Nothing Special   »   [go: up one dir, main page]

WO2023082918A1 - 锂离子电池、电池模块、电池包及用电装置 - Google Patents

锂离子电池、电池模块、电池包及用电装置 Download PDF

Info

Publication number
WO2023082918A1
WO2023082918A1 PCT/CN2022/124812 CN2022124812W WO2023082918A1 WO 2023082918 A1 WO2023082918 A1 WO 2023082918A1 CN 2022124812 W CN2022124812 W CN 2022124812W WO 2023082918 A1 WO2023082918 A1 WO 2023082918A1
Authority
WO
WIPO (PCT)
Prior art keywords
lithium
ion battery
battery
optionally
electrolyte
Prior art date
Application number
PCT/CN2022/124812
Other languages
English (en)
French (fr)
Inventor
吴则利
韩昌隆
黄磊
张翠平
Original Assignee
宁德时代新能源科技股份有限公司
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 宁德时代新能源科技股份有限公司 filed Critical 宁德时代新能源科技股份有限公司
Priority to EP22891717.5A priority Critical patent/EP4362156A1/en
Priority to JP2024501264A priority patent/JP2024525681A/ja
Priority to KR1020247001257A priority patent/KR20240019835A/ko
Publication of WO2023082918A1 publication Critical patent/WO2023082918A1/zh
Priority to US18/599,285 priority patent/US20240266606A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—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
    • H01M10/058—Construction or manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2220/00—Batteries for particular applications
    • H01M2220/10—Batteries in stationary systems, e.g. emergency power source in plant
    • 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
    • H01M2220/00—Batteries for particular applications
    • H01M2220/30—Batteries in portable systems, e.g. mobile phone, laptop
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0025—Organic electrolyte
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present application relates to the field of lithium-ion batteries, in particular to a lithium-ion battery with high energy density, a battery module, a battery pack, and an electrical device.
  • lithium-ion batteries have been widely used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, as well as power tools, electric bicycles, electric motorcycles, electric vehicles, Military equipment, aerospace and other fields.
  • the ratio CB value (cell balance) of the negative electrode capacity to the positive electrode capacity is usually designed above 1.07 to ensure the cycle performance of the battery, but the higher The CB value leads to a significant decrease in battery energy density. Therefore, it is desirable to be able to reduce the CB value of Li-ion batteries to increase the energy density of the batteries while still ensuring good cycle performance of the batteries.
  • the present application was made in view of the above problems, and an object thereof is to provide a lithium ion battery having a low CB value and good cycle performance.
  • the first aspect of the present application provides a lithium ion battery, which has a positive pole piece, a negative pole piece, a separator and an electrolyte, wherein,
  • the ratio of the negative electrode capacity of the battery to the positive electrode capacity is a, and the electrolyte contains a thiourea compound with a content of b% by weight based on the total weight of the electrolyte, and the lithium ion battery satisfies the following relationship:
  • the present application can make the battery have good cycle performance even when the CB value of the battery is low by adding the amount of thiourea compounds in the electrolyte.
  • a/b is in the range of 0.8 to 2, optionally in the range of 1 to 1.8.
  • a is in the range of 0.9 to less than 1.05, optionally in the range of 0.98 to 1.04.
  • b is in the range of 0.2 to 5, optionally in the range of 0.5 to 2, further optionally in the range of 0.5 to 1.0.
  • the thiourea compound has the following general structural formula:
  • R and X are each independently selected from H, C1-C10 alkyl, C1-C10 alkenyl, phenyl, or R and X together represent C1-C10 alkylene or C1-C10 alkenylene, Wherein the C1-C10 alkylene or C1-C10 alkenylene is optionally substituted by oxy, optionally, R and X are each independently selected from H, C1-C6 alkyl, C1-C6 Alkenyl, or R and X together represent C1-C6 alkylene or C1-C6 alkenylene, wherein the C1-C6 alkylene or C1-C6 alkenylene is optionally oxy replace.
  • the cycle performance of lithium-ion batteries can be further improved by selecting thiourea compounds.
  • the electrolyte also contains at least one additive selected from metal nitrate, fluoroethylene carbonate and vinylene carbonate, optionally, the metal nitrate is nitric acid One or more of lithium, magnesium nitrate and copper nitrate.
  • the content of the additive is in the range of 0.5% by weight to 2% by weight, based on the total mass of the electrolyte.
  • the thickness of the negative electrode film layer is ⁇ 140 ⁇ m.
  • the cycle performance of the battery can be further improved.
  • a second aspect of the present application provides a battery module including the lithium-ion battery of the first aspect of the present application.
  • a third aspect of the present application provides a battery pack, including the battery module of the second aspect of the present application.
  • the fourth aspect of the present application provides an electric device, including at least one selected from the lithium ion battery of the first aspect of the present application, the battery module of the second aspect of the present application, or the battery pack of the third aspect of the present application kind.
  • FIG. 1 is a schematic diagram of a lithium ion battery according to an embodiment of the present application.
  • FIG. 2 is an exploded view of the lithium ion battery according to one embodiment of the present application shown in FIG. 1 .
  • FIG. 3 is a schematic diagram of a battery module according to an embodiment of the present application.
  • FIG. 4 is a schematic diagram of a battery pack according to an embodiment of the present application.
  • FIG. 5 is an exploded view of the battery pack according to one embodiment of the present application shown in FIG. 4 .
  • FIG. 6 is a schematic diagram of an electrical device in which a lithium-ion battery is used as a power source according to an embodiment of the present application.
  • ranges disclosed herein are defined in terms of lower and upper limits, and a given range is defined by selecting a lower limit and an upper limit that define the boundaries of the particular range. Ranges defined in this manner may be inclusive or exclusive and may be combined in any combination, ie any lower limit may be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a particular parameter, it is understood that ranges of 60-110 and 80-120 are contemplated. Additionally, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are listed, the following ranges are all expected: 1-3, 1-4, 1-5, 2- 3, 2-4 and 2-5.
  • the numerical range "a-b” represents an abbreviated representation of any combination of real numbers between a and b, where a and b are both real numbers.
  • the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article, and "0-5" is only an abbreviated representation of the combination of these values.
  • a certain parameter is an integer ⁇ 2
  • the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed in sequence, and may also include steps (b) and (a) performed in sequence.
  • steps (c) means that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c) , may also include steps (a), (c) and (b), may also include steps (c), (a) and (b) and so on.
  • the “comprising” and “comprising” mentioned in this application mean open or closed.
  • the “comprising” and “comprising” may mean that other components not listed may be included or included, or only listed components may be included or included.
  • the term "or” is inclusive unless otherwise stated.
  • the phrase "A or B” means “A, B, or both A and B.” More specifically, the condition "A or B” is satisfied by either of the following: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists) ; or both A and B are true (or exist).
  • the negative electrode capacity/positive electrode capacity that is, the CB (cell balance) value—is relatively high, usually above 1.07, and some even exceed 1.1.
  • a higher CB value means that the negative electrode capacity exceeds the positive electrode capacity more, which can provide enough space for lithium during charge and discharge, avoid lithium deposition on the surface of the negative electrode and form dendrites, and make the battery have better cycle performance.
  • a higher CB value also means the waste of the negative electrode, resulting in a lower energy density of the battery. Therefore, it is desirable to be able to reduce the CB value of Li-ion batteries to increase the energy density of the batteries while still ensuring good cycle performance of the batteries.
  • the present application obtains a lithium-ion battery with a lower CB value than existing lithium-ion batteries by adding a specific amount of thiourea compounds to the electrolyte of the lithium-ion battery, and the lithium-ion battery has good cycle performance.
  • the present application provides a lithium ion battery, which has a positive pole piece, a negative pole piece, a separator and an electrolyte, the ratio of the negative electrode capacity of the battery to the positive electrode capacity is a, and the
  • the electrolytic solution contains a thiourea compound whose content is b% by weight based on the total weight of the electrolytic solution, and the lithium-ion battery satisfies the following relational formula:
  • the lithium-ion battery designed above has both good cycle performance and energy density.
  • the negative electrode capacity and the positive electrode capacity of the battery can be detected by the following method respectively: by fully discharging the lithium-ion battery (for example, for the lithium-ion battery of this application, discharging to 2.5V is to achieve full discharge), disassembling the battery to obtain the positive and negative electrodes respectively
  • metal lithium is used as the counter electrode for the positive and negative pole pieces respectively, and they are assembled into button batteries respectively, and the capacity is discharged at 0.1mA to test the corresponding capacity.
  • CB value test process refer to the test method in the embodiment of this application part.
  • a/b is in the range of 0.8 to 2, optionally in the range of 1 to 1.8.
  • a is in the range of 0.9 to less than 1.05, optionally in the range of 0.98 to 1.04. As a result, lithium-ion batteries can achieve a better balance between cycle performance and energy density.
  • b is in the range of 0.2 to 5, optionally in the range of 0.5 to 2, further optionally in the range of 0.5 to 1.0.
  • the thiourea compound has the following general structural formula:
  • R and X are each independently selected from H, C1-C10 alkyl, C1-C10 alkenyl, phenyl, or R and X together represent C1-C10 alkylene or C1-C10 alkenylene, Wherein the C1-C10 alkylene or C1-C10 alkenylene is optionally substituted by oxy, optionally, R and X are each independently selected from H, C1-C6 alkyl, C1-C6 Alkenyl, or R and X together represent C1-C6 alkylene or C1-C6 alkenylene, wherein the C1-C6 alkylene or C1-C6 alkenylene is optionally oxy replace.
  • the thiourea compound has one of the following structures:
  • the cycle performance of lithium-ion batteries can be further improved by selecting thiourea compounds.
  • the electrolyte also contains an additive selected from at least one of metal nitrate, fluoroethylene carbonate and vinylene carbonate, optionally, the metal nitrate is nitric acid One or more of lithium, magnesium nitrate and copper nitrate.
  • the content of the additive is in the range of 0.5% by weight to 2% by weight.
  • the thickness of the negative electrode film layer is ⁇ 140 microns.
  • the cycle performance of the battery can be further improved.
  • a lithium ion battery is provided.
  • a lithium-ion battery typically includes a positive pole piece, a negative pole piece, an electrolyte, and a separator.
  • active ions are intercalated and extracted back and forth between the positive electrode and the negative electrode.
  • the electrolyte plays the role of conducting ions between the positive pole piece and the negative pole piece.
  • the separator is arranged between the positive pole piece and the negative pole piece, which mainly plays a role in preventing the short circuit of the positive and negative poles, and at the same time allows ions to pass through.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode collector, and the positive electrode film layer includes the positive electrode active material according to the first aspect of the present application.
  • the positive electrode current collector has two opposing surfaces in its own thickness direction, and the positive electrode film layer is disposed on any one or both of the two opposing surfaces of the positive electrode current collector.
  • the positive electrode current collector can be a metal foil or a composite current collector.
  • aluminum foil can be used as the metal foil.
  • the composite current collector may include a polymer material base and a metal layer formed on at least one surface of the polymer material base.
  • the composite current collector can be formed by forming metal materials (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as polypropylene (PP), polyethylene terephthalic acid It is formed on substrates such as ethylene glycol ester (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).
  • PP polypropylene
  • PET polyethylene glycol ester
  • PBT polybutylene terephthalate
  • PS polystyrene
  • PE polyethylene
  • the positive electrode active material may be a positive electrode active material known in the art for batteries.
  • the positive active material may include at least one of the following materials: olivine-structured lithium-containing phosphate, lithium transition metal oxide, and their respective modified compounds.
  • the present application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials of batteries can also be used. These positive electrode active materials may be used alone or in combination of two or more.
  • lithium transition metal oxides may include, but are not limited to, lithium cobalt oxides (such as LiCoO 2 ), lithium nickel oxides (such as LiNiO 2 ), lithium manganese oxides (such as LiMnO 2 , LiMn 2 O 4 ), lithium Nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1/3 Co 1/3 Mn 1/3 O 2 (also referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O 2 (also abbreviated as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O 2 (also abbreviated as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O 2 (also abbreviated as NCM 622 ), LiNi At least one of 0.8 Co 0.1 Mn 0.1 O 2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi
  • the olivine structure contains Examples of lithium phosphates may include, but are not limited to, lithium iron phosphate (such as LiFePO 4 (also may be abbreviated as LFP)), composite materials of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO 4 ), lithium manganese phosphate and carbon At least one of a composite material, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon.
  • lithium iron phosphate such as LiFePO 4 (also may be abbreviated as LFP)
  • composite materials of lithium iron phosphate and carbon such as LiMnPO 4
  • LiMnPO 4 lithium manganese phosphate and carbon
  • the positive electrode film layer may further optionally include a binder.
  • the binder may include polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene At least one of ethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer and fluorine-containing acrylate resin.
  • the positive electrode film layer may also optionally include a conductive agent.
  • the conductive agent may include at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.
  • the positive electrode sheet can be prepared in the following manner: the above-mentioned components used to prepare the positive electrode sheet, such as positive electrode active material, conductive agent, binder and any other components, are dispersed in a solvent (such as N -methylpyrrolidone) to form a positive electrode slurry; the positive electrode slurry is coated on the positive electrode current collector, and after drying, cold pressing and other processes, the positive electrode sheet can be obtained.
  • a solvent such as N -methylpyrrolidone
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode film layer arranged on at least one surface of the negative electrode current collector, and the negative electrode film layer includes a negative electrode active material.
  • the negative electrode current collector has two opposing surfaces in its own thickness direction, and the negative electrode film layer is disposed on any one or both of the two opposing surfaces of the negative electrode current collector.
  • the negative electrode current collector can be a metal foil or a composite current collector.
  • copper foil can be used as the metal foil.
  • the composite current collector may include a base layer of polymer material and a metal layer formed on at least one surface of the base material of polymer material.
  • Composite current collectors can be formed by metal materials (copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver and silver alloys, etc.) on polymer material substrates (such as polypropylene (PP), polyethylene terephthalic acid It is formed on substrates such as ethylene glycol ester (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).
  • the negative electrode active material can be a negative electrode active material known in the art for batteries.
  • the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based material, tin-based material, lithium titanate, and the like.
  • the silicon-based material may be selected from at least one of elemental silicon, silicon-oxygen compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys.
  • the tin-based material may be selected from at least one of simple tin, tin oxide compounds and tin alloys.
  • the present application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials of batteries can also be used. These negative electrode active materials may be used alone or in combination of two or more.
  • the negative electrode film layer may further optionally include a binder.
  • the binder can be selected from styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), poly At least one of methacrylic acid (PMAA) and carboxymethyl chitosan (CMCS).
  • the negative electrode film layer may also optionally include a conductive agent.
  • the conductive agent can be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.
  • the negative electrode film layer may optionally include other additives, such as thickeners (such as sodium carboxymethylcellulose (CMC-Na)) and the like.
  • thickeners such as sodium carboxymethylcellulose (CMC-Na)
  • CMC-Na sodium carboxymethylcellulose
  • the negative electrode sheet can be prepared in the following manner: the above-mentioned components used to prepare the negative electrode sheet, such as negative electrode active material, conductive agent, binder and any other components, are dispersed in a solvent (such as deionized water) to form a negative electrode slurry; the negative electrode slurry is coated on the negative electrode current collector, and after drying, cold pressing and other processes, the negative electrode sheet can be obtained.
  • a solvent such as deionized water
  • electrolyte plays the role of conducting ions between the positive pole piece and the negative pole piece.
  • the application does not have specific restrictions on the type of electrolyte, which can be selected according to requirements.
  • electrolytes can be liquid, gel or all solid.
  • the electrolyte is an electrolytic solution.
  • the electrolyte solution includes an electrolyte salt and a solvent.
  • the electrolyte salt may be selected from lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonyl imide, lithium bistrifluoromethanesulfonyl imide, trifluoromethane At least one of lithium sulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium difluorooxalate borate, lithium difluorodifluorooxalatephosphate and lithium tetrafluorooxalatephosphate.
  • the solvent may be selected from ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, Butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate At least one of ester, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone.
  • the electrolyte may optionally include other additives.
  • additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain performances of the battery, such as additives that improve battery overcharge performance, additives that improve high-temperature or low-temperature performance of batteries, and the like.
  • a separator is also included in the lithium ion battery.
  • the present application has no particular limitation on the type of the isolation membrane, and any known porous structure isolation membrane with good chemical stability and mechanical stability can be selected.
  • the material of the isolation film can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.
  • the separator can be a single-layer film or a multi-layer composite film, without any particular limitation. When the separator is a multilayer composite film, the materials of each layer may be the same or different, and there is no particular limitation.
  • the positive pole piece, the negative pole piece and the separator can be made into an electrode assembly through a winding process or a lamination process.
  • a lithium ion battery can include an outer packaging.
  • the outer package can be used to package the above-mentioned electrode assembly and electrolyte.
  • the outer packaging of the lithium-ion battery can be a hard case, such as a hard plastic case, aluminum case, steel case, and the like.
  • the outer packaging of the lithium-ion battery can also be a soft bag, such as a bag-type soft bag.
  • the material of the soft case may be plastic, and examples of the plastic include polypropylene, polybutylene terephthalate, polybutylene succinate, and the like.
  • FIG. 1 shows a lithium-ion battery 5 with a square structure as an example.
  • the outer package may include a housing 51 and a cover 53 .
  • the housing 51 may include a bottom plate and a side plate connected to the bottom plate, and the bottom plate and the side plates enclose to form an accommodating cavity.
  • the housing 51 has an opening communicating with the accommodating cavity, and the cover plate 53 can cover the opening to close the accommodating cavity.
  • the positive pole piece, the negative pole piece and the separator can be formed into an electrode assembly 52 through a winding process or a lamination process.
  • the electrode assembly 52 is packaged in the accommodating cavity. Electrolyte is infiltrated in the electrode assembly 52 .
  • the number of electrode assemblies 52 contained in the lithium-ion battery 5 can be one or more, and those skilled in the art can select according to specific actual needs.
  • lithium-ion batteries can be assembled into a battery module, and the number of lithium-ion batteries contained in the battery module can be one or more, and the specific number can be selected by those skilled in the art according to the application and capacity of the battery module.
  • FIG. 3 is a battery module 4 as an example.
  • a plurality of lithium ion batteries 5 may be arranged in sequence along the length direction of the battery module 4 .
  • the plurality of lithium ion batteries 5 can be fixed by fasteners.
  • the battery module 4 may also include a housing with an accommodating space, and a plurality of lithium-ion batteries 5 are accommodated in the accommodating space.
  • the above-mentioned battery modules can also be assembled into a battery pack, and the number of battery modules contained in the battery pack can be one or more, and the specific number can be selected by those skilled in the art according to the application and capacity of the battery pack.
  • the battery pack 1 may include a battery box and a plurality of battery modules 4 disposed in the battery box.
  • the battery box includes an upper box 2 and a lower box 3 , the upper box 2 can cover the lower box 3 and form a closed space for accommodating the battery module 4 .
  • Multiple battery modules 4 can be arranged in the battery box in any manner.
  • the present application also provides an electric device, which includes at least one of the lithium-ion battery, battery module, or battery pack provided in the present application.
  • the lithium ion battery, battery module, or battery pack can be used as a power source of the electric device, and can also be used as an energy storage unit of the electric device.
  • the electric devices may include mobile devices (such as mobile phones, notebook computers, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, etc.) , electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc., but not limited thereto.
  • a lithium-ion battery, a battery module or a battery pack can be selected according to its use requirements.
  • FIG. 6 is an example of an electrical device.
  • the electric device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle.
  • a battery pack or a battery module can be used.
  • a device may be a cell phone, tablet, laptop, or the like.
  • the device is usually required to be light and thin, and a lithium-ion battery can be used as a power source.
  • the positive electrode active material nickel-cobalt-manganese ternary material LiNi 0.8 Co 0.1 Mn 0.1 O 2 , with a capacity of 180mAh/g
  • the binder polyvinylidene fluoride LiNi 0.8 Co 0.1 Mn 0.1 O 2
  • the conductive agent acetylene black at a mass ratio of 8:1:1.
  • the solvent NMP N-methylpyrrolidone
  • the positive electrode slurry is obtained under the action of a vacuum stirrer.
  • the positive electrode slurry was evenly coated on the positive electrode current collector aluminum foil with a thickness of 13 ⁇ m in the amount of 0.2826g (dry weight) /1540.25mm2 ; after the aluminum foil was dried at room temperature, it was transferred to a 120°C oven to dry for 1h, and then subjected to cold pressing , Slitting to obtain the positive pole piece.
  • the isolation film was purchased from Cellgard, and the model was cellgard2400.
  • the preparation process of the lithium-ion battery is basically the same as that of Comparative Example 1, the difference is that the preparation steps of the electrolyte are: in an argon atmosphere glove box with a water content of ⁇ 10ppm, add 26.1g EC, 60.9g EMC, 12.5g LiPF 6 and 0.5 g of thiourea compound 1 were fully stirred and dissolved to obtain the electrolyte solution for this comparative example.
  • the preparation process of the lithium-ion battery is basically the same as that of Comparative Example 1, the difference is that the preparation steps of the electrolyte are: in an argon atmosphere glove box with a water content of ⁇ 10ppm, add 25.29g EC, 59.01g EMC, 12.5g LiPF 6 and 3.2 g of thiourea compound 1 were fully stirred and dissolved to obtain the electrolyte solution for this comparative example.
  • the preparation process of the lithium-ion battery is basically the same as that of Comparative Example 1, the difference is that the preparation steps of the electrolyte are: in an argon atmosphere glove box with a water content of ⁇ 10ppm, add 25.95g EC, 60.55g EMC, 12.5g LiPF 6 and 1 g of thiourea compound 1 were fully stirred and dissolved to obtain the electrolyte solution for this example.
  • the preparation process of the lithium-ion battery is basically the same as that of Comparative Example 1, the difference is that the preparation steps of the electrolyte are: in an argon atmosphere glove box with a water content of ⁇ 10ppm, add 26.01g EC, 60.69g EMC, 12.5g LiPF 6 and 0.8 g of thiourea compound 1 were fully stirred and dissolved to obtain the electrolyte solution for this example.
  • the preparation process of the lithium-ion battery is basically the same as that of Comparative Example 1, the difference is that the preparation steps of the electrolyte are: in an argon atmosphere glove box with a water content of ⁇ 10ppm, add 25.8g EC, 60.2g EMC, 12.5g LiPF 6 and 1.5 g of thiourea compound 1 were fully stirred and dissolved to obtain the electrolyte solution for this example.
  • the preparation process of the lithium-ion battery is basically the same as that of Comparative Example 1, the difference is that the preparation steps of the electrolyte are: in an argon atmosphere glove box with a water content of ⁇ 10ppm, add 25.9g EC, 60.4g EMC, 12.5g LiPF 6 and 1.2 g of thiourea compound 1 were fully stirred and dissolved to obtain the electrolyte solution for this example.
  • the preparation process of the lithium-ion battery is basically the same as Comparative Example 1, except that the negative electrode slurry is evenly coated on the negative electrode current collector copper foil with a thickness of 8 ⁇ m in an amount of 0.1315g (dry weight) /1540.25mm ;
  • the preparation steps are: in an argon atmosphere glove box with a water content of ⁇ 10ppm, add 26.07g EC, 60.83g EMC, 12.5g LiPF 6 , and 0.6g thiourea compound 1 to a beaker, stir and dissolve them to obtain this example Use electrolyte.
  • the preparation process of the lithium-ion battery is basically the same as Comparative Example 1, except that the negative electrode slurry is evenly coated on the negative electrode current collector copper foil with a thickness of 8 ⁇ m in an amount of 0.1315g (dry weight) /1540.25mm ;
  • the preparation steps are: in an argon atmosphere glove box with a water content ⁇ 10ppm, respectively add 26.085g EC, 60.865g EMC, 12.5g LiPF 6 , and 0.55g thiourea compound 1 into a beaker and fully stir and dissolve to obtain this example Use electrolyte.
  • the preparation process of the lithium-ion battery is basically the same as Comparative Example 1, except that the negative electrode slurry is evenly coated on the negative electrode current collector copper foil with a thickness of 8 ⁇ m in an amount of 0.1315g (dry weight) /1540.25mm ;
  • the preparation steps are: in an argon atmosphere glove box with a water content of ⁇ 10ppm, add 26.1g EC, 60.9g EMC, 12.5g LiPF 6 , and 0.5g thiourea compound 1 to a beaker, stir and dissolve them fully to obtain this example Use electrolyte.
  • the preparation process of the lithium-ion battery is basically the same as Comparative Example 1, except that the negative electrode slurry is evenly coated on the negative electrode current collector copper foil with a thickness of 8 ⁇ m in an amount of 0.1239g (dry weight) /1540.25mm ;
  • the preparation steps are: in an argon atmosphere glove box with a water content ⁇ 10ppm, respectively add 25.65g EC, 59.85g EMC, 12.5g LiPF 6 , 2g thiourea compound 1 into a beaker and fully stir and dissolve to obtain the Electrolyte
  • the preparation process of the lithium-ion battery is basically the same as Comparative Example 1, except that the negative electrode slurry is evenly coated on the negative electrode current collector copper foil with a thickness of 8 ⁇ m in an amount of 0.115g (dry weight)/1540.25mm;
  • the preparation steps are: in an argon atmosphere glove box with a water content ⁇ 10ppm, respectively add 25.05g EC, 58.45g EMC, 12.5g LiPF 6 , 4g thiourea compound 1 into a beaker and fully stir and dissolve to obtain the Electrolyte
  • the preparation process of the lithium-ion battery is basically the same as in Example 1, except that the thiourea compound added in the preparation of the electrolyte in this example is thiourea compound 2.
  • the preparation process of the lithium-ion battery is basically the same as in Example 1, except that the thiourea compound added in the preparation of the electrolyte in this example is thiourea compound 3.
  • the preparation process of the lithium-ion battery is basically the same as in Example 1, except that the thiourea compound added in the preparation of the electrolyte in this example is thiourea compound 4.
  • the preparation process of the lithium-ion battery is basically the same as in Example 1, except that the thiourea compound added in the preparation of the electrolyte in this example is thiourea compound 5.
  • the preparation process of the lithium-ion battery is basically the same as in Example 1, the difference being that the electrolyte preparation process is:
  • the preparation process of the lithium-ion battery is basically the same as in Example 1, the difference being that the electrolyte preparation process is:
  • the preparation process of the lithium-ion battery is basically the same as in Example 1, the difference being that the electrolyte preparation process is:
  • the preparation process of the lithium-ion battery is basically the same as in Example 1, the difference being that the electrolyte preparation process is:
  • the preparation process of the lithium-ion battery is basically the same as that of Example 1, except that the thickness of the negative electrode film layer after cold pressing is 90 microns.
  • the preparation process of the lithium-ion battery is basically the same as in Example 1, except that the thickness of the negative electrode film layer after cold pressing is 140 microns.
  • the preparation process of the lithium-ion battery is basically the same as in Example 1, except that the thickness of the negative electrode film layer after cold pressing is 150 microns.
  • the battery is disassembled to obtain the negative electrode sheet.
  • Metal lithium is used as the counter electrode for the negative pole piece, and it is assembled into a button battery.
  • the button battery adopts a standard 2046 button battery metal shell, the pole piece is cut into a small disc with a diameter of 14mm, the metal lithium plate is made of a small disc with a diameter of 16mm, and the middle separator is a PP separator with a diameter of 18mm.
  • the battery After being fully charged by charging the lithium-ion battery to 4.4V, the battery is disassembled to obtain the positive pole piece.
  • Metal lithium is used as the counter electrode for the positive pole piece and assembled into a button battery.
  • the button battery adopts a standard 2046 button battery metal shell, the pole piece is cut into a small disc with a diameter of 14mm, the metal lithium plate is made of a small disc with a diameter of 16mm, and the middle separator is a PP separator with a diameter of 18mm.
  • the middle separator is a PP separator with a diameter of 18mm.
  • the lithium-ion battery was charged to 4.35V at a constant current of 0.5C, then charged to a current of 0.05C at a constant voltage, and then discharged to 2.8V at a constant current of 0.5C, and the discharge capacity was recorded as U1. Afterwards, the lithium-ion battery was repeated 600 times in the above-mentioned charge and discharge process at an ambient temperature of 25°C, and the discharge capacity of the 600th cycle was recorded as U2,
  • the Li-ion battery was charged at a constant current of 1A to 4.3V, and then charged at a constant voltage until the current was less than 0.5A. Then discharge the battery to 2.5V with a constant current of 1A, then discharge to 2.5V with a constant current of 0.5A, and finally discharge to 2.5V with 0.1A, record the discharge capacity C (Ah) of the battery, and record the discharge capacity The voltage value U(V) of the battery at half time.
  • Comparative Examples 1-3 and Examples 1-20 use low CB values, and compared with Comparative Examples 1-3, Examples 1-20 all show better cycle performance.
  • the content of thiourea compounds in Comparative Example 2 is relatively low, so although the cycle performance is improved compared with Comparative Example 1 which does not contain thiourea compounds at all, the improvement is limited.
  • the content of thiourea compounds in comparative example 3 is relatively high, although the cycle performance has been greatly improved, but the expansion rate of the battery after high temperature storage is too high. It can be seen from Examples 1-4 and Examples 5-7 that when a/b is in the range of 0.8-2, especially 1-1.8, the cycle performance of the battery is further improved.
  • a is in the range of 0.9 to less than 1.05, especially in the range of 0.98-1.04, the cycle performance of the battery is further improved.
  • the lithium-ion battery can obtain cycle performance.
  • b is in the range of 0.5-2, especially 0.5-1.0, the cycle performance of the battery is further improved.
  • the present application is not limited to the above-mentioned embodiments.
  • the above-mentioned embodiments are merely examples, and within the scope of the technical solutions of the present application, embodiments that have substantially the same configuration as the technical idea and exert the same effects are included in the technical scope of the present application.
  • various modifications conceivable by those skilled in the art are added to the embodiments, and other forms constructed by combining some components in the embodiments are also included in the scope of the present application. .

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Inorganic Chemistry (AREA)
  • Secondary Cells (AREA)
  • Battery Electrode And Active Subsutance (AREA)

Abstract

本申请提供了一种锂离子电池，其具有正极极片、负极极片、隔离膜及电解液，其特征在于，所述电池的负极容量与正极容量的比值为a，且所述电解液中含有含量基于电解液的总重量计为b重量％的硫脲类化合物，所述锂离子电池满足下述关系式：a＜1.05；且25×(1.05-a)≤b≤100×(1.05-a)。由于在电解液中含有特定量的硫脲类化合物，因此所述电池具有较低的CB值且同时具有良好的循环性能。

Description

锂离子电池、电池模块、电池包及用电装置 技术领域
本申请涉及锂离子电池领域，尤其涉及一种具有高能量密度的锂离子电池、电池模块、电池包、以及用电装置。
背景技术
近年来，随着锂离子电池的应用范围越来越广泛，锂离子电池广泛应用于水力、火力、风力和太阳能电站等储能电源系统，以及电动工具、电动自行车、电动摩托车、电动汽车、军事装备、航空航天等多个领域。
现有的卷绕式锂离子电池中，为了解决拐角析锂的问题，其负极容量与正极容量的比值CB值(cell balance)通常设计在1.07以上，以确保电池的循环性能，但较高的CB值导致电池能量密度显著降低。因此，期望能够降低锂离子电池的CB值，以提高电池的能量密度，同时仍确保电池具有良好的循环性能。
发明内容
本申请是鉴于上述课题而进行的，其目的在于，提供一种具有低CB值且同时具有良好循环性能的锂离子电池。
为了达到上述目的，本申请的第一方面提供了一种锂离子电池，其具有正极极片、负极极片、隔离膜及电解液，其中，
所述电池的负极容量与正极容量的比值为a，且所述电解液中含有含量基于电解液的总重量计为b重量％的硫脲类化合物，所述锂离子电池满足下述关系式：
a＜1.05；且
25×(1.05-a)≤b≤100×(1.05-a)。
由此，本申请通过在电解液中加入所述量的硫脲类化合物，使得 即使在电池的CB值较低的情况下，也能使电池具有良好的循环性能。
在任意实施方式中，a/b在0.8至2的范围内，可选地在1至1.8的范围内。由此，锂离子电池的能量密度和循环性能可进一步改善。
在任意实施方式中，a在0.9至小于1.05的范围内，可选地在0.98至1.04的范围内。由此，锂离子电池可获得循环性能和能量密度的更好平衡。
在任意实施方式中，b在0.2至5的范围内，可选地在0.5至2的范围内，进一步可选地在0.5至1.0的范围内。通过选择硫脲类化合物的含量，可进一步改善电池的循环性能。
在任意实施方式中，所述硫脲类化合物具有如下结构通式：
Figure PCTCN2022124812-appb-000001
其中R和X各自独立地选自H、C1-C10的烷基、C1-C10的烯基、苯基、或者R和X一起代表C1-C10的亚烷基或C1-C10的亚烯基，其中所述C1-C10的亚烷基或C1-C10的亚烯基任选地被氧基取代，可选地，R和X各自独立地选自H、C1-C6的烷基、C1-C6的烯基、或者R和X一起代表C1-C6的亚烷基或C1-C6的亚烯基，其中所述C1-C6的亚烷基或C1-C6的亚烯基任选地被氧基取代。
通过对硫脲类化合物的选择可以进一步改善锂离子电池的循环性能。
在任意实施方式中，所述电解液中还含有选自金属的硝酸盐、氟代碳酸乙烯酯和碳酸亚乙烯酯中的至少一种的添加剂，可选地，所述金属的硝酸盐为硝酸锂、硝酸镁和硝酸铜中的一种或多种，可选地，所述添加剂的含量在0.5重量％-2重量％范围内，基于电解液的总质量计。通过添加所述添加剂，能够进一步改善电池的循环性能。
在任意实施方式中，所述锂离子电池的负极极片中，负极膜层的厚度≤140μm。由此，可以进一步改善电池的循环性能。
本申请的第二方面提供一种电池模块，包括本申请的第一方面的 锂离子电池。
本申请的第三方面提供一种电池包，包括本申请的第二方面的电池模块。
本申请的第四方面提供一种用电装置，包括选自本申请的第一方面的锂离子电池、本申请的第二方面的电池模块或本申请的第三方面的电池包中的至少一种。
附图说明
图1是本申请一实施方式的锂离子电池的示意图。
图2是图1所示的本申请一实施方式的锂离子电池的分解图。
图3是本申请一实施方式的电池模块的示意图。
图4是本申请一实施方式的电池包的示意图。
图5是图4所示的本申请一实施方式的电池包的分解图。
图6是本申请一实施方式的锂离子电池用作电源的用电装置的示意图。
附图标记说明：
1电池包；2上箱体；3下箱体；4电池模块；5锂离子电池；51壳体；52电极组件；53顶盖组件
具体实施方式
以下，适当地参照附图详细说明本申请的锂离子电池、电池模块、电池包和电学装置的实施方式。但是会有省略不必要的详细说明的情况。例如，有省略对已众所周知的事项的详细说明、实际相同结构的重复说明的情况。这是为了避免以下的说明不必要地变得冗长，便于本领域技术人员的理解。此外，附图及以下说明是为了本领域技术人员充分理解本申请而提供的，并不旨在限定权利要求书所记载的主题。
本申请所公开的“范围”以下限和上限的形式来限定，给定范围是通过选定一个下限和一个上限进行限定的，选定的下限和上限限定了特别范围的边界。这种方式进行限定的范围可以是包括端值或不包括端值的，并且可以进行任意地组合，即任何下限可以与任何上限组 合形成一个范围。例如，如果针对特定参数列出了60-120和80-110的范围，理解为60-110和80-120的范围也是预料到的。此外，如果列出的最小范围值1和2，和如果列出了最大范围值3，4和5，则下面的范围可全部预料到：1-3、1-4、1-5、2-3、2-4和2-5。在本申请中，除非有其他说明，数值范围“a-b”表示a到b之间的任意实数组合的缩略表示，其中a和b都是实数。例如数值范围“0-5”表示本文中已经全部列出了“0-5”之间的全部实数，“0-5”只是这些数值组合的缩略表示。另外，当表述某个参数为≥2的整数，则相当于公开了该参数为例如整数2、3、4、5、6、7、8、9、10、11、12等。
如果没有特别的说明，本申请的所有实施方式以及可选实施方式可以相互组合形成新的技术方案。
如果没有特别的说明，本申请的所有技术特征以及可选技术特征可以相互组合形成新的技术方案。
如果没有特别的说明，本申请的所有步骤可以顺序进行，也可以随机进行，优选是顺序进行的。例如，所述方法包括步骤(a)和(b)，表示所述方法可包括顺序进行的步骤(a)和(b)，也可以包括顺序进行的步骤(b)和(a)。例如，所述提到所述方法还可包括步骤(c)，表示步骤(c)可以任意顺序加入到所述方法，例如，所述方法可以包括步骤(a)、(b)和(c)，也可包括步骤(a)、(c)和(b)，也可以包括步骤(c)、(a)和(b)等。
如果没有特别的说明，本申请所提到的“包括”和“包含”表示开放式，也可以是封闭式。例如，所述“包括”和“包含”可以表示还可以包括或包含没有列出的其他组分，也可以仅包括或包含列出的组分。
如果没有特别的说明，在本申请中，术语“或”是包括性的。举例来说，短语“A或B”表示“A，B，或A和B两者”。更具体地，以下任一条件均满足条件“A或B”：A为真(或存在)并且B为假(或不存在)；A为假(或不存在)而B为真(或存在)；或A和B都为真(或存在)。
现有的锂离子电池中，其负极容量/正极容量——即CB(cell balance)值——较高，通常为1.07以上，有些甚至超过1.1。较高的CB值意味着负极容量更多地超过正极容量，可在充放电过程中为锂提供足够的空间，避免锂在负极表面沉积形成枝晶，使电池具有较好的循环性能。但较高的CB值也意味着负极的浪费，导致电池能量密度较低。因此，期望能够降低锂离子电池的CB值，以提高电池的能量密度，同时仍确保电池具有良好的循环性能。
本申请通过在锂离子电池的电解液中加入特定量的硫脲类化合物，获得了比现有的锂离子电池具有更低CB值的锂离子电池，且该锂离子电池具有良好的循环性能。
本申请的一个实施方式中，本申请提供一种锂离子电池，其具有正极极片、负极极片、隔离膜及电解液，所述电池的负极容量与正极容量的比值为a，且所述电解液中含有含量基于电解液的总重量计为b重量％的硫脲类化合物，所述锂离子电池满足下述关系式：
a<1.05；且
25×(1.05-a)≤b≤100×(1.05-a)。
虽然机理尚不明确，但本申请人意外地发现：本申请通过在电解液中加入所述量的硫脲类化合物，使得即使在电池的CB值较低的情况下，也能使电池具有良好的循环性能。如果硫脲类化合物含量过低，则对循环性能的改善不够，如果含量过高也会由于硫脲被氧化而导致电池在存储期间产气。通过上述设计的锂离子电池，兼具良好的循环性能与能量密度。
电池的负极容量和正极容量各自可通过如下方法检测：通过将锂离子电池满放(例如对于本申请的锂离子电池，放电到2.5V即实现满放)后，拆解电池分别得到正负极极片，对正负极极片各自使用金属锂作为对电极，分别组装成扣式电池，以0.1mA进行容量放电，测试对应的容量，详细的CB值测试过程参见本申请实施例的测试方法部分。
在一些实施方式中，a/b在0.8至2的范围内，可选地在1至1.8 的范围内。由此，锂离子电池的能量密度和循环性能可进一步改善。
在一些实施方式中，a在0.9至小于1.05的范围内，可选地在0.98至1.04的范围内。由此，锂离子电池可获得循环性能和能量密度的更好平衡。
在一些实施方式中，b在0.2至5的范围内，可选地在0.5至2的范围内，进一步可选地在0.5至1.0的范围内。通过选择硫脲类化合物的含量，可进一步改善电池的循环性能。
在一些实施方式中，所述硫脲类化合物具有如下结构通式：
Figure PCTCN2022124812-appb-000002
其中R和X各自独立地选自H、C1-C10的烷基、C1-C10的烯基、苯基、或者R和X一起代表C1-C10的亚烷基或C1-C10的亚烯基，其中所述C1-C10的亚烷基或C1-C10的亚烯基任选地被氧基取代，可选地，R和X各自独立地选自H、C1-C6的烷基、C1-C6的烯基、或者R和X一起代表C1-C6的亚烷基或C1-C6的亚烯基，其中所述C1-C6的亚烷基或C1-C6的亚烯基任选地被氧基取代。可选地，所述硫脲类化合物具有以下结构之一：
Figure PCTCN2022124812-appb-000003
通过对硫脲类化合物的选择可以进一步改善锂离子电池的循环性能。
在一些实施方式中，所述电解液中还含有选自金属的硝酸盐、氟代碳酸乙烯酯和碳酸亚乙烯酯中的至少一种的添加剂，可选地，所述金属的硝酸盐为硝酸锂、硝酸镁和硝酸铜中的一种或多种，可选地，所述添加剂的含量在0.5重量％-2重量％范围内。通过添加所述添加剂，能够进一步改善电池的循环性能。
在一些实施方式中，所述锂离子电池的负极极片中，负极膜层的 厚度≤140微米。由此，可以进一步改善电池的循环性能。
另外，以下适当参照附图对本申请的锂离子电池、电池模块、电池包和用电装置进行说明。
本申请的一个实施方式中，提供一种锂离子电池。
通常情况下，锂离子电池包括正极极片、负极极片、电解质和隔离膜。在电池充放电过程中，活性离子在正极极片和负极极片之间往返嵌入和脱出。电解质在正极极片和负极极片之间起到传导离子的作用。隔离膜设置在正极极片和负极极片之间，主要起到防止正负极短路的作用，同时可以使离子通过。
[正极极片]
正极极片包括正极集流体以及设置在正极集流体至少一个表面的正极膜层，所述正极膜层包括本申请第一方面的正极活性材料。
作为示例，正极集流体具有在其自身厚度方向相对的两个表面，正极膜层设置在正极集流体相对的两个表面的其中任意一者或两者上。
在一些实施方式中，所述正极集流体可采用金属箔片或复合集流体。例如，作为金属箔片，可采用铝箔。复合集流体可包括高分子材料基层和形成于高分子材料基层至少一个表面上的金属层。复合集流体可通过将金属材料(铝、铝合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子材料基材(如聚丙烯(PP)、聚对苯二甲酸乙二醇酯(PET)、聚对苯二甲酸丁二醇酯(PBT)、聚苯乙烯(PS)、聚乙烯(PE)等的基材)上而形成。
在一些实施方式中，正极活性材料可采用本领域公知的用于电池的正极活性材料。作为示例，正极活性材料可包括以下材料中的至少一种：橄榄石结构的含锂磷酸盐、锂过渡金属氧化物及其各自的改性化合物。但本申请并不限定于这些材料，还可以使用其他可被用作电池正极活性材料的传统材料。这些正极活性材料可以仅单独使用一种，也可以将两种以上组合使用。其中，锂过渡金属氧化物的示例可包括但不限于锂钴氧化物(如LiCoO 2)、锂镍氧化物(如LiNiO 2)、锂锰 氧化物(如LiMnO 2、LiMn 2O 4)、锂镍钴氧化物、锂锰钴氧化物、锂镍锰氧化物、锂镍钴锰氧化物(如LiNi 1/3Co 1/3Mn 1/3O 2(也可以简称为NCM 333)、LiNi 0.5Co 0.2Mn 0.3O 2(也可以简称为NCM 523)、LiNi 0.5Co 0.25Mn 0.25O 2(也可以简称为NCM 211)、LiNi 0.6Co 0.2Mn 0.2O 2(也可以简称为NCM 622)、LiNi 0.8Co 0.1Mn 0.1O 2(也可以简称为NCM 811)、锂镍钴铝氧化物(如LiNi 0.85Co 0.15Al 0.05O 2)及其改性化合物等中的至少一种。橄榄石结构的含锂磷酸盐的示例可包括但不限于磷酸铁锂(如LiFePO 4(也可以简称为LFP))、磷酸铁锂与碳的复合材料、磷酸锰锂(如LiMnPO 4)、磷酸锰锂与碳的复合材料、磷酸锰铁锂、磷酸锰铁锂与碳的复合材料中的至少一种。
在一些实施方式中，正极膜层还可选地包括粘结剂。作为示例，所述粘结剂可以包括聚偏氟乙烯(PVDF)、聚四氟乙烯(PTFE)、偏氟乙烯-四氟乙烯-丙烯三元共聚物、偏氟乙烯-六氟丙烯-四氟乙烯三元共聚物、四氟乙烯-六氟丙烯共聚物及含氟丙烯酸酯树脂中的至少一种。
在一些实施方式中，正极膜层还可选地包括导电剂。作为示例，所述导电剂可以包括超导碳、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨烯及碳纳米纤维中的至少一种。
在一些实施方式中，可以通过以下方式制备正极极片：将上述用于制备正极极片的组分，例如正极活性材料、导电剂、粘结剂和任意其他的组分分散于溶剂(例如N-甲基吡咯烷酮)中，形成正极浆料；将正极浆料涂覆在正极集流体上，经烘干、冷压等工序后，即可得到正极极片。
[负极极片]
负极极片包括负极集流体以及设置在负极集流体至少一个表面上的负极膜层，所述负极膜层包括负极活性材料。
作为示例，负极集流体具有在其自身厚度方向相对的两个表面，负极膜层设置在负极集流体相对的两个表面中的任意一者或两者上。
在一些实施方式中，所述负极集流体可采用金属箔片或复合集流 体。例如，作为金属箔片，可以采用铜箔。复合集流体可包括高分子材料基层和形成于高分子材料基材至少一个表面上的金属层。复合集流体可通过将金属材料(铜、铜合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子材料基材(如聚丙烯(PP)、聚对苯二甲酸乙二醇酯(PET)、聚对苯二甲酸丁二醇酯(PBT)、聚苯乙烯(PS)、聚乙烯(PE)等的基材)上而形成。
在一些实施方式中，负极活性材料可采用本领域公知的用于电池的负极活性材料。作为示例，负极活性材料可包括以下材料中的至少一种：人造石墨、天然石墨、软炭、硬炭、硅基材料、锡基材料和钛酸锂等。所述硅基材料可选自单质硅、硅氧化合物、硅碳复合物、硅氮复合物以及硅合金中的至少一种。所述锡基材料可选自单质锡、锡氧化合物以及锡合金中的至少一种。但本申请并不限定于这些材料，还可以使用其他可被用作电池负极活性材料的传统材料。这些负极活性材料可以仅单独使用一种，也可以将两种以上组合使用。
在一些实施方式中，负极膜层还可选地包括粘结剂。所述粘结剂可选自丁苯橡胶(SBR)、聚丙烯酸(PAA)、聚丙烯酸钠(PAAS)、聚丙烯酰胺(PAM)、聚乙烯醇(PVA)、海藻酸钠(SA)、聚甲基丙烯酸(PMAA)及羧甲基壳聚糖(CMCS)中的至少一种。
在一些实施方式中，负极膜层还可选地包括导电剂。导电剂可选自超导碳、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨烯及碳纳米纤维中的至少一种。
在一些实施方式中，负极膜层还可选地包括其他助剂，例如增稠剂(如羧甲基纤维素钠(CMC-Na))等。
在一些实施方式中，可以通过以下方式制备负极极片：将上述用于制备负极极片的组分，例如负极活性材料、导电剂、粘结剂和任意其他组分分散于溶剂(例如去离子水)中，形成负极浆料；将负极浆料涂覆在负极集流体上，经烘干、冷压等工序后，即可得到负极极片。
[电解质]
电解质在正极极片和负极极片之间起到传导离子的作用。本申请 对电解质的种类没有具体的限制，可根据需求进行选择。例如，电解质可以是液态的、凝胶态的或全固态的。
在一些实施方式中，所述电解质采用电解液。所述电解液包括电解质盐和溶剂。
在一些实施方式中，电解质盐可选自六氟磷酸锂、四氟硼酸锂、高氯酸锂、六氟砷酸锂、双氟磺酰亚胺锂、双三氟甲磺酰亚胺锂、三氟甲磺酸锂、二氟磷酸锂、二氟草酸硼酸锂、二草酸硼酸锂、二氟二草酸磷酸锂及四氟草酸磷酸锂中的至少一种。
在一些实施方式中，溶剂可选自碳酸亚乙酯、碳酸亚丙酯、碳酸甲乙酯、碳酸二乙酯、碳酸二甲酯、碳酸二丙酯、碳酸甲丙酯、碳酸乙丙酯、碳酸亚丁酯、氟代碳酸亚乙酯、甲酸甲酯、乙酸甲酯、乙酸乙酯、乙酸丙酯、丙酸甲酯、丙酸乙酯、丙酸丙酯、丁酸甲酯、丁酸乙酯、1,4-丁内酯、环丁砜、二甲砜、甲乙砜及二乙砜中的至少一种。
在一些实施方式中，所述电解液还可选地包括其他添加剂。例如添加剂可以包括负极成膜添加剂、正极成膜添加剂，还可以包括能够改善电池某些性能的添加剂，例如改善电池过充性能的添加剂、改善电池高温或低温性能的添加剂等。
[隔离膜]
在一些实施方式中，锂离子电池中还包括隔离膜。本申请对隔离膜的种类没有特别的限制，可以选用任意公知的具有良好的化学稳定性和机械稳定性的多孔结构隔离膜。
在一些实施方式中，隔离膜的材质可选自玻璃纤维、无纺布、聚乙烯、聚丙烯及聚偏二氟乙烯中的至少一种。隔离膜可以是单层薄膜，也可以是多层复合薄膜，没有特别限制。在隔离膜为多层复合薄膜时，各层的材料可以相同或不同，没有特别限制。
在一些实施方式中，正极极片、负极极片和隔离膜可通过卷绕工艺或叠片工艺制成电极组件。
在一些实施方式中，锂离子电池可包括外包装。该外包装可用于封装上述电极组件及电解质。
在一些实施方式中，锂离子电池的外包装可以是硬壳，例如硬塑料壳、铝壳、钢壳等。锂离子电池的外包装也可以是软包，例如袋式软包。软包的材质可以是塑料，作为塑料，可列举出聚丙烯、聚对苯二甲酸丁二醇酯以及聚丁二酸丁二醇酯等。
本申请对锂离子电池的形状没有特别的限制，其可以是圆柱形、方形或其他任意的形状。例如，图1是作为一个示例的方形结构的锂离子电池5。
在一些实施方式中，参照图2，外包装可包括壳体51和盖板53。其中，壳体51可包括底板和连接于底板上的侧板，底板和侧板围合形成容纳腔。壳体51具有与容纳腔连通的开口，盖板53能够盖设于所述开口，以封闭所述容纳腔。正极极片、负极极片和隔离膜可经卷绕工艺或叠片工艺形成电极组件52。电极组件52封装于所述容纳腔内。电解液浸润于电极组件52中。锂离子电池5所含电极组件52的数量可以为一个或多个，本领域技术人员可根据具体实际需求进行选择。
在一些实施方式中，锂离子电池可以组装成电池模块，电池模块所含锂离子电池的数量可以为一个或多个，具体数量本领域技术人员可根据电池模块的应用和容量进行选择。
图3是作为一个示例的电池模块4。参照图3，在电池模块4中，多个锂离子电池5可以是沿电池模块4的长度方向依次排列设置。当然，也可以按照其他任意的方式进行排布。进一步可以通过紧固件将该多个锂离子电池5进行固定。
可选地，电池模块4还可以包括具有容纳空间的外壳，多个锂离子电池5容纳于该容纳空间。
在一些实施方式中，上述电池模块还可以组装成电池包，电池包所含电池模块的数量可以为一个或多个，具体数量本领域技术人员可根据电池包的应用和容量进行选择。
图4和图5是作为一个示例的电池包1。参照图4和图5，在电池包1中可以包括电池箱和设置于电池箱中的多个电池模块4。电池 箱包括上箱体2和下箱体3，上箱体2能够盖设于下箱体3，并形成用于容纳电池模块4的封闭空间。多个电池模块4可以按照任意的方式排布于电池箱中。
另外，本申请还提供一种用电装置，所述用电装置包括本申请提供的锂离子电池、电池模块、或电池包中的至少一种。所述锂离子电池、电池模块、或电池包可以用作所述用电装置的电源，也可以用作所述用电装置的能量存储单元。所述用电装置可以包括移动设备(例如手机、笔记本电脑等)、电动车辆(例如纯电动车、混合动力电动车、插电式混合动力电动车、电动自行车、电动踏板车、电动高尔夫球车、电动卡车等)、电气列车、船舶及卫星、储能系统等，但不限于此。
作为所述用电装置，可以根据其使用需求来选择锂离子电池、电池模块或电池包。
图6是作为一个示例的用电装置。该用电装置为纯电动车、混合动力电动车、或插电式混合动力电动车等。为了满足该用电装置对锂离子电池的高功率和高能量密度的需求，可以采用电池包或电池模块。
作为另一个示例的装置可以是手机、平板电脑、笔记本电脑等。该装置通常要求轻薄化，可以采用锂离子电池作为电源。
实施例
以下，说明本申请的实施例。下面描述的实施例是示例性的，仅用于解释本申请，而不能理解为对本申请的限制。实施例中未注明具体技术或条件的，按照本领域内的文献所描述的技术或条件或者按照产品说明书进行。所用试剂或仪器未注明生产厂商者，均为可以通过市购获得的常规产品。
实施例和对比例中使用的硫脲添加剂如下：
Figure PCTCN2022124812-appb-000004
Figure PCTCN2022124812-appb-000005
对比例1
【电解液的制备】
在含水量<10ppm的氩气气氛手套箱中，于烧杯中分别加入26.25g EC(碳酸亚乙酯)、61.25g EMC(碳酸甲乙酯)、12.5g LiPF 6，充分搅拌溶解后得到本对比例用电解液。
【正极极片的制备】
将正极活性材料镍钴锰三元材料(LiNi 0.8Co 0.1Mn 0.1O 2，容量为180mAh/g)、粘结剂聚偏氟乙烯、导电剂乙炔黑按照质量比8：1：1进行混合，加入溶剂NMP(N-甲基吡咯烷酮)，在真空搅拌机作用下获得正极浆料。将正极浆料以0.2826g(干重)/1540.25mm 2的量均匀涂敷在厚度为13μm的正极集流体铝箔上；将铝箔在室温晾干后转移至120℃烘箱干燥1h，然后经过冷压、分切得到正极极片。
【负极极片的制备】
将人造石墨(容量为350mAh/g)、导电剂碳黑、粘结剂丙烯酸酯按照质量比92:2:6进行混合，加入去离子水，在真空搅拌机作用下获得负极浆料。将负极浆料以0.1290g(干重)/1540.25mm 2的量均匀涂覆在厚度为8μm的负极集流体铜箔上；将铜箔在室温晾干后转移至120℃烘箱干燥1h，然后经过冷压达到负极膜层厚度为100微米，分切得到负极极片。
【隔离膜】
隔离膜采购自Cellgard企业，型号为cellgard2400。
【锂离子电池的制备】
将正极极片、隔离膜、负极极片按顺序叠好，使隔离膜处于正、负极极片之间起到隔离的作用，然后卷绕得到裸电芯。将裸电芯置于外包装箔中，将上述制备好的8.6g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，获得锂离子电池。
对比例2
锂离子电池的制备过程基本与对比例1相同，区别在于电解液的制备步骤为：在含水量<10ppm的氩气气氛手套箱中，于烧杯中分别加入26.1g EC、60.9g EMC、12.5g LiPF 6、0.5g硫脲类化合物1充分搅拌溶解后得到本对比例用电解液。
对比例3
锂离子电池的制备过程基本与对比例1相同，区别在于电解液的制备步骤为：在含水量<10ppm的氩气气氛手套箱中，于烧杯中分别加入25.29g EC、59.01g EMC、12.5g LiPF 6、3.2g硫脲类化合物1充分搅拌溶解后得到本对比例用电解液。
实施例1
锂离子电池的制备过程基本与对比例1相同，区别在于电解液的制备步骤为：在含水量<10ppm的氩气气氛手套箱中，于烧杯中分别加入25.95g EC、60.55g EMC、12.5g LiPF 6、1g硫脲类化合物1充分搅拌溶解后得到本实施例用电解液。
实施例2
锂离子电池的制备过程基本与对比例1相同，区别在于电解液的制备步骤为：在含水量<10ppm的氩气气氛手套箱中，于烧杯中分别 加入26.01g EC、60.69g EMC、12.5g LiPF 6、0.8g硫脲类化合物1充分搅拌溶解后得到本实施例用电解液。
实施例3
锂离子电池的制备过程基本与对比例1相同，区别在于电解液的制备步骤为：在含水量<10ppm的氩气气氛手套箱中，于烧杯中分别加入25.8g EC、60.2g EMC、12.5g LiPF 6、1.5g硫脲类化合物1充分搅拌溶解后得到本实施例用电解液。
实施例4
锂离子电池的制备过程基本与对比例1相同，区别在于电解液的制备步骤为：在含水量<10ppm的氩气气氛手套箱中，于烧杯中分别加入25.9g EC、60.4g EMC、12.5g LiPF 6、1.2g硫脲类化合物1充分搅拌溶解后得到本实施例用电解液。
实施例5
锂离子电池的制备过程基本与对比例1相同，区别在于将负极浆料以0.1315g(干重)/1540.25mm 2的量均匀涂覆在厚度为8μm的负极集流体铜箔上；电解液的制备步骤为：在含水量<10ppm的氩气气氛手套箱中，于烧杯中分别加入26.07g EC、60.83g EMC、12.5g LiPF 6、0.6g硫脲类化合物1充分搅拌溶解后得到本实施例用电解液。
实施例6
锂离子电池的制备过程基本与对比例1相同，区别在于将负极浆料以0.1315g(干重)/1540.25mm 2的量均匀涂覆在厚度为8μm的负极集流体铜箔上；电解液的制备步骤为：在含水量<10ppm的氩气气氛手套箱中，于烧杯中分别加入26.085g EC、60.865g EMC、12.5g LiPF 6、0.55g硫脲类化合物1充分搅拌溶解后得到本实施例用电解液。
实施例7
锂离子电池的制备过程基本与对比例1相同，区别在于将负极浆料以0.1315g(干重)/1540.25mm 2的量均匀涂覆在厚度为8μm的负极集流体铜箔上；电解液的制备步骤为：在含水量<10ppm的氩气气氛手套箱中，于烧杯中分别加入26.1g EC、60.9g EMC、12.5g LiPF 6、0.5g硫脲类化合物1充分搅拌溶解后得到本实施例用电解液。
实施例8
锂离子电池的制备过程基本与对比例1相同，区别在于将负极浆料以0.1239g(干重)/1540.25mm 2的量均匀涂覆在厚度为8μm的负极集流体铜箔上；电解液的制备步骤为：在含水量<10ppm的氩气气氛手套箱中，于烧杯中分别加入25.65g EC、59.85g EMC、12.5g LiPF 6、2g硫脲类化合物1充分搅拌溶解后得到本实施例用电解液
实施例9
锂离子电池的制备过程基本与对比例1相同，区别在于将负极浆料以0.115g(干重)/1540.25mm 2的量均匀涂覆在厚度为8μm的负极集流体铜箔上；电解液的制备步骤为：在含水量<10ppm的氩气气氛手套箱中，于烧杯中分别加入25.05g EC、58.45g EMC、12.5g LiPF 6、4g硫脲类化合物1充分搅拌溶解后得到本实施例用电解液
实施例10
锂离子电池的制备过程基本与实施例1相同，区别在于该实施例的电解液制备中加入的硫脲类化合物为硫脲类化合物2。
实施例11
锂离子电池的制备过程基本与实施例1相同，区别在于该实施例的电解液制备中加入的硫脲类化合物为硫脲类化合物3。
实施例12
锂离子电池的制备过程基本与实施例1相同，区别在于该实施例的电解液制备中加入的硫脲类化合物为硫脲类化合物4。
实施例13
锂离子电池的制备过程基本与实施例1相同，区别在于该实施例的电解液制备中加入的硫脲类化合物为硫脲类化合物5。
实施例14
锂离子电池的制备过程基本与实施例1相同，区别在于电解液制备过程为：
在含水量<10ppm的氩气气氛手套箱中，于烧杯中分别加入25.35g EC、59.15g EMC、12.5g LiPF 6、1g硫脲类化合物1、1g FEC(氟代碳酸乙烯酯)、1g LiNO 3充分搅拌溶解后得到本实施例用电解液。
实施例15
锂离子电池的制备过程基本与实施例1相同，区别在于电解液制备过程为：
在含水量<10ppm的氩气气氛手套箱中，于烧杯中分别加入25.35g EC、59.15g EMC、12.5g LiPF 6、1g硫脲类化合物1、1g FEC、1g Mg(NO 3) 2充分搅拌溶解后得到本实施例用电解液。
实施例16
锂离子电池的制备过程基本与实施例1相同，区别在于电解液制备过程为：
在含水量<10ppm的氩气气氛手套箱中，于烧杯中分别加入25.35g EC、59.15g EMC、12.5g LiPF 6、1g硫脲类化合物1、1g VC(碳酸亚乙烯酯)、1g LiNO 3充分搅拌溶解后得到本实施例用电解液。
实施例17
锂离子电池的制备过程基本与实施例1相同，区别在于电解液制备过程为：
在含水量<10ppm的氩气气氛手套箱中，于烧杯中分别加入25.35g EC、59.15g EMC、12.5g LiPF 6、1g硫脲类化合物1、2g LiNO 3充分搅拌溶解后得到本实施例用电解液。
实施例18
锂离子电池的制备过程基本与实施例1相同，区别在于负极膜层冷压后的厚度为90微米。
实施例19
锂离子电池的制备过程基本与实施例1相同，区别在于负极膜层冷压后的厚度为140微米。
实施例20
锂离子电池的制备过程基本与实施例1相同，区别在于负极膜层冷压后的厚度为150微米。
测试方法
1.CB值测量
通过将锂离子电池放电至2.5V后，拆解电池得到负极极片。对负极极片使用金属锂作为对电极，组装成扣式电池。扣式电池采用标准的2046纽扣电池用金属壳，极片裁剪成直径为14mm的小圆片，金属锂片采用直径为16mm的小圆片，中间的隔离膜采用直径为18mm的PP隔离膜。对于上述扣电，用36mA进行放电至0.05V，此时记录其放电容量为N1。
通过将锂离子电池充电至4.4V以达到满充后，拆解电池得到正极 极片。对正极极片使用金属锂作为对电极，组装成扣式电池。扣式电池采用标准的2046纽扣电池用金属壳，极片裁剪成直径为14mm的小圆片，金属锂片采用直径为16mm的小圆片，中间的隔离膜采用直径为18mm的PP隔离膜。对于上述扣电，用18mA进行放电至3.0V，此时记录其放电容量为N2。
由此，获得锂离子电池的CB值＝N1/N2。
2. 25℃循环性能测试
在25℃下，将锂离子电池以0.5C恒流充电至4.35V，再恒压充电至电流为0.05C，再以0.5C恒流放电至2.8V，记录放电容量为U1。之后将锂离子电池在25℃的环境温度下，重复上述的充放电流程600次，并记录第600次循环的放电容量为U2，
锂离子电池25℃循环600圈后的容量保持率＝[U2/U1]×100％。
3. 60℃存储性能测试
在60℃下，将锂离子电池以0.5C恒流充电至4.35V，再恒压充电至电流为0.05C，此时测试锂离子电池的厚度并记为h0。之后将锂离子电池放入60℃的恒温箱，储存30天后取出，测试此时锂离子电池的厚度并记为h1。锂离子电池存储30天后的厚度膨胀率＝[(h1-h0)/h0]×100％。
4.能量密度测试
在25℃下，将锂离子电池以1A恒流充电至4.3V，然后恒压充电至电流小于0.5A。接着再将电池以1A恒流放电至2.5V，再以0.5A恒流放电至2.5V，最后再以0.1A放电至2.5V，记录该电池的放电容量C(Ah)，并记录放电达到容量一半时电池的电压值U(V)。
此时将电池称重并记录质量m(kg)。
电池能量W＝C×U，电池的能量密度＝W/m。
各实施例和对比例的性能测试结果显示在下表1-4中。
表1
Figure PCTCN2022124812-appb-000006
Figure PCTCN2022124812-appb-000007
表2
Figure PCTCN2022124812-appb-000008
表3
Figure PCTCN2022124812-appb-000009
表4
Figure PCTCN2022124812-appb-000010
对比例1-3与实施例1-20均采用了低CB值，与对比例1-3相比，实施例1-20均显示出更好的循环性能。另外，对比例2中硫脲类化合物含量偏低，因此虽然相对于完全不含硫脲类化合物的对比例1提升了循环性能，但提升有限。对比例3中硫脲类化合物含量偏高，虽然在循环性能上有较大改善，但高温存储后的电池膨胀率过高。由实施例1-4、实施例5-7可以看出，当a/b在0.8-2、尤其是1-1.8范围内时，电池的循环性能进一步改善。当a在0.9至小于1.05的范围内、尤其是0.98-1.04的范围内时，电池的循环性能进一步改善。由此，锂离子电池可获得循环性能当b在0.5-2、尤其是0.5-1.0范围内时，电池的循环性能进一步改善。
由实施例10-13可以看出，采用其他硫脲类化合物也在低CB值下实现了良好的循环性能。
由实施例14-17可以看出，当在电解液中进一步加入特定的其他添加剂时，电池的循环性能进一步改善。
由实施例18-20可以看出，将负极膜层厚度控制在140μm以下可以进一步改善电池的循环性能。
需要说明的是，本申请不限定于上述实施方式。上述实施方式仅为示例，在本申请的技术方案范围内具有与技术思想实质相同的构成、发挥相同作用效果的实施方式均包含在本申请的技术范围内。此外，在不脱离本申请主旨的范围内，对实施方式施加本领域技术人员能够想到的各种变形、将实施方式中的一部分构成要素加以组合而构筑的其它方式也包含在本申请的范围内。

Claims (10)

  1. 一种锂离子电池，其具有正极极片、负极极片、隔离膜及电解液，其特征在于，
    所述电池的负极容量与正极容量的比值为a，且所述电解液中含有含量基于电解液的总重量计为b重量％的硫脲类化合物，所述锂离子电池满足下述关系式：
    a＜1.05；且
    25×(1.05-a)≤b≤100×(1.05-a)。
  2. 根据权利要求1所述的锂离子电池，其特征在于，a/b在0.8至2的范围内，可选地在1至1.8的范围内。
  3. 根据权利要求1所述的锂离子电池，其特征在于，a在0.9至小于1.05的范围内，可选地在0.98至1.04的范围内。
  4. 根据权利要求1所述的锂离子电池，其特征在于，b在0.2至5的范围内，可选地在0.5至2的范围内，进一步可选地在0.5至1.0的范围内。
  5. 根据权利要求1所述的锂离子电池，其特征在于，所述硫脲类化合物具有如下结构通式：
    Figure PCTCN2022124812-appb-100001
    其中R和X各自独立地选自H、C1-C10的烷基、C1-C10的烯基、苯基、或者R和X一起代表C1-C10的亚烷基或C1-C10的亚烯基，其中所述C1-C10的亚烷基或C1-C10的亚烯基任选地被氧基取代，可选地，R和X各自独立地选自H、C1-C6的烷基、C1-C6的烯基、或者R和X一起代表C1-C6的亚烷基或C1-C6的亚烯基，其中所述C1-C6的亚烷基或C1-C6的亚烯基任选地被氧基取代。
  6. 根据权利要求1所述的锂离子电池，其特征在于，所述电解液中还含有选自金属的硝酸盐、氟代碳酸乙烯酯和碳酸亚乙烯酯中的 至少一种的添加剂，可选地，所述金属的硝酸盐为硝酸锂、硝酸镁和硝酸铜中的一种或多种，可选地，所述添加剂的含量在0.5重量％-2重量％范围内，基于电解液的总质量计。
  7. 根据权利要求1所述的锂离子电池，其特征在于，所述锂离子电池的负极极片中，负极膜层的厚度≤140μm。
  8. 一种电池模块，其特征在于，包括权利要求1所述的锂离子电池。
  9. 一种电池包，其特征在于，包括权利要求8所述的电池模块。
  10. 一种用电装置，其特征在于，包括选自权利要求1-7任一项所述的锂离子电池、权利要求8所述的电池模块或权利要求9所述的电池包中的至少一种。
PCT/CN2022/124812 2021-11-15 2022-10-12 锂离子电池、电池模块、电池包及用电装置 WO2023082918A1 (zh)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP22891717.5A EP4362156A1 (en) 2021-11-15 2022-10-12 Lithium ion battery, battery module, battery pack, and electric apparatus
JP2024501264A JP2024525681A (ja) 2021-11-15 2022-10-12 リチウムイオン電池、電池ユニット、電池パックおよび電気装置
KR1020247001257A KR20240019835A (ko) 2021-11-15 2022-10-12 리튬 이온 배터리, 배터리 모듈, 배터리팩 및 전기 장치
US18/599,285 US20240266606A1 (en) 2021-11-15 2024-03-08 Lithium-ion battery, battery module, battery pack, and electric device

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202111350705.2A CN115810797A (zh) 2021-11-15 2021-11-15 锂离子电池、电池模块、电池包及用电装置
CN202111350705.2 2021-11-15

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US18/599,285 Continuation US20240266606A1 (en) 2021-11-15 2024-03-08 Lithium-ion battery, battery module, battery pack, and electric device

Publications (1)

Publication Number Publication Date
WO2023082918A1 true WO2023082918A1 (zh) 2023-05-19

Family

ID=85482102

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/124812 WO2023082918A1 (zh) 2021-11-15 2022-10-12 锂离子电池、电池模块、电池包及用电装置

Country Status (6)

Country Link
US (1) US20240266606A1 (zh)
EP (1) EP4362156A1 (zh)
JP (1) JP2024525681A (zh)
KR (1) KR20240019835A (zh)
CN (2) CN115810797A (zh)
WO (1) WO2023082918A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116526069A (zh) * 2023-07-04 2023-08-01 宁德时代新能源科技股份有限公司 隔离膜、电池单体、电池和用电装置

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116404265B (zh) * 2023-06-07 2023-09-12 宁德新能源科技有限公司 一种电化学装置和电子装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009266706A (ja) * 2008-04-28 2009-11-12 Hitachi Vehicle Energy Ltd リチウムイオン二次電池
CN104733785A (zh) * 2013-12-20 2015-06-24 苏州宝时得电动工具有限公司 电池
CN105742695A (zh) * 2016-04-28 2016-07-06 深圳市力为锂能科技有限公司 一种锂离子电池及其制备方法
CN109273771A (zh) * 2018-08-21 2019-01-25 宁德时代新能源科技股份有限公司 二次电池
CN112582673A (zh) * 2019-09-29 2021-03-30 比亚迪股份有限公司 一种锂离子电池电解液及锂离子电池
CN113394456A (zh) * 2021-06-11 2021-09-14 厦门大学 一种锂金属电池电解液添加剂及其应用

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11126633A (ja) * 1997-08-30 1999-05-11 Samsung Display Devices Co Ltd Ｌｉイオン電池用電解液及びそれを採用したＬｉイオン電池
CN113437250B (zh) * 2021-06-21 2022-06-10 宁德新能源科技有限公司 电化学装置和电子装置
CN113258140B (zh) * 2021-07-07 2022-02-15 北京壹金新能源科技有限公司 锂二次电池电解液及其制备方法和应用

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009266706A (ja) * 2008-04-28 2009-11-12 Hitachi Vehicle Energy Ltd リチウムイオン二次電池
CN104733785A (zh) * 2013-12-20 2015-06-24 苏州宝时得电动工具有限公司 电池
CN105742695A (zh) * 2016-04-28 2016-07-06 深圳市力为锂能科技有限公司 一种锂离子电池及其制备方法
CN109273771A (zh) * 2018-08-21 2019-01-25 宁德时代新能源科技股份有限公司 二次电池
CN112582673A (zh) * 2019-09-29 2021-03-30 比亚迪股份有限公司 一种锂离子电池电解液及锂离子电池
CN113394456A (zh) * 2021-06-11 2021-09-14 厦门大学 一种锂金属电池电解液添加剂及其应用

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116526069A (zh) * 2023-07-04 2023-08-01 宁德时代新能源科技股份有限公司 隔离膜、电池单体、电池和用电装置
CN116526069B (zh) * 2023-07-04 2023-09-15 宁德时代新能源科技股份有限公司 隔离膜、电池单体、电池和用电装置

Also Published As

Publication number Publication date
EP4362156A1 (en) 2024-05-01
JP2024525681A (ja) 2024-07-12
CN117747952A (zh) 2024-03-22
CN115810797A (zh) 2023-03-17
US20240266606A1 (en) 2024-08-08
KR20240019835A (ko) 2024-02-14

Similar Documents

Publication Publication Date Title
WO2023142340A1 (zh) 一种极片及具备其的二次电池
WO2023082918A1 (zh) 锂离子电池、电池模块、电池包及用电装置
WO2024012166A1 (zh) 二次电池及用电装置
WO2023029002A1 (zh) 负极集流体、含有其的二次电池、电池模块、电池包及用电装置
WO2023130888A1 (zh) 二次电池、电池模块、电池包及其用电装置
WO2023137624A1 (zh) 二次电池、电池模块、电池包以及用电装置
WO2023240598A1 (zh) 改性正极材料、其制备方法、正极极片、二次电池、电池模块、电池包和用电装置
WO2023142024A1 (zh) 一种长寿命二次电池及电池模块、电池包和用电装置
WO2023130210A1 (zh) 二次电池的补锂方法及充放电方法
WO2023060554A1 (zh) 电解液、二次电池和用电装置
WO2023060493A1 (zh) 电极组件、二次电池、电池模块、电池包及用电装置
WO2023060494A1 (zh) 电极组件、二次电池、电池模块、电池包及用电装置
WO2023044752A1 (zh) 锂离子电池、电池模块、电池包及用电装置
WO2023130310A1 (zh) 电解液、二次电池和用电装置
WO2023193230A1 (zh) 电解液、二次电池、电池模块、电池包和用电装置
WO2023130212A1 (zh) 一种锂离子二次电池、电池模块、电池包和用电装置
WO2023137625A1 (zh) 二次电池、电池模块、电池包以及用电装置
WO2023087168A1 (zh) 电解液、二次电池、电池模块、电池包以及用电装置
WO2023060587A1 (zh) 负极极片、二次电池、电池模块、电池包及用电装置
WO2024065181A1 (zh) 负极组合物及制备方法、负极浆料及制备方法、负极极片及制备方法、二次电池、用电装置以及噻蒽类化合物的应用
WO2023133882A1 (zh) 隔膜及其相关的二次电池、电池模块、电池包和用电装置
WO2023065128A1 (zh) 负极极片、二次电池、电池模块、电池包和用电装置
WO2022188163A1 (zh) 电解液、二次电池、电池模块、电池包和装置
WO2024221320A1 (zh) 二次电池和用电装置
WO2024207353A1 (zh) 正极极片及其制备方法、电池单体、电池和用电装置

Legal Events

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

Ref document number: 22891717

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2024501264

Country of ref document: JP

Kind code of ref document: A

ENP Entry into the national phase

Ref document number: 20247001257

Country of ref document: KR

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 1020247001257

Country of ref document: KR

WWE Wipo information: entry into national phase

Ref document number: 2022891717

Country of ref document: EP

ENP Entry into the national phase

Ref document number: 2022891717

Country of ref document: EP

Effective date: 20240122