WO2025000867A1 - 锂离子电池及用电装置 - Google Patents

锂离子电池及用电装置 Download PDF

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Publication number
WO2025000867A1
WO2025000867A1 PCT/CN2023/134415 CN2023134415W WO2025000867A1 WO 2025000867 A1 WO2025000867 A1 WO 2025000867A1 CN 2023134415 W CN2023134415 W CN 2023134415W WO 2025000867 A1 WO2025000867 A1 WO 2025000867A1
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lithium
ion battery
value
negative electrode
low
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English (en)
French (fr)
Inventor
吴凯
蒋昊
杨成龙
高靖宇
陈傲赛
张海明
喻鸿钢
金海族
罗莉
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Contemporary Amperex Technology Co Ltd
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Contemporary Amperex Technology Co Ltd
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Priority to EP23943343.6A priority Critical patent/EP4641729A4/en
Publication of WO2025000867A1 publication Critical patent/WO2025000867A1/zh
Priority to US19/287,788 priority patent/US12620633B2/en
Anticipated expiration legal-status Critical
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    • 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
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
    • 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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • 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
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H01M10/0567—Liquid materials characterised by the additives
    • 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
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H01M10/0568—Liquid materials characterised by the solutes
    • 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
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H01M10/0569—Liquid materials characterised by the solvents
    • 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
    • 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
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/133—Electrodes based on 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
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of manufacture
    • H01M4/1391—Processes of manufacture of 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
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of manufacture
    • H01M4/1393—Processes of manufacture of electrodes based on 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
    • 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
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/002—Inorganic electrolyte
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0025—Organic electrolyte
    • 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 field of batteries, and more specifically, to a lithium-ion battery and an electrical device.
  • lithium-ion batteries have been widely used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, as well as power tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, aerospace and other fields, and have thus achieved great development.
  • the present application is made in view of the above technical problems, and its purpose is to provide a lithium ion battery and an electric device.
  • the lithium ion battery includes an electrolyte containing metal ions, which can effectively improve the lithium precipitation problem in the low CB value area.
  • a lithium-ion battery comprising: an electrolyte, the electrolyte comprising metal ions, the reduction potential of the metal ions being higher than the reduction potential of lithium ions; and a low CB value region, the CB value of the lithium-ion battery in the low CB value region satisfies: 0 ⁇ CB ⁇ 1, and the CB value is the ratio of the capacity of a negative electrode active material per unit area to the capacity of a positive electrode active material per unit area.
  • the CB value is less than 1.
  • the capacity of the positive electrode active material per unit area is greater than the capacity of the negative electrode active material per unit area. Therefore, during the cycle, lithium deposition is prone to occur at the negative electrode piece corresponding to the low CB value area.
  • metal ions with a reduction potential higher than that of lithium ions are introduced into the electrolyte.
  • the metal ions in the electrolyte can move freely to the position of lithium deposition and be reduced to a metal element by lithium.
  • the lithium deposition in the low CB value area is improved, helping to improve the reversible capacity and cycle performance of the lithium-ion battery.
  • the lithium-ion battery includes a negative electrode plate, and the percentage X of the area of the negative electrode plate corresponding to the low CB value region to the area of the negative electrode plate satisfies: 0% ⁇ X; optionally, 0% ⁇ X ⁇ 10%; optionally, 0% ⁇ X ⁇ 2%.
  • the CB value of the lithium-ion battery in the low CB value region satisfies: 0.5 ⁇ CB ⁇ 1.
  • the reduction potential of the metal ion is satisfy: Wherein, Mn + represents the metal ion, n represents the valence of the metal ion, C represents the molar concentration of the metal ion in the electrolyte, R represents the ideal gas constant, T represents the temperature, and F represents the Faraday constant. Represents the standard electrode potential of lithium ions.
  • the metal ions by selecting metal ions whose reduction potentials satisfy the above conditions, the metal ions can be reduced to metal elements by the precipitated lithium, thereby improving the lithium precipitation problem in the low CB value region.
  • the reduction potential of the metal ion is satisfy:
  • metal ions whose reduction potentials satisfy the above conditions, while the metal ions can be reduced by lithium, it helps to reduce the oxidizing properties of the metal ions, thereby reducing the impact of the metal ions on the electrolyte and the positive and negative electrode plates.
  • the molar concentration C of the metal ions in the electrolyte satisfies: 0.001M ⁇ C ⁇ 0.2M.
  • lithium precipitation is suppressed while also helping to reduce the self-discharge of the lithium-ion battery.
  • the metal ions include Mg 2+ , Al 3+ , Zn 2+ , Sb 2+ At least one of .
  • a lithium ion battery comprising: a low CB value region, wherein the CB value of the lithium ion battery in the low CB value region satisfies: 0.5 ⁇ CB ⁇ 1; a negative electrode plate, wherein the content of the metal element per unit area at the negative electrode plate corresponding to the low CB value region is greater than the content of the metal element per unit area at the negative electrode plate corresponding to the high CB value region; wherein the CB value of the lithium ion battery in the high CB value region satisfies: CB ⁇ 1; the CB value is the ratio of the capacity of the negative electrode active material per unit area to the capacity of the positive electrode active material per unit area; and the reduction potential of the metal ion corresponding to the metal element is higher than the reduction potential of the lithium ion.
  • the percentage X of the area of the negative electrode sheet corresponding to the low CB value region to the area of the negative electrode sheet satisfies: 0% ⁇ X; optionally, 0% ⁇ X ⁇ 10%; optionally, 0% ⁇ X ⁇ 2%.
  • the CB value of the lithium-ion battery in the low CB value region satisfies: 0.5 ⁇ CB ⁇ 1.
  • the metal element includes at least one of Mg, Al, Zn, and Sb.
  • the lithium-ion battery includes: an electrolyte, the electrolyte includes metal ions, and the metal ions are ions corresponding to the metal element.
  • the molar concentration C' of the metal ions in the electrolyte satisfies: 0M ⁇ C' ⁇ 0.2M.
  • an electrical device comprising a lithium-ion battery in any possible implementation of the first aspect and/or a lithium-ion battery in any possible implementation of the second aspect.
  • FIG1 is a schematic diagram showing the principle of metal ion inhibition of lithium dendrites.
  • FIG. 2 is a schematic diagram of a low CB value region.
  • FIG. 3 is a schematic diagram of a battery cell.
  • FIG. 4 is a schematic diagram of a battery module.
  • FIG. 5 is a schematic diagram of a battery.
  • FIG. 6 is another schematic diagram of a battery.
  • “Scope” disclosed in the present application is limited in the form of lower limit and upper limit, and a given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range.
  • the scope limited in this way can be including end values or not including end values, and can be arbitrarily combined, that is, any lower limit can form a scope with any upper limit combination. For example, if the scope of 60-120 and 80-110 is listed for a specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected.
  • the numerical range "a-b" represents the abbreviation of any real number combination between a and b, wherein a and b are 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.
  • a and/or B means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A and/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 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.
  • CB (Cell balance) value refers to the ratio of the negative electrode capacity to the positive electrode capacity on the opposite side of the battery, also known as the N/P (Negative/Positive) ratio.
  • the CB value is equal to the ratio of the capacity of the negative electrode active material per unit area to the capacity of the positive electrode active material per unit area.
  • the “low CB value region” refers to the region in the battery where the CB value is less than 1.
  • the "high CB value region” refers to the region in the battery where the CB value is greater than or equal to 1.
  • the standard electrode potential of a substance refers to the electrode potential of the substance measured when the substance is combined with a standard hydrogen electrode to form a primary cell.
  • the standard electrode potential of lithium relative to hydrogen is -3.04V.
  • the electrode potential is also called the reduction potential.
  • 3 V vs. Li + /Li means that the electrode potential is 3 V relative to the lithium electrode, with lithium being the counter electrode.
  • secondary batteries have been widely used in power tools, electronic products, electric vehicles, aerospace and other fields due to their high energy density and long service life, and have made great progress.
  • secondary batteries include positive electrode sheets, negative electrode sheets, electrolytes and separators.
  • active ions are embedded and released back and forth between the positive electrode sheets and the negative electrode sheets.
  • the electrolyte plays a role in conducting active ions between the positive electrode and the negative electrode.
  • the separator is arranged between the positive electrode and the negative electrode, which prevents the positive and negative electrodes from short-circuiting while allowing active ions to pass through, so that the electrochemical reaction of the secondary battery proceeds normally.
  • Lithium-ion batteries are a typical secondary battery. Because they rely on the chemical reaction of lithium ions intercalating and disintercalating between the positive and negative electrodes for charging and discharging, lithium-ion batteries are also called rocking-chair batteries. During the charging process of lithium-ion batteries, lithium ions are released from the positive electrode active material, move to the negative electrode through the conduction of the electrolyte and embed into the negative electrode active material; and during the discharge process, lithium ions are released from the negative electrode active material, move to the positive electrode through the conduction of the electrolyte and embed into the positive electrode active material.
  • lithium insertion and “embedding” processes described in this application refer to the process in which lithium ions are embedded in the positive electrode active material or the negative electrode active material due to an electrochemical reaction
  • extraction, “delithium” and “extraction” processes described in this application refer to the process in which lithium ions are extracted from the positive electrode active material or the negative electrode active material due to an electrochemical reaction.
  • an embodiment of the present application provides a lithium-ion battery and an electrical device, wherein the electrolyte of the lithium-ion battery includes metal ions, which can improve lithium precipitation and inhibit the growth of lithium dendrites during the cycle of the lithium-ion battery, thereby helping to improve the capacity retention rate and cycle performance of the lithium-ion battery.
  • a lithium-ion battery includes a positive electrode sheet, a negative electrode sheet, an electrolyte, and a separator. Next, the lithium-ion battery provided in the present application and various parts of the lithium-ion battery are introduced.
  • a lithium-ion battery which includes an electrolyte, the electrolyte includes metal ions, and the reduction potential of the metal ions is higher than the reduction potential of lithium ions; a low CB value region, the CB value of the lithium-ion battery in the low CB value region satisfies: 0 ⁇ CB ⁇ 1, and the CB value is the ratio of the capacity of the negative electrode active material per unit area to the capacity of the positive electrode active material per unit area.
  • the CB value of the low CB value zone can be any value between 0 and 1, or within the range obtained by combining any two values between 0 and 1. Since the CB value of the low CB value zone of the lithium-ion battery is less than 1, lithium deposition is likely to occur during the cycle.
  • FIG1 is a schematic diagram of the lithium-ion battery provided in an embodiment of the present application for inhibiting lithium deposition.
  • the negative electrode plate 1 includes a negative electrode current collector 11 and a negative electrode active material layer 12 disposed on the negative electrode current collector 11. After the lithium-ion battery is formed, the negative electrode plate 1 also includes a solid electrolyte interface (SEI) film 13 formed on the surface of the negative electrode active material layer 12. Region a is a region corresponding to the low CB value region, and region b is a region corresponding to the high CB value region. As lithium is continuously precipitated in the low CB value region, lithium dendrites 14 grow and pierce the SEI film 13.
  • SEI solid electrolyte interface
  • metal ions with a higher reduction potential than lithium ions are introduced into the lithium-ion battery so that the metal ions can be reduced by lithium. Therefore, once lithium dendrites grow and pierce the SEI membrane, the free metal ions in the electrolyte will move to the lithium dendrites, and the precipitated lithium will be reduced to a metal element, which can further form an alloy or with lithium, thereby inhibiting lithium precipitation and helping to improve the capacity retention rate and cycle performance of the lithium-ion battery.
  • the low CB value area a in FIG1 is only an example of a low CB value area, which shows that the thickness of the negative active material layer 12 on the negative electrode sheet 1 is uniform, but due to the thick thickness of the active material layer on the positive electrode sheet (not shown in the figure), this position is a low CB value area a.
  • FIG2 shows another example of forming a low CB value area a.
  • the positive electrode sheet 2 includes a positive electrode current collector 21 and a positive electrode active material layer 22 disposed on the positive electrode current collector 21. In the case where the thickness of the positive electrode active material layer 22 is uniform, the thin thickness of the negative electrode active material layer will also cause this position to become a low CB value area a.
  • the thickness of the positive electrode active material layer and the negative electrode active material layer at a certain position are not uniform.
  • the positive electrode active material layer is thicker while the negative electrode active material layer is thinner, which may also cause the position to become a low CB value area a.
  • the lithium-ion battery includes a negative electrode plate, and the percentage X of the area of the negative electrode plate corresponding to the low CB value region to the area of the negative electrode plate satisfies: 0% ⁇ X; optionally, 0% ⁇ X ⁇ 10%; optionally, 0% ⁇ X ⁇ 2%.
  • X can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or its numerical range is within the range obtained by combining any two of the above numerical values.
  • the low CB value area is generated due to the process limitations in the production process of lithium-ion batteries. Therefore, under normal circumstances, 0% ⁇ X. On the other hand, based on the existing production process of lithium-ion batteries, the area of the low CB value area will not be unlimitedly large. Based on the consideration of factors such as the yield rate of lithium-ion battery products, the value of X also needs to meet the following requirements: X ⁇ 10%. It should be understood that under normal circumstances, the smaller the area of the low CB value area, the smaller X, the smaller the area on the negative electrode sheet where lithium deposition or lithium dendrite growth is likely to occur, and the more favorable it is for the product yield of lithium-ion batteries.
  • the position of the negative electrode sheet corresponding to the low CB value area is very prone to lithium deposition. Therefore, the lithium-ion battery after the cycle can be disassembled, and the area of the lithium deposition area on the negative electrode sheet can be measured to approximate it to the area of the negative electrode sheet corresponding to the low CB value area.
  • some low CB value areas can be artificially manufactured during the preparation of the lithium-ion battery, so that the area of the low CB value area can be artificially controlled and adjusted.
  • the CB value of the designated area can be calculated by measuring the capacity of the positive electrode sheet and the negative electrode sheet, thereby determining whether the area is a low CB value area.
  • the CB value of the lithium-ion battery in the low CB value region satisfies: 0.5 ⁇ CB ⁇ 1.
  • the CB value in the low CB value region may be any value between 0.5 and 1, or within a range obtained by combining any two values between 0.5 and 1.
  • the reduction potential of the metal ion satisfy:
  • Mn + represents the metal ion
  • n represents the valence of the metal ion
  • C represents the molar concentration of the metal ion in the electrolyte
  • R represents the ideal gas constant
  • T represents the temperature
  • F represents the Faraday constant. Represents the standard electrode potential of lithium ions.
  • R is equal to 8.314J ⁇ K -1 ⁇ mol - 1
  • T is in K
  • F is equal to 96485C ⁇ mol -1 .
  • the reduction potential of the metal ion satisfy:
  • metal ions whose reduction potential meets the above conditions when the reduction potential of the metal ions is higher than that of lithium ions and can be reduced by lithium; by controlling the upper limit of the reduction potential of the metal ions, metal ions with relatively weak oxidizing properties can be selected, thereby reducing the influence of metal ions on the electrolyte, positive electrode plate, and negative electrode plate.
  • the molar concentration C of the metal ions in the electrolyte satisfies: 0.001M ⁇ C ⁇ 1M; optionally, 0.001M ⁇ C ⁇ 0.2M.
  • C can be 0.001M, 0.002M, 0.003M, 0.004M, 0.005M, 0.006M, 0.007M, 0.008M, 0.009M, 0.01M, 0.02M, 0.03M, 0.04M, 0.05M, 0.06M, 0.07M, 0.08M, 0.09M, 0.1M, 0.2M, 0.3M, 0.4M, 0.5M, 0.6M, 0.7M, 0.8M, 0.9M, 1M, or its value is within the range obtained by combining any two of the above values.
  • the molar concentration of metal ions in the electrolyte is too low, the inhibitory effect on lithium dendrites is limited, and it is impossible to achieve continuous inhibition of lithium dendrites during the long cycle of lithium-ion batteries.
  • the molar concentration of metal ions in the electrolyte is too high, too many metal ions are reduced by lithium, there is too much metal on the surface of the negative electrode, the insulation performance of the SEI film is reduced, and the self-discharge of the lithium-ion battery is increased.
  • the metal ion concentration in the electrolyte within a suitable range, it is possible to suppress lithium dendrites while reducing the effect of reduced metal ions on the insulating properties of the SEI film, thereby helping to reduce the self-discharge of the lithium-ion battery.
  • the metal ions include at least one of Mg 2+ , Al 3+ , Zn 2+ , and Sb 2+ .
  • the metal ions can be provided by salts that can be dissolved in the electrolyte. Taking magnesium ions as an example, magnesium ions can be introduced by adding magnesium nitrate to the electrolyte.
  • the metal salt includes anions, and illustratively, the anions can be acetate ions, nitrate ions, hexafluorophosphate ions, and bis(fluorosulfonyl)imide ions.
  • a lithium ion battery capable of suppressing lithium dendrites for a long time is introduced.
  • the lithium ion battery after the above lithium ion battery has been cycled is introduced.
  • An embodiment of the present application also provides a cycled lithium-ion battery, comprising a low CB value zone, wherein the CB value of the lithium-ion battery in the low CB value zone satisfies: 0.5 ⁇ CB ⁇ 1; a negative electrode plate, wherein the content of the metal element per unit area at the negative electrode plate corresponding to the low CB value zone is greater than the content of the metal element per unit area at the negative electrode plate corresponding to the high CB value zone; wherein the CB value of the lithium-ion battery in the high CB value zone satisfies: CB ⁇ 1; the CB value is the ratio of the capacity of the negative electrode active material to the capacity of the positive electrode active material; and the reduction potential of the metal ion corresponding to the metal element is higher than the reduction potential of the lithium ion.
  • the lithium-ion battery after cycling can be considered as a lithium-ion battery in which lithium deposition has occurred, that is, a lithium-ion battery after lithium deposition.
  • the electrolyte of the lithium-ion battery includes metal ions. Therefore, the lithium-ion battery after cycling deposits lithium at the negative electrode corresponding to the low CB value area, and the deposited lithium is consumed by the metal ions, so that the lithium-ion battery after cycling is In the lithium-ion battery, the metal element content per unit area at the negative electrode piece corresponding to the low CB value area is greater than the metal element content per unit area at the negative electrode piece corresponding to the high CB value area.
  • the percentage X of the area of the negative electrode sheet corresponding to the low CB value region to the area of the negative electrode sheet satisfies: 0% ⁇ X; optionally, 0% ⁇ X ⁇ 10%; optionally, 0% ⁇ X ⁇ 2%.
  • the CB value of the lithium-ion battery in the low CB value region satisfies: 0.5 ⁇ CB ⁇ 1.
  • the metal element includes at least one of Mg, Al, Zn, and Sb.
  • a lithium-ion battery includes: an electrolyte, wherein the electrolyte includes metal ions, and the metal ions are ions corresponding to metal elements.
  • the electrolyte may also include some metal ions that have not been reduced by lithium.
  • the molar concentration C' of the metal ions in the electrolyte satisfies: 0M ⁇ C' ⁇ 0.2M.
  • C' may be 0 or not.
  • C' may be 0M, 0.02M, 0.04M, 0.06M, 0.08M, 0.1M, 0.12M, 0.14M, 0.16M, 0.18M, 0.2M, or a numerical range thereof within the range obtained by combining any two of the above numerical values.
  • the negative electrode sheet generally includes a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector.
  • the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material layer is disposed on any one or both of the two facing surfaces of the negative electrode current collector.
  • the negative electrode current collector may be a metal foil or a composite current collector.
  • a metal foil a copper foil may be used.
  • 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 material.
  • the composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material base material.
  • the substrate is formed on a substrate such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.
  • the negative electrode active material may adopt the negative electrode active material for batteries known in the art.
  • the negative electrode active material 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 layer further includes a binder.
  • the binder can be selected from at least one of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA) and carboxymethyl chitosan (CMCS).
  • the negative electrode active material layer further includes a conductive agent, which may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.
  • a conductive agent which 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 negative electrode active material layer further includes other additives, such as a thickener (eg, sodium carboxymethyl cellulose (CMC-Na)).
  • a thickener eg, sodium carboxymethyl cellulose (CMC-Na)
  • the negative electrode sheet can be prepared in the following manner: the components for preparing the negative electrode sheet are formed into a negative electrode slurry.
  • the negative electrode active material, the conductive agent, the binder and any other components are dispersed in a solvent (such as N-methylpyrrolidone) to form a negative electrode slurry.
  • the negative electrode slurry is coated on the negative electrode current collector, and after drying, cold pressing and other processes, the negative electrode sheet can be obtained.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector.
  • the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material layer is disposed on any one or both of the two facing surfaces of the positive electrode current collector.
  • the positive electrode current collector may be a metal foil or a composite current collector.
  • the metal foil aluminum foil may be used.
  • the composite current collector may include a polymer material base and a A metal layer on at least one surface of a molecular material substrate.
  • 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 a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).
  • PP polypropylene
  • PET polyethylene terephthalate
  • PBT polybutylene terephthalate
  • PS polystyrene
  • PE polyethylene
  • the positive electrode active material may be a positive electrode active material for a battery known in the art.
  • the positive electrode active material may include at least one of the following materials: an olivine-structured lithium-containing phosphate, a lithium transition metal oxide, 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 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 LiCoO2 ), lithium nickel oxide (such as LiNiO2 ), lithium manganese oxide (such as LiMnO2 , LiMn2O4 ), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi1 /3Co1 / 3Mn1/ 3O2 (also referred to as NCM333), LiNi0.5Co0.2Mn0.3O2 (also referred to as NCM523 ), LiNi0.5Co0.25Mn0.25O2 (also referred to as NCM211), LiNi0.6Co0.2Mn0.2O2 (also referred to as NCM622), LiNi0.8Co0.1Mn0.1O2 (also referred to as NCM811), lithium nickel cobalt aluminum oxide (such as LiNi0.85Co0.2Mn0.3O2 ) , LiNi0.5Co0.2M
  • lithium-containing phosphates with an olivine structure may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO 4 (also referred to as LFP)), 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.
  • LiFePO 4 also referred to as LFP
  • LiMnPO 4 lithium manganese phosphate
  • the battery is accompanied by the deintercalation and consumption of Li during the charging and discharging process, and the molar content of Li in the positive electrode active material is different when the battery is discharged to different states.
  • the molar content of Li is the initial state of the material, that is, the state before feeding.
  • the positive electrode active material is applied to the battery system, and after the charge and discharge cycle, the molar content of Li will change.
  • the molar content of O is only an ideal state value. The release of lattice oxygen will cause the molar content of O to change, and the actual molar content of O will fluctuate.
  • the positive electrode active material layer further includes 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
  • vinylidene fluoride-tetrafluoroethylene-propylene terpolymer vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer
  • the positive electrode active material layer further includes 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 positive electrode sheet can be prepared in the following manner: the components for preparing the positive electrode sheet are respectively formed into positive electrode slurries.
  • the first positive electrode active material and/or the second 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.
  • a solvent such as N-methylpyrrolidone
  • 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.
  • 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 includes an electrolyte salt, a solvent, and a metal ion, and the reduction potential of the metal ion is higher than the reduction potential of the lithium ion.
  • the electrolyte salt can be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl imide), lithium bis(trifluoromethanesulfonyl imide), lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.
  • the solvent can be selected from at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane sulfone, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone.
  • the metal ions include at least one of Mg 2+ , Al 3+ , Zn 2+ , and Sb 2+ .
  • the metal ion is provided by an inorganic salt.
  • the electrolyte includes an inorganic salt
  • the inorganic salt includes the metal ion and an anion.
  • the anion includes at least one of acetate, nitrate, hexafluorophosphate, and perchlorate.
  • the reduction potential of the metal ion satisfy: Among them, Mn + represents the metal ion, n represents the valence of the metal ion, C represents the molar concentration of the metal ion in the electrolyte, R represents the ideal gas constant, T represents the temperature, and F represents the Faraday constant. Represents the standard electrode potential of lithium ions.
  • the reduction potential of the metal ion satisfy:
  • the molar concentration C of the metal ions in the electrolyte satisfies: 0.001M ⁇ C ⁇ 1M; optionally, 0.001M ⁇ C ⁇ 0.2M.
  • the molar concentration C' of the metal ions in the electrolyte satisfies: 0M ⁇ C' ⁇ 0.2M.
  • the electrolyte may further include additives, which may include negative electrode film-forming additives, positive electrode film-forming additives, and may also include additives that can improve certain performance of the battery, such as additives that improve the overcharge performance of the battery, additives that improve the high or low temperature performance of the battery, etc.
  • additives may include negative electrode film-forming additives, positive electrode film-forming additives, and may also include additives that can improve certain performance of the battery, such as additives that improve the overcharge performance of the battery, additives that improve the high or low temperature performance of the battery, etc.
  • the battery further includes a separator.
  • a separator has no particular limitation on the type of separator, for example, any known porous structure 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, without particular limitation.
  • the negative electrode sheet, the positive electrode sheet and the separator may be formed into an electrode assembly by a winding process or a lamination process.
  • the battery cell may include an outer packaging, which may be used to encapsulate the electrode assembly and the electrolyte.
  • the outer packaging of the battery cell may be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc.
  • the outer packaging of the battery cell 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.
  • FIG3 is a battery cell 300 of a square structure as an example.
  • the battery cell 300 may include the lithium-ion battery in the aforementioned embodiment.
  • FIG4 is a battery module 400 as an example.
  • a plurality of battery cells 300 may be arranged in sequence along the length direction of the battery module 400. Of course, they may also be arranged in any other manner.
  • the plurality of battery cells 300 may be fixed by fasteners.
  • the plurality of battery cells 300 may be battery cells 300 of the same chemical system.
  • the battery cells 300 may also be of different chemical systems.
  • the battery module 400 may further include a housing having an accommodation space, and the plurality of battery cells 300 are accommodated in the accommodation space.
  • the battery modules 400 may also be assembled into a battery.
  • the number of battery modules 400 contained in the battery may be one or more, and the specific number may be selected by those skilled in the art according to the application and capacity of the battery.
  • FIG5 and FIG6 are battery 500 as an example.
  • the battery 500 may include a battery box and a plurality of battery modules 400 disposed in the battery box.
  • the battery box includes an upper box body 501 and a lower box body 502, and the upper box body 501 can be covered on the lower box body 502 to form a closed space for accommodating the battery module 400.
  • the plurality of battery modules 400 can be arranged in the battery box in any manner.
  • the battery 500 is also referred to as a battery pack.
  • the battery cells 300 may first form a battery module 400, and the battery 500 may be formed by the battery module 400.
  • the battery 500 may be directly formed by the battery cells 300, omitting the intermediate form of the battery module 400.
  • the present application also provides an electrical device, which includes the lithium-ion battery in the aforementioned embodiment.
  • the electrical device includes at least one of the battery cell 300, battery module 400, or battery 500 provided in the present application.
  • the battery cell 300, battery module 400, or battery 500 can be used as a power source for the electrical device, or 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 thereto.
  • a battery cell 300, a battery module 400, or a battery 500 may be selected according to its usage requirements.
  • 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.
  • a device may be a mobile phone, a tablet computer, a notebook computer, etc. Such a device is usually required to be thin and light, and a secondary battery may be used as a power source.
  • the negative electrode active material artificial graphite (1kg, particle size 15 ⁇ m), conductive agent acetylene black (10g), binder styrene butadiene rubber (30g), thickener sodium carboxymethyl cellulose (20g) were dissolved in solvent deionized water (1kg), mixed evenly to obtain negative electrode slurry. Then the negative electrode slurry was evenly coated on the negative electrode current collector copper foil. After drying, rolling and cutting, the negative electrode sheet was obtained.
  • the positive electrode active material LiNi 5 Co 2 Mn 3 O 2 (1kg), the conductive agent carbon nanotube (20g), and the binder polyvinylidene fluoride (20g) were dissolved in the solvent N-methylpyrrolidone (1kg), and mixed evenly to obtain the positive electrode slurry. Then the positive electrode slurry was evenly coated on the positive electrode current collector aluminum foil. After drying, rolling, and cutting, the positive electrode sheet was obtained.
  • electrolytes E1 and E2 were prepared, wherein E1 was used for the initial injection of the lithium-ion battery, and E2 was used for the secondary injection after the lithium-ion battery was formed; in the lithium-ion battery after formation, the volume ratio of E1 to E2 was 4:1.
  • Electrolyte E1 configuration organic solvents ethylene carbonate (EC), dimethyl carbonate (DMC) and diethyl carbonate (DEC) were mixed evenly in a volume ratio of 1:1:1, and then 1.25 M lithium hexafluorophosphate (LiPF 6 ) was added and dissolved in the solvent, and stirred evenly to obtain electrolyte E1.
  • EC ethylene carbonate
  • DMC dimethyl carbonate
  • DEC diethyl carbonate
  • Electrolyte E2 configuration organic solvents ethylene carbonate (EC), dimethyl carbonate (DMC) and diethyl carbonate (DEC) were mixed evenly in a volume ratio of 1:1:1, and then 0.25 M magnesium bis(trifluoromethylsulfonyl)imide was added and dissolved in the solvent, and stirred evenly to obtain electrolyte E2.
  • EC ethylene carbonate
  • DMC dimethyl carbonate
  • DEC diethyl carbonate
  • the positive electrode sheet, the separator, and the negative electrode sheet are stacked in order, so that the separator is between the positive electrode sheet and the negative electrode sheet and can separate the positive electrode sheet from the negative electrode sheet; then the stacked components are wound and placed in a shell, and the electrolyte E1 is injected after drying.
  • the above battery was formed under the following conditions: using the Blue Electric test system, the positive electrode Connect to the negative electrode, let it stand for 1 minute, charge to 4.2V at 0.33C, then charge at 4.2V at constant voltage, with a cut-off current of 0.05C, then let it stand for 10 minutes, discharge at 0.33C, with a cut-off voltage of 2.5V, and let it stand for 50 hours.
  • SEI film is formed during the formation of the battery and helps to reduce the polarization of the battery.
  • the formed battery is injected with electrolyte E2 for the second time, and the lithium-ion battery is obtained after packaging.
  • the CB value of the low CB value region was 0.95
  • the CB value of the high CB value region was 1.1
  • the lithium ion concentration in the electrolyte was 1M
  • the reduction potential of magnesium ions was 0.59V vs.Li + /Li.
  • Example 4 Compared with Example 1, in the lithium ion battery of Example 4, the CB value in the low CB value region is 0.9.
  • the CB value in the low CB value region is 0.8.
  • Example 6 Compared with Example 1, in the lithium ion battery of Example 6, the CB value in the low CB value region is 0.7.
  • the CB value in the low CB value region is 0.5.
  • the electrolyte of the lithium ion battery of Comparative Example 1 does not include metal ions.
  • the process of preparing the E2 electrolyte in Comparative Example 1 is as follows: In an argon atmosphere glove box (H 2 O ⁇ 0.1ppm, O 2 ⁇ 0.1ppm), organic solvents ethylene carbonate (EC), dimethyl carbonate (DMC) and diethyl carbonate (DEC) are mixed uniformly in a volume ratio of 1:1:1 to obtain the E2 electrolyte.
  • EC ethylene carbonate
  • DMC dimethyl carbonate
  • DEC diethyl carbonate
  • metal ion represents the metal ion whose reduction potential in the electrolyte is higher than the ion reduction potential.
  • S1/S represents the percentage of the area of the negative electrode sheet corresponding to the low CB value zone to the area of the negative electrode sheet.
  • C represents the molar concentration of the metal ion in the electrolyte.
  • 500-cycle capacity retention rate refers to the ratio of the discharge capacity of the lithium-ion battery after 500 cycles to the discharge capacity of the first cycle. The specific calculation process will be introduced in the test method later, so I will not go into details here.
  • m1/m2 represents the ratio of the content m1 of the metal element on the negative electrode sheet corresponding to the low CB value zone to the content m2 of the metal element on the negative electrode sheet corresponding to the high CB value zone per unit area.
  • C' represents the electrolyte of the lithium-ion battery after the cycle. The molar concentration of metal ions in the solution.
  • the lithium-ion batteries in Examples 1-10 after 500 cycles can be disassembled to obtain the negative electrode plates, electrolyte and other parts after the cycle.
  • the metal ion content m1 in the negative electrode plates corresponding to the low CB value area and the metal ion content m2 in the negative electrode plates corresponding to the high CB value area, as well as the metal ion concentration C' in the electrolyte can be detected.
  • Example 3 and Comparative Example 1 that although the area of the negative electrode sheet corresponding to the low CB value area of Example 3 accounts for a greater percentage of the area of the negative electrode sheet than that of Comparative Example 1, the capacity retention rate of Example 3 is still higher than that of the Comparative Example, which illustrates the effective inhibition of lithium precipitation and lithium dendrites by metal ions.
  • the higher the percentage of the area of the negative electrode sheet corresponding to the low CB value area to the area of the negative electrode sheet of the lithium-ion battery the greater the m1/m2 after cycling, and the smaller the content C' of metal ions in the electrolyte.
  • the capacity retention rate of Examples 4-7 shows a gradually decreasing trend. Therefore, by controlling the CB value in the low CB value zone within an appropriate range, the probability of serious lithium deposition in the battery caused by too small a CB value can be reduced.
  • the smaller the CB value of the lithium-ion battery in the low CB value zone the greater the m1/m2 after cycling, and the smaller the content C' of metal ions in the electrolyte. The inhibitory effect of metal ions on lithium deposition and lithium dendrites is verified again.
  • the metal ion in Example 10 is Al 3+ , which indicates that metal ions with a reduction potential higher than that of lithium ions can effectively inhibit lithium dendrites.
  • test methods of the physical and chemical parameters and performance parameters involved in the embodiments of the present application. It should be understood that the following test methods are only examples, and other test methods known in the art may also be used for testing.
  • the reduction potential of metal ions can be obtained by measuring the potential difference between them and a standard electrode, or by calculating them based on the concentration and the Nernst equation.
  • the metal or metal ion solution to be tested, the standard hydrogen electrode or the lithium electrode can be used as the counter electrode to form a primary cell, and the potential difference between the two electrodes can be measured to obtain the reduction potential of the metal ions.
  • CB value (capacity of negative electrode active material per unit area)/(capacity of positive electrode active material per unit area).
  • the molar concentration of metal ions in the electrolyte can be determined by various methods such as titration, electrochemical analysis, spectrophotometry, and inductively coupled plasma.
  • reverse aqua regia concentrated nitric acid: concentrated hydrochloric acid 3:1
  • the first cycle charging refers to the battery being charged to 4.2V at a constant current of 60mA after formation, and then being charged at a constant voltage at 4.2V to a cut-off current of 2mA;
  • the first cycle discharge capacity refers to the capacity W1 released by the battery when it is discharged to a voltage of 2.5V at a constant current of 60mA after formation.
  • the test process was: charging at a constant current of 60mA, with a cut-off voltage of 4.2V; constant voltage charging at 4.2V, with a cut-off current of 2mA; after standing for 10 minutes, discharging at a constant current of 60mA, with a cut-off voltage of 2.5V, and then charging to 4.2V after 500 cycles before the test was stopped.
  • the discharge capacity after 500 cycles was W2.
  • the capacity retention rate of lithium-ion batteries after 500 cycles was W2/W1 ⁇ 100%.

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Abstract

本申请实施例公开了一种锂离子电池及用电装置，该锂离子电池包括电解液，该电解液包括金属离子，该金属离子的还原电位高于锂离子的还原电位；低CB值区，该锂离子在该低CB值区的CB值满足：0＜CB＜1，CB值为单位面积的负极活性物质的容量与单位面积的正极活性物质的容量的比值。本申请提供的锂离子电池能够有效改善低CB值区析锂的问题。

Description

锂离子电池及用电装置
相关申请的交叉引用
本专利文件要求于2023年6月30日提交的发明名称为“锂离子电池及用电装置”的申请号为202310794171.5的中国专利申请的优先权和权益。上述专利申请的全部内容通过引用并入本专利文件公开内容的一部分。
技术领域
本申请涉及电池领域，更为具体地，涉及一种锂离子电池及用电装置。
背景技术
近年来，锂离子电池被广泛应用于水力、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、电动汽车、军事装备、航空航天等多个领域，从而得到了极大的发展。
在锂离子电池的制备过程中，由于工艺限制，不可避免地会出现正负极容量不匹配的位置，即存在低CB值区。低CB值区对应的负极极片上容易发生析锂，对锂离子电池的容量和安全性产生不利影响。因此，如何改善析锂对离子电池性能的影响是一项亟待解决的技术问题。
发明内容
本申请是鉴于上述技术问题而进行的，其目的在于，提供一种锂离子电池及用电装置。该锂离子电池包括含有金属离子的电解液，能够有效改善低CB值区的析锂问题。
第一方面，提供一种锂离子电池，所述锂离子电池包括：电解液，所述电解液包括金属离子，所述金属离子的还原电位高于锂离子的还原电位；低CB值区，所述锂离子电池在所述低CB值区的CB值满足：0＜CB＜1，所述CB值为单位面积的负极活性物质的容量与单位面积的正极活性物质的容量的比值。
在锂离子电池的低CB值区处，CB值小于1，换言之，在低CB值区，单位面积的正极活性物质的容量大于单位面积的负极活性物质的容量。因此，在循环过程中，低CB值区对应的负极极片处容易发生析锂。本申请的实施例中，电解液中引入了还原电位高于锂离子的金属离子，在低CB值区对应的负极极片处发生析锂的情况下，电解液中的金属离子能够自由移动至析锂的位置，被锂还原成金属单质，由此，改善低CB值区析锂的情况，帮助提高锂离子电池的可逆容量和循环性能。
在一种可能的实现方式中，所述锂离子电池包括负极极片，所述低CB值区对应的负极极片的面积占所述负极极片的面积的百分比X满足：0％＜X；可选地，0％＜X≤10％；可选地，0％＜X≤2％。
在一种可能的实现方式中，所述锂离子电池在所述低CB值区的CB值满足：0.5＜CB＜1。
在一种可能的实现方式中，所述金属离子的还原电位满足：其中，Mn+代表所述金属离子，n代表所述金属离子的化合价，C代表所述金属离子在所述电解液中的摩尔浓度，R代表理想气体常数，T代表温度，F代表法拉第常数，代表锂离子的标准电极电势。
本申请的实施例中，通过选择还原电位满足上述条件的金属离子，能够使得金属离子被析出的锂还原成金属单质，从而改善低CB值区的析锂问题。
在一种可能的实现方式中，所述金属离子的还原电位满足：
本申请的实施例中，通过选择还原电位满足上述条件的金属离子，在金属离子能够被锂还原的同时，有助于降低金属离子的氧化性，从而降低金属离子对电解液以及正、负极极片的影响。
在一种可能的实现方式中，所述金属离子在所述电解液中的摩尔浓度C满足：0.001M≤C≤0.2M。
本申请的实施例中，通过控制金属离子在电解液中的浓度在合适的范围内，在抑制析锂的同时，还有助于降低锂离子电池的自放电。
在一种可能的实现方式中，所述金属离子包括Mg2+、Al3+、Zn2+、Sb2+ 中的至少一种。
第二方面，提供一种锂离子电池，所述锂离子电池包括：低CB值区，所述锂离子电池在所述低CB值区的CB值满足：0.5＜CB＜1；负极极片，所述低CB值区对应的所述负极极片处单位面积内的金属元素的含量大于高CB值区对应的所述负极极片处单位面积内的所述金属元素的含量；其中，所述锂离子电池在所述高CB值区的CB值满足：CB≥1；所述CB值为单位面积的负极活性物质的容量与单位面积的正极活性物质的容量的比值；所述金属元素对应的金属离子的还原电位高于锂离子的还原电位。
在一种可能的实现方式中，所述低CB值区对应的所述负极极片的面积占所述负极极片的面积的百分比X满足：0％＜X；可选地，0％＜X≤10％；可选地，0％＜X≤2％。
在一种可能的实现方式中，所述锂离子电池在所述低CB值区处的CB值满足：0.5＜CB＜1。
在一种可能的实现方式中，所述金属元素包括Mg、Al、Zn、Sb中的至少一种。
在一种可能的实现方式中，所述锂离子电池包括：电解液，所述电解液包括金属离子，所述金属离子为所述金属元素对应的离子。
在一种可能的实现方式中，所述金属离子在所述电解液中的摩尔浓度C’满足：0M≤C’＜0.2M。
第三方面，提供一种用电装置，所述用电装置包括第一方面任一可能的实现方式中的锂离子电池和/或第二方面任一可能的实现方式中的锂离子电池。
附图说明
为了更清楚地说明本申请实施例的技术方案，下面将对本申请实施例中所需要使用的附图作简单地介绍，显而易见地，下面所描述的附图仅仅是本申请的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据附图获得其他的附图。
图1为金属离子抑制锂枝晶的示意性原理图。
图2为一种低CB值区的示意图。
图3为一种电池单体的示意图。
图4为一种电池模块的示意图。
图5为一种电池的示意图。
图6为一种电池的另一示意图。
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锂离子电池及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。
在本申请的描述中，需要说明的是，除非另有说明，“多个”的含义是两个以上；术语“上”、“下”、“左”、“右”、“内”、“外”等指示的方位或位置关系仅是为了便于描述本申请和简化描述，而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本申请的限制。此外，术语“第一”、“第二”、“第三”等仅用于描述目的，而不能理解为指示或暗示相对重要性。
如果没有特别的说明，在本申请中，短语“A和/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和/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)。
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，以下术语具有以下含义。任何未定义的术语具有它们在技术上公认的含义。
如有提及，“CB(Cell balance)值”指的是电池中正对面的负极容量和正极容量的比值，也被称作N/P(Negative/Positive)比。换言之，CB值等于单位面积负极活性物质的容量与单位面积正极活性物质的容量的比值。
如有提及，“低CB值区”指的是电池中CB值小于1的区域。
如有提及，“高CB值区”指的是电池中CB值大于等于1的区域。
如有提及，指的是锂离子的标准电极电势。某物质的标准电极电势指的是该物质与标准氢电极组成原电池，测得的该物质的电极电势。例如，锂相对于氢的标准电极电势为-3.04V。本申请中，电极电势也称为还原电位。
如有提及，“3V vs.Li+/Li”指的是以锂作为对电极，相对于锂电极的电极电势为3V。
接下来，对本申请的实施例进行介绍。
近年来，二次电池由于其较高的能量密度、较长的使用寿命被广泛应用于电动工具、电子产品、电动汽车、航空航天等多个领域，从而得到了长足的发展。通常情况下，二次电池包括正极极片、负极极片、电解液和隔离件。在电池的充放电过程中，活性离子在正极极片和负极极片之间往返嵌入和脱 出。其中，电解液在正极极片和负极极片之间起到传导活性离子的作用。隔离件设置于正极极片和负极极片之间，在防止正负极短路的同时使得活性离子能够从中通过，使得二次电池电化学反应正常进行。
以锂离子电池为例，锂离子电池是一种典型的二次电池，由于其依靠锂离子在正负极之间脱嵌的化学反应进行充放电，锂离子电池又被成为摇椅式电池。锂离子电池的充电过程中，锂离子从正极活性材料中脱出，经过电解液的传导移动至负极并嵌入到负极活性材料中；而放电过程中，锂离子从负极活性材料中脱出，经过电解液的传导移动至正极并嵌入到正极活性材料中。
应理解，本申请所述“嵌锂”、“嵌入”过程指锂离子由于电化学反应在正极活性材料或负极活性材料中嵌入的过程，本申请所述“脱出”、“脱锂”、“脱嵌”过程指锂离子由于电化学反应在正极活性材料或负极活性材料中脱出的过程。
在锂离子电池的生产过程中，需要将含有活性物质的浆料涂布至集流体上，以形成极片。由于涂布工艺、涂布后极片上不同位置的浆料干燥速度不同等因素的限制，通常无法获得厚度完全均一的极片。这使得锂离子电池中出现低CB值区。在锂离子电池的循环过程中，由于低CB值区对应的负极极片处容量较低，无法完全容纳低CB值区对应的正极极片处脱出的锂离子，使得多余的锂离子无法嵌入负极活性材料中，出现析锂的现象。随着锂离子的进一步析出，锂枝晶的生长不断地消耗活性锂离子，导致电池的容量和循环寿命的衰减。
有鉴于此，本申请实施例提供一种锂离子电池及用电装置，该锂离子电池的电解液包括金属离子，能够在锂离子电池的循环过程中改善析锂、抑制锂枝晶的生长，帮助提高锂离子电池的容量保持率和循环性能。
通常情况下，锂离子电池包括正极极片、负极极片、电解液和隔离件。接下来对本申请提供的锂离子电池以及锂离子电池中的各个部分进行介绍。
首先，提供一种锂离子电池，该锂离子电池包括电解液，该电解液包括金属离子，该金属离子的还原电位高于锂离子的还原电位；低CB值区，锂离子电池在该低CB值区的CB值满足：0＜CB＜1，CB值为单位面积的负极活性物质的容量与单位面积的正极活性物质的容量的比值。
具体来说，低CB值区的CB值可以为0-1之间的任一数值，或0-1之间的任意两个数值组合所获得的范围之内。锂离子电池的低CB值区由于CB值小于1，容易在循环过程中发生析锂。图1为本申请实施例提供的锂离子电池抑制析锂的示意性原理图。
如图1所示，负极极片1包括负极集流体11和设置于负极集流体11上的负极活性材料层12。在锂离子电池化成后，负极极片1还包括形成于负极活性材料层12的表面的固体电解质界面(Solid electrolyte interface,SEI)膜13。区域a为低CB值区对应的区域，区域b为高CB值区对应的区域。随着低CB值区不断析锂，锂枝晶14生长从而刺破SEI膜13。
本实施例中，通过在锂离子电池中引入还原电位高于锂离子的金属离子，使得金属离子能够被锂还原。由此，一旦锂枝晶生长、刺破SEI膜，电解液中游离的金属离子将移动至锂枝晶处，被析出的锂还原成金属单质，该金属单质可进一步与锂形成合金或，从而抑制析锂，帮助提高锂离子电池的容量保持率和循环性能。
应理解，图1中的低CB值区a仅作为一种低CB值区的示例，其展示了负极极片1上负极活性材料层12厚度均一，但由于正极极片上活性材料层厚度较厚(图中未示出)导致该位置为低CB值区a的情况。图2展示了形成低CB值区a的另一种示例。如图2所示，正极极片2包括正极集流体21和设置于正极集流体21上的正极活性材料层22。在正极活性材料层22厚度均一的情况下，负极活性材料层的厚度较薄也会导致该位置成为低CB值区a。
在另一种可能的情况中，正极活性材料层和负极活性材料层在某一位置的厚度均不均一，例如，正极活性材料层较厚的同时，负极活性材料层较薄，也可能造成该位置成为低CB值区a。
在一个实施例中，锂离子电池包括负极极片，低CB值区对应的负极极片的面积占该负极极片的面积的百分比X满足：0％＜X；可选地，0％＜X≤10％；可选地，0％＜X≤2％。
具体来说，X可以是0.1％、0.2％、0.3％、0.4％、0.5％、0.6％、0.7％、0.8％、0.9％、1％、2％、3％、4％、5％、6％、7％、8％、9％、10％，或其数值范围在上述任意两个数值组合所获得的范围之内。
低CB值区的产生是由于锂离子电池生产过程中的工艺限制，因此，通常情况下，0％＜X。另一方面，基于现有的锂离子电池的生产工艺，低CB值区的面积不会无限制的大，基于对锂离子电池产品良率等因素的考虑，X的值还需要满足：X≤10％。应理解，通常情况下，低CB值区的面积越小，X越小，负极极片上容易发生析锂或锂枝晶生长的区域越小，越有利于锂离子电池的产品良率。
在一个示例中，由于低CB值区对应的负极极片的位置极易发生析锂。因此，可以通过拆解循环后的锂离子电池，测量负极极片上析锂区域的面积从而将其近似为低CB值区对应的负极极片的面积。在另一个示例中，为了便于测试，还可以在制备锂离子电池的过程中人为制造部分低CB值区，使得该部分低CB值区的面积可以被人为控制和调整。测试过程中，可以通过测量正极极片、负极极片指定区域的容量从而计算该指定区域的CB值，由此，判断该区域是否为低CB值区。
在一个实施例中，锂离子电池在低CB值区处的CB值满足：0.5＜CB＜1。
具体来说，低CB值区处的CB值可以是0.5-1之间的任一数值，或0.5-1之间的任意两个数值组合所获得的范围之内。
在一个实施例中，金属离子的还原电位满足：
其中，Mn+代表金属离子，n代表金属离子的化合价，C代表金属离子在电解液中的摩尔浓度，R代表理想气体常数，T代表温度，F代表法拉第常数，代表锂离子的标准电极电势。通常情况下，R等于8.314J·K-1·mol- 1，T的单位为K，F等于96485C·mol-1。
在一个实施例中，金属离子的还原电位满足：
本实施例中，通过选择还原电位满足上述条件的金属离子，在金属离子的还原电位高于锂离子的还原电位，能够被锂还原的情况下；通过控制金属离子还原电位的上限，能够选择氧化性相对较弱的金属离子，从而减少金属离子对电解液、正极极片、负极极片的影响。
在一个实施例中，金属离子在电解液中的摩尔浓度C满足：0.001M≤ C≤1M；可选地，0.001M≤C≤0.2M。
具体来说，C可以是0.001M、0.002M、0.003M、0.004M、0.005M、0.006M、0.007M、0.008M、0.009M、0.01M、0.02M、0.03M、0.04M、0.05M、0.06M、0.07M、0.08M、0.09M、0.1M、0.2M、0.3M、0.4M、0.5M、0.6M、0.7M、0.8M、0.9M、1M，或其数值在上述任意两个数值组合所获得的范围之内。
一方面，电解液中金属离子的摩尔浓度过低，其对锂枝晶的抑制效果有限，无法在锂离子电池的长循环过程中实现对锂枝晶的持续性抑制。另一方面，电解液中金属离子的摩尔浓度过高，被锂还原的金属离子过多，负极极片的表面金属过多，SEI膜的绝缘性能下降，使得锂离子电池自放电增大。
由此，本实施例中，通过控制电解液中的金属离子浓度在合适的范围内，能够在抑制锂枝晶的同时，降低被还原的金属离子对SEI膜绝缘性能的影响，从而帮助减少锂离子电池的自放电。
在一个实施例中，金属离子包括Mg2+、Al3+、Zn2+、Sb2+中的至少一种。
应理解，金属离子可以由能够溶解于电解液的盐提供。以镁离子为示例，可以通过在电解液中加入硝酸镁从而引入镁离子。金属盐包括阴离子，示例性地，阴离子可以是醋酸根离子、硝酸根离子、六氟磷酸根离子、双氟磺酰亚胺根离子。
上述实施例中，介绍了能够长效抑制锂枝晶的锂离子电池。接下来，对上述锂离子电池经过循环后的锂离子电池进行介绍。
本申请的实施例还提供一种循环后的锂离子电池，包括低CB值区，锂离子电池在低CB值区的CB值满足：0.5＜CB＜1；负极极片，低CB值区对应的该负极极片处单位面积内的金属元素的含量大于高CB值区对应的负极极片处单位面积内的金属元素的含量；其中，锂离子电池在高CB值区的CB值满足：CB≥1；CB值为负极活性物质的容量与正极活性物质的容量的比值；金属元素对应的金属离子的还原电位高于锂离子的还原电位。
应理解，本申请的实施例中，循环后的锂离子电池可以被认为是已经发生了析锂现象的锂离子电池，即析锂后的锂离子电池。前述实施例中已经提到，锂离子电池的电解液中包括金属离子。因此，循环后的锂离子电池在低CB值区对应的负极极片处析锂，析出的锂被金属离子消耗，使得循环后 的锂离子电池中，低CB值区对应的负极极片处单位面积内的金属元素含量大于高CB值区对应的负极极片处单位面积内的金属元素含量。
在一个实施例中，低CB值区对应的负极极片的面积占该负极极片的面积的百分比X满足：0％＜X；可选地，0％＜X≤10％；可选地，0％＜X≤2％。
在一个实施例中，锂离子电池在低CB值区处的CB值满足：0.5＜CB＜1。
在一个实施例中，金属元素包括Mg、Al、Zn、Sb中的至少一种。
在一个实施例中，锂离子电池包括：电解液，该电解液包括金属离子，该金属离子为金属元素对应的离子。
具体来说，随着锂离子电池循环圈数增加，电解液中的金属离子被析出的锂消耗，由此，金属离子的浓度逐渐降低。因此，在循环后的锂离子电池中，电解液中还可以包括部分还未被锂还原的金属离子。
在一个实施例中，金属离子在电解液中的摩尔浓度C’满足：0M≤C’＜0.2M。
应理解，循环后的锂离子电池中金属离子可以被完全消耗，也可以有部分残留，因此C’可以为0，也可以不为0。具体来说，C’可以是0M、0.02M、0.04M、0.06M、0.08M、0.1M、0.12M、0.14M、0.16M、0.18M、0.2M，或其数值范围在上述任意两个数值组合所获得的范围之内。
接下来，对锂离子电池中的正极极片、负极极片、隔离件以及电解液进行详细介绍。
[负极极片]
负极极片通常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活性材料层。
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，负极活性材料层设置在负极集流体相对的两个表面的其中任意一者或两者上。
在一个实施例中，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(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)上而形成。
在一个实施例中，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，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、软碳、硬碳、硅基材料、锡基材料和钛酸锂等。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。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。
在一个实施例中，负极活性材料层还包括粘结剂。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。
在一个实施例中，负极活性材料层还包括导电剂。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。
在一个实施例中，负极活性材料层还包括其他助剂，例如增稠剂(如羧甲基纤维素钠(CMC-Na))等。
在一个实施例中，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形成负极浆料。例如将负极活性材料、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，形成负极浆料。然后将负极浆料涂覆在负极集流体上，经烘干、冷压等工序后，即可得到负极极片。
[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活性材料层。
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，正极活性材料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。
在一个实施例中，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(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)等的基材)上而形成。
在一个实施例中，正极活性材料可采用本领域公知的用于电池的正极活性材料。作为示例，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。电池在充放电过程中会伴随Li的脱嵌及消耗，电池在放电到不同状态时正极活性材料中的Li的摩尔含量不同。本申请关于正极活性材料的列举中，Li的摩尔含量为材料初始状态，即投料前状态，正极活性材料应用于电池体系中，经过充放电循环，Li的摩尔含量会发生变化。本申请关于正极活性材料的列举中，O的摩尔含量仅为理想状态值，晶格释氧会导致O的摩尔含量发生变化，实际O的摩尔含量会出现浮动。
在一个实施例中，正极活性材料层还包括粘结剂。作为示例，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。
在一个实施例中，正极活性材料层还包括导电剂。作为示例，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。
在一个实施例中，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分别形成正极浆料。例如将第一正极活性材料和/或第二正极活性材料、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。然后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。
[电解液]
电解液在正极极片和负极极片之间起到传导离子的作用。本申请对电解液的种类没有具体的限制，可根据需求进行选择。电解液包括电解质盐、溶剂以及金属离子，该金属离子的还原电位高于锂离子的还原电位。
在一个实施例中，电解质盐可选自六氟磷酸锂、四氟硼酸锂、高氯酸锂、六氟砷酸锂、双氟磺酰亚胺锂、双三氟甲磺酰亚胺锂、三氟甲磺酸锂、二氟磷酸锂、二氟草酸硼酸锂、二草酸硼酸锂、二氟二草酸磷酸锂及四氟草酸磷酸锂中的至少一种。
在一个实施例中，溶剂可选自碳酸亚乙酯、碳酸亚丙酯、碳酸甲乙酯、碳酸二乙酯、碳酸二甲酯、碳酸二丙酯、碳酸甲丙酯、碳酸乙丙酯、碳酸亚丁酯、氟代碳酸亚乙酯、甲酸甲酯、乙酸甲酯、乙酸乙酯、乙酸丙酯、丙酸甲酯、丙酸乙酯、丙酸丙酯、丁酸甲酯、丁酸乙酯、1,4-丁内酯、环丁砜、二甲砜、甲乙砜及二乙砜中的至少一种。
在一个实施例中，金属离子包括Mg2+、Al3+、Zn2+、Sb2+中的至少一种。
在一个实施例中，金属离子由无机盐提供。换言之，电解液包括无机盐，无机盐包括该金属离子和阴离子。示例性地，阴离子包括醋酸根、硝酸根、六氟磷酸根、高氯酸根中的至少一种。
在一个实施例中，金属离子的还原电位满足：其中，Mn+代表金属离子，n代表金属离子的化合价，C代表金属离子在电解液中的摩尔浓度，R代表理想气体常数，T代表温度，F代表法拉第常数，代表锂离子的标准电极电势。
在一个实施例中，金属离子的还原电位满足：
在一个实施例中，在循环前的锂离子电池中，金属离子在电解液中的摩尔浓度C满足：0.001M≤C≤1M；可选地，0.001M≤C≤0.2M。
在一个实施例中，在循环后的锂离子电池中，金属离子在电解液中的摩尔浓度C’满足：0M≤C’＜0.2M。
在一个实施例中，电解液还可以包括添加剂，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。
[隔离件]
在一个实施例中，电池中还包括隔离件。本申请对隔离件的种类没有特别的限制，例如，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。
在一个实施例中，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。
在一个实施例中，负极极片、正极极片和隔离件可以通过卷绕工艺或叠片工艺制成电极组件。
在一个实施例中，电池单体可包括外包装。该外包装可用于封装上述电极组件及电解液。
在一个实施例中，电池单体的外包装可以是硬壳，例如硬塑料壳、铝壳、钢壳等。电池单体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。
本申请对电池单体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3是作为一个示例的方形结构的电池单体300。
应理解，电池单体300可以包括前述实施例中的锂离子电池。
图4是作为一个示例的电池模块400。参照图4，在电池模块400中，多个电池单体300可以是沿电池模块400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电池单体300进行固定。多个电池单体300可以是相同化学体系的电池单体300， 也可以是不同化学体系的电池单体300。
可选地，在一个实施例中，电池模块400还可以包括具有容纳空间的外壳，多个电池单体300容纳于该容纳空间。
可选地，在一个实施例中，上述电池模块400还可以组装成电池，电池所含电池模块400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的应用和容量进行选择。
图5和图6是作为一个示例的电池500。参照图5和图6，在电池500中可以包括电池箱和设置于电池箱中的多个电池模块400。电池箱包括上箱体501和下箱体502，上箱体501能够盖设于下箱体502，并形成用于容纳电池模块400的封闭空间。多个电池模块400可以按照任意的方式排布于电池箱中。
应理解，在另一些实施例中，上述电池500又称作电池包。电池单体300可以先组成电池模块400，电池500由电池模块400组成。也可以直接由电池单体300组成电池500，省去电池模块400这一中间形态。
另外，本申请还提供一种用电装置，该用电装置包括前述实施例中的锂离子电池。
在另一个实施例中，用电装置包括本申请提供的电池单体300、电池模块400、或电池500中的至少一种。电池单体300、电池模块400、或电池500可以用作用电装置的电源，也可以用作用电装置的能量存储单元。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。
作为用电装置，可以根据其使用需求来选择电池单体300、电池模块400、或电池500。
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，说明本申请的实施例。下面描述的实施例是示例性的，仅用于 解释本申请，而不能理解为对本申请的限制。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。
[实施例1-10及对比例1]
实施例1
(1)负极极片的制备
将负极活性材料人造石墨(1kg，粒径15μm)、导电剂乙炔黑(10g)、粘结剂丁苯橡胶(30g)、增稠剂羧甲基纤维素钠(20g)溶解于溶剂去离子水(1kg)中，混合均匀后得到负极浆料。随后将负极浆料均匀涂覆于负极集流体铜箔上。再经过烘干、辊压、分切得到负极极片。
(2)正极极片的制备
将正极活性材料LiNi5Co2Mn3O2(1kg)、导电剂碳纳米管(20g)、粘结剂聚偏二氟乙烯(20g)溶解于溶剂N-甲基吡咯烷酮(1kg)中，混合均匀后得到正极浆料。随后将正极浆料均匀涂覆于正极集流体铝箔上。再经过烘干、辊压、分切得到正极极片。
(3)电解液的制备
在氩气气氛手套箱中(H2O<0.1ppm，O2<0.1ppm)，配置电解液E1和E2，其中E1用于锂离子电池首次注液，E2用于锂离子电池化成后的二次注液；化成后的锂离子电池中，E1和E2的体积比4：1。
电解液E1配置：将有机溶剂碳酸乙烯酯(EC)、碳酸二甲酯(DMC)以及碳酸二乙酯(DEC)按照体积比1:1:1混合均匀，再加入1.25M六氟磷酸锂(LiPF6)溶解于溶剂中，搅拌均匀，得到电解液E1。
电解液E2配置：将有机溶剂碳酸乙烯酯(EC)、碳酸二甲酯(DMC)以及碳酸二乙酯(DEC)按照体积比1:1:1混合均匀，再加入0.25M双三氟甲基磺酰亚胺镁溶解于溶剂中，搅拌均匀，得到电解液E2。
(4)锂离子电池的制备
将正极极片、隔离膜、负极极片按顺序叠放，使得隔离膜出于正极极片和负极极片之间并能够隔离正极极片和负极极片；然后将上述叠放好的部件卷绕并至于壳体中，干燥后注入电解液E1。
对上述电池进行化成，化成条件具体为：使用蓝电测试系统，将正极 和负极连接，静置1分钟，在0.33C电流下恒流充电到4.2V，再在4.2V下恒压充电，截止电流为0.05C，然后静置10分钟后，在0.33C电流下恒流放电，截止电压为2.5V，静置50小时。电池的化成过程中形成了SEI膜并有助于减轻电池的极化。
对化成后的上述电池进行二次注液，将电解液E2注入到电池中，封装后得到锂离子电池。
对实施例1中的锂离子电池进行测试，低CB值区对应的负极极片的面积S1占负极极片总面积S的5％，即S1/S＝5％。低CB值区的CB值为0.95，高CB值区的CB值为1.1，电解液中锂离子浓度为1M，镁离子的摩尔浓度C＝0.05M，镁离子的还原电位为0.59V vs.Li+/Li。
实施例2
与实施例1相比，实施例2的锂离子电池中，S1/S＝0.1％。
实施例3
与实施例1相比，实施例3的锂离子电池中S1/S＝10％。
实施例4
与实施例1相比，实施例4的锂离子电池中，低CB值区的CB值为0.9。
实施例5
与实施例1相比，实施例5的锂离子电池中，低CB值区的CB值为0.8。
实施例6
与实施例1相比，实施例6的锂离子电池中，低CB值区的CB值为0.7。
实施例7
与实施例1相比，实施例7的锂离子电池中，低CB值区的CB值为0.5。
实施例8
与实施例1相比，实施例8的锂离子电池中，C＝0.001M。
实施例9
与实施例1相比，实施例9的锂离子电池中，C＝0.2M。
实施例10
与实施例1相比，实施例10的锂离子电池的电解液中的金属离子为铝离子，铝离子的摩尔浓度C＝0.05M，铝离子的还原电位为。
对比例1
与实施例1相比，对比例1的锂离子电池的电解液中不包括金属离子。对比例1中制备E2电解液的过程如下：在氩气气氛手套箱中(H2O<0.1ppm，O2<0.1ppm)，将有机溶剂碳酸乙烯酯(EC)、碳酸二甲酯(DMC)以及碳酸二乙酯(DEC)按照体积比1:1:1混合均匀得到E2电解液。
实施例1-10以及对比例1的产品参数及性能测试参数详见表1。
表1：实施例1-10以及对比例1的产品及性能参数
表1中，“金属离子”代表电解液中还原电位高于离子还原电位的金属离子。“S1/S”代表低CB值区对应的负极极片的面积占负极极片的面积的百分比。“C”代表金属离子在电解液中的摩尔浓度。“500圈的容量保持率”指的是将锂离子电池循环500圈后的放电容量和首圈放电容量的比值，具体计算过程将在后边的测试方法中介绍，此处先不赘述。“m1/m2”表示单位面积内，低CB值区对应的负极极片上金属元素的含量m1和高CB值区对应的负极极片上金属元素的含量m2的比值。“C’”表示循环后的锂离子电池的电解 液中金属离子的摩尔浓度。
对于表1中的“m1/m2”和“C’”，可以对循环了500圈后的实施例1-10中的锂离子电池进行拆解，得到循环后的负极极片、电解液等部分，由此，可以检测低CB值区对应的负极极片中金属离子的含量m1和高CB值区对应的负极极片中金属离子的含量m2，以及电解液中金属离子的浓度C’。
根据实施例与对比例的对比分析可知，通过在电解液中引入金属离子，能够有效抑制锂枝晶的生长，提高锂离子电池的容量保持率和循环性能。
根据实施例1-3的分析对比可知，锂离子电池中的低CB值区对应的负极极片的面积占负极极片的面积的百分比越高，低CB值区的面积越大，锂离子电池循环后负极极片上出现析锂现象的区域面积越大，在其他条件相同的情况下，锂离子电池的容量保持率将随着低CB值区对应的负极极片的面积占负极极片的面积的百分比增大而下降。但从实施例3和对比例1可以看出，尽管实施例3的低CB值区对应的负极极片的面积占负极极片的面积的百分比大于对比例1，但实施例3的容量保持率仍高于对比例，说明了金属离子对析锂和锂枝晶的有效抑制。另外，低CB值区对应的负极极片的面积占负极极片的面积的百分比越高的锂离子电池，循环后m1/m2越大，电解液中金属离子的含量C’越小。由此，说明低CB值区对应的负极极片的面积占负极极片的面积的百分比越高的锂离子电池中，更多的金属离子被锂还原成金属单质，再次验证了金属离子对析锂和锂枝晶的抑制效果。
根据实施例1、4-7的分析对比可知，低CB值区的CB值越小，单位面积的正极活性物质的容量超过单位面积的负极活性物质的容量越多，低CB值区对应的负极极片上析出的锂越多。在其他条件相同的情况下，可以看到
实施例4-7的容量保持率呈逐渐下降的趋势。由此，通过控制低CB值区的CB值在合适的范围内，能够降低CB值过小导致的电池严重析锂的概率。另外，低CB值区的CB值越小的锂离子电池，循环后m1/m2越大，电解液中金属离子的含量C’越小。再次验证了金属离子对析锂和锂枝晶的抑制效果。
根据实施例1、8-9的对比分析可知，电解液中的金属离子浓度越高，锂离子电池的自放电越大；电解液中金属离子的浓度过小(例如实施例8)，对锂枝晶的抑制作用有限。由此，说明通过控制电解液中金属离子的浓度在合适的范围内，有助于在抑制析锂和锂枝晶的同时，改善锂离子电池的自放 电。
实施例10中的金属离子是Al3+，由此，说明还原电位高于锂离子的金属离子均可以有效抑制锂枝晶。
以下对本申请实施例涉及的理化参数、性能参数的测试方法进行简单介绍。应理解，以下测试方法仅作为示例，也可以采用本领域公知的其他测试方法进行测试。
1.金属离子的还原电位的测试方法
金属离子的还原电位可以通过测量其与标准电极之间的电势差得到，也可以根据浓度和能斯特方程计算得到。示例性地，可以将待测金属或金属离子溶液、标准氢电极或锂电极分别作为对电极组成原电池，测试两个电极之间的电势差，从而得到金属离子的还原电位。
2.CB值的测试方法
取单位面积的正极极片、负极极片，表面用DMC清洗后，分别与锂片组装成正极或负极对锂的半电池，以0.04C电流充电/放电循环2圈，取第二圈的阴极的充电容量和阳极的放电容即及为单位面积的正极或负极的活性物质容量。CB值＝(单位面积负极活性物质的容量)/(单位面积正极活性物质的容量)。
3.摩尔浓度的测试方法
可以通过滴定法、电化学分析法、分光光度法、电感耦合等离子法等多种方法测定电解液中金属离子的摩尔浓度。
示例性地，ICP(Inductively coupled plasma，电感耦合等离子法)测试方法过程如下：采用王水(浓盐酸：浓硝酸＝3：1)或逆王水(浓硝酸：浓盐酸3：1)对待测样品进行消解后通过ICP测试仪进行元素含量。
4.负极极片中金属离子的含量的测试方法
取部分待测样品(负极极片)，通过ICP测试，直接测得目标元素在样品中的含量。
5.锂离子电池自放电的测试方法
使用蓝电测试系统，将锂离子电池以8mA恒流充电充电至3.8V；然后进行静置，静置时间T＝48h；静置前后的电池电压分别为V1和V2；K值(自放电率)的计算方法为(V1-V2)/T。
6.锂离子电池500圈容量保持率的测试方法
使用蓝电测试系统，首先对电池进行首圈充放电。
首圈充电指的是电池在化成后，先以60mA恒流充电到4.2V，再在4.2V下恒压充电到截止电流为2mA；首圈放电容量指的是电池在化成后以60mA恒流放电到电压为2.5V时电池放出的容量W1。
然后对电池进行充放电测试。测试过程为：以60mA恒流充电，截止电压为4.2V；在4.2V下恒压充电，截止电流为2mA；静置10分钟后，以60mA恒流放电，截止电压2.5V，然后循环500圈后再充电至4.2V测试停止。循环500圈后的放电容量为W2。锂离子电池500圈容量保持率为W2/W1×100％。
虽然已经参考优选实施例对本申请进行了描述，但在不脱离本申请的范围的情况下，可以对其进行各种改进并且可以用等效物替换其中的部件。尤其是，只要不存在结构冲突，各个实施例中所提到的各项技术特征均可以任意方式组合起来。本申请并不局限于文中公开的特定实施例，而是包括落入权利要求的范围内的所有技术方案。

Claims (14)

  1. 一种锂离子电池，其特征在于，所述锂离子电池包括：
    电解液，所述电解液包括金属离子，所述金属离子还原电位高于锂离子的还原电位；
    低CB值区；
    所述锂离子电池在所述低CB值区的CB值满足：0＜CB＜1，所述CB值为单位面积的负极活性物质的容量与单位面积的正极活性物质的容量的比值。
  2. 根据权利要求1所述的锂离子电池，其特征在于，所述锂离子电池包括：
    负极极片，所述低CB值区对应的负极极片的面积占所述负极极片的面积的百分比X满足：0％＜X；可选地，0％＜X≤10％；可选地，0％＜X≤2％。
  3. 根据权利要求1或2所述的锂离子电池，其特征在于，所述锂离子电池在所述低CB值区处的CB值满足：0.5＜CB＜1。
  4. 根据权利要求1-3中任一项所述的锂离子电池，其特征在于，所述金属离子的还原电位满足：
    其中，Mn+代表所述金属离子，n代表所述金属离子的化合价，C代表所述金属离子在所述电解液中的摩尔浓度，R代表理想气体常数，T代表温度，F代表法拉第常数，代表锂离子的标准电极电势。
  5. 根据权利要求1-4中任一项所述的锂离子电池，其特征在于，所述金属离子的还原电位满足：
  6. 根据权利要求1-5中任一项所述的锂离子电池，其特征在于，所述金属离子在所述电解液中的摩尔浓度C满足：0.001M≤C≤0.2M。
  7. 根据权利要求1-6中任一项所述的锂离子电池，其特征在于，所述金属离子包括Mg2+、Al3+、Zn2+、Sb2+中的至少一种。
  8. 一种锂离子电池，其特征在于，所述锂离子电池包括：
    低CB值区，所述锂离子电池在所述低CB值区的CB值满足：0＜CB＜1；
    负极极片，所述低CB值区对应的所述负极极片处单位面积内的金属元素的含量大于高CB值区对应的所述负极极片处单位面积内的所述金属元素 的含量；
    其中，所述锂离子电池在所述高CB值区的CB值满足：CB≥1；所述CB值为单位面积的负极活性物质的容量与单位面积的正极活性物质的容量的比值；所述金属元素对应的金属离子的还原电位高于锂离子的还原电位。
  9. 根据权利要求8所述的锂离子电池，其特征在于，所述低CB值区对应的所述负极极片的面积占所述负极极片的面积的百分比X满足：0％＜X；可选地，0％＜X≤10％；可选地，0％＜X≤2％。
  10. 根据权利要求8或9所述的锂离子电池，其特征在于，所述锂离子电池在所述低CB值区处的CB值满足：0.5＜CB＜1。
  11. 根据权利要求8-10中任一项所述的锂离子电池，其特征在于，所述金属元素包括Mg、Al、Zn、Sb中的至少一种。
  12. 根据权利要求8-11中任一项所述的锂离子电池，其特征在于，所述锂离子电池包括：
    电解液，所述电解液包括金属离子，所述金属离子为所述金属元素对应的离子。
  13. 根据权利要求12所述的锂离子电池，其特征在于，所述金属离子在所述电解液中的摩尔浓度C’满足：0≤C’＜0.2M。
  14. 一种用电装置，其特征在于，所述用电装置包括如权利要求1-7中任一项所述的锂离子电池，和/或如权利要求8-13中任一项所述的锂离子电池。
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