WO2025199689A1 - 二次电池以及电子装置 - Google Patents

二次电池以及电子装置

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Publication number
WO2025199689A1
WO2025199689A1 PCT/CN2024/083599 CN2024083599W WO2025199689A1 WO 2025199689 A1 WO2025199689 A1 WO 2025199689A1 CN 2024083599 W CN2024083599 W CN 2024083599W WO 2025199689 A1 WO2025199689 A1 WO 2025199689A1
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WO
WIPO (PCT)
Prior art keywords
secondary battery
positive electrode
electrolyte
lithium
substance
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.)
Pending
Application number
PCT/CN2024/083599
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English (en)
French (fr)
Inventor
王美茸
周邵云
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.)
Ningde Amperex Technology Ltd
Original Assignee
Ningde Amperex Technology 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 Ningde Amperex Technology Ltd filed Critical Ningde Amperex Technology Ltd
Priority to PCT/CN2024/083599 priority Critical patent/WO2025199689A1/zh
Publication of WO2025199689A1 publication Critical patent/WO2025199689A1/zh
Anticipated expiration legal-status Critical
Pending legal-status Critical Current

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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
    • H01M10/052—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
    • 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
    • H01M10/0569—Liquid materials characterised by the solvents
    • 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 belongs to the field of battery technology, and specifically relates to a secondary battery and an electronic device.
  • Secondary batteries as rechargeable energy storage devices, are widely used in electronic devices such as mobile phones, laptops, and cameras. There is a growing demand for improved performance in secondary batteries, including power, lifespan, and safety. As a key component of secondary batteries, the electrolyte directly impacts their performance.
  • electrolytes typically utilize a mixture of organic solvents and lithium salts.
  • deficiencies in ionic conductivity, stability, and fluidity can lead to issues such as poor cycling performance.
  • some existing technologies propose adjusting the electrolyte formulation to improve it, this process can also lead to poor compatibility between components, which can reduce the safety and performance of secondary batteries. Therefore, it is necessary to comprehensively consider the advantages and disadvantages of electrolyte improvements to further enhance the cycling performance of secondary batteries.
  • the present application provides a secondary battery that can exhibit better cycle performance while also taking into account higher storage performance.
  • the present application also provides an electronic device including the secondary battery.
  • the present application provides a secondary battery comprising a positive electrode plate and an electrolyte, wherein the electrolyte comprises a carboxylate compound and lithium difluorophosphate; the carboxylate compound comprises at least one of the molecular formula R1COOR2 , wherein R1 and R2 are each independently selected from a C1 to C6 alkyl group or a halogenated alkyl group; based on the electrolyte, the mass content of the carboxylate compound is a%, and the mass content of the lithium difluorophosphate is b%.
  • the value range of b is 2 ⁇ b ⁇ 8.8, and a and b satisfy the relationship: 6 ⁇ a/b ⁇ 28.
  • the present application adopts lithium difluorophosphate and carboxylate compounds to work closely together.
  • the stability of lithium difluorophosphate in the electrolyte can be improved by the appropriate content of carboxylate compounds, making high-concentration lithium difluorophosphate possible.
  • high concentrations of lithium difluorophosphate can promote the formation of stable CEI and SEI to inhibit the decomposition of carboxylate compounds, and prevent the excessive content of carboxylate compounds from causing deterioration of the performance of the secondary battery due to its own insufficient stability.
  • the carboxylate compound can also reduce or avoid the effect of high concentrations of lithium difluorophosphate on the electrolyte dynamics due to low conductivity.
  • the present application controls the content relationship so that the two interact with each other, which can not only ensure that lithium difluorophosphate is completely dissolved, but also improve the defect of insufficient stability of the carboxylate compound, while balancing the dynamics of the entire battery system, thereby improving the cycle performance and high-temperature storage performance of the secondary battery.
  • the carboxylate compound includes at least one of methyl formate, methyl acetate, methyl propionate, methyl butyrate, ethyl formate, ethyl acetate, ethyl propionate, ethyl butyrate, propyl formate, propyl acetate, propyl propionate, propyl butyrate, or ethyl fluoroacetate.
  • the carboxylate compound is selected from at least one of methyl formate, ethyl formate, methyl acetate, or ethyl acetate. These carboxylate compounds can ensure that high-concentration lithium difluorophosphate is fully dissolved. When combined with lithium difluorophosphate, they can further improve the stability of lithium difluorophosphate, resulting in a secondary battery with better cycle performance and high-temperature storage performance.
  • the value range of b is 2 ⁇ b ⁇ 7.5.
  • a and b satisfy the relationship: 6 ⁇ a/b ⁇ 15, for example, a and b satisfy the relationship: 7 ⁇ a/b ⁇ 15; further, a and b satisfy the relationship: 6 ⁇ a/b ⁇ 13.64.
  • the positive electrode plate includes a positive electrode material, the specific surface area of the positive electrode material is cm 2 /g, and the value range of c is 0.2 ⁇ c ⁇ 1.0.
  • the electrolyte further includes a first substance; the first substance includes at least one of 1,3-propane sultone, 1,3-propylene sultone, vinyl sulfate, 1,3-propylene glycol sulfate, 2,4-butane sultone, 1,4-butane sultone, vinylene carbonate, and fluoroethylene carbonate.
  • the present application introduces the first substance to synergize with lithium difluorophosphate to enhance the stability of the SEI/CEI, further improving the battery's cycling performance.
  • the mass content of the second substance is y%, based on the electrolyte, where y is in the range of 0.05 ⁇ y ⁇ 8, and 2.05 ⁇ (y + b) ⁇ 16.6.
  • the present application further provides an electronic device comprising any of the aforementioned secondary batteries.
  • the secondary battery provided herein has low impedance, good low-temperature cycling performance, and high-temperature storage performance, thereby providing the electronic device with a long service life and good performance.
  • a carboxylate compound is used to cooperate with lithium difluorophosphate to promote the formation of an excellent interface film through lithium difluorophosphate, thereby reducing or avoiding the carboxylate compound from being unstable due to its own
  • the poor performance of the positive and negative electrode materials will produce side reactions, while the carboxylate compound can improve the stability of lithium difluorophosphate in the electrolyte, promote the dissolution of lithium difluorophosphate and prevent precipitation.
  • the present application controls the content relationship of the carboxylate compound and lithium difluorophosphate so that the two complement each other and work closely together to improve the circulation and high temperature storage performance of the secondary battery.
  • any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, and similarly, any upper limit can be combined with any other upper limit to form an unspecified range.
  • each point or individual value between the endpoints of a range is included in the range.
  • each point or individual value can serve as its own lower limit or upper limit and be combined with any other point or individual value, or with other lower limits or upper limits, to form an unspecified range.
  • the terms “include” and “comprising” mentioned in this application may be open-ended or closed-ended.
  • the terms “include” and “comprising” may mean that other components not listed may also be included or that only the listed components are included.
  • the present application provides a secondary battery in a first aspect, comprising a positive electrode and an electrolyte, wherein the electrolyte comprises a carboxylate compound and lithium difluorophosphate; the carboxylate compound comprises a molecular formula of R 1 COOR 2 to At least one, wherein R 1 and R 2 are each independently selected from an alkyl group or a halogenated alkyl group ranging from C 1 to C 6 ; based on the electrolyte, the mass content of the carboxylate compound is a%, and the mass content of the lithium difluorophosphate is b%; wherein the value range of b is 2 ⁇ b ⁇ 8.8, and a and b satisfy the relationship: 6 ⁇ a/b ⁇ 28.
  • the electrolyte of the present application adopts a carboxylate compound and lithium difluorophosphate (LiPO 2 F 2) to cooperate to improve the solubility and stability of lithium difluorophosphate in the electrolyte solvent system, breaking through the 1% mass content limit of lithium difluorophosphate in the electrolyte solvent system, making it possible to use high-concentration lithium difluorophosphate in the electrolyte.
  • LiPO 2 F 2 F 2 lithium difluorophosphate
  • the high-concentration lithium difluorophosphate in the present application can promote the formation of an excellent interface film, can reduce the side reactions between the carboxylate compound and the positive and negative electrodes, and the cooperation between the two can further improve the cycle, storage and other performances of the secondary battery.
  • the alkyl group can be selected from a C 1 to C 6 chain alkyl group or a cyclic alkyl group;
  • the haloalkyl group can be selected from a C 1 to C 6 chain alkyl group or a cyclic alkyl group substituted by any one of a halogen atom, a F atom, a Cl atom, a Br atom, and an I atom.
  • the mass content of lithium difluorophosphate is b%
  • the value range of b is 2 ⁇ b ⁇ 8.8, and a and b satisfy the relationship: 6 ⁇ a/b ⁇ 28.
  • b can be selected from 2, 2.5, 3, 3.5, 4, 4.4, 5, 5.8, 6, 6.6, 7, 7.5, 8, 8.6, 8.8, or a range consisting of any two of the above values
  • a/b can be selected from 6, 6.67, 6.98, 7, 8, 9.09, 9.5, 10, 10.34, 12, 13.5, 13.64, 14, 15, 16, 17.5, 18, 20, 21, 22, 24, 26, 28, or a range consisting of any two of the above values.
  • the carboxylate compound includes at least one of methyl formate (MF), methyl acetate (MA), methyl propionate (MP), methyl butyrate (MB), ethyl formate (EF), ethyl acetate (EA), ethyl propionate (EP), ethyl butyrate (EB), propyl formate, propyl acetate, propyl propionate, propyl butyrate or ethyl fluoroacetate.
  • MF methyl formate
  • MA methyl acetate
  • MP methyl propionate
  • MB methyl butyrate
  • EF ethyl formate
  • EA ethyl acetate
  • EP ethyl propionate
  • EB ethyl butyrate
  • the above-mentioned carboxylate compound has a relatively high DN number, and after being combined with lithium difluorophosphate, it can significantly enhance the solubility and stability of the latter in the electrolyte, thereby increasing the application mass concentration of lithium difluorophosphate in the electrolyte, and then exerting a gain effect on the performance of the secondary battery.
  • ethyl acetate has good wettability and excellent power, but ethyl acetate has a poor adhesion to the positive and negative electrodes.
  • the reaction is not as good as that of carbonate, which leads to the impairment of high temperature and cycle performance of secondary batteries.
  • Lithium difluorophosphate can form an excellent interfacial film, which can improve these defects of ethyl acetate.
  • Lithium difluorophosphate has low solubility in carbonate solvents, but has a higher solubility in ethyl acetate due to its higher DN number. It can cooperate with high-concentration lithium difluorophosphate to overcome the problems between them, solving the problem of secondary battery wetting difficulties while improving the cycle and high-temperature storage performance.
  • the mass content of the carboxylate compound is a%, and the value range of a is 12 ⁇ a ⁇ 60.
  • a can be selected from 12, 19, 27, 35, 42, 56, 60 or a range consisting of any two of the above values.
  • the electrolyte further includes a first substance; the first substance includes at least one of 1,3-propane sultone (1,3-PS), 1,3-propylene sultone, vinyl sulfate, 1,3-propylene glycol sulfate, 2,4-butane sultone, 1,4-butane sultone (1,4-BS), vinylene carbonate (VC), and fluoroethylene carbonate (FEC).
  • 1,3-propane sultone 1,3-PS
  • 1,3-propylene sultone vinyl sulfate
  • 1,3-propylene glycol sulfate 1,3-propylene glycol sulfate
  • VC vinylene carbonate
  • FEC fluoroethylene carbonate
  • the mass content of the first substance is x%, where x is in the range of 0.05 ⁇ x ⁇ 12, and 2.05 ⁇ (x + b) ⁇ 20.8.
  • x can be selected from 0.05, 2, 3, 5, 8, 10, 12, or a range consisting of any two of the above values; and x + b can be selected from 2.05, 4.43, 6.4, 7.4, 8.85, 14.4, 16.4, 17.8, 18.7, 19.5, 19.9, 20.8, or a range consisting of any two of the above values.
  • the electrolyte further includes a second substance; the second substance includes at least one of lithium bis(oxalatoborate) (LiBOB), lithium tetrafluoroborate (LiBF 4 ), lithium difluorooxalatoborate (LiDFOB), lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium trifluoromethanesulfonate (LiCF 3 SO 3 ), lithium 4,5-dicyano-2-(trifluoromethyl)isopyrazole (LiTDI), and lithium tetraborate (Li 2 B 4 O 7 ).
  • LiBOB lithium bis(oxalatoborate)
  • LiBF 4 lithium tetrafluoroborate
  • LiDFOB lithium difluorooxalatoborate
  • LiFSI lithium bis(fluorosulfonyl)imide
  • the mass content of the second substance is y%, based on the electrolyte, and the value range of y is 0.05 ⁇ y ⁇ 8, and 2.05 ⁇ (y+b) ⁇ 16.6.
  • y can be selected from 0.05, 0.10, 0.20, 0.60, 1.20, 1.80, 2, 4, 6, 8, or a range consisting of any two of the above values;
  • y+b can be selected from 2.05, 4.42, 4.45, 4.5, 4.6, 5, 5.6, 6.2, 9.3, 10.3, 10.5, 11.4, 11.5, 12.4, 15.6, 16.6 or a range consisting of any two of the above values.
  • the electrolyte also includes a non-aqueous solvent.
  • a non-aqueous solvent may include but is not limited to at least one of a carbonate compound and an ether compound.
  • the above-mentioned carbonate compound may include but is not limited to at least one of a chain carbonate compound, a cyclic carbonate compound, and a fluorinated carbonate compound.
  • the above-mentioned chain carbonate compound may include but is not limited to at least one of dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC) or methylethyl carbonate (MEC).
  • Cyclic carbonate may include but is not limited to at least one of ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC) or vinylethylene carbonate (VEC).
  • the fluorinated carbonate compound may include, but is not limited to, at least one of fluoroethylene carbonate (FEC), 1,2-difluoroethylene carbonate, 1,1-difluoroethylene carbonate, 1,1,2-trifluoroethylene carbonate, 1,1,2-tetrafluoroethylene carbonate, 1-fluoro-2-methylethylene carbonate, 1-fluoro-1-methylethylene carbonate, 1,2-difluoro-1-methylethylene carbonate, 1,1,2-trifluoro-2-methylethylene carbonate, or trifluoromethylethylene carbonate.
  • FEC fluoroethylene carbonate
  • the above-mentioned ether compound may include, but is not limited to, at least one of dibutyl ether, tetraethylene glycol dimethyl ether, diethylene glycol dimethyl ether, 1,2-dimethoxyethane, 1,2-diethoxyethane, ethoxymethoxyethane, 2-methyltetrahydrofuran, or tetrahydrofuran.
  • the preparation process of the electrolyte in this application is well known to those skilled in the art and is not particularly limited in this application.
  • it may include but is not limited to the following steps: in an argon atmosphere glove box with a water content of ⁇ 10ppm, lithium difluorophosphate, a carboxylate compound and a sufficiently dried lithium salt LiPF6 are added to a non-aqueous solvent in a mass ratio for dissolution treatment to prepare the electrolyte in this application.
  • the first substance and/or the second substance may also be added to the non-aqueous solvent to prepare the electrolyte in some embodiments of this application.
  • This application does not particularly limit the order of adding lithium difluorophosphate, the carboxylate compound, the lithium salt LiPF6 , the first substance and the second substance, and can be selected according to actual needs, as long as the purpose of this application can be achieved.
  • the positive electrode sheet in the present application includes a positive electrode material, the specific surface area of the positive electrode material is cm 2 /g; the value range of c is 0.2 ⁇ c ⁇ 1.0, for example, c can be selected from 0.2, 0.4, 0.5, 0.6, 0.8, 1.0 or a range consisting of any two of the above values.
  • the inventors of the present application have found that as the specific surface area of the positive electrode material increases, the capacity, cycle and storage performance of the secondary battery will decline. The reason may be that there are residual alkali impurities on the surface of the positive electrode material. The decomposition of the residual alkali during the service of the battery will cause deterioration of the performance.
  • the positive electrode material refers to the substance disposed on the surface of the positive electrode current collector, which may include but is not limited to the positive electrode active material, the positive electrode conductive agent, and the positive electrode binder.
  • the positive electrode material can be disposed on one surface of the positive electrode current collector along its own thickness direction, or on two surfaces of the positive electrode current collector along its thickness direction.
  • the "surface” here can be the entire area of the positive electrode current collector or a partial area of the positive electrode current collector. This application is not particularly limited, as long as the purpose of this application can be achieved.
  • the positive electrode material includes a ternary material, and the ternary material includes manganese and/or aluminum.
  • the ternary material with a high nickel content comes into contact with air, the residual alkali content on its surface will increase.
  • the high residual alkali content will not only cause the processing performance of the ternary material to drop sharply, but also significantly deteriorate the cycle performance of the secondary battery.
  • the ternary material of the present application is combined with a carboxylate compound and lithium difluorophosphate, it can reduce or avoid the impact of residual alkali on the performance of the secondary battery, give full play to the advantages of the ternary material with high specific capacity, low cost and good safety performance, and ensure the excellent capacity, cycle and storage performance of the secondary battery.
  • cathode materials with different specific surface areas can be obtained by mechanical crushing, grinding, screening, etc.
  • cathode materials with different specific surface areas can be obtained by ball milling during mechanical crushing. Generally, extending the ball milling time increases the specific surface area, while shortening the ball milling time decreases the specific surface area.
  • the positive electrode sheet of the present application may further include a positive electrode current collector.
  • the present application has no particular limitation on the positive electrode current collector, as long as it can achieve the purpose of the present application.
  • it may include but is not limited to aluminum foil, aluminum alloy foil, or a composite current collector (e.g., an aluminum-carbon composite current collector).
  • the positive electrode material may also include a positive electrode conductor and a positive electrode binder.
  • This application does not specifically limit the types of the positive electrode conductor and the positive electrode binder, as long as the objectives of this application can be achieved.
  • the positive electrode binder may include, but is not limited to, at least one of polyvinyl alcohol, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, an ethylene oxide-containing polymer, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin, or nylon.
  • the present application has no particular restrictions on the negative electrode current collector, as long as the purpose of the present application can be achieved.
  • the negative electrode current collector may include but is not limited to copper foil, copper alloy foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam or composite current collector (such as carbon copper composite current collector, nickel copper composite current collector, titanium copper composite current collector, etc.).
  • the thickness of the negative electrode current collector and the negative electrode material layer as long as the purpose of the present application can be achieved, for example, the thickness of the negative electrode current collector is 6 ⁇ m to 12 ⁇ m, and the thickness of the negative electrode material layer is 30 ⁇ m to 130 ⁇ m.
  • the thickness of the negative electrode pole piece is 50 ⁇ m to 280 ⁇ m.
  • the negative electrode material layer of the present application includes a negative electrode active material, which may include but is not limited to at least one of graphite, mesophase microcarbon beads (MCMB), hard carbon, soft carbon, silicon, silicon-carbon composite, SiO x (0.5 ⁇ x ⁇ 1.6), Li Sn alloy, Li Sn O alloy, Sn, SnO, SnO 2 , spinel-structured lithium titanate TiO 2 Li 4 Ti 5 O 12 , Li Al alloy and metallic lithium.
  • MCMB mesophase microcarbon beads
  • the negative electrode material layer in the present application may further include a negative electrode binder and a negative electrode conductor, or the negative electrode material layer may further include a negative electrode binder, a negative electrode conductor and a thickener.
  • the present application has no particular restrictions on the types of negative electrode binders and negative electrode conductors, as long as the purpose of the present application can be achieved.
  • the negative electrode binder may include but is not limited to at least one of the above-mentioned positive electrode binders
  • the negative electrode conductor may include but is not limited to at least one of the above-mentioned positive electrode conductors.
  • the present application has no particular restrictions on the type of thickener, as long as the purpose of the present application can be achieved.
  • the thickener may include but is not limited to at least one of sodium carboxymethyl cellulose or carboxymethyl cellulose.
  • the material of the isolation membrane may include but is not limited to polyethylene (PE), polypropylene (PP)-based polyolefins (PO), polyester (such as polyethylene terephthalate (PET) film), cellulose, polyimide (PI), polyamide (PA), spandex or aramid at least one;
  • the type of isolation membrane may include woven membrane, non-woven membrane, microporous membrane, composite membrane, rolled membrane or spun membrane at least one.
  • the isolation membrane may include a substrate layer and a surface treatment layer.
  • the substrate layer may be a non-woven fabric, membrane or composite membrane with a porous structure, and the material of the substrate layer may include at least one of polyethylene, polypropylene, polyethylene terephthalate or polyimide. Any Selected, polypropylene porous film, polyethylene porous film, polypropylene non-woven fabric, polyethylene non-woven fabric or polypropylene polyethylene polypropylene porous composite film can be used.
  • a surface treatment layer is provided on at least one surface of the substrate layer, and the surface treatment layer can be a polymer layer or an inorganic layer, or a layer formed by a mixed polymer and an inorganic substance.
  • the inorganic layer includes inorganic particles and a binder
  • the present application has no particular restrictions on the inorganic particles, for example, it can include at least one of aluminum oxide, silicon oxide, magnesium oxide, titanium oxide, hafnium dioxide, tin oxide, cerium dioxide, nickel oxide, zinc oxide, calcium oxide, zirconium oxide, yttrium oxide, silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide or barium sulfate.
  • the present application has no particular restrictions on the binder, for example, it can be at least one of the above-mentioned positive electrode binders.
  • the polymer layer contains a polymer, and the present application has no particular restrictions on the polymer, for example, the polymer includes at least one of polyamide, polyacrylonitrile, acrylate polymer, polyacrylic acid, polyacrylate, polyvinyl pyrrolidone, polyvinyl ether or polyvinylidene fluoride or poly (vinylidene fluoride hexafluoropropylene).
  • the thickness of the isolation film there is no particular limitation on the thickness of the isolation film, as long as the purpose of the present application can be achieved.
  • the thickness of the isolation film can be 5 ⁇ m to 500 ⁇ m.
  • the secondary battery of this application also includes a packaging bag for containing the positive electrode sheet, separator, negative electrode sheet, and electrolyte, as well as other components of secondary batteries known in the art.
  • a packaging bag for containing the positive electrode sheet, separator, negative electrode sheet, and electrolyte, as well as other components of secondary batteries known in the art.
  • This application does not particularly limit these other components.
  • This application does not particularly limit the packaging bag and can be any packaging bag known in the art, as long as it can achieve the purpose of this application. For example, an aluminum-plastic film packaging bag can be used.
  • the preparation process of a secondary battery is well known to those skilled in the art and is not particularly limited in this application.
  • it may include but is not limited to the following steps: stacking the positive electrode sheet, the separator, and the negative electrode sheet in order, and winding, folding, and other operations as needed to obtain an electrode assembly with a wound structure, placing the electrode assembly in a packaging bag, injecting an electrolyte into the packaging bag and sealing it to obtain a secondary battery; or stacking the positive electrode sheet, the separator, and the negative electrode sheet in order, and then fixing the four corners of the entire stacked structure with tape to obtain an electrode assembly with a stacked structure, placing the electrode assembly in a packaging bag, injecting an electrolyte into the packaging bag and sealing it to obtain a secondary battery.
  • overcurrent protection elements, guide plates, etc. may be placed in the packaging bag to prevent pressure rise and overcharging and discharging inside the secondary battery.
  • the present application provides an electronic device in a second aspect, which includes the secondary battery provided in the first aspect of the present application.
  • the electronic device of the present application is not particularly limited and can be any electronic device known in the art.
  • the electronic device can include, but is not limited to, a laptop computer, a pen-type computer, a mobile computer, an electronic book player, a portable phone, a portable fax machine, a portable copier, a portable printer, a headset, a video recorder, an LCD television, a portable cleaner, a portable CD player, a mini-disc, a transceiver, an electronic notepad, a calculator, a memory card, a portable recorder, a radio, a backup power supply, a motor, an automobile, a motorcycle, a power-assisted bicycle, a bicycle, a lighting fixture, a toy, a game console, a clock, a power tool, a flashlight, a camera, a large household battery, and a lithium-ion capacitor.
  • the surface area of the cathode material was measured using a Tristar II 3020M surface area analyzer using nitrogen adsorption. This testing was conducted in accordance with the national standard GB/T 19587-2017, "Determination of the Specific Surface Area of Solids by the BET Method for Gas Adsorption.”
  • Cycling performance test method At 25°C, charge the battery to 4.28V at 1C, charge it to 0.05C at a constant voltage at 4.28V, and then discharge it to 2.5V at 1C. Cycle this way for 800 cycles, and record the cycle capacity retention rate after 800 cycles.
  • 50% SOC impedance test discharge the battery to 2.5V at 0.5C current at 25°C and let it stand 5 minutes, then charge at 0.5C to 4.28V, constant voltage at 4.28V to 0.025C. Let it rest for 5 minutes, then discharge at 0.1C to 2.5V, marking the capacity released at this time as C 1 . Charge to 4.28V with 0.5C 1 , constant voltage at 4.28V to 0.025C 1 , let it rest for 5 minutes, then discharge at 0.1C 1 for 5 hours, marking the battery voltage at this time as V 1 . Then discharge at 1C for 1 second, and record the voltage at the end of discharge as V 2 .
  • the 50% SOC impedance calculation formula is: (V 1 -V 2 )/(1C - 0.1C 1 ).
  • NCM613 active material
  • Super-P conductive agent Super-P conductive agent
  • PVDF polyvinylidene fluoride binder
  • NMP N-methylpyrrolidone
  • This slurry was applied to an Al foil positive electrode current collector, dried, and cold-pressed to produce a positive electrode sheet.
  • the resulting positive electrode sheet had a manganese content (d%) of 10% by molarity, based on the molar content of metal elements other than lithium in the positive electrode material.
  • the positive electrode material included NCM613, a positive conductive agent, and a positive binder.
  • a single-layer PE porous polymer film is used as the separator, with a thickness of 16 microns and a porosity of 39%.
  • the inorganic coating is Al 2 O 3
  • the organic particles are polyvinylidene fluoride.
  • the formation process is as follows: at 45 ⁇ 5°C, perform the first cycle of charge and discharge, and the process is as follows: first, charge at a constant current rate of 0.1C for 10 minutes, then charge at a constant current rate of 0.5C to a specified voltage of 4.3V, then charge at a constant voltage until the current is less than or equal to 0.05C, and then discharge at a constant current rate of 0.5C to 2.5V.
  • the secondary batteries of Examples I-2 to I-14 and Comparative Examples I-1 to I-8 differ from Example I-1 only in the mass content of lithium difluorophosphate and the type and/or mass content of the carboxylate compound.
  • the specific differences and performance test results are shown in Table 1 below.
  • Examples I-1 to I-6 of the present application on the basis of adding 2 wt % of lithium difluorophosphate, control the mass content a% of the carboxylate compound and the mass content b% of lithium difluorophosphate to satisfy the mathematical relationship: 6 ⁇ a/b ⁇ 28. Compared with Comparative Examples I-1 to I-5, they can show a higher 25°C cycle retention rate and a lower 60°C storage thickness expansion rate while maintaining a good 50% SOCDCR performance, and have more excellent cycle performance and high temperature storage performance.
  • the present application controls the mass content of lithium difluorophosphate to 2-8.8%, and after combining with ethyl acetate, the secondary battery can have even better cycle performance and high-temperature storage performance.
  • Examples I-1 to I-14 that the present application uses lithium difluorophosphate and carboxylate compounds in close combination to promote the formation of stable CEI and SEI, which can improve the cycle performance and high-temperature storage performance of the secondary battery.
  • the secondary batteries of Examples II-1 to II-9 differ from Example I-8 only in the mass content of lithium difluorophosphate and/or the specific surface area of the positive electrode material.
  • the specific differences and performance test results are shown in Table 2 below.
  • the specific surface area c of the positive electrode material is further controlled to ensure 3 ⁇ c/b ⁇ 45.
  • the 50% SOC DCR performance of the secondary battery can be reduced, and the secondary battery performance can be improved. 25°C, 800 cycle retention rate and 60°C high temperature storage performance.
  • the secondary batteries of Examples III-1 to III-12 differ from those of Example I-8 only in that the electrolyte further includes a first substance, and the mass content of lithium difluorophosphate and/or the type and content of the first substance are different.
  • the specific differences and performance test results are shown in Table 3 below.
  • the carboxylate compound and lithium difluorophosphate are On the basis of the combination, controlling the content of the added first substance and lithium difluorophosphate to satisfy the relationship of 2.05 ⁇ (x+b) ⁇ 20.8 is beneficial to improving the cycle performance and high-temperature storage performance of the secondary battery. Further preferably, in the embodiment of the present application, the content of the added first substance and lithium difluorophosphate is controlled to satisfy the relationship of 7.4 ⁇ (x+b) ⁇ 19.5, which can promote the synergistic cooperation between lithium difluorophosphate and the first substance, thereby further improving the cycle performance and high-temperature storage performance of the secondary battery.
  • Example III-3 shows that the type of the first substance also affects the impedance, cycling performance, and storage performance of the secondary battery.
  • the present application effectively improves the cycling performance and high-temperature storage performance of the secondary battery by combining the first substance with lithium difluorophosphate.
  • the secondary batteries of Examples IV-1 to IV-11 differ from those of Example I-8 only in that the electrolyte further includes a second substance, and the mass content of lithium difluorophosphate and/or the type and content of the second substance are different.
  • the specific differences and performance test results are shown in Table 4 below.
  • the type and content of the second substance will affect the cycle performance and high-temperature storage performance of the secondary battery.
  • the content of the added second substance is controlled to satisfy the relationship 2.05 ⁇ (y+b) ⁇ 16.6 with the lithium difluorophosphate, which can improve the cycle performance and high-temperature storage performance of the secondary battery.

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Abstract

一种二次电池以及电子装置，属于电池技术领域。二次电池，包括正极极片和电解液，该电解液包括羧酸酯化合物和二氟磷酸锂；该羧酸酯化合物包括分子式为R 1COOR 2的化合物中的至少一种，其中R 1和R 2各自独立地选自C 1至C 6的烷基或卤代烷基；以电解液为基准，羧酸酯化合物的质量含量为a％，该二氟磷酸锂的质量含量为b％，2≤b≤8.8，6≤a/b≤28。通过二氟磷酸锂与羧酸酯化合物紧密配合，提高二次电池的循环性能和高温储存性能。

Description

二次电池以及电子装置 技术领域
本申请属于电池技术领域，具体涉及一种二次电池以及电子装置。
背景技术
二次电池作为可充电的储能设备，被广泛应用于手机、笔记本、相机等电子设备中。二次电池的功率、寿命和安全等性能始终有持续增长的需求，电解液作为二次电池中的关键组成部分，直接影响着电池的各项性能指标。
现有技术中，电解液通常采用有机溶剂和锂盐的混合物，然而现有电解液的离子传导性、稳定性和流动性等方面的不足可能会带来循环性能差等问题。有现有技术提出调整电解液配方进行改进，但是改进过程中也容易出现各组分兼容性差的问题，进而导致二次电池的安全性能等降低。因此需要综合考虑电解液改进存在的优势和问题，以进一步提升二次电池的循环性能。
发明内容
有鉴于此，本申请提供了一种二次电池，能够表现出更好的循环性能，同时还兼顾较高的储存性能。本申请另一方面还提供了包括该二次电池的电子装置。
第一方面，本申请提供了一种二次电池，包括正极极片和电解液，该电解液包括羧酸酯化合物和二氟磷酸锂；所述羧酸酯化合物包括分子式为R1COOR2中的至少一种，其中R1和R2各自独立地选自C1至C6的烷基或卤代烷基；以电解液为基准，羧酸酯化合物的质量含量为a％，二氟磷酸锂的质量含量为b％； 其中，b的取值范围为2≤b≤8.8，a和b满足关系：6≤a/b≤28。本申请采用二氟磷酸锂与羧酸酯化合物紧密配合，通过合适的羧酸酯化合物含量能够提高二氟磷酸锂在电解液中的稳定性，使得高浓度二氟磷酸锂成为可能。同时高浓度的二氟磷酸锂能够促进形成稳定的CEI和SEI抑制羧酸酯化合物的分解，防止羧酸酯化合物含量过高由于其自身稳定性不足对二次电池的性能造成恶化，另一方面羧酸酯化合物也能够减少或避免高浓度二氟磷酸锂因电导率低对电解液动力学的影响。本申请控制含量关系使二者相互作用，既可以保证二氟磷酸锂完全溶解，又可以改善羧酸酯化合物的稳定性不足的缺陷，同时平衡整个电池体系的动力学，从而提高二次电池的循环性能和高温储存性能。
在一些实施方式中，羧酸酯化合物包括甲酸甲酯、乙酸甲酯、丙酸甲酯、丁酸甲酯、甲酸乙酯、乙酸乙酯、丙酸乙酯、丁酸乙酯、甲酸丙酯、乙酸丙酯、丙酸丙酯、丁酸丙酯或氟代乙酸乙酯中的至少一种。
进一步地，羧酸酯化合物选自甲酸甲酯、甲酸乙酯、乙酸甲酯或乙酸乙酯中的至少一种。这些羧酸酯化合物能够保证高浓度二氟磷酸锂充分溶解，与二氟磷酸锂配合后能够进一步提高二氟磷酸锂的稳定性，使二次电池表现出更优的循环性能和高温储存性能。
在一些实施方式中，a的取值范围为12≤a≤60。
进一步地，b的取值范围为2≤b≤7.5。
在一些优选实施方式中，a和b满足关系：6≤a/b≤15，例如a和b满足关系：7≤a/b≤15；更进一步地，a和b满足关系：6≤a/b≤13.64。
在一些实施方式中，正极极片包括正极材料，正极材料的比表面积为cm2/g；c的取值范围为0.2≤c≤1.0。
在一些实施方式中，c和b满足关系：3≤c/b≤45。
在一些实施方式中，正极材料包括三元材料，三元材料包括锰元素和/或铝元素。
在一些实施方式中，基于正极材料中除Li元素以外的金属元素的摩尔量，所述锰元素和/或铝元素的摩尔含量为d，d的取值范围为5％≤d≤35％。例如，基于正极材料中除Li元素以外的金属元素的摩尔量，所述锰元素和/或铝元素的摩尔含量为1/20至1/3。
在一些实施方式中，电解液还包括第一物质；第一物质包括1,3-丙烷磺内酯、1,3-丙烯磺酸内酯、硫酸乙烯酯、1,3丙二醇硫酸酯、2,4-丁磺内酯、1,4-丁烷磺内酯、碳酸亚乙烯酯、氟代碳酸乙烯酯中的至少一种。本申请在二氟磷酸锂与羧酸酯化合物配合的基础上，引入第一物质与二氟磷酸锂协同配合，增强SEI/CEI的稳定性，能够进一步提升电池的循环性能。
在一些实施方式中，以电解液为基准，第一物质的质量含量为x％，x的取值范围为0.05≤x≤12；且2.05≤(x+b)≤20.8。本申请控制第一物质与二氟磷酸锂的含量关系，使二氟磷酸锂与第一物质合理适配，减少或避免由于过高的高阻抗添加剂的加入会导致电芯的整体阻抗上升，从而提升二次电池性能。
在一些实施方式中，电解液还包含第二物质；第二物质包括二草酸硼酸锂、四氟硼酸锂、二氟草酸硼酸锂、双氟磺酰亚胺锂、双三氟甲烷磺酰亚胺锂、三氟甲磺酸锂、4,5-二氰基-2-(三氟甲基)异吡唑锂、四硼酸锂中的至少一种。
在一些实施方式中，以电解液为基准，第二物质的质量含量为y％，y的取值范围为0.05≤y≤8，且2.05≤(y+b)≤16.6。通过合理调整二氟磷酸锂与第二物质的含量关系，使二者在成膜过程中起到协同配合关系，更有利于电极界面形成坚固且阻抗较低的SEI/CEI，进一步改善电池性能。
第二方面，本申请还提供了一种电子装置，该电子装置包括上述任意一种二次电池。本申请提供的二次电池具有较低的阻抗，良好的低温循环性能和高温存储性能，从而本申请提供的电子装置具有较长的使用寿命和良好的性能。
基于本申请提供的二次电池，采用羧酸酯化合物与二氟磷酸锂相互配合，通过二氟磷酸锂促进形成优良的界面膜，减少或避免羧酸酯化合物因自身稳定 性较差与正负极材料发生副反应，同时羧酸酯化合物能够提高二氟磷酸锂在电解液中的稳定性，起到促进二氟磷酸锂溶解和防止析出的作用。本申请通过控制羧酸酯化合物和二氟磷酸锂的含量关系，使二者相辅相成，紧密配合提高二次电池的循环和高温储存性能。另一方面，本申请在羧酸酯化合物与二氟磷酸锂配合的基础上，进一步结合正极材料的比表面积，能够减少正极材料与电解液间的副反应，进而使得二次电池的循环和高温存储性得到更加显著的改善。
具体实施方式
为了使本申请的目的、技术方案及优点更加清楚明白，以下结合附图及实施例，对本申请进行进一步详细说明。应当理解，此处所描述的具体实施例仅仅用以解释本申请，并不用于限定本申请。
为了简便，本发明仅明确地公开了一些数值范围。然而，任意下限可以与任何上限组合形成未明确记载的范围；以及任意下限可以与其它下限组合形成未明确记载的范围，同样任意上限可以与任意其它上限组合形成未明确记载的范围。此外，尽管未明确记载，但是除另有规定外，范围端点间的每个点或单个数值都包含在该范围内。因而，每个点或单个数值可以作为自身的下限或上限与任意其它点或单个数值组合或与其它下限或上限组合形成未明确记载的范围。
如果没有特别的说明，本申请所提到的“包括”和“包含”可以表示开放式，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。
本申请的发明人发现，在常规的电解液例如碳酸酯类电解液中，二氟磷酸锂的质量含量难以超过1％，否则可能出现电解液性能的恶化。有鉴于此，本申请于第一方面提供了一种二次电池，包括正极极片和电解液，该电解液包括羧酸酯化合物和二氟磷酸锂；所述羧酸酯化合物包括分子式为R1COOR2中的至 少一种，其中R1和R2各自独立地选自C1至C6的烷基或卤代烷基；以电解液为基准，羧酸酯化合物的质量含量为a％，二氟磷酸锂的质量含量为b％；其中，b的取值范围为2≤b≤8.8，a和b满足关系：6≤a/b≤28。本申请的电解液采用羧酸酯化合物与二氟磷酸锂(LiPO2F2)进行配合，提高二氟磷酸锂在电解液溶剂体系中的溶解度和稳定性，突破了二氟磷酸锂在电解液溶剂体系中1％的质量含量限制，使得高浓度二氟磷酸锂在电解液中应用成为可能。另一方面由于羧酸酯化合物的稳定性不如碳酸酯化合物，本申请中高浓度二氟磷酸锂能够促进形成优良的界面膜，能够减少羧酸酯化合物与正负极发生的副反应，二者相互配合能够进一步改善二次电池的循环、储存等性能。
可选地，羧酸酯化合物的分子式中，烷基可选自C1至C6的链状烷基或环状烷基；卤代烷基可选自F原子、Cl原子、Br原子、I原子中的任意一种卤素原子取代的C1至C6的链状烷基或环状烷基。
在一些示例性的实施例中，以电解液为基准，二氟磷酸锂的质量含量为b％，b的取值范围为2≤b≤8.8，a和b满足关系：6≤a/b≤28。例如b可以选自2、2.5、3、3.5、4、4.4、5、5.8、6、6.6、7、7.5、8、8.6、8.8或上述任意两个数值组成的范围，a/b可以选自6、6.67、6.98、7、8、9.09、9.5、10、10.34、12、13.5、13.64、14、15、16、17.5、18、20、21、22、24、26、28或上述任意两个数值所组成的范围。
在一些示例性的实施例中，羧酸酯化合物包括甲酸甲酯(MF)、乙酸甲酯(MA)、丙酸甲酯(MP)、丁酸甲酯(MB)、甲酸乙酯(EF)、乙酸乙酯(EA)、丙酸乙酯(EP)、丁酸乙酯(EB)、甲酸丙酯、乙酸丙酯、丙酸丙酯、丁酸丙酯或氟代乙酸乙酯中的至少一种。上述羧酸酯化合物具有相对较高的DN数，与二氟磷酸锂配合后能够显著增强后者在电解液中的溶解度和稳定性，从而提高二氟磷酸锂在电解液的应用质量浓度，进而发挥对二次电池性能的增益效果。其中乙酸乙酯的浸润性好、动力优良，但是乙酸乙酯在正负极副 反应不如碳酸酯，导致二次电池的高温和循环性能受损，而二氟磷酸锂能形成优良的界面膜，可以改善乙酸乙酯的这些缺陷，且二氟磷酸锂在碳酸酯溶剂中溶解度低，在乙酸乙酯由于其较高的DN数而有较高的溶解度，能够配合高浓度二氟磷酸锂克服彼此间的问题，在解决二次电池浸润困难的问题同时提升了循环和高温存储的性能。
在一些示例性的实施例中，以电解液为基准，羧酸酯化合物的质量含量为a％，a的取值范围为12≤a≤60，例如a可以选自12、19、27、35、42、56、60或上述任意两个数值所组成的范围。
在一些实施方式中，电解液还包括第一物质；第一物质包括1,3-丙烷磺内酯(1,3-PS)、1,3-丙烯磺酸内酯、硫酸乙烯酯、1,3丙二醇硫酸酯、2,4-丁磺内酯、1,4-丁烷磺内酯(1,4-BS)、碳酸亚乙烯酯(VC)、氟代碳酸乙烯酯(FEC)中的至少一种。
在一些实施方式中，以电解液为基准，第一物质的质量含量为x％，x的取值范围为0.05≤x≤12；且2.05≤(x+b)≤20.8。例如x可以选自0.05、2、3、5、8、10、12或上述任意两个数值所组成的范围；x+b可以选自2.05、4.43、6.4、7.4、8.85、14.4、16.4、17.8、18.7、19.5、19.9、20.8或上述任意两个数值所组成的范围。
在一些实施方式中，电解液还包含第二物质；第二物质包括二草酸硼酸锂(LiBOB)、四氟硼酸锂(LiBF4)、二氟草酸硼酸锂(LiDFOB)、双氟磺酰亚胺锂(LiFSI)、双三氟甲烷磺酰亚胺锂(LiTFSI)、三氟甲磺酸锂(LiCF3SO3)、4,5-二氰基-2-(三氟甲基)异吡唑锂(LiTDI)、四硼酸锂(Li2B4O7)中的至少一种。
在一些实施方式中，以电解液为基准，第二物质的质量含量为y％，y的取值范围为0.05≤y≤8，且2.05≤(y+b)≤16.6。例如，y可以选自0.05、0.10、0.20、0.60、1.20、1.80、2、4、6、8或上述任意两个数值所组成的范围；y+b可以选 自2.05、4.42、4.45、4.5、4.6、5、5.6、6.2、9.3、10.3、10.5、11.4、11.5、12.4、15.6、16.6或上述任意两个数值所组成的范围。
本申请中，电解液还包括非水溶剂。本申请对非水溶剂的种类没有特别限制，只要能够实现本申请目的即可。例如可以包括但不限于碳酸酯化合物、醚化合物中的至少一种。上述碳酸酯化合物可以包括但不限于链状碳酸酯化合物、环状碳酸酯化合物、氟代碳酸酯化合物中的至少一种。上述链状碳酸酯化合物可以包括但不限于碳酸二甲酯(DMC)、碳酸二乙酯(DEC)、碳酸二丙酯(DPC)、碳酸甲丙酯(MPC)、碳酸乙丙酯(EPC)或碳酸甲乙酯(MEC)中的至少一种。环状碳酸酯可以包括但不限于碳酸乙烯酯(EC)、碳酸亚丙酯(PC)、碳酸亚丁酯(BC)或碳酸乙烯基亚乙酯(VEC)中的至少一种。氟代碳酸酯化合物可以包括但不限于氟代碳酸乙烯酯(FEC)、碳酸1,2二氟亚乙酯、碳酸1,1二氟亚乙酯、碳酸1,1,2三氟亚乙酯、碳酸1,1,2,2四氟亚乙酯、碳酸1氟2甲基亚乙酯、碳酸1氟1甲基亚乙酯、碳酸1,2二氟1甲基亚乙酯、碳酸1,1,2三氟2 甲基亚乙酯或碳酸三氟甲基亚乙酯中的至少一种。上述醚化合物可以包括但不限于二丁醚、四甘醇二甲醚、二甘醇二甲醚、1,2二甲氧基乙烷、1,2二乙氧基乙烷、乙氧基甲氧基乙烷、2甲基四氢呋喃或四氢呋喃中的至少一种。
本申请中电解液的制备过程为本领域技术人员所熟知的，本申请没有特别的限制，例如，可以包括但不限于以下步骤：在含水量<10ppm的氩气气氛手套箱中，向非水溶剂中按质量比例加入二氟磷酸锂、羧酸酯化合物和充分干燥的锂盐LiPF6进行溶解处理，配成本申请中的电解液。可选地，第一物质和/或第二物质也可以加入非水溶剂中，配成本申请一些实施例中的电解液。本申请对二氟磷酸锂、羧酸酯化合物、锂盐LiPF6、第一物质和第二物质的加入顺序没有特别限制，可以根据实际需要选择，只要能够实现本申请目的即可。
在一些示例性的实施例中，本申请中的正极极片包括正极材料，正极材料的比表面积为cm2/g；c的取值范围为0.2≤c≤1.0，例如c可以选自0.2、0.4、 0.5、0.6、0.8、1.0或上述任意两个数值所组成的范围。本申请的发明人发现：随着正极材料比表面积的提高，二次电池的容量、循环和存储性能会出现下降的问题，原因可能在于正极材料表面存在残碱杂质，在电池服役过程中残碱的分解会对性能造成恶化。本申请在羧酸酯化合物与二氟磷酸锂配合的基础上，进一步控制正极材料的比表面积进行配合控制残碱的含量，通过二氟磷酸锂促进生成合适且更加稳定的CEI膜抑制残碱的分解，从而提高二次电池的容量、循环和储存性能。
本申请中正极材料是指设置在正极集流体表面上的物质，可以包括但不限于正极活性材料、正极导电剂、正极粘结剂。在本申请中，正极材料可以设置于正极集流体沿自身厚度方向上的一个表面上，也可以设置于正极集流体厚度方向上的两个表面上。需要说明，这里的“表面”可以是正极集流体的全部区域，也可以是正极集流体的部分区域，本申请没有特别限制，只要能实现本申请目的即可。
在一些示例性的实施例中，正极材料包括三元材料，三元材料包括锰元素和/或铝元素。高镍含量的三元材料与空气接触会导致其表面上的残碱含量增加，较高的残碱含量不仅会导致三元材料的加工性能急剧下降，还会显著恶化二次电池的循环性能。本申请的三元材料与羧酸酯化合物以及二氟磷酸锂配合后，能够减少或避免残碱对二次电池性能的影响，发挥三元材料比容量高、成本低和安全性能好的优势，保证二次电池优异的容量、循环和储存性能。
本申请对调控正极材料比表面积的方法没有特别限制，只要能够实现本申请目的即可。例如，不同比表面积的正极材料可以通过机械破碎、研磨、过筛等方式得到。示例性地，不同比表面积的正极材料可以通过机械破碎中的球磨方式得到。通常情况下，延长球磨时间，比表面积增大；缩短球磨时间，比表面积减小。
在一些示例性的实施例中，三元材料包括镍钴锰酸锂(NCM)和/或镍钴铝 酸锂(NCA)。可选地，镍钴锰酸锂选自LiNi0.8Mn0.1Co0.1O2(NCM811)、LiNi0.6Mn0.1Co0.3O2(NCM613)、LiNi1/3Mn1/3Co1/3O2、LiNi0.35Mn0.28Co0.37O2、LiNi0.6Mn0.2Co0.2O2、LiNi0.5Mn0.3Co0.2O2、LiNi0.7Mn0.15Co0.15O2中的至少一种。镍钴铝酸锂包括但不限于LiNi0.8Al0.05Co0.15O2。Mn。
在一些示例性的实施例中，本申请的正极极片还可以包含正极集流体，本申请对正极集流体没有特别限制，只要能够实现本申请目的即可。例如，可以包括但不限于铝箔、铝合金箔或复合集流体(例如铝碳复合集流体)。
正极材料还可以包括正极导电剂和正极粘结剂，本申请对正极导电剂和正极粘结剂的种类没有特别限制，只要能够实现本申请目的即可，例如，正极粘结剂可以包括但不限于聚乙烯醇、羟丙基纤维素、二乙酰基纤维素、聚氯乙烯、羧化的聚氯乙烯、聚氟乙烯、含亚乙基氧的聚合物、聚乙烯吡咯烷酮、聚氨酯、聚四氟乙烯、聚偏氟乙烯、聚乙烯、聚丙烯、丁苯橡胶、丙烯酸(酯)化的丁苯橡胶、环氧树脂或尼龙中的至少一种；正极导电剂可以包括但不限于基于碳的材料、基于金属的材料或导电聚合物中的至少一种。示例性地，基于碳的材料可以包括天然石墨、人造石墨、导电炭黑(Super P)或碳纤维中的至少一种，基于金属的材料可以包括但不限于金属粉、金属纤维、铜、镍、铝或银中的至少一种；导电聚合物可以包括但不限于聚亚苯基衍生物。本申请对正极材料中三元材料、正极导电剂、正极粘结剂的质量比没有特别限制，可以根据实际需要选择，只要能够实现本申请目的即可。
本申请对负极极片没有特别限制，只要能够实现本申请目的即可。例如，负极极片包含负极集流体和设置在负极集流体至少一个表面上的负极材料层。在本申请中，负极材料层可以设置于负极集流体厚度方向上的一个表面上，也可以设置于负极集流体厚度方向上的两个表面上。需要说明，这里的“表面”可以是负极集流体的全部区域，也可以是负极集流体的部分区域，本申请没有特别限制，只要能实现本申请目的即可。
本申请对负极集流体没有特别限制，只要能够实现本申请目的即可。例如，可以包括但不限于铜箔、铜合金箔、镍箔、不锈钢箔、钛箔、泡沫镍、泡沫铜或复合集流体(例如碳铜复合集流体、镍铜复合集流体、钛铜复合集流体等)等。在本申请中，对负极集流体和负极材料层的厚度没有特别限制，只要能够实现本申请目的即可，例如，负极集流体的厚度为6μm至12μm，负极材料层的厚度为30μm至130μm。本申请中，负极极片的厚度没有特别限制，只要能够实现本申请目的即可，例如，负极极片的厚度为50μm至280μm。
本申请的负极材料层包括负极活性材料，负极活性材料可以包括但不限于石墨、中间相微碳球(MCMB)、硬碳、软碳、硅、硅碳复合物、SiOx(0.5＜x＜1.6)、Li Sn合金、Li Sn O合金、Sn、SnO、SnO2、尖晶石结构的钛酸锂锂化TiO2Li4Ti5O12，Li Al合金及金属锂中的至少一种。
本申请中的负极材料层还可以包括负极粘结剂和负极导电剂，或者，负极材料层还可以包括负极粘结剂、负极导电剂和增稠剂。本申请对负极粘结剂和负极导电剂的种类没有特别限制，只要能够实现本申请目的即可，例如，负极粘结剂可以包括但不限于上述正极粘结剂中的至少一种，负极导电剂可以包括但不限于上述正极导电剂中的至少一种。本申请对增稠剂的种类没有特别限制，只要能够实现本申请目的即可，例如，增稠剂可以包括但不限于羧甲基纤维素钠或羧甲基纤维素中的至少一种。
本申请对隔离膜没有特别限制，只要能够实现本申请目的即可。例如，隔离膜的材料可以包括但不限于聚乙烯(PE)、聚丙烯(PP)为主的聚烯烃(PO)类、聚酯(例如聚对苯二甲酸二乙酯(PET)膜)、纤维素、聚酰亚胺(PI)、聚酰胺(PA)、氨纶或芳纶中的至少一种；隔离膜的类型可以包括织造膜、非织造膜、微孔膜、复合膜、碾压膜或纺丝膜中的至少一种。例如，隔离膜可以包括基材层和表面处理层。基材层可以为具有多孔结构的无纺布、膜或复合膜，基材层的材料可以包括聚乙烯、聚丙烯、聚对苯二甲酸乙二醇酯或聚酰亚胺中的至少一种。任 选地，可以使用聚丙烯多孔膜、聚乙烯多孔膜、聚丙烯无纺布、聚乙烯无纺布或聚丙烯聚乙烯聚丙烯多孔复合膜。任选地，基材层的至少一个表面上设置有表面处理层，表面处理层可以是聚合物层或无机物层，也可以是混合聚合物与无机物所形成的层。例如，无机物层包括无机颗粒和粘结剂，本申请对无机颗粒没有特别限制，例如可以包括氧化铝、氧化硅、氧化镁、氧化钛、二氧化铪、氧化锡、二氧化铈、氧化镍、氧化锌、氧化钙、氧化锆、氧化钇、碳化硅、勃姆石、氢氧化铝、氢氧化镁、氢氧化钙或硫酸钡中的至少一种。本申请对粘结剂没有特别限制，例如可以是上述正极粘结剂中的至少一种。聚合物层中包含聚合物，本申请对聚合物没有特别限制，例如聚合物包括聚酰胺、聚丙烯腈、丙烯酸酯聚合物、聚丙烯酸、聚丙烯酸盐、聚乙烯吡咯烷酮、聚乙烯醚或聚偏氟乙烯或聚(偏氟乙烯六氟丙烯)中的至少一种。在本申请中，隔离膜的厚度没有特别限制，只要能实现本申请的目的即可，例如隔离膜的厚度可以为5μm至500μm。
本申请的二次电池还包括包装袋，用于容纳正极极片、隔离膜、负极极片和电解液，以及二次电池中本领域已知的其它部件，本申请对上述其它部件没有特别限制。本申请对包装袋没有特别限制，可以为本领域公知的包装袋，只要能够实现本申请目的即可。例如，可采用铝塑膜包装袋。
二次电池的制备过程为本领域技术人员所熟知的，本申请没有特别的限制，例如，可以包括但不限于以下步骤：将正极极片、隔离膜和负极极片按顺序堆叠，并根据需要将其卷绕、折叠等操作得到卷绕结构的电极组件，将电极组件放入包装袋内，将电解液注入包装袋并封口，得到二次电池；或者，将正极极片、隔离膜和负极极片按顺序堆叠，然后用胶带将整个叠片结构的四个角固定好得到叠片结构的电极组件，将电极组件置入包装袋内，将电解液注入包装袋并封口，得到二次电池。此外，也可以根据需要将防过电流元件、导板等置于包装袋中，从而防止二次电池内部的压力上升、过充放电。
本申请于第二方面提供了一种电子装置，其包括本申请第一方面提供的二次电池。
本申请的电子装置没有特别限定，其可以是用于现有技术中已知的任何电子装置。例如，电子装置可以包括但不限于：笔记本电脑、笔输入型计算机、移动电脑、电子书播放器、便携式电话、便携式传真机、便携式复印机、便携式打印机、头戴式立体声耳机、录像机、液晶电视、手提式清洁器、便携CD机、迷你光盘、收发机、电子记事本、计算器、存储卡、便携式录音机、收音机、备用电源、电机、汽车、摩托车、助力自行车、自行车、照明器具、玩具、游戏机、钟表、电动工具、闪光灯、照相机、家庭用大型蓄电池和锂离子电容器。
下面结合以下具体实施例对本申请的方案进行说明。如无特殊说明，以下实施例所用原料均来自普通市售产品，所用装置或设备均购自常规市面销售渠道。
测试方法和设备：
比表面积的测试：使用比表面积分析仪(Tristar II 3020M)，通过氮吸附法测量对正极材料进行比表面积测试。其中，具体的测试依据国家标准GB/T195872017《气体吸附BET法测定固态物质比表面积》进行。
循环性能测试方法：在25℃条件下，将电池以1C充电至4.28V，4.28V条件下恒压充电至0.05C，之后以1C的电流放电至2.5V，并以此条件循环进行800圈，并记录800圈后的循环容量保持率。
60℃高温存储性能测试方法：将电池在25℃下以0.5C恒流充电至4.28V，然后恒压充电至电流为0.05C，测试电池的厚度并记为d0，放置到60℃烘箱中储存180天后，测试电池的厚度，记为d。电池60℃高温存储后的厚度膨胀率(％)＝(d-d0)/d0×100％。
50％SOC阻抗测试：25℃温度下将电池以0.5C的电流放电至2.5V，静置 5分钟，后以0.5C的电流充电至4.28V，4.28V下恒压至0.025C。静置5分钟，使用0.1C的电流放电至2.5V，标记此时放出的容量记为C1。使用0.5C1的容量充电至4.28V，在4.28V电压下恒压至0.025C1，静置5分钟，使用0.1C1的电流放电5h，此时的电池电压记为V1，之后采用1C的电流放电1秒，放电末期的电压记为V2。50％SOC阻抗计算公式为：(V1-V2)/(1C-0.1C1)。
25℃电导率测试：将电解液放入25℃恒温水浴锅中保温30min，使用铂黑电极(DJS-1C型)对电解液的电导率进行测试。
实施例I-1
本实施例的二次电池，包括正极极片和电解液，该电解液包括羧酸酯化合物和二氟磷酸锂；所述羧酸酯化合物包括乙酸乙酯；以电解液为基准，乙酸乙酯的质量含量a％为12％，二氟磷酸锂的质量含量b％为2％，a和b满足关系：a/b＝6。
本实施例的二次电池的制备方法，包括以下步骤：
电解液的制备：在含水量<10ppm的氩气气氛手套箱中，将碳酸甲乙酯、碳酸乙烯酯酯按照48.5:25的质量比混合均匀，配制得到非水溶剂，然后向该非水溶剂中按质量比例加入二氟磷酸锂、乙酸乙酯和充分干燥的锂盐LiPF6(LiPF6的摩尔含量为1M)溶解，配成本实施例中的电解液。
正极极片的制备：将NCM613(活性材料)、导电剂Super-P、粘结剂聚偏二氟乙烯(PVDF)按重量比为96:2:2在N-甲基吡咯烷酮(NMP)溶剂中充分搅拌混合，使其形成均匀的正极浆料；将此浆料涂覆于正极集流体Al箔上，烘干、冷压，得到正极极片。所得正极极片中，基于正极材料中除Li元素以外的金属元素的摩尔含量，锰元素的摩尔含量d％为10％。该正极极片中，正极材料包括NCM613、正极导电剂和正极粘结剂，正极材料的比表面积c为0.8m2/g；c和b满足关系：c/b＝40。
负极极片的制备：将负极活性物质石墨、粘结剂丁苯橡胶、增稠剂羧甲基 纤维素钠按照重量比97.4:1.4:1.2在去离子水溶剂中充分搅拌混合，使其形成均匀的负极浆料；将此浆料涂覆于负极集流体Cu箔上，烘干、冷压，得到负极极片。
隔离膜：使用单层PE多孔聚合物薄膜作为隔离膜，其厚度为16微米，孔隙率为39％，无机涂层为Al2O3，有机颗粒为聚偏二氟乙烯。
本申请的二次电池(即锂离子电池)的制备：将正极片、隔离膜、负极片按顺序叠好，使隔离膜处于正极极片和负极极片之间起到隔离的作用，然后卷绕得到裸电池；将裸电池置于外包装箔中，将上述制备好的电解液注入到干燥后的电池中，经过真空封装、静置、化成、整形等工序，即完成锂离子电池的制备。其中，化成工序如下：在45±5℃下，进行首圈充放电，流程如下：首先以0.1C倍率恒流充电10min，随后以0.5C倍率恒流充电至指定电压4.3V，再恒压充电至电流小于等于0.05C，接着以0.5C倍率恒流放电至2.5V。
实施例I-2至I-14以及对比例I-1至I-8的二次电池，与实施例I-1的区别仅在于二氟磷酸锂的质量含量、羧酸酯化合物的种类和/或质量含量不同，具体区别内容以及性能测试结果如下表1所示。
表1

由表1可知，本申请实施例I-1至I-6在加入2wt％的二氟磷酸锂的基础上，控制羧酸酯化合物的质量含量a％和二氟磷酸锂的质量含量b％的值满足数学关系：6≤a/b≤28，与对比例I-1至I-5相比，能够在保持较好的50％SOCDCR性能的情况下，表现出更高的25℃循环保持率和更低的60℃储存厚度膨胀率，具有更加优异的循环性能和高温存储性能。而对比例I-1至I-5中，对比例I-2在a和b满足a/b＝4时，在电解液制备时出现了二氟磷酸锂不完全溶解的问题，造成电解液性能恶化严重，对比例I-1以及对比例I-3至对比例I-5采用更多的乙酸乙酯使得a/b值超过28，其电解液粘度较低，因此DCR性能相对变小，但是在800圈的长时间循环后的循环保持率较低。
实施例I-7至实施例I-12在对比例I-3的基础上，通过增加二氟磷酸锂的含量降低a/b值，根据测试结果可知，二氟磷酸锂的增加在一定程度上会提高二次电池的阻抗，导致50％SOC的DCR性能增加，但本申请通过控制6≤a/b≤28，使乙酸乙酯与二氟磷酸锂二者相互作用进行配合，仍然能够达到更高的循环性能和高温储存性能。同时与对比例I-6相比，本申请控制二氟磷酸锂的质量含量在2～8.8％，与乙酸乙酯配合后能够使二次电池具备更为优异的循环性能和高温储存性能。
另外，与实施例I-7相比，实施例I-1至实施例I-3、实施例I-8至实施例I-12在调整a/b满足6≤a/b≤13.64时，具有更高的25℃循环保持率，证明了本申请在二氟磷酸锂的质量含量b％为2～7.5％时，控制6≤a/b≤13.64使乙酸乙酯和二 氟磷酸锂紧密配合，能够进一步提高二次电池的循环性能，在25℃下循环800圈后容量保持率能够达到76.5％～79.9％，具有极其优异的循环性能。
由实施例I-1至实施例I-14可知，本申请采用二氟磷酸锂与羧酸酯化合物紧密配合，促进形成稳定的CEI和SEI，能够提高二次电池的循环性能和高温储存性能。
实施例II-1至II-9的二次电池，与实施例I-8的区别仅在于二氟磷酸锂的质量含量和/或正极材料的比表面积不同，具体区别内容以及性能测试结果如下表2所示。
表2
由表2可知，本申请实施例II-1至实施例II-9在羧酸酯化合物与二氟磷酸锂配合的基础上，进一步控制正极材料的比表面积c保证3≤c/b≤45，通过三者的共同配合，能够降低二次电池的50％SOC DCR性能，并且提高二次电池 的25℃、800圈循环保持率以及60℃高温储存性能。
其中实施例II-3至实施例II-8进一步控制9.09≤c/b≤15.52，与二氟磷酸锂和羧酸酯化合物紧密配合后，能够对二次电池的循环性能和高温储存性能进行进一步改善。
实施例III-1至III-12的二次电池，与实施例I-8的区别仅在于电解液还包括第一物质，二氟磷酸锂的质量含量和/或第一物质的种类和含量不同，具体区别内容以及性能测试结果如下表3所示。
表3
由表3可知，实施例III-1至实施例III-12在羧酸酯化合物与二氟磷酸锂配 合的基础上，控制加入第一物质的含量与二氟磷酸锂满足关系2.05≤(x+b)≤20.8有利于提高二次电池的循环性能和高温储存性能。进一步优选地，本申请实施例控制加入第一物质的含量与二氟磷酸锂满足关系7.4≤(x+b)≤19.5，能够促进二氟磷酸锂和第一物质协同配合，从而进一步提高二次电池的循环性能和高温储存性能。
另外，通过实施例III-3和实施例III-12的比较可以看出，第一物质的种类也会对二次电池的阻抗、循环性能和储存性能造成影响。本申请通过优选第一物质的种类和含量，使第一物质与二氟磷酸锂共同配合能够有效提高二次电池的循环性能和高温储存性能。
实施例IV-1至IV-11的二次电池，与实施例I-8的区别仅在于电解液还包括第二物质，二氟磷酸锂的质量含量和/或第二物质的种类和含量不同，具体区别内容以及性能测试结果如下表4所示。
表4

由表4可知，第二物质的种类和含量会影响二次电池的循环性能和高温储存性能，实施例IV-1至实施例IV-11在羧酸酯化合物与二氟磷酸锂配合的基础上，控制加入第二物质的含量与二氟磷酸锂满足关系2.05≤(y+b)≤16.6能够提高二次电池的循环性能和高温储存性能。进一步优选地，本申请实施例控制加入第二物质的含量与二氟磷酸锂满足关系4.5≤(x+b)≤11.5，能够促进二氟磷酸锂和第二物质协同配合，使二次电池具备更好的循环性能和高温储存性能。
以上所述仅为本申请的较佳实施例而已，并不用以限制本申请，凡在本申请的原则之内所作的任何修改、等同替换和改进等，均应包含在本申请的保护范围之内。

Claims (10)

  1. 一种二次电池，包括正极极片和电解液，其特征在于，所述电解液包括羧酸酯化合物和二氟磷酸锂；所述羧酸酯化合物包括分子式为R1COOR2的化合物中的至少一种，其中R1和R2各自独立地选自C1至C6的烷基或卤代烷基；
    以所述电解液为基准，所述羧酸酯化合物的质量含量为a％，所述二氟磷酸锂的质量含量为b％，2≤b≤8.8，6≤a/b≤28。
  2. 根据权利要求1所述的二次电池，其特征在于，所述二次电池满足如下至少一者：
    (1)所述羧酸酯化合物包括甲酸甲酯、乙酸甲酯、丙酸甲酯、丁酸甲酯、甲酸乙酯、乙酸乙酯、丙酸乙酯、丁酸乙酯、甲酸丙酯、乙酸丙酯、丙酸丙酯、丁酸丙酯或氟代乙酸乙酯中的至少一种；
    (2)12≤a≤60；
    (3)2≤b≤7.5；
    (4)6≤a/b≤15。
  3. 根据权利要求1所述的二次电池，其特征在于，所述正极极片包括正极材料，所述正极材料的比表面积为c m2/g；0.2≤c≤1.0；和/或，
    3≤c/b≤45。
  4. 根据权利要求1～3中任一项所述的二次电池，其特征在于，所述正极极片包括正极材料，所述正极材料包括三元材料，所述三元材料包括锰元素和/或铝元素。
  5. 根据权利要求4所述的二次电池，其特征在于，基于所述正极材料中除 Li元素以外的金属元素的摩尔量，所述锰元素和/或铝元素的摩尔含量为d，d的取值范围为5％≤d≤35％。
  6. 根据权利要求1～3中任一项所述的二次电池，其特征在于，所述电解液还包括第一物质；
    所述第一物质包括1,3-丙烷磺内酯、1,3-丙烯磺酸内酯、硫酸乙烯酯、1,3丙二醇硫酸酯、2,4-丁磺内酯、1,4-丁烷磺内酯、碳酸亚乙烯酯、氟代碳酸乙烯酯中的至少一种。
  7. 根据权利要求6所述的二次电池，其特征在于，以所述电解液为基准，所述第一物质的质量含量为x％，0.05≤x≤12，2.05≤(x+b)≤20.8。
  8. 根据权利要求6中任一项所述的二次电池，其特征在于，所述电解液还包含第二物质；
    所述第二物质包括二草酸硼酸锂、四氟硼酸锂、二氟草酸硼酸锂、双氟磺酰亚胺锂、双三氟甲烷磺酰亚胺锂、三氟甲磺酸锂、4,5-二氰基-2-(三氟甲基)异吡唑锂、四硼酸锂中的至少一种。
  9. 根据权利要求8所述的二次电池，其特征在于，以所述电解液为基准，所述第二物质的质量含量为y％，0.05≤y≤8，2.05≤(y+b)≤16.6。
  10. 一种电子装置，其特征在于，所述电子装置包括权利要求1～9中任一项所述的二次电池。
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107706455A (zh) * 2017-09-20 2018-02-16 惠州亿纬锂能股份有限公司 一种兼顾高低温性能的高电压倍率电解液及使用该电解液的锂离子电池
CN111129590A (zh) * 2019-12-23 2020-05-08 东莞市杉杉电池材料有限公司 一种高电压锂离子电池非水电解液及高电压锂离子电池
CN111952668A (zh) * 2020-08-13 2020-11-17 梅州市量能新能源科技有限公司 电解液、锂离子电池及其制备方法
CN115149103A (zh) * 2022-08-15 2022-10-04 珠海冠宇电池股份有限公司 一种电池

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107706455A (zh) * 2017-09-20 2018-02-16 惠州亿纬锂能股份有限公司 一种兼顾高低温性能的高电压倍率电解液及使用该电解液的锂离子电池
CN111129590A (zh) * 2019-12-23 2020-05-08 东莞市杉杉电池材料有限公司 一种高电压锂离子电池非水电解液及高电压锂离子电池
CN111952668A (zh) * 2020-08-13 2020-11-17 梅州市量能新能源科技有限公司 电解液、锂离子电池及其制备方法
CN115149103A (zh) * 2022-08-15 2022-10-04 珠海冠宇电池股份有限公司 一种电池

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