WO2023184328A1 - 锂离子电池、电池模块、电池包以及用电装置 - Google Patents

锂离子电池、电池模块、电池包以及用电装置 Download PDF

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WO2023184328A1
WO2023184328A1 PCT/CN2022/084378 CN2022084378W WO2023184328A1 WO 2023184328 A1 WO2023184328 A1 WO 2023184328A1 CN 2022084378 W CN2022084378 W CN 2022084378W WO 2023184328 A1 WO2023184328 A1 WO 2023184328A1
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electrolyte
lithium
battery
ion battery
carbonate
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PCT/CN2022/084378
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English (en)
French (fr)
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黄磊
韩昌隆
王扶林
吴则利
张翠平
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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 PCT/CN2022/084378 priority Critical patent/WO2023184328A1/zh
Publication of WO2023184328A1 publication Critical patent/WO2023184328A1/zh

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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
    • H01M10/0567—Liquid materials characterised by the additives
    • 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 technical field of lithium ion batteries, and in particular to a lithium ion battery, a battery module, a battery pack and a power device.
  • lithium-ion batteries have been widely used in electric tools, electric bicycles, electric motorcycles, electric vehicles, smart grids, military equipment, aerospace and other fields. Due to the great development of lithium-ion batteries, higher requirements have been placed on their initial DC resistance and battery life. However, current lithium-ion batteries are difficult to meet people's higher demand for endurance. For example, in the field of electric vehicles, people suffer from "range anxiety" due to insufficient endurance of lithium-ion batteries. Therefore, there is an urgent need to develop longer batteries. Long life lithium-ion battery.
  • This application was made in view of the above technical problems, and its purpose is to provide a lithium-ion battery that can reduce the initial DC resistance (hereinafter, sometimes referred to as "initial DCR”) and extend the battery life.
  • initial DCR initial DC resistance
  • the inventor of the present application conducted in-depth research and found that the above technical problems can be solved by including a specific first electrolyte solution and a specific second electrolyte solution in a lithium ion battery.
  • a first aspect of the present application provides a lithium ion battery, wherein,
  • d1 is the mass of the first electrolyte
  • d2 is the mass of the second electrolyte
  • t1 is the mass ratio of the additive in the first electrolyte relative to the first electrolyte
  • t2 is the mass ratio of the additive in the second electrolyte relative to the second electrolyte.
  • SEI battery manufacturing and use
  • initial formation of SEI repair and reformation of SEI
  • SEI balance stabilization
  • SEI electrolyte remaining in the electrode assembly
  • the amount of additive in the first electrolyte solution can be expressed as d1 ⁇ t1.
  • the amount of additive in the second electrolyte can be expressed by d2 ⁇ t2.
  • the lithium-ion battery contains the first electrolyte and the second electrolyte and satisfies 0.1 ⁇ [(d2 ⁇ t2)/(d1 ⁇ t1)] ⁇ 11, the above-mentioned lithium-ion battery has a lower initial electrolyte. DC resistance and good battery life.
  • t1 is more than 1wt%, it can fully meet the needs of SEI repair and reforming, so it is preferable; when t1 is less than 4wt%, it can prevent the SEI film from becoming too thick during the repair and reforming stage and avoid large initial DC resistance. So preferred.
  • t2 is more than 3wt%, it can fully meet the consumption requirements during the life process and achieve good battery life; when t2 is less than 15wt%, it can avoid excessive costs.
  • d1/(d1+d2) is more than 60%, it can achieve sufficient infiltration of the pole piece/separator and avoid abnormality of the battery interface, so it is preferred; when d1/(d1+d2) is less than 95%, avoid the d1 part
  • the low additive content ensures a high level of additives within the entire battery and achieves good battery life.
  • the additive in the first electrolyte is selected from the group consisting of vinylene carbonate, fluoroethylene carbonate, tris(trimethylsilylphosphate), lithium difluorodioxalate phosphate, lithium dioxaloborate, One or more types of lithium fluorophosphate.
  • the additives in the first electrolyte mainly participate in the repair and reformation of SEI.
  • the SEI film formed by vinylene carbonate (hereinafter referred to as VC) has a better passivation effect on the electrode, but its film formation resistance is larger; the other several Additive-like film formation resistance is low, but its passivation effect on the electrode is not as good as VC.
  • the first electrolyte contains VC, and also contains fluorinated ethylene carbonate, tris(trimethylsilylphosphate), lithium difluorodioxalate phosphate, lithium dioxaloborate, and lithium difluorophosphate.
  • One or several additives can be used to make the total film-forming resistance of the additives lower and the initial DC resistance of the battery to be lower.
  • the mass ratio of the mass of VC to other additives in the first electrolyte is 0.5 to 0.9 based on "the mass of VC divided by the mass of other additives".
  • the first electrolyte contains a cyclic ester solvent
  • the cyclic ester solvent is a compound represented by Formula I
  • R1 and R2 are independently selected from any one of H atoms, methyl, ethyl, fluoromethyl, and fluoroethyl.
  • the cyclic ester solvent is selected from ethylene carbonate, propylene carbonate, bisfluoroethylene carbonate, trifluoropropylene carbonate 4-(2,2,3,3,4,4,5, 5,5-nonafluoropentyl)-1,3-dioxolane-2-one and 4-((2,2,3,3-tetrafluoropropoxy)methyl)-1,3-di One or more of oxolane-2-ones.
  • the content of the cyclic ester solvent is 20 wt% to 50 wt% relative to the total mass of solvent in the first electrolyte.
  • the first electrolyte is distributed in the electrode assembly. That is to say, the first electrolyte is distributed between the positive electrode pieces, the negative electrode pieces, or the pores of the separator. Since the pores of the pole pieces and the separator have small pore sizes and volumes, the infiltration rate of the electrolyte in the pole pieces and the separator is greatly affected by the solvent. Cyclic ester is a type of electrolyte solvent with high dielectric constant and large viscosity.
  • cyclic ester When cyclic ester is used as a solvent in the electrolyte, it is beneficial to the dissociation of lithium salt in the electrolyte and improves the conductivity of the electrolyte; however, It has a great influence on the infiltration rate of electrolyte in the pole pieces and separators. Therefore, controlling the content of the cyclic ester in the first electrolyte is beneficial to increasing the infiltration rate of the electrolyte during the cycle of the lithium-ion battery, reducing the initial DC impedance of the battery and the DC impedance during the cycle, and improving the performance of the battery. cycle life.
  • the second electrolyte contains a film-forming additive, and the film-forming additive is selected from the group consisting of vinylene carbonate, fluoroethylene carbonate, ethylene ethylene carbonate, and 1,3-propane sultone. one or more of them.
  • the second electrolyte uses the above-mentioned additives to participate in the repair process of the SEI film, it can further prevent the exposure of new active sites after SEI damage and continue to induce side reactions, thereby improving battery life.
  • these additives themselves are relatively stable and can exist in the battery for a long time without decomposing themselves.
  • the mass proportion of the film-forming additive is more than 70 wt% relative to the total mass of additives in the second electrolyte.
  • 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.
  • a fourth aspect of the present application provides an electrical 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.
  • the battery modules, battery packs and electrical devices of the present application include the lithium-ion battery of the first aspect of the present application, and thus have at least the same or similar technical effects as the above-mentioned lithium-ion battery.
  • Figure 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.
  • Figure 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 .
  • Figure 6 is a schematic diagram of an electrical device according to an embodiment of the present application.
  • Ranges disclosed herein are defined in terms of lower and upper limits. 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 of the endpoints, and may be arbitrarily combined, that is, 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, understand that ranges of 60-110 and 80-120 are also expected. Additionally, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are listed, then the following ranges are all expected: 1 to 3, 1 to 4, 1 to 5, 2 to 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" means that all real numbers between "0 ⁇ 5" have been listed in this article, and "0 ⁇ 5" is just an abbreviation of these numerical combinations.
  • 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 sequentially, or may include steps (b) and (a) performed sequentially.
  • step (c) means that step (c) may be added to the method in any order.
  • 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), etc.
  • condition "A or B” is satisfied by any of the following conditions: 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 lithium ion battery of the present application includes an electrode assembly, a case for accommodating the electrode assembly, a first electrolyte solution, and a second electrolyte solution.
  • the electrode assembly includes positive electrode pieces, negative electrode pieces, separators, etc.
  • the first electrolyte distributed in the electrode assembly refers to the distribution in the pores of the pole piece and the separator.
  • the first electrolyte is in direct contact with the cathode and anode active materials.
  • the second electrolyte is distributed in the space between the electrode assembly and the housing.
  • the second electrolyte is deposited at the bottom of the lithium-ion battery; it may also be free outside the electrode assembly, but not necessarily at the bottom.
  • the second electrolyte slowly diffuses toward the motor components, that is, the second electrolyte slowly diffuses toward the pole pieces and separators.
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode membrane disposed on at least one surface of the negative electrode current collector.
  • the negative electrode current collector has two surfaces facing each other in its own thickness direction, and the negative electrode membrane is laminated on any one or both of the two opposite surfaces of the negative electrode current collector.
  • the negative electrode current collector can be made of a material with good electrical conductivity and mechanical strength to conduct electricity and collect current. In some embodiments, the negative electrode current collector may be copper foil.
  • the negative electrode membrane includes a negative electrode material, and the negative electrode material includes at least one of lithium metal and lithium metal alloy.
  • the negative electrode material contains at least one of lithium metal and lithium metal alloy.
  • the energy density of the battery can be further improved by making the negative electrode material include at least one of lithium metal and lithium metal alloy.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode membrane disposed on at least one surface of the positive electrode current collector and including a positive electrode active material.
  • the positive electrode current collector has two surfaces facing each other in its own thickness direction, and the positive electrode membrane is laminated on any one or both of the two opposite surfaces of the positive electrode current collector.
  • the cathode current collector can be made of a material with good electrical conductivity and mechanical strength.
  • the positive electrode current collector may be aluminum foil.
  • the cathode active material may be selected from lithium transition metal oxides and modified materials thereof.
  • the modified materials may be doping modifications and/or coating modifications of the lithium transition metal oxides.
  • the lithium transition metal oxide can be selected from the group consisting of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide and olivine structure-containing oxides.
  • the cathode active material of the lithium-ion battery can be selected from LiCoO 2 , LiNiO 2 , LiMnO 2 , LiMn 2 O 4 , LiNi 1/3 Co 1/3 Mn 1/3 O 2 (NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM523), LiNi 0.6 Co 0.2 Mn 0.2 O 2 (NCM622), LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811), LiNi 0.85 Co 0.15 Al 0.05 O 2 , LiFePO 4 (LFP) and LiMnPO 4 One or several.
  • the cathode active material of the lithium ion battery more preferably includes at least one of lithium nickel cobalt manganate, lithium nickel cobalt aluminate, and lithium iron phosphate.
  • a binder is optionally included in the positive electrode membrane.
  • the binder used for the positive electrode membrane may include one or more of polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE).
  • a conductive agent is optionally included in the positive electrode membrane.
  • the conductive agent used for the positive electrode membrane may include one or more of graphite, superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.
  • the positive electrode membrane has a porous structure with a porosity of 5% to 30%, preferably 10% to 25%.
  • the separator is installed between the positive electrode and the negative electrode to isolate.
  • the type of separator in this application. Any well-known porous structure separator with good chemical stability and mechanical stability can be selected.
  • the material of the separator may be selected from one or more of fiberglass, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.
  • the separator can be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer can be the same or different.
  • the separator has a porosity of 30% to 70%, preferably 35% to 60%.
  • an electrode assembly including a positive electrode, a negative electrode, and a separator located between the positive electrode and the negative electrode is prepared.
  • the first pre-electrolyte is injected into it, and through processes such as formation and standing, the first pre-electrolyte is fully infiltrated into the electrode assembly. This part is the first pre-electrolyte. Electrolyte.
  • the first electrolyte is distributed in the electrode assembly.
  • the first electrolyte solution includes organic solvent, lithium salt and additives.
  • the additives in the first electrolyte include vinylene carbonate (VC for short), fluoroethylene carbonate (FEC for short), tris(trimethylsilylphosphate) (TMSP for short), lithium difluorodioxalate phosphate One or more of (LiDFOP), lithium dioxaloborate (LiBOB), and lithium difluorophosphate (LiPO 2 F 2 ).
  • VC vinylene carbonate
  • FEC fluoroethylene carbonate
  • TMSP tris(trimethylsilylphosphate)
  • LiDFOP lithium difluorodioxalate phosphate
  • LiBOB lithium dioxaloborate
  • LiPO 2 F 2 lithium difluorophosphate
  • the content t1 of the additive contained in the first electrolyte solution is 1 wt% to 4 wt%, preferably 1.5 wt% to 3.9 wt%, and more preferably 1.7 wt% to 3.5%.
  • the additives in the first electrolyte mainly participate in the repair and reforming of SEI.
  • VC has a better film-forming effect, but its film-forming resistance is larger; several other additives have lower film-forming resistance, but their film-forming effect is not as good as VC.
  • the first electrolyte contains VC, and also contains fluoroethylene carbonate, tris(trimethylsilylphosphate), lithium difluorodioxalate phosphate, lithium difluoroborate, and One or more types of lithium phosphate.
  • the mass ratio of the mass of VC to other additives in the first electrolyte is 0.5 to 0.9 based on "the mass of VC divided by the mass of other additives". In the present invention, by combining VC with other additives, the total film-forming resistance of the additives can be further reduced, and the initial DCR of the battery can be further reduced.
  • the lithium salt can be selected from lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonimide, lithium bistrifluoromethanesulfonimide, lithium trifluoromethane At least one of lithium sulfonate, lithium difluorophosphate, lithium difluoroborate, lithium dioxaloborate, lithium difluorodioxalate phosphate and lithium tetrafluoroxalate phosphate.
  • the content of the lithium salt contained in the first electrolyte solution is 0.6 to 1.5 mol/L, preferably 0.7 to 1.3 mol/L, and more preferably 0.8 to 1.2 mol/L.
  • the first electrolyte solution includes an organic solvent, and the organic solvent preferably includes a cyclic ester solvent, and the cyclic ester solvent is a compound represented by Formula I,
  • R1 and R2 are independently selected from any one of H atoms, methyl, ethyl, fluoromethyl, and fluoroethyl.
  • the cyclic ester solvent is preferably selected from the group consisting of ethylene carbonate (EC for short), propylene carbonate (PC for short), bisfluoroethylene carbonate (DFEC for short), trifluoropropylene carbonate (TFPC for short) ), 4-(2,2,3,3,4,4,5,5,5-nonafluoropentyl)-1,3-dioxolane-2-one (NFPEC for short) and 4-(( One or more of 2,2,3,3-tetrafluoropropoxy)methyl)-1,3-dioxolane-2-one (referred to as HFEEC).
  • HFEEC 2,2,3,3-tetrafluoropropoxy
  • the first electrolyte solution may also contain other organic solvents.
  • the types of other organic solvents are not particularly limited and can be selected according to actual needs, and can include other types of chain carbonates and other cyclic carbonic acids in addition to the compounds represented by Formula I above.
  • ester and carboxylic acid ester One or more of ester and carboxylic acid ester.
  • the types of chain carbonates, cyclic carbonates and carboxylic acid esters other than the above-mentioned compound represented by Formula I are not specifically limited and can be selected according to actual needs.
  • the content of the cyclic ester solvent is 20wt% to 50wt%, preferably 15wt% to 45wt%, and more preferably 20wt% to 40wt%.
  • the first electrolyte solution optionally also includes other additives.
  • other additives may include sulfate compounds, sultone compounds, disulfonic acid compounds, nitrile compounds, aromatic compounds, isocyanate compounds, phosphazene compounds, cyclic anhydride compounds, phosphite compounds, phosphate compounds, At least one kind of a borate ester compound and a carboxylate ester compound.
  • the second electrolyte is distributed in the space between the electrode assembly and the housing.
  • the second electrolyte solution includes organic solvent, lithium salt and additives.
  • the lithium salt contained in the second electrolyte solution may be selected from the group consisting of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonimide, and bistrifluoride. At least one of lithium methanesulfonimide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluoroborate, lithium dioxaloborate, lithium difluorodioxalate phosphate and lithium tetrafluorooxalate phosphate.
  • the content of the lithium salt contained in the second electrolyte solution is 0.6 to 1.5 mol/L, preferably 0.7 to 1.3 mol/L, and more preferably 0.8 to 1.2 mol/L.
  • the second electrolyte contains a film-forming additive, and the film-forming additive is selected from the group consisting of vinylene carbonate (VC for short), fluoroethylene carbonate (FEC for short), ethylene carbonate (VEC for short), 1, One or more of 3-propane sultone (PS).
  • VC vinylene carbonate
  • FEC fluoroethylene carbonate
  • VEC ethylene carbonate
  • PS 3-propane sultone
  • the mass ratio t2 of the film-forming additive in the second electrolyte relative to the second electrolyte is 3 wt% to 15 wt%, preferably 4 wt% to 12 wt%, and more preferably 5 wt% to 10 wt%.
  • the second electrolyte solution may also contain other additives.
  • these other additives include unsaturated bond-containing cyclic carbonate compounds, halogen-substituted cyclic carbonate compounds, sulfate compounds, sultone compounds, disulfonic acid compounds, nitrile compounds, aromatic compounds, and isocyanate compounds. , at least one of a phosphazene compound, a cyclic acid anhydride compound, a phosphite compound, a phosphate compound, a borate compound, and a carboxylate compound.
  • the mass proportion of the film-forming additive is more than 70 wt%, preferably 70 wt% to 95 wt%, and more preferably 80 wt% to 90 wt%.
  • the type of organic solvent contained in the second electrolyte which can be selected according to actual needs, and can include one of chain carbonate, cyclic carbonate, carboxylic acid ester, or Several kinds. Among them, there are no specific restrictions on the types of chain carbonate, cyclic carbonate, and carboxylic acid ester, and can be selected according to actual needs.
  • first electrolyte solution and the second electrolyte solution preferably satisfy the following formula:
  • d1 is the mass of the first electrolyte
  • d2 is the mass of the second electrolyte
  • t1 is the mass ratio of the additive in the first electrolyte relative to the first electrolyte
  • t2 is the mass ratio of the additive in the second electrolyte relative to the second electrolyte.
  • SEI battery manufacturing and use
  • initial formation of SEI repair and reformation of SEI
  • SEI balance stabilization
  • SEI electrolyte
  • the amount of additive in the second electrolyte can be expressed by d2 ⁇ t2.
  • 1wt% ⁇ t1 ⁇ 4wt%, and/or, 3wt% ⁇ t2 ⁇ 15wt% When t1 is more than 1wt%, it can fully meet the needs of SEI repair and reforming, so it is preferable; when t1 is less than 4wt%, it can prevent the SEI film from becoming too thick during the repair and reforming stage and avoid large initial DC resistance. So preferred. When t2 is more than 3wt%, it can fully meet the consumption requirements during the life process and achieve good battery life; when t2 is less than 15wt%, it can avoid excessive costs.
  • 60% ⁇ d1/(d1+d2) ⁇ 95% 60% ⁇ d1/(d1+d2) ⁇ 95%.
  • d1/(d1+d2) is more than 60%, it can achieve sufficient infiltration of the pole piece/separator and avoid abnormality of the battery interface, so it is preferred; when d1/(d1+d2) is less than 95%, avoid the d1 part
  • the low additive content ensures a high level of additives within the entire battery and achieves good battery life.
  • a lithium-ion battery includes a case for encapsulating the electrode assembly and the first and second electrolytes.
  • the positive electrode piece, the negative electrode piece, and the separator may be laminated or rolled to form an electrode assembly of a laminate structure or an electrode assembly of a rolled structure.
  • the electrode assembly is enclosed in the casing.
  • the number of electrode components in a lithium-ion battery can be one or several, which can be adjusted according to needs.
  • the casing of the lithium-ion battery may be a soft bag, such as a pouch.
  • the soft bag may be made of plastic, such as one or more of polypropylene PP, polybutylene terephthalate PBT, polybutylene succinate PBS, and the like.
  • the casing of a lithium-ion battery can also be a hard shell, such as a hard plastic shell, aluminum shell, steel shell, etc.
  • This application has no particular limitation on the shape of the lithium-ion battery, which can be cylindrical, square or any other shape. As shown in FIG. 1 , a lithium-ion battery 5 with a square structure is shown as an example.
  • the housing may include a housing body 51 and a cover 53 .
  • the housing body 51 may include a bottom plate and side plates connected to the bottom plate, and the bottom plate and the side plates enclose a receiving cavity.
  • the housing body 51 has an opening communicating with the accommodation cavity, and the cover plate 53 can cover the opening to close the accommodation cavity.
  • the positive electrode piece, the negative electrode piece and the separator can be formed into the electrode assembly 52 through a winding process or a lamination process.
  • the electrode assembly 52 is enclosed in the cavity of the housing.
  • the first electrolyte is distributed in the electrode assembly 52 .
  • the second electrolyte is distributed in the space between the electrode assembly 52 and the housing.
  • the number of electrode assemblies 52 contained in the lithium 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 battery modules, and the number of lithium-ion batteries contained in the battery module can be one or more. 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 having a receiving space in which a plurality of lithium-ion batteries 5 are received.
  • the above-mentioned battery modules can also be assembled into a battery pack.
  • the number of battery modules contained in the battery pack can be one or more. Those skilled in the art can select the specific number 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 be covered with 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 electrical device, which includes at least one of the lithium-ion battery, battery module, or battery pack provided by the present application.
  • the lithium-ion battery, battery module, or battery pack can be used as a power source for the electrical device, or can also be used as an energy storage unit for the electrical device.
  • the electric device may include mobile devices (such as mobile phones, laptops, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, and electric golf carts). , electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc., but are not limited to these.
  • a lithium-ion battery, a battery module or a battery pack can be selected according to its usage requirements.
  • FIG. 6 is an electrical device as an example.
  • the electric device is a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, etc.
  • battery packs or battery modules can be used.
  • the lithium ion batteries of Examples 1 to 20 and Comparative Examples 1 to 2 were prepared according to the following methods.
  • the negative electrode active material artificial graphite: carbon black (SP): styrene-butadiene rubber (SBR): carboxymethyl fiber (CMC) with the solvent at a ratio of 97:0.5:1.5:1, and stir to obtain a uniformly dispersed negative electrode slurry.
  • the negative electrode slurry is evenly coated on both surfaces of the copper foil, and after drying, cold pressing, and cutting, the negative electrode sheet is obtained.
  • the mass of the negative electrode piece is 311.2g, of which the mass of the negative active material is 298.8g.
  • a polyethylene film with a thickness of 12 ⁇ m is used as the separator.
  • the positive electrode piece, separator, and negative electrode piece in order so that the separator plays an isolation role between the positive electrode piece and the negative electrode piece, and then wind it to obtain the electrode assembly; place the electrode assembly in the outer packaging and dry Then inject the first pre-electrolyte. After charging to 60% SOC at 45°C and 0.1C for formation, standing and other processes, the first pre-electrolyte is fully infiltrated into the electrode assembly. Afterwards, the second pre-electrolyte is injected to distribute the second pre-electrolyte in the space between the battery case and the electrode assembly. After sealing, capacity and other processes, lithium-ion batteries are obtained.
  • the lithium ion battery contains 266.9g of the first electrolyte and 75.3g of the second electrolyte. Therefore, the total amount of the first electrolyte and the second electrolyte is 342.2g.
  • the lithium ion batteries prepared in Examples 1 to 20 and Comparative Examples 1 to 2 were tested according to the following detection methods, and the results were recorded in Tables 3 to 5.
  • the rated capacity of the lithium-ion battery is 1C, and at 25°C, fully discharge it to the lower limit of the rated voltage of the battery at a rate of 0.1C.
  • Open a small opening in the battery shell tilt the battery so that the opening is at the lowest position of the battery, and pour the electrolyte from the opening. Pour it out and collect it in a container until no electrolyte drips out within 30 seconds. Weigh the mass of the electrolyte in the container. This weight is the mass of the second electrolyte, recorded as d2.
  • GB/T 9722-2006 use gas chromatography to measure the type and mass proportion t2 of the additives in the second electrolyte.
  • the batteries of each example and comparative example were charged to 3.65V at a constant current of 0.5C, and then charged at a constant voltage to a current of 0.05C; the batteries were left to stand for 5 minutes, and discharged to a constant current of 1/3C to 2.5 V, this is the first charge-discharge cycle process of the battery, and the discharge capacity this time is recorded as the discharge capacity of the battery in the first cycle.
  • the battery capacity retention rate (%) (discharge capacity after battery cycle/discharge capacity of battery for the first cycle) ⁇ 100%. Record the number of cycles at which the battery capacity retention rate is 80%. The results are recorded in the column "Number of cycles at 60° C. cyclic decay to 80% SOH" in Table 5.

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Abstract

本申请涉及一种锂离子电池，其中，包括第一电解液和第二电解液，并且满足下述式： 0.1≤[(d2×t2)/(d1×t1)]≤11，其中， d1为所述第一电解液的质量，d2为所述第二电解液的质量， t1为所述第一电解液中的添加剂相对于所述第一电解液的质量占比，t2为所述第二电解液中的添加剂相对于所述第二电解液的质量占比。

Description

锂离子电池、电池模块、电池包以及用电装置 技术领域
本申请涉及锂离子电池技术领域，尤其涉及一种锂离子电池、电池模块、电池包和用电装置。
背景技术
近年来，锂离子电池被广泛应用于电动工具、电动自行车、电动摩托车、电动汽车、智能电网、军事装备、航空航天等领域。由于锂离子电池取得了极大的发展，因此对其初始直流电阻以及电池寿命等也提出了更高的要求。但目前的锂离子电池难以满足人们对续航能力的更高需求，例如，在电动汽车领域，人们就因锂离子电池的续航能力不足而产生“里程焦虑”，因此，迫切需要开发具有更长电池寿命的锂离子电池。
发明内容
本申请是鉴于上述技术问题而进行的，其目的在于，提供一种锂离子电池，其能够降低初始直流电阻(以下，有时简称为“初始DCR”)的同时延长电池寿命。
为了达到上述目的，本申请发明人进行了深入研究，结果发现通过在锂离子电池中包括特定的第一电解液和第二电解液，从而能够解决上述技术问题。
本申请的第一方面提供了一种锂离子电池，其中，
包括第一电解液和第二电解液，并且满足下述式：
0.1≤[(d2×t2)/(d1×t1)]≤11，其中，
d1为所述第一电解液的质量，
d2为所述第二电解液的质量，
t1为所述第一电解液中的添加剂相对于所述第一电解液的质量占比，
t2为所述第二电解液中的添加剂相对于所述第二电解液的质量占比。
在电池的制造和使用过程中，从SEI的角度可分为：SEI初始形成、SEI的修复重整和SEI平衡稳定三个阶段。
其中，SEI的初始形成发生在电池制造过程中的化成工序。SEI形成后并非一成不变，相反，SEI在初始形成后不够稳定，容易受到破坏。在电池使用前期，仍会消耗残留在电极组件中的电解液(即，第一电解液)，对SEI修复重整，这一阶段往往会持续10～50圈。第一电解液中的添加剂量可用d1×t1表示。
经过修复重整后，SEI稳定性大幅提升。但在电池使用过程中，SEI仍会破损，暴露出新的活性位点，需要消耗第二电解液中的添加剂来修复SEI膜，避免活性位点处持续发生副反应。但此时SEI破损幅度较小，添加剂发生还原反应修复破损速度较快。第二电解液中的添加剂量可用d2×t2来表示。
申请人发现，当锂离子电池中含有第一电解液和第二电解液，且满足0.1≤[(d2×t2)/(d1×t1)]≤11时，上述锂离子电池具有较低的初始直流电阻和良好的电池寿命。
在任意实施方式中，1wt％≤t1≤4wt％，和/或，3wt％≤t2≤15wt％。当t1为1wt％以上时，能够充分满足SEI修复重整所需，所以优选；当t1为4wt％以下时，能够防止修复重整阶段SEI膜变得过厚，能够避免初始直流电阻较大，所以优选。当t2为3wt％以上时，能够充分满足寿命过程消耗所需，实现良好的电池寿命；当t2为15wt％以下时，能够避免成本过高。
在任意实施方式中，60％≤d1/(d1+d2)≤95％。当d1/(d1+d2)为60％以上时，能够实现极片/隔膜的充分浸润，避免电池界面的异常，所以优选；当d1/(d1+d2)为95％以下时，避免d1部分添加剂含量较少，保证整个电池内部添加剂水平较高，实现良好的电池寿命。
在任意实施方式中，第一电解液中的添加剂选自碳酸亚乙烯酯、氟代碳酸乙烯酯、三(三甲基硅基磷酸酯)、二氟二草酸磷酸锂、二草酸硼酸锂、二氟磷酸锂中的一种或几种。
第一电解液中的添加剂主要参与SEI的修复重整，其中，碳酸亚 乙烯酯(以下，简称VC)形成的SEI膜对电极的钝化效果较好，但其成膜阻抗较大；其他几类添加剂成膜阻抗较低，但其对电极的钝化效果不如VC。本申请中，第一电解液中含有VC，并且还含有氟代碳酸乙烯酯、三(三甲基硅基磷酸酯)、二氟二草酸磷酸锂、二草酸硼酸锂、二氟磷酸锂中的一种或几种，由此能够使添加剂的总的成膜阻抗较低，电池初始直流电阻较低。可选地，第一电解液中，VC的质量与其他添加剂的质量比以“VC质量除以其他添加剂的质量计”为0.5～0.9。
在任意实施方式中，第一电解液中含有环状酯溶剂，所述环状酯溶剂为式Ⅰ所示的化合物，
Figure PCTCN2022084378-appb-000001
其中，R1、R2独立地选自H原子、甲基、乙基、氟代甲基、氟代乙基中的任意一种。
在任意实施方式中，环状酯溶剂选自碳酸乙烯酯、碳酸丙烯酯、双氟代碳酸乙烯酯、三氟代碳酸丙烯酯4-(2,2,3,3,4,4,5,5,5-九氟戊基)-1,3-二氧戊环-2-酮和4-((2,2,3,3-四氟丙氧基)甲基)-1,3-二氧戊环-2-酮中的一种或多种。
在任意实施方式中，相对于所述第一电解液中溶剂的总质量，所述环状酯溶剂的含量占比为20wt％～50wt％。
如上所述，在本申请的锂离子电池中，第一电解液分布于所述电极组件中。也就是说，第一电解液分布于正极极片、负极极片、或者隔膜的孔隙间。由于极片及隔膜的孔隙的孔径、体积较小，电解液在极片及隔膜中的浸润速率受溶剂的影响较大。环状酯是一类介电常数高、粘度较大的电解液溶剂，电解液中使用环状酯作为溶剂时，有利于电解液中锂盐的解离，提升电解液的电导率；但是，对电解液在极片和隔膜中的浸润速率影响较大。因此，控制第一电解液中环状酯的 含量，有利于提升锂离子电池的循环过程中的电解液的浸润速率，降低电池的初始直流阻抗、以及循环过程中的直流阻抗，并提升电池的循环寿命。
在任意实施方式中，所述第二电解液中含有成膜添加剂，所述成膜添加剂选自碳酸亚乙烯酯、氟代碳酸乙烯酯、碳酸乙烯亚乙酯、1,3-丙烷磺内酯中的一种或几种。本申请中，当第二电解液使用上述添加剂参与SEI膜的修复过程，能够进一步避免SEI破损后暴露出新的活性位点，持续诱发副反应，从而改善电池寿命。且这几种添加剂本身较稳定，在电池中能够长时间存在，不发生自身分解。
在任意实施方式中，相对于所述第二电解液中的添加剂的总质量，所述成膜添加剂的质量占比为70wt％以上。
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。
本申请的电池模块、电池包和用电装置包括本申请第一方面的锂离子电池，因而至少具有与上述锂离子电池相同或类似的技术效果。
附图说明
图1是本申请一个实施方式的锂离子电池的示意图。
图2是图1所示的本申请一个实施方式的锂离子电池的分解图。
图3是本申请一个实施方式的电池模块的示意图。
图4是本申请一个实施方式的电池包的示意图。
图5是图4所示的本申请一个实施方式的电池包的分解图。
图6是本申请一个实施方式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壳体主体；52电极组件；53盖板。
具体实施方式
以下，适当地参照附图详细说明具体公开了本申请的锂离子电池及其制造方法、电池模块、电池包和用电装置的实施方式。但是会有省略不必要的详细说明的情况。例如，有省略对已众所周知的事项的详细说明、实际相同结构的重复说明的情况。这是为了避免以下的说明不必要地变得冗长，便于本领域技术人员的理解。此外，附图及以下说明是为了本领域技术人员充分理解本申请而提供的，并不旨在限定权利要求书所记载的主题。
本申请所公开的“范围”以下限和上限的形式来限定，给定范围是通过选定一个下限和一个上限进行限定的，选定的下限和上限限定了特别范围的边界。这种方式进行限定的范围可以是包括端值或不包括端值的，并且可以进行任意地组合，即任何下限可以与任何上限组合形成一个范围。例如，如果针对特定参数列出了60～120和80～110的范围，理解为60～110和80～120的范围也是预料到的。此外，如果列出的最小范围值1和2，和如果列出了最大范围值3，4和5，则下面的范围可全部预料到：1～3、1～4、1～5、2～3、2～4和2～5。在本申请中，除非有其他说明，数值范围“a～b”表示a到b之间的任意实数组合的缩略表示，其中a和b都是实数。例如数值范围“0～5”表示本文中已经全部列出了“0～5”之间的全部实数，“0～5”只是这些数值组合的缩略表示。另外，当表述某个参数为≥2的整数，则相当于公开了该参数为例如整数2、3、4、5、6、7、8、9、10、11、12等。
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)。
[锂离子电池]
本申请的锂离子电池包括电极组件、用于容纳所述电极组件的壳体、第一电解液以及第二电解液。
电极组件包括正极极片、负极极片、隔膜等。本申请中，第一电解液分布于电极组件中，指的是分布于极片和隔膜的孔隙中。第一电解液与阴阳极活性物质直接接触。第二电解液分布于电极组件与壳体之间的空间内。一种实施方式中，第二电解液沉积在锂离子电池的底部；还可能是游离在电极组件外，但不一定在底部。在锂离子电池的使用过程中，第二电解液缓慢地向电机组件扩散，即，第二电解液缓慢地向极片及隔膜扩散。
[负极极片]
在一些实施例中，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片。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，负极膜片层合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。
在一些实施例中，负极集流体可以采用具有良好导电性及机械强度的材质，起导电和集流的作用。在一些实施例中，负极集流体可以采用铜箔。
在一些实施例中，负极膜片包含负极材料，该负极材料包含锂金属、锂金属合金中的至少一种。本申请的发明点之一在于，负极材料包含锂金属、锂金属合金中的至少一种。本申请通过使负极材料包含 锂金属、锂金属合金中的至少一种，可以进一步提高电池的能量密度。
[正极极片]
在一些实施例中，正极极片包括正极集流体以及设置在正极集流体至少一个表面上且包括正极活性材料的正极膜片。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，正极膜片层合设置在正极集流体相对的两个表面中的任意一者或两者上。
在一些实施例中，正极集流体可以采用具有良好导电性及机械强度的材质。在一些实施例中，正极集流体可以采用为铝箔。
本申请对正极活性材料的具体种类不做具体限制，可以采用本领域已知的能够用于锂离子电池的正极的材料，本领域技术人员可以根据实际需求进行选择。
在一些实施例中，正极活性材料可选自锂过渡金属氧化物及其改性材料，改性材料可以是对锂过渡金属氧化物进行掺杂改性和/或包覆改性。例如，锂过渡金属氧化物可选自锂钴氧化物、锂镍氧化物、锂锰氧化物、锂镍锰氧化物、锂镍钴锰氧化物、锂镍钴铝氧化物及橄榄石结构的含锂磷酸盐中的一种或几种。
作为示例，锂离子电池的正极活性材料可选自LiCoO 2、LiNiO 2、LiMnO 2、LiMn 2O 4、LiNi 1/3Co 1/3Mn 1/3O 2(NCM333)、LiNi 0.5Co 0.2Mn 0.3O 2(NCM523)、LiNi 0.6Co 0.2Mn 0.2O 2(NCM622)、LiNi 0.8Co 0.1Mn 0.1O 2(NCM811)、LiNi 0.85Co 0.15Al 0.05O 2、LiFePO 4(LFP)和LiMnPO 4中的一种或几种。在一些实施例中，锂离子电池的正极活性材料更优选包含镍钴锰酸锂、镍钴铝酸锂、磷酸铁锂中的至少一种。
在一些实施例中，正极膜片中还可选地包括粘结剂。对粘结剂的种类不做具体限制，本领域技术人员可以根据实际需求进行选择。作为示例，用于正极膜片的粘结剂可包括聚偏氟乙烯(PVDF)和聚四氟乙烯(PTFE)中的一种或几种。
在一些实施例中，正极膜片中还可选地包括导电剂。对导电剂的种类不做具体限制，本领域技术人员可以根据实际需求进行选择。作为示例，用于正极膜片的导电剂可包括石墨、超导碳、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨烯及碳纳米纤维中的一种或几种。
在一些实施例中，正极膜片是多孔结构，其孔隙率为5％～30％， 优选为10％～25％。
[隔膜]
隔膜设置在正极和负极之间起到隔离的作用。本申请对隔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膜。在一些实施例中，隔膜的材质可以选自玻璃纤维、无纺布、聚乙烯、聚丙烯及聚偏二氟乙烯中的一种或几种。隔膜可以是单层薄膜，也可以是多层复合薄膜。隔膜为多层复合薄膜时，各层的材料可以相同或不同。
在一些实施例中，隔膜的孔隙率为30％～70％，优选为35％～60％。
[电极组件]
本申请的一些实施例中，制备包括正极、负极、以及位于所述正极与所述负极之间的隔膜的电极组件。
[第一电解液]
在一些实施例中，在制备电极组件主体之后，向其中注入第一前置电解液，经过化成、静置等工艺，使第一前置电解液充分浸润于电极组件中，这一部分就是第一电解液。
本申请的一些实施例中，第一电解液分布于所述电极组件中。
第一电解液中包括有机溶剂、锂盐和添加剂。
第一电解液中的添加剂包括选自碳酸亚乙烯酯(简称VC)、氟代碳酸乙烯酯(简称FEC)、三(三甲基硅基磷酸酯)(简称TMSP)、二氟二草酸磷酸锂(LiDFOP)、二草酸硼酸锂(LiBOB)、二氟磷酸锂(LiPO 2F 2)中的一种或几种。
第一电解液中含有的添加剂的含量t1为1wt％～4wt％，优选为1.5wt％～3.9wt％，更优选为1.7wt％～3.5％。
第一电解液中的添加剂主要参与SEI的修复重整，其中VC成膜效果较好，但其成膜阻抗较大；其他几种添加剂成膜阻抗较低，但成膜效果不如VC。可选地，本申请中，第一电解液中含有VC，并且还含有氟代碳酸乙烯酯、三(三甲基硅基磷酸酯)、二氟二草酸磷酸锂、二草酸硼酸锂、二氟磷酸锂中的一种或几种。可选地，第一电解液中，VC的质量与其他添加剂的质量比以“VC质量除以其他添加剂的质量计”为0.5～0.9。本申请发明中，通过把VC和其他添加剂搭配使用， 能够使添加剂总的成膜阻抗进一步降低，能够进一步降低电池初始DCR。
在一些实施方式中，锂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。
第一电解液中含有的锂盐的含量为0.6～1.5mol/L，优选为0.7～1.3mol/L，更优选为0.8～1.2mol/L。
第一电解液中包括有机溶剂，有机溶剂中优选包括环状酯溶剂，所述环状酯溶剂为式Ⅰ所示的化合物，
Figure PCTCN2022084378-appb-000002
其中，R1、R2独立地选自H原子、甲基、乙基、氟代甲基、氟代乙基中的任意一种。
在任意实施方式中，环状酯溶剂优选为选自碳酸乙烯酯(简称EC)、碳酸丙烯酯(简称PC)、双氟代碳酸乙烯酯(简称DFEC)、三氟代碳酸丙烯酯(简称TFPC)、4-(2,2,3,3,4,4,5,5,5-九氟戊基)-1,3-二氧戊环-2-酮(简称NFPEC)和4-((2,2,3,3-四氟丙氧基)甲基)-1,3-二氧戊环-2-酮(简称HFEEC)中的一种或多种。这些环状酯溶剂的结构式如下所示。
Figure PCTCN2022084378-appb-000003
第一电解液中除了含有环状酯溶剂之外，还可以含有其他有机溶剂。在一些实施方式中，其他有机溶剂的种类没有特别的限制，可根据实际需求进行选择，可包括其它种类的链状碳酸酯、除了上述的式Ⅰ所示的化合物之外的其他的环状碳酸酯、羧酸酯中的一种或几种。其中，链状碳酸酯、除了上述的式Ⅰ所示的化合物之外的其他的环状碳酸酯、羧酸酯的种类没有具体的限制，可根据实际需求进行选择。可选自碳酸二乙酯、碳酸二丙酯、碳酸甲乙酯、碳酸甲丙酯、碳酸乙丙酯、碳酸乙烯酯、碳酸丙烯酯、碳酸丁烯酯、γ-丁内酯、甲酸甲酯、甲酸乙酯、乙酸甲酯、乙酸乙酯、乙酸丙酯、丙酸甲酯、丙酸乙酯、丙酸甲酯、四氢呋喃中的一种或几种。
本申请中，相对于第一电解液中的溶剂的总质量，环状酯溶剂的含量占比为20wt％～50wt％，优选为15wt％～45wt％，更优选为20wt％～40wt％。
在一些实施方式中，第一电解液中除了含有上述添加剂之外，还可选地包括其它添加剂。作为示例，其它添加剂可以包括含有硫酸酯化合物、磺酸内酯化合物、二磺酸化合物、腈化合物、芳香化合物、异氰酸酯化合物、磷腈化合物、环状酸酐化合物、亚磷酸酯化合物、磷酸酯化合物、硼酸酯化合物、羧酸酯化合物中的至少一种。
[第二电解液]
本申请的一些实施例中，第二电解液分布于电极组件与壳体之间的空间内。
第二电解液中包括有机溶剂、锂盐和添加剂。
在一些实施方式中，作为第二电解液中含有的锂盐，可列举选自六氟磷酸锂、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。
第二电解液中含有的锂盐的含量为0.6～1.5mol/L，优选为0.7～1.3mol/L，更优选为0.8～1.2mol/L。
所述第二电解液中含有成膜添加剂，所述成膜添加剂选自碳酸亚乙烯酯(简称VC)、氟代碳酸乙烯酯(简称FEC)、碳酸乙烯亚乙酯(简称VEC)、1,3-丙烷磺内酯(简称PS)中的一种或几种。
第二电解液中的成膜添加剂相对于所述第二电解液的质量占比t2为3wt％～15wt％，优选为4wt％～12wt％，更优选为5wt％～10wt％。
所述第二电解液中，除了含有上述的成膜添加剂之外，还可以含有其他添加剂。作为这些其他添加剂，可以列举含有不饱和键的环状碳酸酯化合物、卤素取代的环状碳酸酯化合物、硫酸酯化合物、磺酸内酯化合物、二磺酸化合物、腈化合物、芳香化合物、异氰酸酯化合物、磷腈化合物、环状酸酐化合物、亚磷酸酯化合物、磷酸酯化合物、硼酸酯化合物、羧酸酯化合物中的至少一种。
相对于所述第二电解液中的添加剂的总质量，所述成膜添加剂的质量占比为70wt％以上，优选为70wt％～95wt％，更优选为80wt％～90wt％。
在一些实施方式中，对于第二电解液中含有的有机溶剂的种类没有特别的限制，可根据实际需求进行选择，可包括链状碳酸酯、环状碳酸酯、羧酸酯中的一种或几种。其中，链状碳酸酯、环状碳酸酯、羧酸酯的种类没有具体的限制，可根据实际需求进行选择。可选自碳酸二乙酯、碳酸二丙酯、碳酸甲乙酯、碳酸甲丙酯、碳酸乙丙酯、碳酸乙烯酯、碳酸丙烯酯、碳酸丁烯酯、γ-丁内酯、甲酸甲酯、甲酸乙酯、乙酸甲酯、乙酸乙酯、乙酸丙酯、丙酸甲酯、丙酸乙酯、丙酸甲酯、四氢呋喃中的一种或几种。
本申请中，第一电解液和第二电解液优选为满足下述式：
0.1≤[(d2×t2)/(d1×t1)]≤11，其中，
d1为所述第一电解液的质量，
d2为所述第二电解液的质量，
t1为第一电解液中的添加剂相对于第一电解液的质量占比，
t2为第二电解液中的添加剂相对于第二电解液的质量占比。
在电池的制造和使用过程中，从SEI的角度可分为：SEI初始形成、SEI的修复重整和SEI平衡稳定三个阶段。
其中，SEI的初始形成发生在电池制造过程中的化成工序。SEI形成后并非一成不变，相反，SEI在初始形成后不够稳定，容易受到破坏。在电池使用前期，仍会消耗残留在电极组件中的电解液(第一电解液)，对SEI修复重整，这一阶段往往会持续10～50圈。第一电解液中的添加剂量可用d1×t1表示。
经过修复重整后，SEI稳定性大幅提升。但在电池使用过程中，SEI仍会破损，暴露出新的活性位点，需要消耗第二电解液中的添加剂来修复SEI膜，避免活性位点处持续发生副反应。但此时SEI破损幅度较小，添加剂发生还原反应修复破损速度较快。第二电解液中的添加剂量可用d2×t2来表示。申请人发现，当锂离子电池中含有第一电解液和第二电解液，且满足0.1≤[(d2×t2)/(d1×t1)]≤11时，上述锂离子电池具有较低的初始直流电阻和良好的电池寿命。本申请中，优选为0.2≤[(d2×t2)/(d1×t1)]≤8，进一步优选为0.5≤[(d2×t2)/(d1×t1)]≤2.8。
在本申请的任意实施方式中，1wt％≤t1≤4wt％，和/或，3wt％≤t2≤15wt％。当t1为1wt％以上时，能够充分满足SEI修复重整所需，所以优选；当t1为4wt％以下时，能够防止修复重整阶段SEI膜变得过厚，能够避免初始直流电阻较大，所以优选。当t2为3wt％以上时，能够充分满足寿命过程消耗所需，实现良好的电池寿命；当t2为15wt％以下时，能够避免成本过高。
另外，在本申请的任意实施方式中，60％≤d1/(d1+d2)≤95％。当d1/(d1+d2)为60％以上时，能够实现极片/隔膜的充分浸润，避免电池界面的异常，所以优选；当d1/(d1+d2)为95％以下时，避免d1部分添加剂含量较少，保证整个电池内部添加剂水平较高，实现良好的电池寿命。
[壳体]
在一些实施例中，锂离子电池包括壳体，用于封装电极组件和第一电解液以及第二电解液。作为一个示例，正极极片、负极极片和隔膜可经叠片或卷绕形成叠片结构的电极组件或卷绕结构的电极组件。电极组件封装在壳体内。锂离子电池中电极组件的数量可以为一个或几个，可以根据需求来调节。
在一些实施例中，锂离子电池的壳体可以是软包，例如袋式软包。软包的材质可以是塑料，如可包括聚丙烯PP、聚对苯二甲酸丁二醇酯PBT、聚丁二酸丁二醇酯PBS等中的一种或几种。锂离子电池的壳体也可以是硬壳，例如硬塑料壳、铝壳、钢壳等。
[锂离子电池、电池模块、电池包及用电装置]
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。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，壳体可包括壳体主体51和盖板53。其中，壳体主体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。壳体主体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封装于所述壳体的腔内。第一电解液分布于电极组件52中。第二电解液分布于电极组件52与壳体之间的空间内。锂电池电池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。[实施例和对比例]
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，均可以为通过市购获得的常规产品。
实施例1～20和对比例1～2
按照下述方法制备实施例1～20和对比例1～2的锂离子电池。
[实施例1]
正极极片的制备：
将橄榄石结构的磷酸铁锂(LFP)、聚偏氟乙烯(PVDF)、炭黑(SP)按97:2.5:0.5的质量比与溶剂混合，经搅拌得到分散均匀的正极浆料，将正极浆料均匀地涂在铝箔的两个表面，经过干燥、冷压、裁切，得到正极极片。正极极片的质量是700.0g，其中，正极活性物质的质量是679.0g。
负极极片的制备：
将负极活性材料(人造石墨):炭黑(SP):丁苯橡胶(SBR):羧甲基纤维(CMC)按97:0.5:1.5:1与溶剂混合，经搅拌得到分散均匀的负极浆料，将负极浆料均匀地涂在铜箔的两个表面，经过干燥、冷压、裁切，得到负极极片。负极极片的质量是311.2g，其中，负极活性物质的质量是298.8g。
隔膜：采用厚度为12μm的聚乙烯膜作为隔膜。
第一前置电解液的制备：
在氩气气氛手套箱中，以质量％计将碳酸乙烯酯(EC)30％、碳酸二甲酯(DMC)50％、碳酸甲乙酯10％(EMC)和碳酸二乙酯(DEC)混合，制得有机溶剂混合液，然后，在有机溶剂混合液中缓慢加入浓度为1mol/L的六氟磷酸锂(LiPF 6)作为电解质盐。锂盐溶解后加入1％的VC，0.5％的LiPO 2F 2，0.2％的TMSP。然后，进行搅拌，直至完全溶解，得到第一前置电解液。
第二前置电解液的制备：
在氩气气氛手套箱中，以质量％计将碳酸乙烯酯30％、碳酸二甲酯50％和碳酸甲乙酯20％混合，制得有机溶剂混合液，然后，在有机溶剂混合液中缓慢加入浓度为1mol/L的六氟磷酸锂(LiPF 6)作为电解质盐。锂盐溶解后加入6％的VC和1％的丁二腈(SN)。然后，进行搅拌，直至完全溶解，得到第二前置电解液。
锂离子电池的制备：
将正极极片、隔膜、负极极片按顺序叠好，使隔膜处于正极极片和负极极片之间起到隔离的作用，然后卷绕得到电极组件；将电极组件置于外包装中，干燥后注入第前置一电解液。经过在45℃，0.1C充电至60％SOC进行化成、静置等工艺，使第一前置电解液充分浸润于 电极组件中。之后，再注入第前置二电解液，使第二前置电解液分布于电池壳体与电极组件之间的空间内。经过密封、容量等工艺，得到锂离子电池。通过下述的检测方法得知：锂离子电池中含第一电解液266.9g，第二电解液75.3g，所以，第一电解液和第二电解液的合计量是342.2g。
[实施例2～20和对比例1～2]
实施例2～20和对比例1～2与实施例1的制备方法基本上相同，不同点仅在于如表1和表2所示。
对实施例1～20和对比例1～2中制备得到的锂离子电池，按照下述检测方法进行检测，并将其结果记录在表3～5中。
【相关参数检测】
(1)d1、t1、d2、t2的检测方法：
以锂离子电池的额定容量为1C，在25℃条件下以0.1C倍率满放到电池额定电压下限，在电池外壳开一个小口，倾斜电池，使开口处位于电池最低位置，将电解液从开口处倒出来，用容器收集，直至30s内无电解液滴出，称重容器内的电解液质量，此重量为第二电解液的质量，记为d2。参考GB/T 9722-2006，使用气相色谱法，测出第二电解液中添加剂的种类和质量占比t2。
将上述电池称重，记为m1，随后将电池拆解开，放入容器中，倒入≥锂离子电池体积2倍的萃取剂(通常为与该电池电解液溶剂不相同的其他溶剂。例如，当电解液中含有EC、EMC时，萃取剂使用电解液中没有的DMC)，使萃取剂浸没电池，浸泡24h后换一遍新的萃取剂，再浸泡24h，将浸泡电池取出，在相对压力为-80kPa、45℃下烘24h，称取电池重量；随后按相同条件再烘5h，称取电池质量，若两次质量相差≤0.01g，则取第二次称量质量记为m2。若两次称量质量相差＞0.01g，则继续烘，直至最后两次称量质量相差≤0.01g，并取最后一次称量质量记为m2。第一电解液的质量为d1＝m1-m2。
将上述两次浸泡电池后的萃取液混合，参考GB/T 9722-2006，使用气相色谱法，测出第一电解液中添加剂的种类和质量占比t1。
(2)电池初始DCR的检测方法：
在常温下，将电池0.5C恒流充电到3.65V，再恒压充电至电流为 0.05C；将电池以0.5C恒流放电30分钟，以调整电池至50％SOC，此时电池的电压记为U1；将电池以4C恒流放电30秒，采用0.1秒采点，放电末期电压记为U2。用电池50％SOC时的放电DCR表示电池的初始DCR，电池的初始DCR＝(U1-U2)/4C。将其结果记录在表5中的“DCR/mohm”一栏中。
(3)60℃高温循环性能的测定
在60℃下，将各实施例和对比例的电池以0.5C恒流充电至3.65V，再恒压充电至电流为0.05C；将电池静置5分钟，以1/3C恒流放电至2.5V，此为电池的首次充电放电循环过程，此次的放电容量记为电池首次循环的放电容量。按照上述方法对电池进行若干次次循环充电放电过程，电池容量保持率(％)＝(电池循环后的放电容量/电池首次循环的放电容量)×100％。记录电池容量保持率80％的循环圈数。将其结果记录在表5中的“60℃循环衰减到80％SOH时循环圈数”一栏中。 表1
Figure PCTCN2022084378-appb-000004
表2
Figure PCTCN2022084378-appb-000005
表3
Figure PCTCN2022084378-appb-000006
表4
Figure PCTCN2022084378-appb-000007
表5
Figure PCTCN2022084378-appb-000008
从表5的实施例1～20可知：当满足式0.1≤[(d2×t2)/(d1×t1)]≤11的关系时，“60℃循环衰减到80％SOH时循环圈数”较高，并且“DCR/mohm”值较低，这说明锂离子电池具有较低的初始直流电阻和良好的电池寿命。
从表5的对比例1可知：当第二电解液中不含有添加剂时，虽然“DCR/mohm”值低，但是，其“60℃循环衰减到80％SOH时循环圈数”也下降严重，这说明锂离子电池的电池寿命不佳。
从表5的对比例2可知：当[(d2×t2)/(d1×t1)]超过11时，虽然“DCR/mohm”值低，但是，其“60℃循环衰减到80％SOH时循环圈数”也下降严重，这说明锂离子电池的电池寿命不佳。

Claims (12)

  1. 一种锂离子电池，其中，
    包括：
    第一电解液和第二电解液，并且满足下述式：
    0.1≤[(d2×t2)/(d1×t1)]≤11，其中，
    d1为所述第一电解液的质量，
    d2为所述第二电解液的质量，
    t1为所述第一电解液中的添加剂相对于所述第一电解液的质量占比，
    t2为所述第二电解液中的添加剂相对于所述第二电解液的质量占比。
  2. 如权利要求1所述的锂离子电池，其中，
    1wt％≤t1≤4wt％，和/或，3wt％≤t2≤15wt％。
  3. 如权利要求1或2所述的锂离子电池，其中，
    60％≤d1/(d1+d2)≤95％。
  4. 如权利要求1～3中任一项所述的锂离子电池，其中，
    所述第一电解液中的添加剂选自碳酸亚乙烯酯、氟代碳酸乙烯酯、三(三甲基硅基磷酸酯)、二氟二草酸磷酸锂、二草酸硼酸锂、二氟磷酸锂中的一种或几种。
  5. 如权利要求1～4中任一项所述的锂离子电池，其中，
    所述第一电解液中含有环状酯溶剂，所述环状酯溶剂为式Ⅰ所示的化合物，
    Figure PCTCN2022084378-appb-100001
    其中，R1、R2独立地选自H原子、甲基、乙基、氟代甲基、氟代乙基中的任意一种。
  6. 如权利要求5所述的锂离子电池，其中，
    所述环状酯溶剂选自碳酸乙烯酯、碳酸丙烯酯、双氟代碳酸乙烯酯、三氟代碳酸丙烯酯4-(2,2,3,3,4,4,5,5,5-九氟戊基)-1,3-二氧戊环-2-酮和4-((2,2,3,3-四氟丙氧基)甲基)-1,3-二氧戊环-2-酮中的一种或多种。
  7. 如权利要求5或6所述的锂离子电池，其中，
    相对于所述第一电解液中溶剂的总质量，所述环状酯溶剂的质量占比为20wt％～50wt％。
  8. 如权利要求1～7中任一项所述的锂离子电池，其中，
    所述第二电解液中含有成膜添加剂，所述成膜添加剂选自碳酸亚乙烯酯、氟代碳酸乙烯酯、碳酸乙烯亚乙酯、1,3-丙烷磺内酯中的一种或几种。
  9. 如权利要求8所述的锂离子电池，其中，
    相对于所述第二电解液中的添加剂的总质量，所述成膜添加剂的质量占比为70wt％以上。
  10. 一种电池模块，包括权利要求1～9中任一项所述的锂离子电池。
  11. 一种电池包，包括权利要求10所述的电池模块。
  12. 一种用电装置，包括选自权利要求1～9中任一项所述的锂离子电池、权利要求10所述的电池模块或权利要求11所述的电池包中的至少一种。
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117673476A (zh) * 2024-02-02 2024-03-08 如鲲(江苏)新材料科技有限公司 一种锂离子电池、电池模块、电池包及用电装置

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110676425A (zh) * 2019-10-12 2020-01-10 苏州力韬集成电路设计有限公司 一种锂二次电池的变压注液化成工艺
CN110690509A (zh) * 2019-10-15 2020-01-14 金妍 一种锂离子电池的开口化成方法
CN111725564A (zh) * 2020-06-11 2020-09-29 朱虎 一种锂离子电池的化成方法
CN113629365A (zh) * 2021-08-24 2021-11-09 蜂巢能源科技有限公司 电解液注入方法及锂离子电池

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110676425A (zh) * 2019-10-12 2020-01-10 苏州力韬集成电路设计有限公司 一种锂二次电池的变压注液化成工艺
CN110690509A (zh) * 2019-10-15 2020-01-14 金妍 一种锂离子电池的开口化成方法
CN111725564A (zh) * 2020-06-11 2020-09-29 朱虎 一种锂离子电池的化成方法
CN113629365A (zh) * 2021-08-24 2021-11-09 蜂巢能源科技有限公司 电解液注入方法及锂离子电池

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117673476A (zh) * 2024-02-02 2024-03-08 如鲲(江苏)新材料科技有限公司 一种锂离子电池、电池模块、电池包及用电装置
CN117673476B (zh) * 2024-02-02 2024-04-16 如鲲(江苏)新材料科技有限公司 一种锂离子电池、电池模块、电池包及用电装置

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