WO2021031956A1 - 二次电池及其相关的电池模块、电池包和装置 - Google Patents

二次电池及其相关的电池模块、电池包和装置 Download PDF

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WO2021031956A1
WO2021031956A1 PCT/CN2020/108687 CN2020108687W WO2021031956A1 WO 2021031956 A1 WO2021031956 A1 WO 2021031956A1 CN 2020108687 W CN2020108687 W CN 2020108687W WO 2021031956 A1 WO2021031956 A1 WO 2021031956A1
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lithium
secondary battery
group
electrolyte
lithium salt
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PCT/CN2020/108687
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English (en)
French (fr)
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梁成都
陈培培
付成华
彭畅
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宁德时代新能源科技股份有限公司
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Priority to EP20853783.7A priority Critical patent/EP3951944B1/en
Publication of WO2021031956A1 publication Critical patent/WO2021031956A1/zh
Priority to US17/566,699 priority patent/US20220123368A1/en

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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
    • H01M10/05—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
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    • 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
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    • H—ELECTRICITY
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    • 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
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    • 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
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    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H01M4/366—Composites as layered products
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    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
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    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/483—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides for non-aqueous cells
    • H—ELECTRICITY
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    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/60—Selection of substances as active materials, active masses, active liquids of organic compounds
    • H01M4/602—Polymers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/621—Binders
    • H01M4/622—Binders being polymers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
    • 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
    • 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
    • H01M2220/00—Batteries for particular applications
    • H01M2220/20—Batteries in motive systems, e.g. vehicle, ship, plane
    • 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
    • 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
    • H01M2300/0028—Organic electrolyte characterised by the solvent
    • H01M2300/0037—Mixture of solvents
    • H01M2300/0042—Four or more 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

  • This application belongs to the field of electrochemical technology. More specifically, this application relates to a secondary battery. This application also relates to battery modules, battery packs, and devices related to the secondary battery.
  • Secondary batteries are widely used as an important new energy storage device due to their high energy density and good cycle performance. In recent years, secondary batteries have continued to develop in the direction of high energy output and wide application conditions.
  • the four main materials that make up the secondary battery positive electrode material, negative electrode material, separator, and electrolyte have all received attention from researchers.
  • non-carbon-based negative electrode active materials have attracted great attention in the field of negative electrode active materials for secondary batteries.
  • silicon-based materials have higher theoretical capacity (4200mAh/g) than traditional graphite, low lithium intercalation potential, high electrochemical reversible capacity, good safety performance, and abundant resources. The focus of attention.
  • the first aspect of the present application provides a secondary battery, which includes: a positive electrode sheet, a negative electrode sheet, a separator spaced between the positive electrode sheet and the negative electrode sheet, and an electrolyte.
  • the negative electrode sheet includes a negative electrode current collector and The anode active material layer on at least one side of the anode current collector, and the electrolyte includes an organic solvent and a lithium salt, wherein:
  • the negative electrode active material includes a core structure and a polymer network coating layer covering at least a part of the surface of the core structure, accounting for at least 0.5% by mass and at most 10% by mass of the total mass of the negative electrode active material, so
  • the core structure includes SiO x (0 ⁇ x ⁇ 2), and the network coating layer is derived from one or more functional groups of cyano group, amide group, imide group, sulfonyl group, carboxyl group and sulfone group Polymer;
  • the lithium salt includes the first lithium salt represented by the following formula I:
  • R 1 and R 2 each independently represent a fluorine atom, a fluoroalkyl group having 1-20 carbon atoms, or a fluoroalkoxy group having 1-20 carbon atoms, and n is 1, An integer of 2 or 3.
  • the polymer is selected from at least one of polyimide, polyacrylic acid, polyacrylamide, and polyacrylonitrile.
  • the polymer network coating layer is present in an amount of 1% to 5% by mass relative to the total mass of the negative electrode active material.
  • the first lithium salt is selected from lithium bisfluorosulfonimide, lithium fluorosulfonyl (trifluoromethylsulfonyl) imide, bis(trifluoromethylsulfonyl) Lithium fluoromethylsulfonyl) imide, lithium trifluoromethanesulfonyl trifluoromethanesulfonimide, lithium trifluoromethanesulfonyl pentafluoroethylsulfonimide, bis(pentafluoroethylsulfonyl) Lithium amide, LiN(SO 2 OCH 2 CF 3 ) 2 , LiN(SO 2 OCH 2 CF 2 CF 3 ) 2 , LiN(SO 2 OCH 2 CF 2 CF 2 H) 2 , LiN[(SO 2 OCH(CF 3 ) 2], FSO 2 N - (Li +) SO 2 N - (Li +) SO 2 N - (Li +
  • the mass percentage concentration of the first lithium salt in the electrolyte is in the range of 5% to 25%, optionally 10% to 20%. %In the range.
  • the lithium salt further includes a second lithium salt
  • the second lithium salt is selected from lithium hexafluorophosphate, lithium tetrafluoroborate, lithium trifluoromethanesulfonate, One or more of lithium hexafluoroarsenate, lithium bisoxalate borate and lithium perchlorate, optionally selected from one or two of lithium hexafluorophosphate and lithium tetrafluoroborate, and more optionally selected from lithium hexafluorophosphate.
  • the mass percentage concentration of the second lithium salt in the electrolyte is in the range of 0.1% to 10%, optionally 3% to 5%. %In the range.
  • the electrolyte further includes an additive selected from the group consisting of ethylene sulfate (DTD), lithium difluorophosphate (LiPO 2 F 2 ), difluoro One or more of lithium oxalate borate (LiODFB), maleic anhydride, sulfur dioxide (SO 2 ), and tris(trimethylsilane) phosphate (TMSP).
  • DTD ethylene sulfate
  • LiPO 2 F 2 lithium difluorophosphate
  • LiODFB difluoro One or more of lithium oxalate borate
  • SO 2 sulfur dioxide
  • TMSP tris(trimethylsilane) phosphate
  • the mass percentage concentration of the additive in the electrolyte is in the range of 0% to 5%, optionally in the range of 0.1 to 3% , More optionally in the range of 0.2% to 2%.
  • the organic solvent is selected from propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methyl ethyl carbonate Ester, methyl propyl carbonate, vinylene carbonate, fluoroethylene carbonate, methyl formate, ethyl acetate, ethyl propionate, propyl propionate, methyl butyrate, methyl acrylate, vinyl sulfite , Propylene sulfite, dimethyl sulfite, diethyl sulfite, 1,3-propane sultone, vinyl sulfate, acid anhydride, N-methylpyrrolidone, N-methylformamide, N- Methylacetamide, acetonitrile, N,N-dimethylformamide, sulfolane, dimethyl sulfoxide, dimethyl sulfide, ⁇ -butyrolactone, t
  • the battery has a 4C rate of 40% or higher, and a capacity retention rate of 70% or higher.
  • a second aspect of the application provides a battery module including the secondary battery described in the first aspect of the application.
  • a third aspect of the present application provides a battery pack including the battery module described in the second aspect of the present application.
  • the fourth aspect of the present application provides a device, which includes the secondary battery described in the first aspect of the present application, and the secondary battery is used as a power source or a capacity storage unit of the device; optionally, the Devices include electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, electric ships, and energy storage systems.
  • the negative electrode active material has a core-shell structure
  • the silicon-based core material has a higher gram capacity
  • the surface of the silicon-based core material is coated with a polymer network coating layer, which can significantly inhibit The expansion of silicon-based materials improves the cycle performance of the battery.
  • the electrolyte solution containing lithium sulfonimide and the above-mentioned negative electrode active material can be combined to obtain a secondary battery that has both capacity and kinetic cycle performance.
  • the use of lithium imide electrolyte salt on the one hand due to the lithium sulfonimide salt anion lithium salt LiPF their more common anions 6 PF 6 - large, difficult migration itself, It improves the relative mobility of Li + .
  • the sulfonimide anion has a large conjugated structure, the electron cloud density is small, and the interaction force with Li + is small.
  • the anion of the sulfonimide lithium salt has a strong similar compatibility with the polymer in the network coating layer, and the solvated Li + is easier to pass through the network coating layer, which improves the electrolyte at the interface of the negative electrode active material.
  • the wettability and ion conductivity are important to improve the electrolyte at the interface of the negative electrode active material.
  • SiO x coated with a polymer network layer derived from one or more functional groups of cyano group, amide group, imide group, sulfonyl group, carboxyl group and sulfone as the negative electrode active material, although it can improve the performance of the negative electrode sheet Expansion, but usually deteriorates electrochemical performance (such as rate performance).
  • the inventor used the above two in combination, and was surprised to find that the two can produce a synergistic effect.
  • the secondary battery according to the present application has high energy density and kinetic cycle performance.
  • composition is described as including or containing specific components, it is expected that the composition does not exclude optional components that are not covered by this application, and it is expected that the composition may consist or consist of the involved components, or Where a method is described as including or containing specific process steps, it is expected that the method does not exclude optional process steps that are not covered by this application, and it is expected that the method can be composed or composed of the process steps involved.
  • any lower limit may be combined with any upper limit to form an unspecified range; and any lower limit may be combined with other lower limits to form an unspecified range, and any upper limit may be combined with any other upper limit to form an unspecified range.
  • every point or single value between the end points of the range is included in the range. Therefore, each point or single numerical value can be used as its own lower limit or upper limit in combination with any other point or single numerical value or in combination with other lower or upper limits to form an unspecified range.
  • first lithium salt refers to the lithium salt that plays a major role in the electrolyte, and its mass percentage in the electrolyte is usually 5% by mass or more.
  • second lithium salt refers to a lithium salt that plays a secondary role in the electrolyte, for example, it is used to reduce the cost of the electrolyte and suppress the negative effects caused by the use of the first lithium salt. Its mass percentage content in the electrolyte is at most 10% by mass or less, for example, 5% by mass or less, for example, 3% by mass or less.
  • the "polymer network coating layer” is a layer for coating a silicon-based material as a core, which has a network structure formed by a crosslinked polymer.
  • the polymer used usually has one or more functional groups among cyano group, amide group, imide group, sulfonyl group, carboxyl group and sulfone group, and can be selected from The following crosslinking agent: one or more of ethylene glycol, glycerol, triethylenetetramine, dimethylaminopropylamine, and sulfur-containing compounds, optionally ethylene glycol.
  • fluoro refers to a group or compound in which one or more hydrogen atoms are replaced by fluorine atoms.
  • fluoro is perfluoro or partially fluoro.
  • fluoromethyl include but are not limited to -CF 3, -CHF 2 and -CH 2 F.
  • the term "4C rate" is a parameter used to measure the capacity of the secondary battery. Generally, the higher the 4C rate, the greater the capacity of the secondary battery.
  • the term “capacity retention” is a parameter used to measure the cycle performance of the secondary battery at 25°C. Generally, the higher the capacity retention rate, the better the cycle kinetic performance of the secondary battery.
  • Fig. 1 is a perspective view of an embodiment of a secondary battery.
  • Figure 2 is an exploded view of Figure 1.
  • Fig. 3 is a perspective view of an embodiment of a battery module.
  • Fig. 4 is a perspective view of an embodiment of a battery pack.
  • Fig. 5 is an exploded view of Fig. 4.
  • Fig. 6 is a schematic diagram of an embodiment of a device using a secondary battery as a power source.
  • the secondary battery according to the present application includes: a positive electrode sheet, a negative electrode sheet, a separator separated between the positive electrode sheet and the negative electrode sheet, and an electrolyte.
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode active disposed on at least one side of the negative electrode current collector.
  • Material layer, electrolyte includes organic solvent and lithium salt.
  • the negative electrode active material in the secondary battery of the present application has a core-shell structure including a core structure and a network coating layer of a polymer coated on at least a part of the surface of the core structure, and the core structure includes SiO x (0 ⁇ x ⁇ 2)
  • the polymer network coating layer accounts for at least 0.5% by mass and at most 10% by mass of the total mass of the negative active material, and the network coating layer is derived from having cyano groups, amide groups, imide groups, sulfonyl groups, carboxyl groups, and sulfones One or more functional groups in the group.
  • the coating layer for coating the core structure is a network structure formed of a crosslinked polymer.
  • the inventors of the present application surprisingly discovered that the use of a polymer layer with a network structure formed of a cross-linked polymer to coat a silicon-based material can significantly inhibit the expansion of the silicon-based material as a core structure, and it is more effective than the specific When the electrolyte is used in combination, it will not significantly deteriorate the conductivity of the negative electrode active material, which was difficult to foresee before this application.
  • elemental carbon can be used to coat the silicon-based material to reduce the expansion of the silicon-based material.
  • Such a carbon element coating layer is usually formed by a physical vapor deposition method or a chemical vapor deposition method of gaseous organic substances such as methane and acetylene.
  • the anode active material according to the present application can be obtained through a simple mixing and heating cross-linking process, which greatly reduces the production cost and expands the application prospects of silicon-based materials.
  • the network coating layer is derived from polymers including polyimide, polyacrylonitrile, polyacrylamide, polyacrylic acid, sodium alginate or Any combination of it.
  • the network coating layer is coated on 80% or more of the surface of the core structure, optionally on the surface of 85% or more of the core structure. It is selected on the surface of 90% or more of the core structure, and more preferably on the surface of 95% or more of the core structure, and most preferably on the surface of 99% or more of the core structure. If the coating area is too low, too much surface of the core structure will directly contact the electrolyte, and side reactions will continue to occur during the battery cycle, which consumes active ions, thereby deteriorating the battery cycle performance.
  • the mass of the network coating layer accounts for 0.5% to 10% of the total mass of the negative active material, more optionally 1% to 5%.
  • the ratio of the mass of the network coating layer to the total mass of the negative electrode active material is determined by conversion based on the element C from the network coating layer measured by the element analyzer.
  • the mass ratio of the polymer network coating layer in the negative electrode active material can be measured by a high-frequency infrared CS analyzer.
  • the element and the optional S element are determined by conversion.
  • the thickness of the network coating layer is 10 nm to 700 nm, and optionally 100 nm to 400 nm.
  • the rate performance and cycle performance of the battery are closely related to the polymer network coating layer of the negative electrode active material.
  • silicon-based materials due to its high theoretical capacity (4200mAh/g), low lithium insertion potential, high electrochemical reversible capacity, good safety performance, and abundant resources, silicon-based materials have become the most concerned about high-energy density lithium-ion batteries. Anode material.
  • the silicon-based material will have a huge volume expansion (about 20 to 400%) during the cycle, resulting in the pulverization and shedding of the active material during the charging and discharging process, which greatly reduces the cycle performance of the battery.
  • the surface of the Si material is coated with a polymer network coating layer, which can significantly improve the expansion of silicon particles.
  • Too little network coating layer will cause too much surface of the core structure to directly contact the electrolyte, continuously produce side reactions during the battery cycle, consume active ions, and deteriorate the battery cycle performance. If the network coating is too thick, the transmission of conductive electrons and ions will be blocked, which will affect the charging rate and power performance of the battery. Too much charging will lead to ALP, thereby deteriorating the cycle performance.
  • the polymer network coating layer is present in an amount of 0.5% to 10% by mass relative to the total mass of the negative active material, or in an amount relative to the total mass of the negative active material.
  • Exist in an amount of mass% to 10% by mass, or in an amount of 3% to 10% by mass relative to the total mass of the negative electrode active material, or in an amount of 5% to 10% by mass relative to the total mass of the negative electrode active material Exist, either in an amount of 8% to 10% by mass relative to the total mass of the negative electrode active material, or in an amount of 0.5% to 8% by mass relative to the total mass of the negative electrode active material, or in an amount relative to the negative electrode active
  • the total mass of the material is present in an amount of 1% to 8% by mass, or in an amount of 3% to 8% by mass relative to the total mass of the negative active material, or in an amount of 5% to 8% by mass relative to the total mass of the negative active material.
  • the polymer network coating layer is present in an amount of 1% to 5% by mass relative to the total mass of the negative active material.
  • the negative electrode active material can be prepared by the following methods: (1) pulverizing SiOx (0 ⁇ x ⁇ 2) powder to obtain a material with a certain particle size distribution; (2) combining a certain quality The polymer and the corresponding crosslinking agent are dissolved in the solvent to prepare polymer slurry 1; (3) Add the SiOx (0 ⁇ x ⁇ 2) powder of step (1) to the slurry 1, and stir until the mixture is uniform Slurry 2; (4) The slurry 2 is dried at 50°C to 100°C until the solvent is completely removed, the obtained product is sieved and the sizing material is heated to obtain the above-mentioned negative electrode active material.
  • the mass of the polymer accounts for 1% to 10% of the mass of the SiOx (0 ⁇ x ⁇ 2) powder.
  • a certain quality of conductive material can be added to the slurry 1.
  • the solvent in step (1) can be selected from one or more of water, acetone, dimethylpyrrolidone, dimethylformamide, and ethanol.
  • the conductive material can be selected from one or more of conductive carbon black, carbon nanotubes, and graphene.
  • the added amount of the conductive agent accounts for 10 to 30% of the polymer mass.
  • the crosslinking agent may be selected from one or more of ethylene glycol, glycerol, triethylenetetramine, dimethylaminopropylamine, and sulfur-containing compounds, and may optionally be a sulfur-containing compound.
  • the sulfur-containing compound can be selected from one or more of elemental sulfur, hydrogen sulfide, and thiophene.
  • the mass of the crosslinking agent accounts for 10% to 30% of the polymer mass.
  • the cross-linking temperature can be selected from 300°C to 500°C, and controlling the temperature within this range can avoid carbonization of the polymer.
  • the negative active material thus obtained can be used directly or in combination with other conventional negative active materials for manufacturing negative pole pieces.
  • the negative pole piece according to the present application can be selected from various conventional negative pole pieces commonly used in the art, and its composition and preparation methods are well known in the art.
  • the negative pole piece may include a negative current collector and a negative active material layer disposed on the negative current collector.
  • the negative active material layer may include the aforementioned negative active material, optional other negative active materials, binders, conductive materials, and the like.
  • negative electrode active materials are, for example, carbonaceous materials such as graphite (artificial graphite or natural graphite), conductive carbon black, carbon fiber, etc., such as metal or semi-metal materials such as Sn, Ge, Bi, Sn, In, or their alloys, containing lithium nitrogen Compounds or lithium-containing oxides, lithium metal or lithium aluminum alloy, etc.
  • carbonaceous materials such as graphite (artificial graphite or natural graphite), conductive carbon black, carbon fiber, etc.
  • metal or semi-metal materials such as Sn, Ge, Bi, Sn, In, or their alloys, containing lithium nitrogen Compounds or lithium-containing oxides, lithium metal or lithium aluminum alloy, etc.
  • the electrolyte in the secondary battery of the present application will be explained.
  • the electrolyte includes an organic solvent and a lithium salt.
  • the lithium salt includes the first lithium salt represented by the following formula I:
  • R 1 and R 2 each independently represent a fluorine atom, a fluoroalkyl group having 1-20 carbon atoms, or a fluoroalkoxy group having 1-20 carbon atoms, and n is 1, An integer of 2 or 3.
  • the number of fluorine atoms and the substitution position are not particularly limited, and the fluorine atom can be selected according to actual needs. Hydrogen atoms or all hydrogen atoms are substituted.
  • the number of fluorine atoms may be 1, 2, 3, 4 or more.
  • fluoroalkyl groups include: fluoromethyl, 2-fluoroisobutyl, 2-fluoroethyl, 1-fluoroethyl, 3-fluoro-n-propyl, 2-fluoroisopropyl, 4-fluoro-n-butyl, 3-fluoro-sec-butyl, 2-fluoro-sec-butyl, 5-fluoro-pentyl, 1-fluoro-n-pentyl, 4-fluoroisopentyl, 3-fluoroisopentyl, 6 -Fluoro-n-hexyl, 4-fluoro-isohexyl, 7-fluoro-n-heptyl, 8-fluoro-n-octyl, 1,2-difluoroethyl, difluoromethyl, trifluoromethyl, pentafluoro Ethyl, perfluoroisopropyl, perfluorobutyl, perfluorocyclohexyl, etc
  • the type of the alkoxy group connected to the fluorine atom is not specifically limited, and can be selected according to actual needs, such as chain alkoxy Both the cyclic alkoxy group and the cyclic alkoxy group may be used, and the chain alkoxy group includes straight chain alkoxy group and branched chain alkoxy group.
  • the number of oxygen atoms may be one or two.
  • the number of fluorine atoms connected to the alkoxy group may be one, two, three, four, five, or six.
  • fluoroalkoxy specific examples include: fluoromethoxy, 2-fluoroethoxy, 3-fluoron-propoxy, 2-fluoroisopropoxy, 4-fluoron-butoxy, 3-fluoro-sec-butoxy, 5-fluoro-n-pentyloxy, 4-fluoroisopentyloxy, 3-fluoro-tert-pentyloxy, 3-fluoro-2,2-dimethylpropoxy, 3-fluoro -1-ethylpropoxy, 4-fluoro-1-methylbutoxy, 6-fluoron-hexyloxy, 5-fluoroisohexyloxy, 3-fluoro-1,1,2-trimethylpropoxy Group, 2,2,2-trifluoroethoxy, 2,2,3,3,3-pentafluoropropoxy, 2,2,3,3-tetrafluoropropoxy, OCH(CF 3 ) 2 and many more.
  • the first lithium salt is selected from lithium bisfluorosulfonimide, lithium fluorosulfonyl (trifluoromethylsulfonyl) imide, lithium bis(trifluoromethylsulfonyl) imide, methylsulfonyl Lithium trifluoromethylsulfonimide, lithium trifluoromethanesulfonylpentafluoroethylsulfonimide, lithium bis(pentafluoroethylsulfonyl)imide, LiN(SO 2 OCH 2 CF 3 ) 2 , LiN (SO 2 OCH 2 CF 2 CF 3) 2, LiN (SO 2 OCH 2 CF 2 CF 2 H) 2, LiN [(SO 2 OCH (CF 3) 2], FSO 2 N - (Li +) SO 2 N - (Li +) SO 2 F, FSO 2 N - (Li +) SO 2 N - (Li +) SO 2 N - (Li
  • the fluorine-containing sulfonimide lithium salt has a high electrical conductivity due to its special structural characteristics, which can improve the dynamic performance of the battery.
  • the imine anion is larger than the commonly used PF6-, and it is difficult to migrate, which improves the relative mobility of Li+; in addition, the imine anion has a large conjugated structure with an electron cloud density Small, the interaction force with Li+ is small.
  • the above two aspects work together to make the electrolyte containing fluorine-containing sulfonimide lithium salt have a higher conductivity.
  • the imine-type lithium salt anion has a strong similar compatibility with the polymer of the above-mentioned network coating layer, and the solvated Li+ and imine anion can pass through the polymer layer more easily, which improves the infiltration of the electrolyte on the surface of the negative electrode. Sex and ion conductivity, help to improve the dynamic cycle performance of the battery. However, considering practical applications, the amount of the first lithium salt usually cannot be too high, otherwise it will be corrosive to the current collector, especially the aluminum current collector.
  • the mass percentage concentration of the first lithium salt in the electrolyte is in the range of 5% to 25%, and optionally in the range of 10% to 20%.
  • the lithium ion electrolyte further includes a second lithium salt
  • the second lithium salt is selected from lithium hexafluorophosphate, lithium tetrafluoroborate, lithium trifluoromethanesulfonate, lithium hexafluoroarsenate, lithium bisoxalate borate
  • lithium perchlorate optionally selected from one or two of lithium hexafluorophosphate and lithium tetrafluoroborate, and more optionally selected from lithium hexafluorophosphate.
  • the mass percentage concentration of the second lithium salt in the electrolyte is in the range of 0% to 10%, and optionally in the range of 1% to 10%.
  • the lithium ion electrolyte of the present application during the first charge, a part of the second lithium salt will decompose to produce fluoride ions.
  • the fluoride ions react with the aluminum foil as the current collector to form an aluminum fluoride passivation layer, thereby inhibiting corrosion of the aluminum foil The role of.
  • the mass percentage concentration of the second lithium salt in the electrolyte is in the range of 0.1% to 10%, and optionally in the range of 3% to 5%.
  • the lithium ion electrolyte further includes additives selected from the group consisting of ethylene sulfate (DTD), lithium difluorophosphate (LiPO2F2), lithium difluorooxalate (LiODFB), maleic anhydride, sulfur dioxide ( One or more of SO2) and tris(trimethylsilane) phosphate (TMSP), optionally selected from ethylene sulfate (DTD), lithium difluorophosphate (LiPO2F2), lithium difluorooxalate (LiODFB) ), one or more of maleic anhydride and tris(trimethylsilane) phosphate (TMSP).
  • DTD ethylene sulfate
  • LiODFB lithium difluorooxalate
  • TMSP tris(trimethylsilane) phosphate
  • the above additives play the following roles in the charging and discharging process of the battery: During the charging process, the additives will reductively decompose, and part of the reduced decomposition products will be deposited on the negative electrode interface, especially on the new interface formed by the expansion of the silicon-based material in time , Participate in SEI film formation, inhibit the further occurrence of side reactions and improve cycle performance. In addition, the interfacial film formed on the negative electrode by the above additives has less resistance, which further improves the rate performance of the secondary battery.
  • the amount of the additive is 0.1% to 5% by weight, for example, 0.3% to 5% by weight, 0.5% to 5% by weight, or 0.1 % By weight to 2% by weight, 0.3% to 2% by weight, 0.5% to 2% by weight, 0.1% to 1% by weight, 0.3% to 1% by weight, 0.5% to 1% by weight, 0.1% to 0.5% by weight, 0.3% to 0.5% by weight. If the content of the additive is too small, it is difficult to form a stable interface film on the negative electrode interface, and the occurrence of side reactions cannot be effectively suppressed. If the content of the additive is too large, the rate performance of the battery will deteriorate. Optionally, the content of the additive is within each of the above ranges.
  • the electrolyte further includes one or more organic solvents.
  • the organic solvent is selected from dimethyl carbonate, diethyl carbonate, dipropyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, ethylene carbonate, propylene carbonate, ethylene carbonate, propylene carbonate, butene carbonate
  • esters ethylene propyl carbonate, ⁇ -butyrolactone, methyl formate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, methyl propionate and tetrahydrofuran are selected.
  • the mass percentage of the organic solvent in the electrolyte is 65% to 85%.
  • the above non-aqueous organic solvent has good thermal stability and electrochemical stability, and provides a stable electrochemical environment for the electrical performance of the secondary battery.
  • the above-mentioned electrolyte has relatively high electrical conductivity, and is particularly suitable for secondary batteries with silicon-based negative pole pieces.
  • the conductivity of the electrolyte at 25° C. is in the range of 6.5 to 11 mS/cm, optionally in the range of 8.0 to 11 mS/cm.
  • the above-mentioned electrolyte can be prepared according to conventional methods in the art.
  • the organic solvent and the electrolyte lithium salt and optional additives can be mixed uniformly to obtain the electrolyte.
  • the order of addition of each material is not particularly limited.
  • the electrolyte lithium salt and optional additives are added to the organic solvent and mixed uniformly to obtain the electrolyte.
  • the method can be that the electrolyte lithium salt is added to the organic solvent first, and then the optional additives are added to the organic solvent separately or simultaneously.
  • the positive pole piece can be selected from various conventional positive pole pieces commonly used in the field, and its composition and preparation methods are well known in the art.
  • the positive pole piece may include a positive current collector and a positive active material layer disposed on the positive current collector, and the positive active material layer may include a positive active material, a binder, a conductive material, and the like.
  • the positive electrode active material is a high nickel positive electrode active material represented by the structural formula Li a Ni 1-b M b O 2 , where a is in the range of 0.05 to 1.2, optionally 0.95 or greater, more optionally Is 1.0, b is in the range of 0 to 0.5, and M is at least one element selected from the group consisting of iron, cobalt, manganese, copper, zinc, aluminum, boron, gallium, and magnesium.
  • 0.2 ⁇ b ⁇ 0.5 is a high nickel positive electrode active material represented by the structural formula Li a Ni 1-b M b O 2 , where a is in the range of 0.05 to 1.2, optionally 0.95 or greater, more optionally Is 1.0, b is in the range of 0 to 0.5, and M is at least one element selected from the group consisting of iron, cobalt, manganese, copper, zinc, aluminum, boron, gallium, and magnesium.
  • 0.2 ⁇ b ⁇ 0.5 is a high nickel positive electrode active material represented by the structural formula Li
  • the separator used in the battery of the present application can be selected from various separators commonly used in the art.
  • the construction and preparation methods of these batteries are known per se. Due to the use of the above-mentioned negative pole piece and electrolyte, the battery can have improved rate performance and/or cycle performance.
  • the secondary battery has a 4C rate of 40% or higher and a capacity retention rate of 70% or higher.
  • FIG. 1 is a perspective view of an embodiment of a secondary battery 5.
  • Figure 2 is an exploded view of Figure 1. 1 to 2, the secondary battery 5 includes a case 51, an electrode assembly 52, a cap assembly 53, and an electrolyte (not shown).
  • the electrode assembly 52 is housed in the housing 51.
  • the number of electrode assemblies 52 is not limited, and may be one or more.
  • the electrode assembly 52 includes a positive pole piece, a negative pole piece, and a separator. The separator separates the positive pole piece and the negative pole piece.
  • the electrolyte is injected into the casing 51 and impregnates the electrode assembly 52, which includes, for example, a first pole piece, a second pole piece, and an isolation membrane.
  • the secondary battery 5 shown in FIG. 1 is a can type battery, but is not limited to this.
  • the secondary battery 5 may be a pouch type battery, that is, the casing 51 is replaced by a metal plastic film and the top cover assembly 53 is eliminated.
  • FIG. 3 is a perspective view of an embodiment of the battery module 4.
  • the battery module 4 provided by the second aspect of the present application includes the secondary battery 5 of the first aspect of the present application.
  • the battery module 4 includes a plurality of secondary batteries 5.
  • the plurality of secondary batteries 5 are arranged in the longitudinal direction.
  • the battery module 4 can be used as a power source or an energy storage device.
  • the number of secondary batteries 5 in the battery module 4 can be adjusted according to the application and capacity of the battery module 4.
  • FIG. 4 is a perspective view of an embodiment of the battery pack 1.
  • Fig. 5 is an exploded view of Fig. 4.
  • the battery pack 1 provided by the fourth aspect of the present application includes the battery module 4 of the second aspect of the present application.
  • the battery pack 1 includes an upper case 2, a lower case 3 and a battery module 4.
  • the upper case 2 and the lower case 3 are assembled together to form a space for accommodating the battery module 4.
  • the battery module 4 is placed in the space of the upper case 2 and the lower case 3 assembled together.
  • the output pole of the battery module 4 penetrates from one or between the upper case 2 and the lower case 3 to supply power to or charge from the outside.
  • the number and arrangement of the battery modules 4 used in the battery pack 1 can be determined according to actual needs.
  • Fig. 6 is a schematic diagram of an embodiment of a device using a secondary battery as a power source.
  • the device provided by the fourth aspect of the present application includes the secondary battery 5 of the first aspect of the present application, and the secondary battery 5 can be used as a power source or an energy storage unit of the device.
  • the device using the secondary battery 5 is an electric vehicle.
  • the device using the secondary battery 5 can be any electric vehicle except for electric vehicles (for example, electric buses, electric trams, electric bicycles, electric motorcycles, electric scooters, electric golf carts, electric trucks) ), electric ships, electric tools, electronic equipment and energy storage systems.
  • Electric vehicles can be electric pure electric vehicles, hybrid electric vehicles, and plug-in hybrid electric vehicles.
  • the device provided in the fourth aspect of the present application may include the battery module 4 of the second aspect of the present application.
  • the device provided in the fourth aspect of the present application may also include the battery pack of the fourth aspect of the present application. 1.
  • the silica powder is pulverized.
  • the polymers shown in Table 1 including polyacrylamide with a weight average molecular weight of 10 5 g/mol, polyacrylonitrile with a weight average molecular weight of 10 5 g/mol, and 10 4 g/mol polyacrylic acid and pyromellitic dianhydride-4,4'-diaminodiphenyl ether polyimide with a weight average molecular weight of 10 5 g/mol
  • crosslinking agent relative to polymer Ethylene glycol (0.05% by mass
  • the polymer slurry obtained above and the pulverized silica powder were mixed with the coating amount shown in Table 1, and stirred until uniform, thereby obtaining a negative electrode active material slurry.
  • the negative electrode active material slurry is dried at 50°C to 100°C until the solvent is completely removed, and the obtained product is sieved and heated for cross-linking to obtain the negative electrode active material.
  • the positive electrode active material LiNi 0.5 Mn 0.3 Co 0.2 O 2 , the conductive agent acetylene black, and the binder polyvinylidene fluoride (PVDF) are dissolved in the solvent N-methylpyrrolidone (NMP) in a weight ratio of 94:3:3 After fully stirring and mixing uniformly, the positive electrode slurry is obtained; then, the positive electrode slurry is uniformly coated on the positive electrode current collector aluminum (Al) foil, and then the positive electrode pole piece is obtained by drying, cold pressing and slitting.
  • NMP N-methylpyrrolidone
  • the 10wt% aqueous carboxymethyl cellulose binder is fully dissolved in water, and 10wt% carbon black conductive agent and 80wt% of the negative active material prepared above are added to make a uniformly dispersed slurry.
  • the slurry is evenly coated on the surface of the copper foil, and then transferred to a vacuum drying oven to completely dry.
  • the obtained pole piece is rolled and then punched to obtain a negative pole piece.
  • the organic solvent fluoroethylene carbonate/ethylene carbonate/ethyl methyl carbonate (FEC/EC/EMC) is 1:2: Mix at a weight ratio of 7, then dissolve the fully dried first lithium salt and the second lithium salt in the amount shown in Table 1 in an organic solvent, stir and dissolve, then add the additives shown in Table 1 as needed to obtain the corresponding Electrolyte.
  • Polyethylene (PE) porous polymer film is used as the separator.
  • the positive pole piece, the isolation film, and the negative pole piece are stacked in order, so that the isolation film is located between the positive pole piece and the negative pole piece for isolation, and is wound to obtain an electrode assembly. Put the electrode assembly in the outer package, inject the prepared basic electrolyte and package.
  • Test instrument high frequency infrared carbon and sulfur analyzer, model HCS-140, commercially available from: Shanghai Dekai Instrument Co., Ltd.
  • Test process Weigh an appropriate amount of negative electrode active material, and heat and burn it in the above-mentioned high frequency furnace under oxygen-rich conditions, so that the carbon contained in the negative electrode active material is oxidized to carbon dioxide.
  • the generated gas is processed and then introduced into the corresponding absorption cell to absorb the corresponding infrared radiation and convert it into the corresponding digital signal through the detector.
  • the obtained digital signal is sampled by a computer, linearly corrected, converted into a value proportional to the concentration of carbon dioxide or sulfur dioxide, and accumulated to obtain the accumulated value. Divide the accumulated value by the weight of the sample, multiply it by the correction factor, and subtract the blank to get the percentage of carbon or sulfur in the sample.
  • the amount of the polymer network coating layer in the negative active material is converted.
  • the lithium ion battery is discharged at a high rate at 25°C. Specifically, charge to 4.2V with a current of 1C, then discharge to 2.8V with a current of 4C, record the first discharge capacity, and divide the discharge capacity by the lithium-ion battery at 1C/1C charge and discharge at 25°C The first discharge capacity of the battery, the 4C rate performance of the battery is obtained.
  • Comparative Example 1 the silicon-based material is not coated, and although the secondary battery has a higher energy density, its cycle performance is extremely poor.
  • Comparative Example 4 a silicon-based material coated with a polymer network coating layer was used as the negative electrode active material, but since sulfonimide lithium salt was not used as the lithium salt, the rate performance of the secondary battery was significantly reduced.
  • Comparative Examples 2 and 3 the network coating layer covering the silicon-based material was either too large or too small, resulting in unsatisfactory cycle performance and 4C rate of the secondary battery.

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Abstract

一种二次电池（5），包括：正极片、负极片、间隔于正极片和负极片之间的隔离膜以及电解液，负极片包括负极集流体以及设置于负极集流体至少一侧的负极活性材料层，电解液包括有机溶剂和锂盐，其中，负极活性材料包括核结构和包覆在核结构表面至少一部分上的占负极活性材料总重量的至少0.5 wt％且至多10 wt％的聚合物的网络包覆层，核结构包括SiOx(0<x<2)，网络包覆层衍生自具有氰基、酰胺基、酰亚胺基、磺酰基、羧基、砜基中的一种或多种官能团的聚合物；并且锂盐包括下式I所表示的第一锂盐，在式I中，R1、R2各自独立地单独表示氟原子、碳原子数为1-20的氟代烷基或碳原子数为1-20的氟代烷氧基，并且n为1、2或3的整数。

Description

二次电池及其相关的电池模块、电池包和装置
相关申请的交叉引用
本申请要求享有于2019年08月22日提交的名称为“一种二次电池”的中国专利申请201910777649.7的优先权，该申请的全部内容通过引用并入本文中。
技术领域
本申请属于电化学技术领域，更具体地，本申请涉及一种二次电池。本申请还涉及与该二次电池相关的电池模块、电池包及装置。
背景技术
随着能源与环境问题的日益凸显，新能源产业得到了越来越多的重视。二次电池因其能量密度高、循环性能好等特点，作为一种重要的新型储能装置而被广泛应用。近年来，二次电池向高能量输出、宽适用条件方向不断发展。构成二次电池的四大主要材料：正极材料、负极材料、隔离膜、电解液方面均受到研究者的关注。
近年来，非碳类负极活性材料在二次电池的负极活性材料领域引起了极大的关注。作为非碳类负极活性材料的代表，硅基材料具有比传统石墨更高的理论容量(4200mAh/g)，嵌锂电位低，电化学可逆容量高，安全性能好，资源丰富的优势，成为受关注的焦点。
发明内容
本申请的第一方面提供了一种二次电池，其包括：正极片、负极片、间隔于正极片和负极片之间的隔离膜以及电解液，所述负极片包括负极集流体以及设置于所述负极集流体至少一侧的负极活性材料层，所述电解液包括有机溶剂和锂盐，其中，
所述负极活性材料包括核结构和包覆在所述核结构的至少一部分表面上的占所述负极活性材料总质量至少0.5质量％且至多10质量％的量的聚合物网络包覆层，所述核结构包括SiO x(0<x<2)，所述网络包覆层衍生自具有氰基、酰胺基、酰亚胺基、磺酰基、羧基、砜基中的一种或多种官能团的聚合物；并且
所述锂盐包括下式I所表示的第一锂盐：
Figure PCTCN2020108687-appb-000001
在式I中，R 1、R 2各自独立地单独表示氟原子、碳原子数为1-20的氟代烷基或碳原子数为1-20的氟代烷氧基，并且n为1、2或3的整数。
在根据上述第一方面所述的二次电池中，所述聚合物选自聚酰亚胺、聚丙烯酸、聚丙烯酰胺、聚丙烯腈中的至少一种。
在根据上述第一方面所述的任一二次电池中，所述聚合物网络包覆层以相对于所述负极活性材料的总质量1质量％至5质量％的量存在。
在根据上述第一方面所述的任一二次电池中，所述第一锂盐选自双氟磺酰亚胺锂、氟磺酰(三氟甲基磺酰)亚胺锂、双(三氟甲基磺酰)亚胺锂、甲基磺酰三氟甲基磺酰亚胺锂、三氟甲基磺酰五氟乙基磺酰亚胺锂、双(五氟乙基磺酰)亚胺锂、LiN(SO 2OCH 2CF 3) 2、LiN(SO 2OCH 2CF 2CF 3) 2、LiN(SO 2OCH 2CF 2CF 2H) 2、LiN[(SO 2OCH(CF 3) 2]、FSO 2N -(Li +)SO 2N -(Li +)SO 2F、FSO 2N -(Li +)SO 2N -(Li +)SO 2N -(Li +)SO 2F、FSO 2N -(Li +)SO 2N -(Li +)SO 2CF 3、CF 3SO 2N -(Li +)SO 2N -(Li +)SO 2CF 3、FSO 2N -(Li +)SO 2N -(Li +)SO 2N -(Li +)SO 2CF 3中的一种或多种，可选地选自选自双氟磺酰亚胺锂、氟磺酰(三氟甲基磺酰)亚胺锂、双(三氟甲基磺酰)亚胺锂、FSO 2N -(Li +)SO 2N -(Li +)SO 2F、FSO 2N -(Li +)SO 2N -(Li +)SO 2N -(Li +)SO 2F、FSO 2N -(Li +)SO 2N -(Li +)SO 2CF 3、CF 3SO 2N -(Li +)SO 2N -(Li +)SO 2CF 3、FSO 2N -(Li +)SO 2N -(Li +)SO 2N -(Li +)SO 2CF 3中的一种或多种。
在根据上述第一方面所述的任一二次电池中，所述第一锂盐在所述电解液中的质量百分浓度在5％至25％的范围内，可选在10％至20％的范围内。
在根据上述第一方面所述的任一二次电池中，所述锂盐还包括第二锂盐，所述第二锂盐选自六氟磷酸锂、四氟硼酸锂、三氟甲基磺酸锂、六氟砷酸锂、双草酸硼酸锂和高氯酸锂中的一种或多种，可选地选自六氟磷酸锂和四氟硼酸锂中的一种或两种，更可选地选自六氟磷酸锂。
在根据上述第一方面所述的任一二次电池中，所述第二锂盐在所述电解液中的质量百分浓度在0.1％至10％的范围内，可选在3％至5％的范围内。
在根据上述第一方面所述的任一二次电池中，所述电解液还包括添加剂，所述添加剂选自硫酸亚乙酯(DTD)、二氟磷酸锂(LiPO 2F 2)、二氟草酸硼酸锂(LiODFB)、马来酸酐、二氧化硫(SO 2)和三(三甲基硅烷)磷酸酯(TMSP)中的一种或多种。
在根据上述第一方面所述的任一二次电池中，所述添加剂在所述电解液中的质量百分浓度在0％至5％的范围内，可选在0.1至3％的范围内，更可选在0.2％至2％的范围内。
在根据上述第一方面所述的任一二次电池中，所述有机溶剂选自碳酸亚丙酯、碳酸亚乙酯、碳酸二甲酯、碳酸二乙酯、碳酸二丙酯、碳酸甲乙酯、碳酸甲丙酯、碳酸亚乙烯酯、氟代碳酸亚乙酯、甲酸甲酯、乙酸乙酯、丙酸乙酯、丙酸丙酯、丁酸甲酯、丙烯酸甲酯、乙烯亚硫酸酯、丙烯亚硫酸酯、亚硫酸二甲酯、二乙基亚硫酸酯、1,3-丙磺酸内酯、硫酸乙烯酯、酸酐、N-甲基吡咯烷酮、N-甲基甲酰胺、N-甲基乙酰胺、乙腈、N,N-二甲基甲酰胺、环丁砜、二甲亚砜、甲硫醚、γ-丁内酯、四氢呋喃、含氟环状有机酯、含硫环状有机酯和含不饱和键环状有机酯中的一种或多种，可选地，所述有机溶剂在所述电解液中的质量百分数为65％～85％。
在根据上述第一方面所述的任一二次电池中，所述电池具有40％或更高的4C倍率，并且具有70％或更高的容量保持率。
本申请的第二方面提供了一种电池模块，其包括本申请的第一方面所 述的二次电池。
本申请的第三方面提供了一种电池包，其包括本申请的第二方面所述的电池模块。
本申请的第四方面提供了一种装置，其包括本申请的第一方面所述的二次电池，所述二次电池用作所述装置的电源或能力存储单元；可选地，所述装置包括电动车辆、混合动力电动车辆、插电式混合动力电动车辆、电动自行车、电动踏板车、电动高尔夫球车、电动卡车、电动船舶、储能系统。
在根据本申请的二次电池中，负极活性材料具有核壳结构，内核的硅基材料具有较高的克容量，硅基内核材料表面包覆有一层聚合物的网络包覆层，可以明显抑制硅基材料的膨胀，从而改善电池的循环性能。而且，在电池的装配过程中，将含有磺酰亚胺锂的电解液与上述负极活性材料配合可以获得兼顾容量和动力学循环性能的二次电池。
并非受缚于任何理论，发明人提供如下解释，以便本申请能够被更好地理解。
在根据本申请的二次电池中，采用亚胺型锂盐的电解液，一方面由于磺酰亚胺型锂盐的阴离子自身较常用锂盐LiPF 6的阴离子PF 6 -大，自身迁移难，提高了Li +的相对迁移能力，另一方面，磺酰亚胺型阴离子是个大共轭结构，电子云密度小，与Li +的相互作用力小，以上两方面使得由其配制形成的电解液具有较高的电导率。而且，磺酰亚胺型锂盐的阴离子与网络包覆层中的聚合物具有较强的相似相溶性，溶剂化的Li +更易通过网络包覆层，提高了电解液在负极活性材料界面处的浸润性和导离子性。
采用衍生自具有氰基、酰胺基、酰亚胺基、磺酰基、羧基、砜中的一种或多种官能团的聚合物网络层包覆的SiO x作为负极活性材料，虽然可以改善负极片的膨胀，但通常会恶化电化学性能(如倍率性能)。
在根据本申请的二次电池的装配过程中，发明人将以上二者联合使用，并且惊讶地发现了这二者可以产生协同效应。因而，根据本申请的二次电池具有高能量密度和动力学循环性能。
本申请的一个或多个实施方案的细节在以下的说明书中阐明。根据说 明书和权利要求，本申请其它特征、目的和优点将变得清楚。
定义
描述本申请的内容时，不使用数量词时(尤其在权利要求书的内容中)应解释为涵盖单数和复数，除非另有说明或者与上下文明显矛盾。
在组合物被描述为包括或包含特定组分的情况下，预计该组合物中并不排除本申请未涉及的可选组分，并且预计该组合物可由所涉及的组分构成或组成，或者在方法被描述为包括或包含特定工艺步骤的情况下，预计该方法中并不排除本申请未涉及的可选工艺步骤，并且预计该方法可由所涉及的工艺步骤构成或组成。
为了简便，本文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。
在本申请中，术语“第一锂盐”是指在电解液中起主要作用的锂盐，通常其在电解液中的质量百分含量在5质量％或以上。
在本申请中，术语“第二锂盐”是指在电解液中起次要作用的锂盐，例如用于降低电解液的成本、抑制第一锂盐的使用所引起的负面作用等，通常其在电解液中的质量百分含量至多为10质量％或更低，例如为5质量％或以下，例如3质量％或以下。
在本申请中，“聚合物的网络包覆层”是用于包覆作为内核的硅基材料的层，其具有由交联的聚合物形成的网络结构。为了用于形成该网络包覆层，所使用的聚合物通常具有氰基、酰胺基、酰亚胺基、磺酰基、羧基、砜基中中的一种或多种官能团，而且可以使用选自如下交联剂：乙二醇、丙三醇、三亚乙基四胺、二甲胺基丙胺、含硫化合物中的一种或多种，可选为乙二醇。
本文中在描述基团或化合物的上下文中，术语“氟代”是指其中一个或多个氢原子被氟原子取代的基团或化合物。可选地，氟代是全氟代的或部分氟代的。例如，氟代甲基包括但不限于-CF 3、-CHF 2和-CH 2F。
当在二次电池的上下文中使用时，术语“4C倍率”是用于衡量二次电池的容量的参数。通常，4C倍率越高，二次电池的容量越大。
当在二次电池的上下文中使用时，术语“容量保持率”是用于衡量二次电池在25℃下的循环性能的参数。通常，容量保持率越高，二次电池的循环动力学性能越好。
术语“可选的”和“可选地”是指在某些情况下可提供某些益处的本申请实施方案。然而，在相同或其他情况下，其他实施方案也可能是可选的。另外，一个或多个可选的实施方案的叙述不意味着其他实施方案是不可用的，并且不旨在将其他实施方案排除在本申请范围外。
附图说明
图1是二次电池的一实施方式的立体图。
图2是图1的分解图。
图3是电池模块的一实施方式的立体图。
图4是电池包的一实施方式的立体图。
图5是图4的分解图。
图6是二次电池作为电源的装置的一实施方式的示意图。
其中，附图标记说明如下：
1电池包
2上箱体
3下箱体
4电池模块
5二次电池
51壳体
52电极组件
53顶盖组件
具体实施方式
下面详细说明根据本申请的二次电池。
根据本申请的二次电池，包括：正极片、负极片、间隔于正极片和负极片之间的隔离膜以及电解液，负极片包括负极集流体以及设置于负极集流体至少一侧的负极活性材料层，电解液包括有机溶剂和锂盐。
首先说明本申请的二次电池中的负极活性材料。在根据本申请的实施方式中，负极活性材料具有核壳结构，包括核结构和包覆在核结构表面的至少一部分上的聚合物的网络包覆层，核结构包括SiO x(0<x<2)，聚合物网络包覆层占负极活性材料总质量至少0.5质量％且至多10质量％，而且网络包覆层衍生自具有氰基、酰胺基、酰亚胺基、磺酰基、羧基、砜基中的一种或多种官能团的聚合物。在根据本申请的负极活性材料中，用于包覆核结构的包覆层是由交联的聚合物形成的网络结构。本申请的发明人惊讶地发现，将由交联的聚合物形成的具有网络结构的聚合物层用来包覆硅基材料，可以明显抑制作为核结构的硅基材料的膨胀，而且在与特定的电解液配合使用的情况下，并不会明显恶化负极活性材料的导电性能，这在本申请之前是难以预见的。
在二次电池领域，当硅基材料作为负极活性材料使用时，其在嵌锂过程中会产生巨大的体积膨胀(约400％)，导致负极活性材料粉化脱落以及浸润的电解液被大量挤出从而在负极材料与电解液间存在显著的固液界面变化，这都极大地降低了电池的循环性能。在相关应用中，可选使用单质碳来包覆该硅基材料，以减少硅基材料的膨胀。这种碳单质包覆层通常通过甲烷、乙炔等气相有机物的物理蒸镀法、化学蒸镀法来形成。然而，这种方法具有制备工艺复杂、设备投资高的问题。与之相比，根据本申请的负极活性材料可以通过简单的混合、加热交联工艺获得，这大大降低了生产成本，扩大了硅基材料的应用前景。
根据本申请的一些实施方式，在负极活性材料中，可选地，网络包覆层衍生自包括如下的聚合物：聚酰亚胺、聚丙烯腈、聚丙烯酰胺、聚丙烯酸、海藻酸钠或其任意组合。
根据本申请的一些实施方式，在负极活性材料中，可选地，网络包覆层包覆在核结构80％及以上的表面上，可选在核结构85％及以上的表面上，更可选在核结构90％及以上的表面上，还要更可选在核结构95％及以上的表面上，最可选在核结构99％及以上的表面上。包覆面积过低会导致过多的核结构表面直接与电解液接触，在电池循环过程中不断地产生副反应，消耗活性离子，从而恶化电池循环性能。
根据本申请的一些实施方式，在负极活性材料中，可选地，网络包覆层的质量占负极活性材料总质量的0.5％至10％，更可选为1％至5％。网络包覆层的质量占负极活性材料总质量之比是根据元素测定仪测定的来自网络包覆层的C元素经换算确定的。在本申请的聚合物网络包覆层是采用含硫化合物交联的实施方式中，聚合物网络包覆层在负极活性材料中的质量占比可以采用高频红外C-S分析仪通过测定出的C元素和可选的S元素经换算确定。
根据本申请的一些实施方式，在负极活性材料中，可选地，网络包覆层的厚度为10纳米至700纳米，可选为100纳米至400纳米。
申请人通过大量研究发现，电池的倍率性能和循环性能与负极活性材料的聚合物的网络包覆层有很大关系。众所周知，硅基材料由于具有很高的理论容量(4200mAh/g)，嵌锂电位低，电化学可逆容量高，安全性能好，资源丰富等优势，成为其中高能量密度锂离子电池最受关注的负极材料。但是，硅基材料在循环过程中会产生巨大的体积膨胀(约20为400％)，导致在充放电过程中出现活性材料的粉化脱落，极大程度降低了电池的循环性能。Si材料表面包覆一层聚合物网络包覆层，可以明显改善硅颗粒膨胀。网络包覆层过少会导致过多的核结构表面直接与电解液接触，在电池循环过程中不断地产生副反应，消耗活性离子，从而恶化电池循环性能。网络包覆层过厚，导致导电子和离子传输受阻，影响电池的充电倍率和功率性能，太大倍率充电，会导致ALP，从而恶化循环性能。
因此，在本申请的一个可选实施方式中，聚合物网络包覆层以相对于负极活性材料的总质量0.5质量％至10质量％的量存在，或者以相对于负极活性材料的总质量1质量％至10质量％的量存在，或者以相对于负极活 性材料的总质量3质量％至10质量％的量存在，或者以相对于负极活性材料的总质量5质量％至10质量％的量存在，或者以相对于负极活性材料的总质量8质量％至10质量％的量存在，或者以相对于负极活性材料的总质量0.5质量％至8质量％的量存在，或者以相对于负极活性材料的总质量1质量％至8质量％的量存在，或者以相对于负极活性材料的总质量3质量％至8质量％的量存在，或者以相对于负极活性材料的总质量5质量％至8质量％的量存在，或者以相对于负极活性材料的总质量0.5质量％至5质量％的量存在，或者以相对于负极活性材料的总质量1质量％至5质量％的量存在，或者以相对于负极活性材料的总质量3质量％至5质量％的量存在，或者以相对于负极活性材料的总质量5质量％至8质量％的量存在。特别可选地，所述聚合物网络包覆层以相对于负极活性材料的总质量1质量％至5质量％的量存在。
在本申请的一个实施方式中，负极活性材料可以通过如下方法制备：(1)将SiOx(0<x<2)粉末进行粉碎处理，得到一定粒径分布的材料；(2)将一定质量的聚合物以及相应的交联剂溶解到溶剂中，配制成聚合物浆料1；(3)向浆料1中加入步骤(1)的SiOx(0<x<2)粉末，搅拌至混合均匀得到浆料2；(4)将浆料2在50℃至100℃下进行干燥，直到溶剂完全除去，将得到的产物过筛并且升温胶料，以得到上述负极活性材料。可选地，聚合物的质量占SiOx(0<x<2)粉末的质量的1％至10％。可选地，在浆料1中还可以加入一定质量的导电材料。
在上述制备方法中，步骤(1)中的溶剂可选自水、丙酮、二甲基吡咯烷酮、二甲基甲酰胺、乙醇中的一种或几种。
在上述制备方法中，导电材料可选自导电炭黑、碳纳米管、石墨烯中的一种或几种。导电剂的加入量占聚合物质量的范围10至30％。
在上述制备方法中，交联剂可选自乙二醇、丙三醇、三亚乙基四胺、二甲胺基丙胺、含硫化合物中的一种或多种，可选为含硫化合物。含硫化合物可选自硫单质、硫化氢、噻吩中的一种或几种。可选地，交联剂的质量占聚合物质量的10％至30％。
在上述制备方法中，交联温度可选为300℃至500℃，将温度控制在此范围内可避免聚合物发生炭化。
由此得到的负极活性材料直接使用或者与其他常规负极活性材料组合使用用于制造负极极片。
根据本申请的负极极片可以选用本领域常用的各种常规负极极片，其构成和制备方法是本领域公知的。例如，负极极片可以包括负极集流体和设置于负极集流体上负极活性材料层，负极活性材料层可以包括上述负极活性材料、可选的其它负极活性材料、粘结剂和导电材料等。其它负极活性材料例如为诸如石墨(人造石墨或天然石墨)、导电炭黑、碳纤维等的碳质材料，例如Sn、Ge、Bi、Sn、In等金属或半金属材料或其合金，含锂氮化物或含锂氧化物，锂金属或锂铝合金等。
接下来说明本申请的二次电池中的电解液。在根据本申请的一些实施方式中，电解液包含有机溶剂和锂盐。锂盐包括下式I所表示的第一锂盐：
Figure PCTCN2020108687-appb-000002
在式I中，R 1、R 2各自独立地单独表示氟原子、碳原子数为1-20的氟代烷基或碳原子数为1-20的氟代烷氧基，并且n为1、2或3的整数。
在上述通式Ⅰ中，碳原子数为1至20的氟代烷基中，氟原子的取代个数及其取代位置并没有特别的限制，可根据实际需求选择氟原子对烷基中的部分氢原子或者全部氢原子进行取代。例如，氟原子的个数可为1个、2个、3个、4个或多个。
作为氟代烷基的实例，具体可以举出：氟甲基、2-氟异丁基、2-氟乙基、1-氟乙基、3-氟正丙基、2-氟异丙基、4-氟正丁基、3-氟仲丁基、2-氟仲丁基、5-氟正戊基、1-氟正戊基、4-氟异戊基、3-氟异戊基、6-氟-正己基、4-氟-异己基、7-氟-正庚基、8-氟-正辛基、1,2-二氟乙基、二氟甲基、三氟甲基、五氟乙基、全氟异丙基、全氟丁基、全氟环己基等。
在通式I中，碳原子数为1至20的氟代烷氧基中，与氟原子相连的烷氧基的种类并没有受到具体的限制，可根据实际需求进行选择，例如链状烷氧基和环状烷氧基均可，链状烷氧基又包括直链烷氧基和支链烷氧基。在烷氧基中，氧原子的个数可选为1个或2个。另外，与烷氧基相连接的氟原子的个数可为1个、2个、3个、4个、5个或六个。
作为氟代烷氧基的实例，具体可以举出：氟甲氧基、2-氟乙氧基、3-氟正丙氧基、2-氟异丙氧基、4-氟正丁氧基、3-氟仲丁氧基、5-氟正戊氧基、4-氟异戊氧基、3-氟叔戊氧基、3-氟-2,2-二甲基丙氧基、3-氟-1-乙基丙氧基、4-氟-1-甲基丁氧基、6-氟正己氧基、5-氟异己氧基、3-氟-1,1,2-三甲基丙氧基、2,2,2-三氟乙氧基、2,2,3,3,3-五氟丙氧基、2,2,3,3-四氟丙氧基、OCH(CF 3) 2等等。
可选地，第一锂盐选自双氟磺酰亚胺锂、氟磺酰(三氟甲基磺酰)亚胺锂、双(三氟甲基磺酰)亚胺锂、甲基磺酰三氟甲基磺酰亚胺锂、三氟甲基磺酰五氟乙基磺酰亚胺锂、双(五氟乙基磺酰)亚胺锂、LiN(SO 2OCH 2CF 3) 2、LiN(SO 2OCH 2CF 2CF 3) 2、LiN(SO 2OCH 2CF 2CF 2H) 2、LiN[(SO 2OCH(CF 3) 2]、FSO 2N -(Li +)SO 2N -(Li +)SO 2F、FSO 2N -(Li +)SO 2N -(Li +)SO 2N -(Li +)SO 2F、FSO 2N -(Li +)SO 2N -(Li +)SO 2CF 3、CF 3SO 2N -(Li +)SO 2N -(Li +)SO 2CF 3、FSO 2N -(Li +)SO 2N -(Li +)SO 2N -(Li +)SO 2CF 3中的一种或多种，可选地选自双氟磺酰亚胺锂、氟磺酰(三氟甲基磺酰)亚胺锂、双(三氟甲基磺酰)亚胺锂、FSO 2N -(Li +)SO 2N -(Li +)SO 2F、FSO 2N -(Li +)SO 2N -(Li +)SO 2N -(Li +)SO 2F、FSO 2N -(Li +)SO 2N -(Li +)SO 2CF 3、CF 3SO 2N -(Li +)SO 2N -(Li +)SO 2CF 3、FSO 2N -(Li +)SO 2N -(Li +)SO 2N -(Li +)SO 2CF 3中的一种或多种。
采用本申请中的第一锂盐作为主锂盐使用，获得了非常有益的效果。含氟磺酰亚胺锂盐由于本身的特殊结构特性，因而具有较高的电导率，可以提高电池的动力学性能。具体地，在含氟磺酰亚胺锂盐中，亚胺型阴离子较常用PF6-大，迁移难，提高了Li+的相对迁移能力；另外，亚胺型阴离子是个大共轭结构，电子云密度小，与Li+的相互作用力小，以上两方面共同作用，使得含有含氟磺酰亚胺锂盐的电解液具有较高的电导率。另外，亚胺型锂盐阴离子与上述网络包覆层的聚合物具有较强的相似相溶 性，溶剂化的Li+与亚胺阴离子更易通过聚合物层，提高了电解液在负极极片表面的浸润性和离子传导型，有助于提高电池的动力学循环性能。但考虑到实际应用，第一锂盐的用量通常不能过高，否则会对集流体特别是铝制集流体具有一定的腐蚀性。
因此，在根据本申请的一些实施方式中，第一锂盐在电解液中的质量百分浓度在5％至25％的范围内，可选在10％至20％的范围内。
根据本申请的一些实施方式，锂离子电解液还包含第二锂盐，第二锂盐选自六氟磷酸锂、四氟硼酸锂、三氟甲基磺酸锂、六氟砷酸锂、双草酸硼酸锂和高氯酸锂中的一种或多种，可选地选自六氟磷酸锂和四氟硼酸锂中的一种或两种，更可选地选自六氟磷酸锂。
在本申请的一些实施方式中，第二锂盐在电解液中的质量百分浓度在0％至10％的范围内，可选在1％至10％的范围内。
发明人经过研究发现，当含氟磺酰亚胺锂盐含量较少时，电解液的电导率得不到有效提升；含量过多时，高浓度锂盐对铝箔的腐蚀将会体现出来。在本申请的锂离子电解液中，在首次充电时，第二锂盐的一部分会分解产生氟离子，氟离子与作为集流体的铝箔反应生成氟化铝钝化层，进而起到抑制腐蚀铝箔的作用。经研究发现，这些第二锂盐在电解液中质量百分含量为3质量％或更高时，可以有效抑制第一锂盐对铝箔腐蚀。但是，这种第二锂盐的用量不宜过高。第二锂盐加入量过多，一方面导致电解液的粘度过大，另一方面第二锂盐相对于作为第一锂盐的亚胺型锂盐具有明显较低的电导率，会恶化二次电池倍率性能和循环。若加入量过低，对铝箔腐蚀的抑制会降低，导致循环性能恶化。因此，在本申请一些实施方式中，第二锂盐在电解液中的质量百分浓度在0.1％至10％的范围内，可选在3％至5％的范围内。
根据本申请的一些实施方式，锂离子电解液还包含添加剂，添加剂选自硫酸亚乙酯(DTD)、二氟磷酸锂(LiPO2F2)、二氟草酸硼酸锂(LiODFB)、马来酸酐、二氧化硫(SO2)和三(三甲基硅烷)磷酸酯(TMSP)中的一种或多种，可选选自硫酸亚乙酯(DTD)、二氟磷酸锂 (LiPO2F2)、二氟草酸硼酸锂(LiODFB)、马来酸酐和三(三甲基硅烷)磷酸酯(TMSP)中的一种或多种。
以上添加剂在电池的充放电过程中起如下作用：在充电过程中，添加剂会还原分解，部分还原分解产物会沉积在负极界面上，特别地及时沉积在硅基材料膨胀而形成的新的界面上，参与SEI成膜，抑制了副反应的进一步发生，改善了循环性能。另外，上述添加剂在负极上形成的界面膜具有较少的阻抗，进一步提高了二次电池的倍率性能。
在一些可选的实施方式中，相对于电解液的总重量，添加剂的量为0.1重量％至5重量％，例如为0.3重量％至5重量％，为0.5重量％至5重量％，为0.1重量％至2重量％，为0.3重量％至2重量％，为0.5重量％至2重量％，为0.1重量％至1重量％，0.3重量％至1重量％，0.5重量％至1重量％，0.1重量％至0.5重量％，0.3重量％至0.5重量％。如果添加剂的含量过少，则其难以在负极界面形成稳定的界面膜，无法有效的抑制副反应的发生。如果添加剂的含量过多时，则会使电池的倍率性能恶化。可选地，添加剂的含量在上述各范围内。
根据本申请的一些实施方式，电解液还包含一种或多种有机溶剂。有机溶剂选自碳酸二甲酯、碳酸二乙酯、碳酸二丙酯、碳酸甲乙酯、碳酸甲丙酯，碳酸亚乙酯、碳酸亚丙酯、碳酸乙烯酯、碳酸丙烯酯、碳酸丁烯酯、碳酸乙丙酯、γ-丁内酯、甲酸甲酯、乙酸乙酯、乙酸丙酯、丙酸甲酯、丙酸乙酯、丙酸甲酯和四氢呋喃中选择一种或多种。在一些可选的实施方式中，有机溶剂在电解液中的质量百分数为65％至85％。
上述非水有机溶剂具有良好的热稳定性和电化学稳定性，为二次电池的电性能提供了稳定的电化学环境。
上述电解液具有较高的电导率，特别适于具有硅基负极极片的二次电池。在本申请的一些实施方式中，电解液在25℃下的电导率在6.5至11mS/cm的范围内，可选在8.0至11mS/cm的范围内。
上述电解液可以按照本领域常规的方法制备。可以是将有机溶剂和电解质锂盐及可选的添加剂混合均匀，得到电解液。其中各物料的添加顺序并没有特别的限制。例如，将电解质锂盐及可选的添加剂加入到有机溶剂 中混合均匀，得到电解液。其中可以是先将电解质锂盐加入有机溶剂中，然后再将可选的添加剂分别或同时加入有机溶剂中。
正极极片可以选用本领域常用的各种常规正极极片，其构成和制备方法是本领域公知的。例如，正极极片可以包括正极集流体和设置于正极集流体上正极活性材料层，正极活性材料层可以包括正极活性材料、粘结剂和导电材料等。可选地，正极活性材料是由结构式Li aNi 1-bM bO 2所表示的高镍正极活性材料，其中a在0.05至1.2的范围内，可选为0.95或更大，更可选为1.0，b在0至0.5的范围内，并且M选自由铁、钴、锰、铜、锌、铝、硼、镓和镁组成的组的元素中的至少一种。可选地，0.2≤b≤0.5。
用于本申请的电池的隔膜可以选用本领域常用的各种隔膜。
这些电池的构造和制备方法本身是公知的。由于使用了上述的负极极片和电解液，电池可以具有改善的倍率性能和/或循环性能。在本申请的一个实施方式中，二次电池具有40％或更高的4C倍率和70％或更高的容量保持率。
接下来，说明本申请的二次电池的结构。图1是二次电池5的一实施方式的立体图。图2是图1的分解图。参照图1至图2，二次电池5包括壳体51、电极组件52、顶盖组件53以及电解液(未示出)。
电极组件52收容于壳体51内。电极组件52的数量不受限制，可以为一个或多个。电极组件52包括正极极片、负极极片、隔离膜。隔离膜将正极极片和负极极片隔开。电解液注入在壳体51内并浸渍电极组件52，电极组件包括例如第一极片、第二极片以及隔离膜。
注意的是图1所示的二次电池5为罐型电池，但不限于此，二次电池5可以是袋型电池，即壳体51由金属塑膜替代且取消顶盖组件53。
接下来说明本申请第二方面的电池模块。
图3是电池模块4的一实施方式的立体图。
本申请第二方面提供的电池模块4包括本申请的第一方面的二次电池5。
参照图3，电池模块4包括多个二次电池5。多个二次电池5沿纵向排列。电池模块4可以作为电源或储能装置。电池模块4中的二次电池5的数量可以根据电池模块4的应用和容量进行调节。
接下来说明本申请第三方面的电池包。
图4是电池包1的一实施方式的立体图。图5是图4的分解图。
本申请第四方面提供的电池包1包括本申请的第二方面的电池模块4。
具体地，参照图4和图5，电池包1包括上箱体2、下箱体3以及电池模块4。上箱体2和下箱体3组装在一起并形成收容电池模块4的空间。电池模块4置于组装在一起的上箱体2和下箱体3的空间内。电池模块4的输出极从上箱体2和下箱体3的其中之一或二者之间穿出，以向外部供电或从外部充电。电池包1采用的电池模块4的数量和排列可以依据实际需要来确定。
接下来说明本申请第四方面的装置。
图6是二次电池作为电源的装置的一实施方式的示意图。
本申请第四方面提供的装置包括本申请的第一方面的二次电池5，二次电池5可以用作装置的电源或能量存储单元。在图6中，采用二次电池5的装置为电动汽车。当然不限于此，采用二次电池5的装置可以为除电动汽车外的任何电动车辆(例如电动大巴、电动有轨电车、电动自行车、电动摩托车、电动踏板车、电动高尔夫球车、电动卡车)、电动船舶、电动工具、电子设备及储能系统。电动汽车可以为电动纯电动车、混合动力电动车、插电式混合动力电动车。当然，依据实际使用形式，本申请第四方面提供的装置可包括本申请的第二方面的电池模块4，当然，本申请第四方面提供的装置也可包括本申请的第四方面的电池包1。
实施例
为了使本申请的申请目的、技术方案和有益技术效果更加清晰，以下结合实施例进一步详细描述本申请。但是，应当理解的是，本申请的实施例仅仅是为了解释本申请，并非为了限制本申请，且本申请的实施例并不局限于说明书中给出的实施例。实施例中未注明实验条件采用常规条件，或采用材料供应商或设备供应商推荐的条件。
1.负极活性材料的制备
将二氧化硅粉末进行粉碎处理。与此同时，在另一个容器中将表1所示聚合物(包括重均分子量为10 5g/mol的聚丙烯酰胺、重均分子量为10 5g/mol的聚丙烯腈、重均分子量为10 4g/mol的聚丙烯酸以及重均分子量为10 5g/mol的均苯四甲酸二酐-4,4’-二氨基二苯醚聚酰亚胺)以及交联剂(相对于聚合物质量百分比为0.05％的乙二醇)溶解到二甲基吡咯烷酮中，配制成聚合物浆料。接着，以表1所示的包覆量，将以上得到的聚合物浆料与经粉碎的二氧化硅粉末进行混合，并搅拌至均匀，从而得到负极活性材料浆料。将负极活性材料浆料在50℃至100℃下进行干燥，直到溶剂完全除去，将得到的产物过筛并升温交联得到负极活性材料。
2.二次电池的制备过程
(1)正极极片的制备
将正极活性材料LiNi 0.5Mn 0.3Co 0.2O 2、导电剂乙炔黑、粘结剂聚偏二氟乙烯(PVDF)按重量比为94:3:3溶于溶剂N-甲基吡咯烷酮(NMP)中，充分搅拌混合均匀后得到正极浆料；之后将正极浆料均匀涂覆于正极集流体铝(Al)箔上，之后经过烘干、冷压、分切，得到正极极片。
(2)负极极片的制备
将10wt％水性羧甲基纤维素粘结剂充分溶解到水中，加入10wt％炭黑导电剂与80wt％上述制备的负极活性材料制成分散均匀的浆料。将浆料均匀涂敷在铜箔表面，然后转移到真空干燥箱中完全干燥。将得到的极片进行辊压，然后将进行冲裁，得到负极极片。
(3)电解液的制备
在氩气气氛手套箱中(H2O<0.1ppm，O2<0.1ppm)，将有机溶剂氟代 碳酸亚乙酯/碳酸亚乙酯/碳酸甲乙酯(FEC/EC/EMC)按1:2:7的重量比进行混合，接着将表1所示用量的充分干燥的第一锂盐和第二锂盐溶解于有机溶剂中，搅拌溶解后，接着根据需要加入表1所示的添加剂，得到相应电解液。
(4)隔离膜的制备
以聚乙烯(PE)多孔聚合薄膜作为隔离膜。
(5)二次电池的制备
将正极极片、隔离膜、负极极片按顺序叠好，使隔离膜处于正极极片和负极极片中间起到隔离作用，并卷绕得到电极组件。将电极组件置于外包装中，注入配好的基础电解液并封装。
2.性能测试
(1)电解液的电导率测试
量取一定量的以上配制形成的电解液，平均分成3份，然后采用北京格乐普电导率仪DDL-9601，在25℃下测定各个样品的电导率。将所得结果求平均，得到电解液的电导率。
(2)负极活性材料中聚合物包覆量的测试
测试仪器：高频红外碳硫分析仪，型号HCS-140，商购自：上海德凯仪器有限公司。
测试过程：称取适当量的负极活性材料，将其在富氧条件下在上述高频炉中进行加热燃烧，使得负极活性材料中包含的碳氧化成二氧化碳。将生成的气体经处理后引入相应的吸收池中，对相应的红外辐射进行吸收，并经由探测器转化成对应的数字信号。所得数字信号经由计算机采样，经线性校正，转换成与二氧化碳或二氧化硫浓度成正比的数值，进行累加，得到累加值。将所得累加值除以样品重量，乘以校正系数，扣除空白，即可得到样品中的碳或硫百分含量。
基于样品中的碳或硫百分含量以及所采用的聚合物的分子量，换算得到负极活性材料中聚合物网络包覆层的量。
(3)二次电池的循环性能测试将装配形成的锂离子电池在25℃下进行充放电。具体地，先以0.5C的电流充电至4.2V，然后再以0.5C的电流 放电至2.0V，记录下第一次的放电容量。然后，使电池进行0.5C/0.5C充放电循环400次，记录第400次的电池放电容量，将第400次的放电容量除以第1次的放电容量，得到充放电循环400次后的电池容量保持率。
(4)二次电池的倍率测试
对锂离子电池于25℃下进行大倍率放电。具体地，以1C的电流充电至4.2V，然后再以4C的电流放电至2.8V，记录下第一次的放电容量，将该放电容量除以锂离子电池在25℃下1C/1C充放电的第一次放电容量，得到电池的4C倍率性能。
Figure PCTCN2020108687-appb-000003
Figure PCTCN2020108687-appb-000004
由表1的电性能测试结果可以得知，与对比例1-5测试得到的25℃循环性能和4C倍率相比，实施例1-27的综合性能得到提升。以上结果表明了，将含有磺酰亚胺型锂盐的电解液与采用适当量的聚合物的网络包覆层包覆的硅基材料形成负极活性材料二者联用，可以获得具有兼顾的能量密度和循环性能的二次电池。
在对比例1中，硅基材料未进行包覆，二次电池虽然具有较高的能量密度，但循环性能极差。在对比例4中，采用经由聚合物的网络包覆层包覆的硅基材料作为负极活性材料，但是由于未使用磺酰亚胺锂盐作为锂盐，该二次电池的倍率性能显著下降。在对比例2和3中，包覆硅基材料的网络包覆层要么过大要么过小，导致二次电池的循环性能和4C倍率均不理想。
上述结果表明：将含有磺酰亚胺型锂盐的电解液与采用适当量的聚合物的网络包覆层包覆的硅基材料形成负极活性材料二者联用，可以获得具有兼顾的能量密度和循环性能的二次电池。
此外，在那些使用类似于“A，B和C等中的至少一个”的约定的情况下，这样的结构通常是在本领域技术人员会理解的约定的意义(例如，“具有A，B和C中至少一个的系统”将包括但不限于单独有A，单独有B，单独由C，有A和B，有A和C，有B和C和/或有A、B和C等的系统)。在那些使用类似于“A、B或C等中的至少一个”的约定的情况下，这样的结构是在本领域技术人员会理解的约定的意义(例如，“具有A、B或C中至少一个的系统”将包括但不限于单独有A，单独有B，单独有C，有A和B，有A和C，有B和C和/或有A、B和C等)。本领域技术人员将进一步理解，实际上，无论是在说明书、权利要求书还是附图中，呈现两个或更多个替代术语的任何析取词和/或短语应被理解为考虑包括这些术语之一、这些术语中的一个或两个的术语的可能性。例如，短语“A或B”将被理解为包括“A”或“B”或“A和B”的可能性。
此外，在根据马库什组描述本公开的特征或方面的情况下，本领域技术人员将认识到，本公开也因此根据马库什组的任何单个成员或成员的子集进行描述。
根据上述说明书的揭示和教导，本申请所属领域的技术人员还可以对上述实施方式进行适当的变更和修改。因此，本申请并不局限于上面揭示和描述的具体实施方式，对本申请的一些修改和变更也应当落入本申请的权利要求的保护范围内。此外，尽管本说明书中使用了一些特定的术语，但这些术语只是为了方便说明，并不对本申请构成任何限制。

Claims (14)

  1. 一种二次电池，包括：正极片、负极片、间隔于正极片和负极片之间的隔离膜以及电解液，所述负极片包括负极集流体以及设置于所述负极集流体至少一侧的负极活性材料层，所述电解液包括有机溶剂和锂盐，其中，
    所述负极活性材料包括核结构和包覆在所述核结构表面的至少一部分上的占所述负极活性材料总质量至少0.5质量％且至多10质量％的聚合物的网络包覆层，所述核结构包括SiO x(0<x<2)，所述网络包覆层衍生自具有氰基、酰胺基、酰亚胺基、磺酰基、羧基、砜基中的一种或多种官能团的聚合物；并且
    所述锂盐包括下式I所表示的第一锂盐：
    Figure PCTCN2020108687-appb-100001
    在式I中，R 1、R 2各自独立地单独表示氟原子、碳原子数为1-20的氟代烷基或碳原子数为1-20的氟代烷氧基，并且n为1、2或3的整数。
  2. 根据权利要求1所述的二次电池，其中，所述聚合物选自聚酰亚胺、聚丙烯酸、聚丙烯酰胺、聚丙烯腈中的至少一种。
  3. 根据权利要求1或2所述的二次电池，其中，所述聚合物网络包覆层以相对于所述负极活性材料的总质量1质量％至5质量％的量存在。
  4. 根据权利要求1至3中任意一项所述的二次电池，其中，所述第一锂盐选自双氟磺酰亚胺锂、氟磺酰(三氟甲基磺酰)亚胺锂、双(三氟甲基磺酰)亚胺锂、甲基磺酰三氟甲基磺酰亚胺锂、三氟甲基磺酰五氟乙基磺酰亚胺锂、双(五氟乙基磺酰)亚胺锂、LiN(SO 2OCH 2CF 3) 2、LiN(SO 2OCH 2CF 2CF 3) 2、LiN(SO 2OCH 2CF 2CF 2H) 2、LiN[(SO 2OCH(CF 3) 2]、FSO 2N -(Li +)SO 2N -(Li +)SO 2F、FSO 2N -(Li +)SO 2N -(Li +)SO 2N -(Li +)SO 2F、FSO 2N -(Li +)SO 2N -(Li +)SO 2CF 3、CF 3SO 2N -(Li +)SO 2N -(Li +)SO 2CF 3、FSO 2N - (Li +)SO 2N -(Li +)SO 2N -(Li +)SO 2CF 3中的一种或多种，可选地选自双氟磺酰亚胺锂、氟磺酰(三氟甲基磺酰)亚胺锂、双(三氟甲基磺酰)亚胺锂、FSO 2N -(Li +)SO 2N -(Li +)SO 2F、FSO 2N -(Li +)SO 2N -(Li +)SO 2N -(Li +)SO 2F、FSO 2N -(Li +)SO 2N -(Li +)SO 2CF 3、CF 3SO 2N -(Li +)SO 2N -(Li +)SO 2CF 3、FSO 2N -(Li +)SO 2N -(Li +)SO 2N -(Li +)SO 2CF 3中的一种或多种。
  5. 根据权利要求1至4中任意一项所述的二次电池，其中，所述第一锂盐在所述电解液中的质量百分浓度在5％至25％的范围内，可选在10％至20％的范围内。
  6. 根据权利要求1至5中任一项所述的二次电池，其中，所述锂盐还包括第二锂盐，所述第二锂盐选自六氟磷酸锂、四氟硼酸锂、三氟甲基磺酸锂、六氟砷酸锂、双草酸硼酸锂和高氯酸锂中的一种或多种，可选地选自六氟磷酸锂和四氟硼酸锂中的一种或两种，更可选地选自六氟磷酸锂。
  7. 根据权利要求6所述的二次电池，其中，所述第二锂盐在所述电解液中的质量百分浓度在0.1％至10％的范围内，可选在3％至5％的范围内。
  8. 根据权利要求1至7中任一项所述的二次电池，其中，所述电解液还包括添加剂，所述添加剂选自硫酸亚乙酯(DTD)、二氟磷酸锂(LiPO 2F 2)、二氟草酸硼酸锂(LiODFB)、马来酸酐、二氧化硫(SO 2)和三(三甲基硅烷)磷酸酯(TMSP)中的一种或多种。
  9. 根据权利要求8所述的二次电池，其中，所述添加剂在所述电解液中的质量百分浓度在0％至5％的范围内，可选在0.1至3％的范围内，更可选在0.2％至2％的范围内。
  10. 根据权利要求1至9任一项所述的二次电池，其中，所述有机溶剂选自碳酸亚丙酯、碳酸亚乙酯、碳酸二甲酯、碳酸二乙酯、碳酸二丙酯、碳酸甲乙酯、碳酸甲丙酯、碳酸亚乙烯酯、氟代碳酸亚乙酯、甲酸甲酯、乙酸乙酯、丙酸乙酯、丙酸丙酯、丁酸甲酯、丙烯酸甲酯、乙烯亚硫酸酯、丙烯亚硫酸酯、亚硫酸二甲酯、二乙基亚硫酸酯、1,3-丙磺酸内酯、硫酸乙烯酯、酸酐、N-甲基吡咯烷酮、N-甲基甲酰胺、N-甲基乙酰胺、乙腈、N,N-二甲基甲酰胺、环丁砜、二甲亚砜、甲硫醚、γ-丁内酯、四氢呋 喃、含氟环状有机酯、含硫环状有机酯和含不饱和键环状有机酯中的一种或多种，可选地，所述有机溶剂在所述电解液中的质量百分数为65％～85％。
  11. 根据权利要求1至10中任意一项所述的二次电池，其中，所述电池具有40％或更高的4C倍率，并且具有70％或更高的容量保持率。
  12. 一种电池模块，其包括根据权利要求1至11中任一项所述的二次电池。
  13. 一种电池包，其包括根据权利要求12所述的电池模块。
  14. 一种装置，其包括根据权利要求1至11中任一项所述的二次电池，所述二次电池作为所述装置的电源或能量存储单元；可选地，所述装置包括电动车辆、混合动力电动车辆、插电式混合动力电动车辆、电动自行车、电动踏板车、电动高尔夫球车、电动卡车、电动船舶、储能系统。
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WO2023162431A1 (ja) * 2022-02-25 2023-08-31 株式会社村田製作所 二次電池用電解液および二次電池
WO2023162429A1 (ja) * 2022-02-25 2023-08-31 株式会社村田製作所 二次電池用電解液および二次電池
JP2024515150A (ja) * 2022-04-01 2024-04-05 寧徳時代新能源科技股▲分▼有限公司 二次電池、電池モジュール、電池パックおよび電気装置
WO2024087081A1 (zh) * 2022-10-27 2024-05-02 宁德时代新能源科技股份有限公司 复合负极活性材料及其制备方法、负极极片、二次电池及用电装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013084590A (ja) * 2011-09-26 2013-05-09 Nippon Shokubai Co Ltd ラミネート型アルカリ金属電池
CN103456928A (zh) * 2013-09-02 2013-12-18 东莞新能源科技有限公司 锂离子电池用复合阳极材料及其制备方法
CN105633368A (zh) * 2015-12-31 2016-06-01 深圳市贝特瑞新能源材料股份有限公司 一种锂离子电池负极材料及其制备方法
CN105981209A (zh) * 2014-02-06 2016-09-28 日产自动车株式会社 非水电解质二次电池
CN109560262A (zh) * 2017-09-26 2019-04-02 三星电子株式会社 负极活性材料、包括其的锂二次电池和制造负极活性材料的方法
CN109923699A (zh) * 2016-11-07 2019-06-21 日产自动车株式会社 锂离子电池用负极和锂离子电池

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015170542A (ja) * 2014-03-10 2015-09-28 三洋電機株式会社 非水電解質二次電池
US10199643B2 (en) * 2014-12-16 2019-02-05 GM Global Technology Operations LLC Negative electrode for lithium-based batteries
WO2018101391A1 (ja) * 2016-12-02 2018-06-07 日本電気株式会社 リチウムイオン二次電池
CN108054368B (zh) * 2017-12-12 2020-08-11 贝特瑞新材料集团股份有限公司 一种硅基负极材料、其制备方法及在锂离子电池的用途
CN108110240B (zh) * 2017-12-15 2020-09-08 山东大学 一种纳米多孔硅基复合物电极材料及其制备方法
CN109103441A (zh) * 2018-09-10 2018-12-28 江苏塔菲尔新能源科技股份有限公司 含硅基材料的改性复合材料、其制备方法及在锂离子电池的用途

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013084590A (ja) * 2011-09-26 2013-05-09 Nippon Shokubai Co Ltd ラミネート型アルカリ金属電池
CN103456928A (zh) * 2013-09-02 2013-12-18 东莞新能源科技有限公司 锂离子电池用复合阳极材料及其制备方法
CN105981209A (zh) * 2014-02-06 2016-09-28 日产自动车株式会社 非水电解质二次电池
CN105633368A (zh) * 2015-12-31 2016-06-01 深圳市贝特瑞新能源材料股份有限公司 一种锂离子电池负极材料及其制备方法
CN109923699A (zh) * 2016-11-07 2019-06-21 日产自动车株式会社 锂离子电池用负极和锂离子电池
CN109560262A (zh) * 2017-09-26 2019-04-02 三星电子株式会社 负极活性材料、包括其的锂二次电池和制造负极活性材料的方法

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