple battery modules 4 can be arranged in the battery box in any manner.
  • the electric device of the present application includes at least one of the secondary battery, battery module, or battery pack of the present application, and the secondary battery, battery module, or battery pack can be used as The power source of the electrical device may also be used as an energy storage unit of the electrical device.
  • the electric devices include but are not limited to mobile digital devices (such as mobile phones, notebook computers, 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.
  • Figure 8 is an example device.
  • the device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle.
  • battery packs or battery modules can be employed.
  • a device may be a cell phone, tablet, laptop, or the like.
  • the device is generally required to be light and thin, and a secondary battery can be used as a power source.
  • the raw materials used in the present invention are analytically pure, and the water is deionized water.
  • VDF polyvinylidene fluoride
  • the separator 7 ⁇ m polyethylene (PE) was used as the separator.
  • the positive pole piece, separator and negative pole piece are wound into a battery cell, and a lithium-ion secondary battery is obtained through lug welding, packaging aluminum shell packaging, liquid injection, packaging formation and pumping molding, and the width of the battery cell is 148mm , thickness 28mm, height 98mm, capacity 40Ah.
  • the electrolyte is a solution of 1M LiPF 6 ethylene carbonate (EC) and dimethyl carbonate (DMC) (volume ratio 1:2).
  • Example 2-5 Except for controlling CW1/CW2 and CW3/CW4 as described in Table 1 below, the lithium ion secondary batteries of Examples 2-5 were prepared in the same manner as in Example 1.
  • Lithium-ion secondary batteries of Examples 6-11 were prepared according to Example 3, except that LiFePO 4 (hereinafter abbreviated as LFP) was used instead of NCM523 as the positive electrode sheet material, and CapA/CapB was controlled as described in Table 1 below.
  • LFP LiFePO 4
  • Example 17 In addition to using NaFePO4 (hereinafter abbreviated as NaVP) instead of LFP as the R1 surface positive pole material, and using NaVP instead of NCM811 as the R2 surface positive pole material, the lithium ion secondary battery of Example 17 was prepared in the manner of Example 16.
  • NaFePO4 hereinafter abbreviated as NaVP
  • NaVP NaFePO4
  • NCM811 NCM811
  • the lithium ion secondary battery of Comparative Example 1 was prepared according to the method of Example 1.
  • the lithium ion secondary battery of Comparative Example 2 was prepared in the same manner as in Example 6, except that CapA/CapB was controlled to be 0.21 as described in Table 1 below.
  • the resistance per unit area of the positive pole piece can be tested by a test method known in the art.
  • the test instrument is Yuanneng Technology IEST BER1000 electrode sheet resistance meter.
  • the specific steps include: cut the positive electrode sheet (double-sided coated positive electrode active material layer) into a 10cm ⁇ 10cm square test sample, clamp the upper and lower sides of the test sample between the two conductive terminals of the internal resistance tester, And apply a certain pressure to fix it, and test the resistance R of the detection sample.
  • the diameter of the conductive terminal is 14mm
  • the applied pressure is 15MPa-27MPa
  • the sampling time ranges from 5s to 17s.
  • S is the contact area between the conductive terminal and the test sample (usually it can be considered as the cross-sectional area of the conductive terminal);
  • R is the sample read by the testing instrument resistance resistance value.
  • R1 is controlled between 0.1 ⁇ -20 ⁇
  • R2 is controlled between 0.15 ⁇ -22 ⁇
  • R3 is controlled between 0.7m ⁇ -40m ⁇
  • R4 is controlled between 0.5m ⁇ -35m ⁇ between.
  • the positive pole piece or the negative pole piece were cut into small discs respectively, and assembled into a button battery in a glove box, wherein the electrode was made of lithium metal, the separator was Celgard C2400, and the electrolyte was 1.3M LiPF 6 EC and DMC (volume ratio 1 :2) the solution.
  • the assembled button battery is tested for capacity with a blue battery tester.
  • the overall mass of the secondary battery is the energy density of the secondary battery.
  • Comparing Example 1 with Comparative Example 1 it can be seen that controlling CW1/CW2 (ie, R2>R1) and CW3/CW4 (ie, R3 ⁇ R4) has a significant impact on the cycle life and gravimetric energy density of the secondary battery.
  • Comparing Example 6 with Comparative Example 2 it can be seen that controlling CapA/CapB has a significant impact on the cycle life and gravimetric energy density of the secondary battery.
  • Comparing Example 12 with Comparative Example 3 it can be seen that controlling (R1+R4)/(R2+R3) also has a significant impact on the cycle life and gravimetric energy density of the secondary battery.
  • the present application is not limited to the above-mentioned embodiments.
  • the above-mentioned embodiments are merely examples, and within the scope of the technical solutions of the present application, embodiments that have substantially the same configuration as the technical idea and exert the same effects are included in the technical scope of the present application.
  • various modifications conceivable by those skilled in the art are added to the embodiments, and other forms constructed by combining some components in the embodiments are also included in the scope of the present application. .

Landscapes

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

Abstract

本申请涉及二次电池、电池模组、电池包以及用电装置。所述二次电池包括正极极片、负极极片，其中，所述正极极片包括正极集流体、分布在所述正极集流体一面上的第一正极活性物质层、以及分布在所述正极集流体另一面上的第二正极活性物质层；所述负极极片包括负极集流体、分布在所述负极集流体一面上且与所述第二正极活性物质层相对的第一负极活性物质层、以及分布在所述负极集流体另一面上的第二负极活性物质层，其中，所述第一正极活性物质层的电阻为R1，所述第二正极活性物质层的电阻为R2，所述第一负极活性物质层的电阻为R3，所述第二负极活性物质层的电阻为R4，且满足以下关系式：(1)R2＞R1，(2)R3≥R4，(3)0＜(R1+R4)/(R2+R3)≤1，以及(4)R1/R2＝A×R4/R3，式中，A为0.8-1.2。

Description

二次电池、电池模组、电池包以及用电装置 技术领域
本申请涉及一种二次电池，具体涉及二次电池，例如，锂离子电池，以及包含该二次电池的电池模组、电池包以及用电装置。
背景技术
随着国家大力推广新能源电动车，其市场占有率也在不断加大，人们在享受清洁环保能源带来的福利的同时，往往也在关注其自身发展过程中的一些不足，并不断改善提升。目前新能源电动车用的最多的储能电池主要是锂离子二次电池，主要包括磷酸铁锂、锰酸锂、钴酸锂以及含有镍钴锰元素的三元材料等化学体系。目前，二次电池循环寿命普遍在1000-2000次充放电之后容量就衰减到初始时的80％左右，此时再继续使用则电池发生安全事故的几率就会逐渐增大，所以为避免安全事故的发生一般就会把电池淘汰处理。这不仅极大的造成电池的浪费，还带来环境污染等一系列问题。现有技术中，为了增加电池的使用寿命，一般的方法是：(1)改善活性材料的表面包覆，减小表面副反应；(2)提高导电物质含量，降低电阻；(3)减小电池使用区间等等。现有技术存在高昂的成本提升和技术挑战的问题，因此对二次电池的改进仍为亟待解决的问题。
发明内容
为了解决现有技术中存在的问题，本申请通过在正极极片中预存活性离子(例如，锂离子)并使其在使用过程缓慢释放来补充活性离子消耗来达到减小电池衰减延长使用寿命的问题。
根据本申请的第一方面，提供一种二次电池，所述二次电池包括正极极片、负极极片，其中，所述正极极片包括正极集流体、分布在所述正极集流体一面上的第一正极活性物质层、以及分布在所述正极集流体另一面上的第二正极活 性物质层；
所述负极极片包括负极集流体、分布在所述负极集流体一面上且与所述第二正极活性物质层相对的第一负极活性物质层、以及分布在所述负极集流体另一面上的第二负极活性物质层，
其中，所述第一正极活性物质层的电阻为R1，所述第二正极活性物质层的电阻为R2，所述第一负极活性物质层的电阻为R3，所述第二负极活性物质层的电阻为R4，且满足以下关系式：
(1)R2＞R1，
(2)R3≥R4，
(3)0＜(R1+R4)/(R2+R3)≤1，以及
(4)R1/R2＝A×R4/R3，式中，A为0.8-1.2。
在本申请的实施方式中，A为0.95-1.05。
在本申请的实施方式中，R1为0.1Ω-20Ω，R2为0.15Ω-22Ω，R3为0.7mΩ-40mΩ，以及R4为0.5mΩ-35mΩ；或R1为0.5Ω-10Ω，R2为0.55Ω-12Ω，R3为1mΩ-30mΩ，以及R4为1.1mΩ-30mΩ。
在本申请的实施方式中，所述第一正极活性物质层的单位面积涂布重量为CW1，所述第二正极活性物质层的单位面积涂布重量为CW2的正极活性物质，且满足0.5≤CW1/CW2＜1。
在本申请的实施方式中，6.5mg/cm 2≤CW1≤32.5mg/cm 2，6.5mg/cm 2≤CW2≤32.5mg/cm 2；可选地，13.0mg/cm 2≤CW1≤26.0mg/cm 2，13.0mg/cm 2≤CW2≤26.0mg/cm 2。
在本申请的实施方式中，所述第一负极活性物质层的单位面积涂布重量为CW3，所述第二负极活性物质层的单位面积涂布重量为CW4，且满足1≤CW3/CW4≤1.5。
在本申请的实施方式中，5.2mg/cm 2≤CW3≤19.5mg/cm 2，5.2mg/cm 2≤CW4≤19.5mg/cm 2；可选地，8.4mg/cm 2≤CW3≤16.9mg/cm 2，8.4mg/cm 2≤CW4≤16.9mg/cm 2。
在本申请的实施方式中，所述第二正极活性物质层的单位面积容量为CapA，所述第一负极活性物质层的单位面积容量为CapB，且满足0.300≤ CapA/CapB≤1.00；可选地，0.468≤CapA/CapB≤0.870。
在本申请的实施方式中，所述第一正极活性物质层的厚度为T1，所述第二正极活性物质层的厚度为T2，且满足T1≤T2。
在本申请的实施方式中，所述第一负极活性物质层的厚度为T3，所述第二负极活性物质层的厚度为T4，且满足T4≤T3。
在本申请的实施方式中，0＜(T1+T4)/(T2+T3)≤1。
在本申请的实施方式中，所述第一正极活性物质层和/或所述第二正极活性物质层的压实密度为2.0g/cm 3-3.6g/cm 3，所述第一负极活性物质层和/或第二负极活性物质层的压实密度为0.5g/cm 3-2g/cm 3；或者所述第一正极活性物质层和/或所述第二正极活性物质层的压实密度为2.3g/cm 3-3.5g/cm 3，所述第一负极活性物质层和/或第二负极活性物质层的压实密度为1.0g/cm 3-1.8g/cm 3。
在本申请的实施方式中，所述第一正极活性物质层和/或第二正极活性物质层中各自独立的含有NCM三元材料、NCA三元材料、磷酸铁锂、锰酸锂、钴酸锂以及包含活性钠离子的氧化物、聚阴离子材料或普鲁士蓝类材料中的至少一种。
在本申请的实施方式中，所述第一正极活性物质层和/或第二正极活性物质层中各自独立的含有石墨、炭黑、乙炔黑、石墨烯、碳纳米管和上述物质组合的导电剂，以及选自聚偏氟乙烯、聚丙烯酸、聚四氟乙烯、聚酰亚胺和它们组合的粘结剂。
在本申请的实施方式中，所述第一负极活性物质层和/或第二负极活性物质层中各自独立的含有天然石墨、人造石墨、石墨烯、碳纳米管、软碳、硬碳和它们两种或多种的组合。
根据本申请的第二方面，提供一种电池模组，其中包括本申请所述的二次电池。
根据本申请的第三方面，提供一种电池包，其中包括本申请所述的二次电池或电池模组。
根据本申请的第四方面，提供一种用电装置，其中包括本申请所述的二次电池、电池模组或电池包，所述二次电池或所述电池模组或所述电池包用作所 述用电装置的电源或所述用电装置的能量存储单元。
与现有技术相比，通过调整正极极片中集流体两侧活性物质层的电阻、以及负极极片中集流体两侧活性物质层的电阻，并对其进行匹配，达到了延长电池使用寿命、并提高电池能量密度的效果。
通过阅读下面的详细描述并参考相关联的附图，这些及其他特点和优点将变得显而易见。应该理解，前面的概括说明和下面的详细描述只是说明性的，不会对所要求保护的各方面形成限制。
附图说明
图1是本申请一些实施方式中二次电池正极极片和负极极片的示意图。
图2是本申请具体实施方式和对比实施方式的电池循环寿命曲线。
图3是本申请二次电池的一实施方式的示意图。
图4是图3所示二次电池的分解图。
图5是本申请电池模块的一实施方式的示意图。
图6是本申请电池包的一实施方式的示意图。
图7是图6所示电池包的分解图。
图8是使用本申请的二次电池用作电源的装置的一实施方式的示意图。
附图标记说明：
1、电池包
2、上箱体
3、下箱体
4、电池模块
5、二次电池
51、壳体
52、电极组件
53、盖板
具体实施方式
下面结合附图详细描述本申请，本申请的特点将在以下的具体描述中得到进一步的显现。
本文所公开的“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。
在本申请中，如果没有特别的说明，本文所提到的所有实施方式以及优选实施方式可以相互组合形成新的技术方案。在本申请中，如果没有特别的说明，本文所提到的所有技术特征以及优选特征可以相互组合形成新的技术方案。
在本申请中，如果没有特别的说明，本文所提到的“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。
在本文的描述中，除非另有说明，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)。
在本申请中，第一正极活性物质层的电阻为R1，第二正极活性物质层的电阻为R2，第一负极活性物质层的电阻为R3，第二负极活性物质层的电阻为R4，且满足以下关系式：(1)R2＞R1，(2)R3≥R4，(3)0＜(R1+R4)/(R2+R3)≤1，以及(4)R1/R2＝A×R4/R3，式中，A为0.8-1.2。
通常，二次电池开始充电时，正极集流体两侧的活性物质层同时开始进行活性锂离子从正极材料里面脱出、穿过隔膜、嵌入负极石墨，而电子通过正极 集流体和外电路向负极转移，此时正极集流体两侧活性物质层的电势差相等。本申请中，将正极集流体两侧的活性物质层的电阻设置为R2＞R1，在二次电池的充电过程中，电阻较大的一侧活性物质层(下述称为R2面)中锂离子脱出的速度相对较慢。当电池达到充电截止电压时，R2面中活性物质层中留有部分尚未脱出的锂，有助于实现在正极极片中的一侧预存部分活性锂，此部分活性锂随着电池充放电的进行，逐渐被释放出来，有效缓解电池容量衰减。为保证正极极片中两侧正极活性物质层与相对的负极活性物质层之间的电势匹配，还需将与R2面相对的第一负极活性物质层(又称为R3面)的电阻大于R1面所面对的第二负极活性物质层(又称为R4面)的电阻。在此基础上，本申请进一步限定正极极片与负极极片满足0＜(R1+R4)/(R2+R3)≤1，且R1/R2＝A×R4/R3，A的范围可以在0.8～1.2之间，由此可以在确保二次电池中预存活性锂离子的量的同时，保证电池内的极化较低，电池的能量密度较高，有利于延长二次电池的循环寿命，提升电池的能量密度。
在本申请的一个实施方式中，A可以在以下所列数值中任意两个作为端值而构成的数值范围之内：0.80、0.85、0.90、0.95、1.00、1.05、1.10、1.15、1.20。需要特别强调的是，虽然将上述数值并列地列出，但是并不意味着上述任意两个数值作为端点组成的数值范围都可以得到相当或相近的性能。这一点同样适用于下文提及的数值范围。关于本申请优选的实施方式，仅仅基于下文中的具体讨论以及具体实验数据来进行选择。在本申请可选的实施方式中，A为0.95-1.05。
在本申请的一个实施方式中，在满足以上关系式(1)-(4)的基础上，R1可以在以下所列数值中任意两个作为端值而构成的数值范围之内：0.1Ω、0.5Ω、1Ω、5Ω、10Ω、15Ω、20Ω；R2可以在以下所列数值中任意两个作为端值而构成的数值范围之内：0.15Ω、0.55Ω、1Ω、3Ω、6Ω、9Ω、12Ω、16Ω、19Ω、22Ω；R3可以在以下所列数值中任意两个作为端值而构成的数值范围之内：0.7mΩ、1mΩ、5mΩ、10mΩ、20mΩ、30mΩ、35mΩ、40mΩ；以及R4可以在以下所列数值中任意两个作为端值而构成的数值范围之内：0.5mΩ、1.1mΩ、5mΩ、10mΩ、20mΩ、30mΩ、35mΩ。在本申请中，所述R1、R2、R3和R4可以确保二次电池中正极极片的两面在同时放电时，可转移活性物质多的一面 会有存留，随着二次电池循环老化，存留的可转移活性物质会逐渐释放出来，延缓电池衰老，并增加循环寿命。在本申请可选的实施方式中，R1为0.1Ω-20Ω，R2为0.15Ω-22Ω，R3为0.7mΩ-40mΩ，以及R4为0.5mΩ-35mΩ；或R1为0.5Ω-10Ω，R2为0.55Ω-12Ω，R3为1mΩ-30mΩ，以及R4为1.1mΩ-30mΩ。
在本申请的一个实施方式中，第一正极活性物质层包含量为CW1的活性离子化合物，第二正极活性物质层包含量为CW2的活性离子化合物，且满足0.5≤CW1/CW2＜1。CW1/CW2可以在以下所列数值中任意两个作为端值而构成的数值范围之内：0.5、0.6、0.7、0.8、0.9、0.95、0.99。这上述CW1/CW2范围内，可转移活性物质多(CW2)的一面会有存留，随着二次电池循环老化，存留的可转移活性物质会逐渐释放出来，延缓电池衰老，并增加循环寿命。
在本申请的一个实施方式中，在满足0.5≤CW1/CW2＜1的基础上，以单位面积活性离子的重量计，CW1可以在以下所列数值中任意两个作为端值而构成的数值范围之内：6.5mg/cm 2、9.5mg/cm 2、13.0mg/cm 2、18.5mg/cm 2、26.0mg/cm 2、32.5mg/cm 2；CW2可以在以下所列数值中任意两个作为端值而构成的数值范围之内：6.5mg/cm 2、9.5mg/cm 2、13.0mg/cm 2、18.5mg/cm 2、26.0mg/cm 2、32.5mg/cm 2。在本申请可选的实施方式中，以单位面积活性离子的重量计，6.5mg/cm 2≤CW1≤32.5mg/cm 2，和6.5mg/cm 2≤CW2≤32.5mg/cm 2；或13.0mg/cm 2≤CW1≤26.0mg/cm 2，和13.0mg/cm 2≤CW2≤26.0mg/cm 2。
在本申请的一个实施方式中，第一负极活性物质层包含量为CW3的活性离子空位物质，第二负极活性物质层包含量为CW4的活性离子空位物质，且满足1≤CW3/CW4≤1.5。在本申请中，CW3/CW4可以在以下所列数值中任意两个作为端值而构成的数值范围之内：1.0、1.05、1.10、1.15、1.20、1.25、1.30、13.5、1.40、1.45、1.50。这上述CW3/CW4范围内，本申请二次电池的能量密度得以提高。
在本申请的一个实施方式中，在满足1≤CW3/CW4≤1.5的基础上，以单位面积活性离子空位物质的重量计，CW3可以在以下所列数值中任意两个作为端值而构成的数值范围之内：5.2mg/cm 2、8.4mg/cm 2、12.0mg/cm 2、14.6mg/cm 2、16.9mg/cm 2、19.5mg/cm 2；CW4可以在以下所列数值中任意两个作为端值而构成的数值范围之内：5.2mg/cm 2、8.4mg/cm 2、12.0mg/cm 2、 14.6mg/cm 2、16.9mg/cm 2、19.5mg/cm 2。在本申请可选的实施方式中，以单位面积活性离子空位物质的重量计，5.2mg/cm 2≤CW3≤19.5mg/cm 2，和5.2mg/cm 2≤CW4≤19.5mg/cm 2；或8.4mg/cm 2≤CW3≤16.9mg/cm 2，和8.4mg/cm 2≤CW4≤16.9mg/cm 2。
在本申请的一个实施方式中，第一正极活性物质层和第二正极活性物质层的单位面积容量为CapA，第一负极活性物质层和第二负极活性物质层的单位面积容量为CapB，且满足0.300≤CapA/CapB≤0.933。在本申请中，CapA/CapB可以在以下所列数值中任意两个作为端值而构成的数值范围之内：0.300、0.368、0.400、0.450、0.500、0.550、0.670、0.933。在上述CapA/CapB范围内，本申请二次电池可以避免正极活性物质(例如，锂)过多，而导致负极容纳不了而导致出现“析锂”现象，从而恶化二次电池的循环寿命。
在本申请的一个实施方式中，第一正极活性物质层包含厚度为T1的活性离子化合物层，第二正极活性物质层包含厚度为T2的活性离子化合物层，且满足T1＜T2。在本申请中，第二正极活性物质层中活性离子化合物的涂布厚度可以大于第一正极活性物质层中活性离子化合物的涂布厚度，由此，第二正极活性物质层(又称为R2面)的可转移的活性物质(例如，锂)比第一正极活性物质层(又称为R1面)的多。
在本申请的一个实施方式中，第一负极活性物质层包含厚度为T3的活性离子空位物质层，第二负极活性物质层包含厚度为T4的活性离子空位物质层，且满足T4＜T3。在本申请中，与R2面相对的第一负极活性物质层(又称为R3面)中活性离子空位物质的涂布厚度可以大于R1面所面对的第二负极活性物质层(又称为R4面)中活性离子空位物质的涂布厚度，以达到负极提供足够的空位容纳锂离子。
在本申请的一个实施方式中，0＜(T1+T4)/(T2+T3)≤1，由此确保正极极片上涂布可转移活性物质少/相应负极极片上活性离子空位物质量少的一面的极片总电阻小，极化小，可以优先发生可转移活性物质(例如，锂)的转移转移，并最终确保涂布量大的一面能有可转移活性物质存留。
在本申请中，所述二次电池的第一正极活性物质层和第二正极活性物质层的压实密度进行控制，可以减小离子传输路径，以提高二次电池的循环寿命， 同时又不会因为压实密度过高而导致活性物质的颗粒破碎，出现比表面积(BET)增大的情况，导致出现副反应而在一定程度上恶化二次电池的循环寿命。在本申请的一个实施方式中，所述第一正极活性物质层和/或第二正极活性物质层的压实密度可以在以下所列数值中任意两个作为端值而构成的数值范围之内：2.0g/cm 3、2.3g/cm 3、2.6g/cm 3、2.9g/cm 3、3.2g/cm 3、3.5g/cm 3、3.6g/cm 3。所述第一负极活性物质层和/或第二负极活性物质层的压实密度可以在以下所列数值中任意两个作为端值而构成的数值范围之内：0.5g/cm 3、0.8g/cm 3、1.0g/cm 3、1.3g/cm 3、1.5g/cm 3、1.8g/cm 3、2.0g/cm 3。在本申请可选的实施方式中，所述第一正极活性物质层和/或第二正极活性物质层的压实密度为2.0g/cm 3-3.6g/cm 3或2.3g/cm 3-3.5g/cm 3；所述第一负极活性物质层和/或第二负极活性物质层的压实密度为0.5g/cm 3-2g/cm 3或1.0g/cm 3-1.8g/cm 3。
在下文中，主要基于二次电池，特别是基于锂离子二次电池来对本申请的正极极片两侧涂布不同量的可转移活性物质所带来的性能改善之处进行表征，但是此处需要特别强调，本申请的正极极片两侧差异化涂布设计可以用于任意包括碳基电极的用电装置，并使得该用电装置从中获益。
二次电池
在本申请的一个实施方式中，提供了一种二次电池，该二次电池可以是锂离子二次电池、钾离子二次电池、钠离子二次电池、锂硫电池等，特别优选是锂离子二次电池。本申请的二次电池包括正极(极片)、负极(极片)、隔离膜、电解质/液等。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。
[正极极片]
本申请的二次电池中，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且包括正极活性材料的正极膜层(或称为正极活性物质层)。例如，正极集流体具有在自身厚度方向相背的两个表面，正极膜层设置于正极集流体的两个相背表面中的任意一者或两者上。本申请的二次电池中，所述正极集流体可以是金属箔片或复合集流体，例如所述金属箔片可以是铝箔，而所述复合集流体可包括高分子材料基层和形成于该高分子材料基层至少 一个表面上的金属层。所述复合集流体可通过将金属材料(铝、铝合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子材料基材(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及其共聚物等的基材)上而形成。
在本申请的二次电池中，所述正极活性材料(物质)可采用本领域公知的用于二次电池的正极活性材料。例如，该正极活性材料可包括以下的一种或多种：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二次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LiCoO 2)、锂镍氧化物(如LiNiO 2)、锂锰氧化物(如LiMnO 2、LiMn 2O 4)、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LiNi 1/3Co 1/3Mn 1/3O 2(NCM333)、LiNi 0.5Co 0.2Mn 0.3O 2(NCM523)、LiNi 0.5Co 0.25Mn 0.25O 2(NCM211)、LiNi 0.6Co 0.2Mn 0.2O 2(NCM622)、LiNi 0.8Co 0.1Mn 0.1O 2(NCM811))、锂镍钴铝氧化物(如LiNi 0.85Co 0.15Al 0.05O 2)及其改性化合物等中的一种或几种。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LiFePO 4(LFP))、磷酸铁锂与碳的复合材料、磷酸锰锂(如LiMnPO 4)、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一种或几种。在本申请的实施方式中，所述第二正极活性物质和第三正极活性物质相同或不同，选自磷酸铁锂(LFP)、锰酸锂(LMO)、镍钴锰酸锂(NCM)、钴酸锂(LCO)、镍钴铝酸锂(NCA)以及包含活性钠离子的氧化物、聚阴离子材料或普鲁士蓝类材料。
在一些实施方式中，正极膜层还可选地包括粘结剂。可用于正极膜层的粘结剂的非限制性例子可以包括以下的一种或多种：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。在本申请的实施方式中，所述第一正极活性物质层和/或第二正极活性物质层中各自独立的含有选自聚偏氟乙烯、聚丙烯酸、聚四氟乙烯、聚酰亚胺和它们组合的粘结剂。
在一些实施方式中，正极膜层还可任选地包含导电剂。用于正极膜层的导电剂的例子可以包括超导碳、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一种或几种。在本申请的实施方式中，所述第一正极活性物质层和/或第二正极活性物质层中各自独立的含有石墨、炭黑、乙炔黑、石墨烯、碳纳米管和上述物质组合的导电剂。
在本申请的一个实施方式中，可以通过以下方式制备正极：将上述用于制备正极的组分，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，形成均匀的正极浆料；将正极浆料涂覆在正极集流体上，经烘干、冷压等工序后，即可得到正极极片。
[负极极片]
本申请的二次电池中包括负极极片，所述负极极片包括负极集流体以及设置在所述负极集流体至少一个表面上的负极膜层(或称为负极活性物质层)，在本申请的实施方式中，所述第一负极活性物质和第二负极活性物质相同或不同，各自独立地含有天然石墨、人造石墨、石墨烯、碳纳米管、软碳、硬碳和它们两种或多种的组合。
在本申请的一个实施方式中，负极膜层除了包括本申请上述的负极活性材料外，还可以包括一定量的其它常用负极活性材料，例如，天然石墨、其它人造石墨、软炭、硬炭、硅基材料、锡基材料、钛酸锂中的一种或几种。所述硅基材料可选自单质硅、硅氧化物、硅碳复合物中的一种或几种。所述锡基材料可选自单质锡、锡氧化合物、锡合金中的一种或几种。
本申请的二次电池中，所述负极膜片包含负极活性材料以及可选的粘结剂、可选的导电剂和其他可选助剂，通常是由负极浆料涂布干燥而成的。负极浆料涂通常是将负极活性材料以及可选的导电剂和粘结剂等分散于溶剂中并搅拌均匀而形成的。溶剂可以是N-甲基吡咯烷酮(NMP)或去离子水。
作为示例，导电剂可包括超导碳、炭黑(例如乙炔黑、科琴黑)、碳点、碳纳米管、石墨烯及碳纳米纤维中一种或几种。
作为示例，粘结剂可包括丁苯橡胶(SBR)、水溶性不饱和树脂SR-1B、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)和羧甲基壳聚糖(CMCS)中的一种或几种。作 为示例，粘结剂可包括丁苯橡胶(SBR)、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)中的一种或几种。其他可选助剂例如是增稠剂(如羧甲基纤维素钠CMC-Na)、PTC热敏电阻材料等。
另外，本申请的二次电池中，负极极片并不排除除了负极膜层之外的其他附加功能层。例如在某些实施方式中，本申请的负极极片还可包括夹在负极集流体和第一负极膜层之间、设置于负极集流体表面的导电底涂层(例如由导电剂和粘结剂组成)。在另外一些实施方式中，本申请的负极极片还可包括覆盖在第二负极膜层表面的覆盖保护层。
本申请的二次电池中，所述负极集流体可以是金属箔片或复合集流体，例如金属箔片可以是铜箔、银箔、铁箔、或者上述金属的合金构成的箔片。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，可通过将金属材料(铜、铜合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子材料基层(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及其共聚物等材料制成的基层)上而形成。
[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。电解质可以选自固态电解质及液态电解质(即电解液)中的至少一种。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，电解质盐可选自LiPF 6(六氟磷酸锂)、LiBF 4(四氟硼酸锂)、LiClO 4(高氯酸锂)、LiAsF 6(六氟砷酸锂)、LiFSI(双氟磺酰亚胺锂)、LiTFSI(双三氟甲磺酰亚胺锂)、LiTFS(三氟甲磺酸锂)、LiDFOB(二氟草酸硼酸锂)、LiBOB(二草酸硼酸锂)、LiPO 2F 2(二氟磷酸锂)、LiDFOP(二氟二草酸磷酸锂)及LiTFOP(四氟草酸磷酸锂)中的一种或几种。在本申请的一个实施方式中，溶剂可选自以下的一种或多种：碳酸亚乙酯(EC)、碳酸亚丙酯(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)、氟代碳酸亚乙酯(FEC)、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)。在本申请的一个实施方式中，以所述电解液的总重量为基准计，所述溶剂的含量为60-99重量％，例如65-95重量％，或者70-90重量％，或者75-89重量％，或者80-85重量％。在本申请的一个实施方式中，以所述电解液的总重量为基准计，所述电解质的含量为1-40重量％，例如5-35重量％，或者10-30重量％，或者11-25重量％，或者15-20重量％。
在本申请的一个实施方式中，所述电解液中还可任选地包含添加剂。例如添加剂可以包括以下的一种或多种：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、改善电池高温性能的添加剂、改善电池低温性能的添加剂等。
[隔离膜]
在本申请的一个实施方式中，所述二次电池还包括隔离膜，隔离膜将二次电池的阳极侧与阴极侧隔开，对体系内不同种类、尺寸和电荷的物质提供选择性透过或阻隔，例如隔离膜可以对电子绝缘，将二次电池的正负极活性物质物理隔离，防止内部发生短路并形成一定方向的电场，同时使得电池中的离子能够穿过隔离膜在正负极之间移动。在本申请的一个实施方式中，用来制备隔离膜的材料可包括玻璃纤维、无纺布、聚乙烯、聚丙烯及聚偏二氟乙烯中的一种或几种。隔离膜可以是单层薄膜，也可以是多层复合薄膜。隔离膜为多层复合薄膜时，各层的材料可以相同或不同。在本申请的实施方式中，所述隔离膜选自聚烯烃类隔离膜、聚酯隔离膜、聚酰亚胺隔离膜、聚酰胺隔离膜和纤维素隔离膜。
在本申请的一个实施方式中，上述正极极片、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/裸电芯。
在本申请的一个实施方式中，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。在另一些实施方式中，所述二次电池的外包装可以是软包，例如袋式软包。软包的材质可以是塑料，如聚丙烯(PP)、聚对 苯二甲酸丁二醇酯(PBT)、聚丁二酸丁二醇酯(PBS)等中的一种或几种。
在本申请中，如图1所示，正极极片和负极极片相面设置；其中，正极极片的R1面具有较多可转移的活性物质，或者涂布的活性物质层的厚度较高；而正极极片的R2面具有较少可转移的活性物质，或者涂布的活性物质层的厚度较小。与正极极片的R1面相面对的R3面类似地具有较多活性离子空位物质，或者涂布的活性离子空位物质层的厚度较高。同样地，负极极片的R4面具有较少活性离子空位物质，或者涂布的活性离子空位物质层的厚度较小。
本申请二次电池的形状可以是圆柱形、方形或其他任意的形状。图3是作为一个示例的方形结构的二次电池5。图4显示了图3的二次电池5的分解图，所述外包装可包括壳体51和盖板53，壳体51可包括底板和连接于底板上的侧板，所述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，该电极组件封装于所述容纳腔中，所述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。
在本申请的一个实施方式中，可以将若干个二次电池组装在一起以构成电池模块，电池模块中包含两个或更多个二次电池，具体数量取决于电池模块的应用和单个电池模块的参数。
图5是作为一个示例的电池模块4。参照图5，在电池模块4中，多个二次电池5可以是沿电池模块4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4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。
在本申请的一个实施方式中，可以将两个或更多个上述电池模块组装成电池包，电池包所含电池模块的数量取决于电池包的应用和单个电池模块的参数。电池包可以包括电池箱和设置于电池箱中的多个电池模块，该电池箱包括上箱体和下箱体，上箱体能够盖在下箱体上并与之良好匹配，形成用于容纳电池模块的封闭空间。两个或更多个电池模块可以按照所需的方式排布于该电池箱中。
图6和图7是作为一个示例的电池包1。参照图6和图7，在电池包1中可以包括电池箱和设置于电池箱中的多个电池模块4。电池箱包括上箱体2和下箱体3，上箱体2用于盖设下箱体3，并形成用于容纳电池模块4的封闭空间。多个电池模块4可以按照任意的方式排布于电池箱中。
用电装置
在本申请的一个实施方式中，本申请的用电装置包括本申请的二次电池、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。所述用电装置包括但不限于移动数字装置(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。
图8是作为一个示例的装置。该装置为纯电动车、混合动力电动车、或插电式混合动力电动车等。为了满足该装置对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。
在下文中，基于具体的实施例表征了按照本申请实施方式制造的二次电池对电化学装置性能的影响，但是需要特别指出的是，本申请的保护范围由权利要求书限定，而不仅限于以上的具体实施方式。
实施例
除非另外说明本发明使用的原料均为分析纯，水均为去离子水。
实施例1
正极片的制备
将NCM523正极材料、导电碳黑(Super-P)、聚偏氟乙烯(PVDF)以96.2:2.3:1.1的重量比与N-甲基吡咯烷酮混合，搅拌均匀得到涂布正极片的浆料，搅拌过程中可以通过N-甲基吡咯烷酮调节粘度，并且可以在真空度 -80KPa下进行。然后，将所述浆料以一定宽度均匀涂布在13μm厚的正极集流体(铝箔)的两面，确保两面之间活性物质的CW1/CW2为0.5。所述正极极片经冷压、切片(即对极片进行裁减、切割成所需要大小的尺寸)制得正极极片。
负极片的制备
将人造石墨、导电碳黑(Super-P)、羧甲基纤维素钠(CMC)、丁苯橡胶(SBR)以97:0.5:1:1.5的重量比与水混合，搅拌均匀得到涂布负极片的浆料，搅拌过程中可以通过水调节粘度。然后，将浆料以一定宽度涂布在6μm厚的负极集流体(铜箔)的两面，确保两面的活性离子空位物质之比CW3/CW4为1.3。经过冷压、切片制得负极极片。
锂离子二次电池的制备
采用7μm聚乙烯(PE)作为隔离膜。将所述正极极片、隔离膜和负极极片卷绕成电芯，经过极耳焊接、包装铝壳封装、注液、封装化成和抽气成型制得锂离子二次电池，电芯宽度148mm，厚度28mm，高度98mm，容量为40Ah。其中，电解液为1MLiPF 6碳酸乙烯酯(EC)和碳酸二甲酯(DMC)的溶液(体积比1:2)。
实施例2-5
除了如下表1所述控制CW1/CW2和CW3/CW4以外，按照实施例1的方式制备实施例2-5的锂离子二次电池。
实施例6-11
除了使用LiFePO 4(后简写为LFP)代替NCM523作为正极极片材料、并如下表1所述控制CapA/CapB以外，按照实施例3的方式制备实施例6-11的锂离子二次电池。
实施例12-16
除了使用LFP代替NCM523作为R1面正极极片材料、使用NCM811代替NCM523作为R2面正极极片材料、并如下表1所述控制(R1+R4)/(R2+R3)以外，按照实施例3的方式制备实施例12-16的锂离子二次电池。
实施例17
除了使用NaFePO4(后简写为NaVP)代替LFP作为R1面正极极片材料、以及使用NaVP代替NCM811作为R2面正极极片材料以外，按照实施例16的方式制备实施例17的锂离子二次电池。
对比例1
除了如下表1所述将CW1/CW2和CW3/CW4分别控制为0.2和1.5以外，按照实施例1的方式制备对比例1的锂离子二次电池。
对比例2
除了如下表1所述将CapA/CapB控制为0.21以外，按照实施例6的方式制备对比例2的锂离子二次电池。
对比例3
除了如下表1所述将(R1+R4)/(R2+R3)控制为0.05以外，按照实施例12的方式制备对比例3的锂离子二次电池。
活性物质层的电阻测试
正极极片的单位面积电阻可以采用本领域公知的测试方法进行测试。作为示例的，可以采用如下方法：测试仪器为元能科技IEST BER1000型极片电阻仪。具体步骤包括：将正极极片(双面涂布正极活性物质层)裁取10cm×10cm大小的正方形检测样品，检测样品的上下两侧夹持于内阻测试仪的两个导电端子之间，并施加一定的压力固定，测试检测样品的电阻R。其中，导电端子的直径为14mm，施加的压力为15MPa～27MPa，采点时间 的范围为5s～17s。根据公式r＝R/S计算出正极极片的单位面积电阻，式中，S为导电端子与测试样品的接触面积(通常可以认为是导电端子的截面积)；R为检测仪器读取的样品的电阻阻值。在本申请实施例所得二次电池中，R1控制在0.1Ω-20Ω之间，R2控制在0.15Ω-22Ω之间，R3控制在0.7mΩ-40mΩ之间，以及R4控制在0.5mΩ-35mΩ之间。
极片容量测试
将正极极片或负极极片分别裁成小圆片，在手套箱中组装成纽扣电池，其中，电极采用锂金属，隔膜为Celgard C2400，电解液为1.3M LiPF 6 EC和DMC(体积比1:2)的溶液。组装好的纽扣电池用蓝电测试仪进行容量测试。
能量密度的测试
在0.1C的倍率下对二次电池进行恒流充电至额定电压4.0V并恒压30分钟，而后在0.1C的倍率恒流放电至2.5V，记录恒流放电时释放的能量，除以二次电池整体的质量即得二次电池的能量密度。
循环性能测试
将制作好的二次电池置于新威机上。在25℃的温度下，以0.5C的倍率恒流充电至额定电压，静置5分钟后以0.5C的倍率下恒流放电至截止电压，记录放电容量，再静置5分钟。如此循环，直至能量密度降低至循环前能量密度的约80％，记录当前的循环次数。
Figure PCTCN2021127721-appb-000001
Figure PCTCN2021127721-appb-000002
如表1所示，在实施例1-5中，随着CW1/CW2的增大，二次电池的循环寿命呈先提高而降低的趋势。如表1所述，当为0.62时，二次电池的循环寿命高达2450次。相比实施例5所得二次电池，二次电池的循环寿命提高了22.5％。同时，随着CW3/CW4不断从上限值1.3向下限值1.0靠近，二次电池的重量能量密度逐渐升高。
如表1所示，在实施例6-11中，随着CapA/CapB的增大，二次电池的循环寿命呈先提高而降低的趋势。如表1所述，当CapA/CapB为0.671时，二次电池的循环寿命高达4680次。相比实施例6所得二次电池，二次电池的循环寿命提高了15.6％。同时，随着CapA/CapB不断从0.312向0.933靠近，二次电池的重量能量密度也逐渐升高。
如表1所示，在实施例12-16中，随着(R1+R4)/(R2+R3)的增大，二次电池的循环寿命呈先提高而降低的趋势。如表1所述，当(R1+R4)/(R2+R3)为0.62时，二次电池的循环寿命高达2600次。相比实施例16所得二次电池，二次电池的循环寿命提高了15.6％。同时，随着(R1+R4)/(R2+R3)不断从0.12向1.00靠近，二次电池的重量能量密度也逐渐升高。
比较实施例1与对比例1可知，控制CW1/CW2(即，R2＞R1)和CW3/CW4(即，R3≥R4)对二次电池的循环寿命和重量能量密度均具有显著的影响。比较实施例6与对比例2可知，控制CapA/CapB对二次电池的循环寿命和重量能量密度具有显著的影响。比较实施例12与对比例3可知，控制(R1+R4)/(R2+R3)对二次电池的循环寿命和重量能量密度也具有显著的影响。
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 (20)

  1. 一种二次电池，所述二次电池包括正极极片、负极极片，其中，所述正极极片包括正极集流体、分布在所述正极集流体一面上的第一正极活性物质层、以及分布在所述正极集流体另一面上的第二正极活性物质层；
    所述负极极片包括负极集流体、分布在所述负极集流体一面上且与所述第二正极活性物质层相对的第一负极活性物质层、以及分布在所述负极集流体另一面上的第二负极活性物质层，
    其中，所述第一正极活性物质层的电阻为R1，所述第二正极活性物质层的电阻为R2，所述第一负极活性物质层的电阻为R3，所述第二负极活性物质层的电阻为R4，且满足以下关系式：
    (1)R2＞R1，
    (2)R3≥R4，
    (3)0＜(R1+R4)/(R2+R3)≤1，以及
    (4)R1/R2＝A×R4/R3，式中，A为0.8-1.2。
  2. 根据权利要求1所述的二次电池，其中，A为0.95-1.05。
  3. 根据权利要求1或2所述的二次电池，其中，R1为0.1Ω-20Ω，R2为0.15Ω-22Ω，R3为0.7mΩ-40mΩ，以及R4为0.5mΩ-35mΩ。
  4. 根据权利要求1-3任一项所述的二次电池，其中，R1为0.5Ω-10Ω，R2为0.55Ω-12Ω，R3为1mΩ-30mΩ，以及R4为1.1mΩ-30mΩ。
  5. 根据权利要求1-4任一项所述的二次电池，其中，所述第一正极活性物质层的单位面积涂布重量为CW1，所述第二正极活性物质层的单位面积涂布重量为CW2的正极活性物质，且满足0.5≤CW1/CW2＜1。
  6. 根据权利要求5所述的二次电池，其中，6.5mg/cm 2≤CW1≤32.5mg/cm 2，6.5mg/cm 2≤CW2≤32.5mg/cm 2；
    可选地，13.0mg/cm 2≤CW1≤26.0mg/cm 2，13.0mg/cm 2≤CW2≤26.0mg/cm 2。
  7. 根据权利要求1-6任一项所述的二次电池，其中，所述第一负极活性物质层的单位面积涂布重量为CW3，所述第二负极活性物质层的单位面积涂布 重量为CW4，且满足1≤CW3/CW4≤1.5。
  8. 根据权利要求7所述的二次电池，其中，5.2mg/cm 2≤CW3≤19.5mg/cm 2，5.2mg/cm 2≤CW4≤19.5mg/cm 2；
    可选地，8.4mg/cm 2≤CW3≤16.9mg/cm 2，8.4mg/cm 2≤CW4≤16.9mg/cm 2。
  9. 根据权利要求1-8任一项所述的二次电池，其中，所述第二正极活性物质层的单位面积容量为CapA，所述第一负极活性物质层的单位面积容量为CapB，且满足0.300≤CapA/CapB≤1.00；可选地，0.468≤CapA/CapB≤0.870。
  10. 根据权利要求1-9任一项所述的二次电池，其中，所述第一正极活性物质层的厚度为T1，所述第二正极活性物质层的厚度为T2，且满足T1≤T2。
  11. 根据权利要求1-10任一项所述的二次电池，其中，所述第一负极活性物质层的厚度为T3，所述第二负极活性物质层的厚度为T4，且满足T4≤T3。
  12. 根据权利要求10或11所述的二次电池，其中，0＜(T1+T4)/(T2+T3)≤1。
  13. 根据权利要求1-12任一项所述的二次电池，其中，所述第一正极活性物质层和/或所述第二正极活性物质层的压实密度为2.0g/cm 3-3.6g/cm 3，所述第一负极活性物质层和/或第二负极活性物质层的压实密度为0.5g/cm 3-2g/cm 3。
  14. 根据权利要求1-13任一项所述的二次电池，其中，所述第一正极活性物质层和/或所述第二正极活性物质层的压实密度为2.3g/cm 3-3.5g/cm 3，所述第一负极活性物质层和/或第二负极活性物质层的压实密度为1.0g/cm 3-1.8g/cm 3。
  15. 根据权利要求1-14任一项所述的二次电池，其中，所述第一正极活性物质层和/或第二正极活性物质层中各自独立的含有NCM三元材料、NCA三元材料、磷酸铁锂、锰酸锂、钴酸锂以及包含活性钠离子的氧化物、聚阴离子材料或普鲁士蓝类材料中的至少一种。
  16. 根据权利要求1-15任一项所述的二次电池，其中，所述第一正极活性物质层和/或第二正极活性物质层中各自独立的含有石墨、炭黑、乙炔黑、石墨烯、碳纳米管和上述物质组合的导电剂，以及选自聚偏氟乙烯、聚丙烯酸、聚四氟乙烯、聚酰亚胺和它们组合的粘结剂。
  17. 根据权利要求1-16任一项所述的二次电池，其中，所述第一负极活性 物质层和/或第二负极活性物质层中各自独立的含有天然石墨、人造石墨、石墨烯、碳纳米管、软碳、硬碳和它们两种或多种的组合。
  18. 一种电池模组，其中，包括根据权利要求1-17中任一项所述的二次电池。
  19. 一种电池包，其中，包括根据权利要求1-17中任一项所述的二次电池或根据权利要求18所述的电池模组。
  20. 一种用电装置，其中，包括根据权利要求1-17中任一项所述的二次电池、或根据权利要求18所述的电池模组、或根据权利要求19所述的电池包，所述二次电池或所述电池模组或所述电池包用作所述用电装置的电源或所述用电装置的能量存储单元。
PCT/CN2021/127721 2021-10-29 2021-10-29 二次电池、电池模组、电池包以及用电装置 Ceased WO2023070600A1 (zh)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP21961952.5A EP4287331A4 (en) 2021-10-29 2021-10-29 SECONDARY BATTERY, BATTERY MODULE, BATTERY PACK AND ELECTRICAL DEVICE
PCT/CN2021/127721 WO2023070600A1 (zh) 2021-10-29 2021-10-29 二次电池、电池模组、电池包以及用电装置
CN202180093127.0A CN116868398A (zh) 2021-10-29 2021-10-29 二次电池、电池模组、电池包以及用电装置
US18/366,342 US12218311B2 (en) 2021-10-29 2023-08-07 Secondary battery, battery module, battery pack, and electrical device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2021/127721 WO2023070600A1 (zh) 2021-10-29 2021-10-29 二次电池、电池模组、电池包以及用电装置

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US18/366,342 Continuation US12218311B2 (en) 2021-10-29 2023-08-07 Secondary battery, battery module, battery pack, and electrical device

Publications (1)

Publication Number Publication Date
WO2023070600A1 true WO2023070600A1 (zh) 2023-05-04

Family

ID=86158922

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/127721 Ceased WO2023070600A1 (zh) 2021-10-29 2021-10-29 二次电池、电池模组、电池包以及用电装置

Country Status (4)

Country Link
US (1) US12218311B2 (zh)
EP (1) EP4287331A4 (zh)
CN (1) CN116868398A (zh)
WO (1) WO2023070600A1 (zh)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117154004A (zh) * 2023-10-31 2023-12-01 宁德时代新能源科技股份有限公司 正极极片、电池和用电装置
EP4560732A1 (en) * 2023-11-23 2025-05-28 AESC Japan Ltd. Secondary battery and electronic apparatus

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN121507147A (zh) * 2024-08-09 2026-02-10 宁德时代新能源科技股份有限公司 电池单体、电池和用电设备
CN119275373A (zh) * 2024-09-30 2025-01-07 厦门新能安科技有限公司 二次电池及电子装置

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20150340730A1 (en) * 2014-05-20 2015-11-26 Samsung Sdi Co., Ltd. Electrode structure and lithium battery including the same
US20150340732A1 (en) * 2014-05-21 2015-11-26 Samsung Sdi Co., Ltd. Electrode structure and lithium battery including the same
CN107394209A (zh) * 2017-07-07 2017-11-24 郑州比克电池有限公司 一种锂离子电池正极片及其制造方法
CN113241423A (zh) * 2021-04-30 2021-08-10 珠海冠宇电池股份有限公司 极片及其制备方法、锂离子电池

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001351672A (ja) * 2000-06-08 2001-12-21 Sanyo Electric Co Ltd アルカリ蓄電池
JP2005038612A (ja) * 2003-07-15 2005-02-10 Ngk Spark Plug Co Ltd リチウムイオン二次電池およびその製造方法
CN109980177B (zh) * 2019-03-29 2021-10-22 东莞新能安科技有限公司 电极极片和包含所述电极极片的电化学装置

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20150340730A1 (en) * 2014-05-20 2015-11-26 Samsung Sdi Co., Ltd. Electrode structure and lithium battery including the same
US20150340732A1 (en) * 2014-05-21 2015-11-26 Samsung Sdi Co., Ltd. Electrode structure and lithium battery including the same
CN107394209A (zh) * 2017-07-07 2017-11-24 郑州比克电池有限公司 一种锂离子电池正极片及其制造方法
CN113241423A (zh) * 2021-04-30 2021-08-10 珠海冠宇电池股份有限公司 极片及其制备方法、锂离子电池

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP4287331A4 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117154004A (zh) * 2023-10-31 2023-12-01 宁德时代新能源科技股份有限公司 正极极片、电池和用电装置
EP4560732A1 (en) * 2023-11-23 2025-05-28 AESC Japan Ltd. Secondary battery and electronic apparatus
JP2025085055A (ja) * 2023-11-23 2025-06-04 株式会社Ａｅｓｃジャパン 二次電池及び電子機器
JP7797463B2 (ja) 2023-11-23 2026-01-13 株式会社Ａｅｓｃジャパン 二次電池及び電子機器

Also Published As

Publication number Publication date
US20230378546A1 (en) 2023-11-23
EP4287331A4 (en) 2024-12-25
CN116868398A (zh) 2023-10-10
EP4287331A1 (en) 2023-12-06
US12218311B2 (en) 2025-02-04

Similar Documents

Publication Publication Date Title
CN114982027B (zh) 电池组、电池包、电学装置以及电池组的制造方法及制造设备
WO2022133963A1 (zh) 电池组、电池包、电学装置以及电池组的制造方法及制造设备
WO2023070600A1 (zh) 二次电池、电池模组、电池包以及用电装置
US12191475B2 (en) Electrode assembly, secondary battery, battery module, battery pack and electrical device
WO2023023984A1 (zh) 负极极片、二次电池、电池模块、电池包和用电装置
JP2023549998A (ja) リチウムイオン電池
CN119786528A (zh) 负极极片、二次电池以及用电装置
WO2024174170A1 (zh) 隔离膜、二次电池及用电装置
CN116830319A (zh) 负极极片、二次电池和用电装置
CN116960274A (zh) 正极极片、二次电池、电子设备和移动装置
CN115832221B (zh) 极片结构、二次电池及用电装置
CN116130651A (zh) 极片、锂离子电池、电池模块、电池包及用电装置
CN116941084A (zh) 一种二次电池
WO2022205221A1 (zh) 电池组、电池包、用电装置以及电池组的制造方法及制造设备
US12176492B2 (en) Electrode assembly, secondary battery, battery module, battery pack and electrical device
CN115832175B (zh) 二次电池、电池模组、电池包以及用电装置
WO2024212200A1 (zh) 负极极片以及包含其的二次电池和用电装置
CN118841519A (zh) 负极极片、电池和用电装置
WO2024164109A1 (zh) 预锂化电极材料及其制备方法、二次电池和用电装置
WO2023216130A1 (zh) 一种电解液、二次电池、电池模块、电池包和用电装置
WO2023078071A1 (zh) 正极材料极片、制备方法、二次电池、电池模组、电池包及用电装置
CN118507653A (zh) 负极添加剂、负极极片、二次电池和用电装置
CN115939386B (zh) 正极组合物、相应的正极极片、二次电池和用电装置
CN115832176B (zh) 正极极片及其设计方法、二次电池、电池模块、电池包及用电装置
WO2025145728A1 (zh) 负极组合物、负极极片及其制备方法、电池和用电装置

Legal Events

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

Ref document number: 21961952

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 202180093127.0

Country of ref document: CN

WWE Wipo information: entry into national phase

Ref document number: 2021961952

Country of ref document: EP

ENP Entry into the national phase

Ref document number: 2021961952

Country of ref document: EP

Effective date: 20230828

NENP Non-entry into the national phase

Ref country code: DE