WO2020119802A1 - 锂离子电池及装置 - Google Patents

锂离子电池及装置 Download PDF

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WO2020119802A1
WO2020119802A1 PCT/CN2019/125319 CN2019125319W WO2020119802A1 WO 2020119802 A1 WO2020119802 A1 WO 2020119802A1 CN 2019125319 W CN2019125319 W CN 2019125319W WO 2020119802 A1 WO2020119802 A1 WO 2020119802A1
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ion battery
unsubstituted
substituted
lithium ion
lithium
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PCT/CN2019/125319
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English (en)
French (fr)
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蒋耀
胡春华
伊天成
钭舒适
梁成都
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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 EP19896283.9A priority Critical patent/EP3809507B1/en
Publication of WO2020119802A1 publication Critical patent/WO2020119802A1/zh
Priority to US17/146,758 priority patent/US11177508B2/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H01M4/364—Composites as mixtures
    • 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
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • 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
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D239/00—Heterocyclic compounds containing 1,3-diazine or hydrogenated 1,3-diazine rings
    • C07D239/02—Heterocyclic compounds containing 1,3-diazine or hydrogenated 1,3-diazine rings not condensed with other rings
    • C07D239/04—Heterocyclic compounds containing 1,3-diazine or hydrogenated 1,3-diazine rings not condensed with other rings having no double bonds between ring members or between ring members and non-ring members
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D241/00—Heterocyclic compounds containing 1,4-diazine or hydrogenated 1,4-diazine rings
    • C07D241/02—Heterocyclic compounds containing 1,4-diazine or hydrogenated 1,4-diazine rings not condensed with other rings
    • C07D241/04—Heterocyclic compounds containing 1,4-diazine or hydrogenated 1,4-diazine rings not condensed with other rings having no double bonds between ring members or between ring members and non-ring members
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D251/00—Heterocyclic compounds containing 1,3,5-triazine rings
    • C07D251/02—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings
    • C07D251/04—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having no double bonds between ring members or between ring members and non-ring members
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/028—Positive electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2220/00—Batteries for particular applications
    • H01M2220/20—Batteries in motive systems, e.g. vehicle, ship, plane
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0025—Organic electrolyte
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • This application relates to the field of energy storage materials, in particular, to a lithium ion battery and device.
  • Lithium ion batteries are widely used in electric vehicles and consumer electronic products due to their advantages such as high energy density, high output power, long cycle life, and low environmental pollution.
  • the current demand for lithium ion batteries is: high voltage, high power, long cycle life, long storage life and excellent safety performance.
  • LiCoO 2 is currently widely used as a positive electrode active material for lithium ion batteries. Its performance is relatively stable when cycling between fully discharged LiCoO 2 and semi-charged Li 0.5 CoO 2 (4.2V vs. Li), so it is actually truly The lithium ion used is only 1/2 of its actual lithium ion content. When the voltage is greater than 4.2V, the remaining 1/2 content of lithium ions in LiCoO 2 can continue to be extracted, but in the process of deep delithiation, Co 3+ will be oxidized to very unstable Co 4+ , and the loss of a lot of electrons Oxygen on the surface co-oxidizes the electrolyte. At this time, a large amount of gas will be generated inside the battery to cause the battery to swell.
  • Co 4+ is dissolved in the electrolyte and deposited on the surface of the negative electrode, which catalyzes the reduction of the electrolyte, and also generates a large amount of gas to cause the battery to swell.
  • the object of the present application is to provide a lithium-ion battery and a device, the lithium-ion battery has excellent cycle performance and storage performance, especially in the case of high temperature and high voltage with excellent cycle performance and Storage performance.
  • the present application provides a lithium-ion battery including an electrode assembly and an electrolyte, the electrode assembly including a positive pole piece, a negative pole piece, and a separator.
  • the positive electrode active material in the positive electrode sheet simultaneously includes Li x1 Co y1 M1 1-y1 O 2-a Q1 a and Li l Ni m1 Co n1 M2 p M3 q O 2-b Q2 b , Li x1 Co y1 M1 1 -y1 O 2-a Q1 a and Li l Ni m1 Co n1 M2 p M3 q O 2-b Q2 b mass ratio is 1:1 ⁇ 9:1; among them, 0.5 ⁇ x1 ⁇ 1.2, 0.8 ⁇ y1 ⁇ 1.0 , 0 ⁇ a ⁇ 0.1, M1 is selected from at least one element of Al, Ti, Zr, Y, Mg, Q1 is selected from one or more of F, Cl, S; 0.5 ⁇ l ⁇ 1.2, 0.33 ⁇ m1
  • the electrolyte contains an additive A, which is selected from one or more of the compounds represented by Formula I-1, Formula I-2, and Formula I-3.
  • R 1 , R 2 , R 3 , and R 4 are each independently selected from a hydrogen atom, a halogen atom, and a substituted or unsubstituted C 1 to C 12 alkane Group, substituted or unsubstituted C 1 -C 12 alkoxy group, substituted or unsubstituted C 1 -C 12 amine group, substituted or unsubstituted C 2 -C 12 alkenyl group, substituted or unsubstituted C 2 ⁇ C 12 alkynyl, substituted or unsubstituted C 6 to C 26 aryl, substituted or unsubstituted C 2 to C 12 heterocyclic, wherein the substituent is selected from halogen atom, nitrile group, C 1 to C 6 alkane One or more of C
  • the present application provides a device, which includes the lithium ion battery described in the first aspect of the present application.
  • the present application includes at least the following beneficial effects:
  • This application uses a positive electrode active material containing lithium cobaltate materials Li x1 Co y1 M1 1-y1 O 2-a Q1 a doped with metal ions M.
  • the doping element M serves as a skeleton in the lithium cobaltate materials, which can be reduced.
  • the lattice deformation of the lithium cobaltate-based materials during deep lithium removal delays the degradation of the bulk phase structure of the lithium cobaltate-based materials and improves the structural stability of lithium-ion batteries when used at high voltages greater than 4.2V.
  • This application also mixes a certain amount of ternary material Li l Ni m1 Co n1 M2 p M3 q O 2-b Q2 b , ternary lithium cobaltate-based materials Li x1 Co y1 M1 1-y1 O 2-a Q1 a
  • the material can be evenly distributed in the gap between the particles of the lithium cobaltate-based materials, effectively separating the lithium cobaltate-based materials, and at the same time after mixing, the compaction density of the positive pole pieces can be increased, and the energy of the lithium-ion battery can be improved Density;
  • the higher thermal stability of the ternary material not only can ensure its own structural stability, but also can effectively prevent the heat transfer caused by the decomposition of local lithium cobalt oxide materials, and improve the thermal stability of the entire positive pole piece.
  • the electrolyte used in this application also contains a polynitrile six-membered nitrogen heterocyclic compound with a low oxidation potential, which can form a stable complex layer on the surface of the positive electrode active material when the battery is formed, and effectively passivate the surface of the positive electrode active material. Reduce the surface activity of the positive electrode active material, inhibit the dissolution of transition metals (especially cobalt) into the electrolyte, thereby reducing battery gas production while reducing side reactions.
  • the lithium ion battery of the present application can have excellent cycle performance and storage performance, especially under high temperature and high voltage conditions.
  • the device of the present application includes the lithium ion battery described in the first aspect of the present application, and therefore has at least the same advantages as the lithium ion battery.
  • Figure 1 shows the NMR carbon spectrum of compound A1.
  • Figure 2 shows the NMR carbon spectrum of the A2 compound.
  • Figure 3 is the NMR carbon spectrum of A3 compound.
  • FIG. 4 is a schematic diagram of an embodiment of a lithium ion battery.
  • FIG. 5 is a schematic diagram of an embodiment of a battery module.
  • FIG. 6 is a schematic diagram of an embodiment of a battery pack.
  • FIG. 7 is an exploded view of FIG. 6.
  • FIG. 8 is a schematic diagram of an embodiment of a device using a lithium ion battery as a power source.
  • the lithium-ion battery and device according to the present application will be described in detail below.
  • the lithium ion battery according to the present application includes an electrode assembly and an electrolyte, and the electrode assembly includes a positive pole piece, a negative pole piece, and a separator.
  • the positive electrode active material in the positive electrode sheet simultaneously includes Li x1 Co y1 M1 1-y1 O 2-a Q1 a and Li l Ni m1 Co n1 M2 p M3 q O 2-b
  • the mass ratio of Q2 b , Li x1 Co y1 M1 1-y1 O 2-a Q1 a and Li l Ni m1 Co n1 M2 p M3 q O 2-b Q2 b is 1:1 to 9:1.
  • the electrolyte contains an additive A, and the additive A is selected from one or more of the compounds represented by Formula I-1, Formula I-2, and Formula I-3.
  • R 1 , R 2 , R 3 , and R 4 are each independently selected from a hydrogen atom, a halogen atom, and a substituted or unsubstituted C 1 to C 12 alkane Group, substituted or unsubstituted C 1 -C 12 alkoxy group, substituted or unsubstituted C 1 -C 12 amine group, substituted or unsubstituted C 2 -C 12 alkenyl group, substituted or unsubstituted C 2 ⁇ C 12 alkynyl, substituted or unsubstituted C 6 to C 26 aryl, substituted or unsubstituted C 2 to C 12 heterocyclic, wherein the substituent (in this application means “substituted or un
  • the lithium ion battery of the present application has excellent cycle performance and storage performance, especially under high temperature and high voltage conditions.
  • This application uses a positive electrode active material containing lithium cobaltate materials doped with metal ions M, Li x1 Co y1 M 1-y1 O 2-z1 Q z1 , and the doping element M serves as a skeleton in the lithium cobaltate materials It can reduce the lattice deformation of lithium cobaltate materials during the deep delithiation process, delay the degradation of the bulk structure of lithium cobaltate materials, and improve the structural stability of lithium ion batteries when used at high voltages greater than 4.2V.
  • the positive electrode active material of the present application includes both lithium cobaltate-based materials Li x1 Co y1 M1 1-y1 O 2-a Q1 a and ternary materials Li l Ni m1 Co n1 M2 p M3 q O 2-b Q2 b .
  • the thermal stability of the ternary material is better than that of lithium cobalt oxide-based materials
  • the gram capacity is higher than that of lithium cobalt oxide-based materials
  • the particle size is smaller than that of lithium cobalt oxide-based materials.
  • the ternary material Li l Ni m1 Co n1 M2 p M3 q O 2-b Q2 b in the lithium cobaltate-based material Li x1 Co y1 M1 1-y1 O 2-a Q1 a , the ternary material It can be evenly distributed in the gap between the lithium cobaltate particles and the particles, effectively separating the lithium cobaltate materials, and at the same time after mixing, it can also increase the compaction density of the positive pole pieces and increase the energy density of the lithium ion battery .
  • the high thermal stability of the ternary material can not only ensure its own structural stability, but also effectively prevent the heat transfer caused by the decomposition of the local lithium cobaltate-based materials and improve the overall Thermal stability of the positive pole piece.
  • the mixed positive electrode active material when the content of the ternary material is too low, it cannot effectively isolate the lithium cobalt oxide-based materials, which does not provide good protection and cannot improve the thermal stability of the entire positive pole piece, and the content of the ternary material is too high.
  • the additive A contained in the electrolyte of the present application is a polynitrile six-membered nitrogen heterocyclic compound with a low oxidation potential.
  • the nitrogen atom in the nitrile group contains a lone pair of electrons, which is comparable to the transition metal in the positive electrode active material. Strong complexation, after being applied in the electrolyte, can be adsorbed on the surface of the positive electrode active material during the formation of the battery to form a loose and porous complex layer and effectively passivate the surface of the positive electrode active material.
  • the complex layer can isolate the surface of the positive electrode active material from direct contact with the electrolyte and reduce the surface activity of the positive electrode active material, and can also reduce a large number of side reactions on the surface of the positive electrode active material and inhibit the dissolution of transition metals (especially cobalt) into the electrolyte Therefore, the electrolyte of the present application can play a role in reducing side reaction products and reducing gas production.
  • the additive A of this application has a special six-membered nitrogen heterocyclic structure, the distance between the nitrile group and the nitrile group is closer to the distance between the transition metal and the transition metal on the surface of the positive electrode active material, and it can maximize the complexation of the nitrile group And make a larger number of nitrile groups play a complexing role, so compared with the conventional linear nitrile compounds, the polynitrile six-membered nitrogen heterocyclic compound of the present application has a better passivation effect.
  • the special six-membered nitrogen heterocyclic structure of Additive A of this application can also lower the oxidation potential of the molecule, and can form a stable complex layer on the surface of the positive electrode active material when the battery is formed, improving the electricity of the entire battery system Chemical properties, such as reducing gas production and increasing cycle life at high temperatures and voltages.
  • the mass percentage content of the additive A is 0.1% to 10% based on the total mass of the electrolyte. If the content of additive A is too low, the improvement effect on the electrolyte is not obvious; if the content of additive A is too high, the complex layer formed on the surface of the positive electrode active material adsorbed by it is too thick and dense, which affects the diffusion and migration of lithium ions The positive electrode impedance is greatly increased. At the same time, the excessively high content of additive A also causes the overall viscosity of the electrolyte to increase and the ionic conductivity to decrease. Therefore, the excessively high content affects the performance of the lithium-ion battery.
  • the upper limit of the content range of the additive A may be selected from 10%, 9%, 8%, 7%, 6%, 5%, 4.5%, 4%, 3.5%, 3%, 2.5%, 2% , 1.5%, 1%, 0.8%
  • the lower limit of the content range of the additive A can be optionally selected from 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0 %, 1.2%.
  • the mass percentage content of the additive A is 0.1% to 6%. Even more preferably, based on the total mass of the electrolyte, the mass percentage content of the additive A is 0.1% to 3.5%.
  • the electrolyte may further contain an additive B, and the additive B is LiBF 4 .
  • the positive electrode active material easily releases oxygen, and the B atoms in LiBF 4 can stabilize the oxygen atoms in the positive electrode active material and play a role in suppressing the oxygen release of the positive electrode active material, thus helping to promote high The life of the voltage lithium-ion battery system, especially the storage life.
  • the mass percentage content of the additive B is 0.1% to 10%. Further preferably, based on the total mass of the electrolyte, the mass percentage content of the additive B is 0.1% to 5%.
  • the electrolyte may further contain an additive C selected from vinylene carbonate (VC), fluoroethylene carbonate (FEC), 1, One or more of 3-propane sultone (PS).
  • Additive C can form a surface film containing one or more of double bonds, fluorine atoms, and sulfonate groups on the surface of the positive and negative electrodes.
  • the surface film has good chemical, electrochemical, mechanical, and thermal stability.
  • the mass percentage content of the additive C is 0.1% to 10%. Further preferably, based on the total mass of the electrolyte, the mass percentage content of the additive C is 0.1% to 5%.
  • the electrolyte may further contain additive B and additive C at the same time.
  • the mass percentages of the additive B and the additive C are respectively 0.1% to 10%.
  • the electrolyte further includes an organic solvent and a lithium salt.
  • the organic solvent used in the electrolyte of the examples of the present application may include cyclic carbonate and chain carbonate, which can further improve the cycle performance and storage performance of the lithium ion battery at high temperature and high voltage, and it is easy to use the electrolyte
  • the electrical conductivity of the is adjusted to a suitable range, which is more conducive to each additive to achieve a better film-forming effect.
  • the organic solvent used in the electrolyte as an example of the present application may further include a carboxylic acid ester, that is, the organic solvent according to the present application may include a mixture of cyclic carbonate, chain carbonate, and carboxylic acid ester.
  • Carboxylic acid esters have the characteristics of large dielectric constant and low viscosity, which can effectively prevent the association of lithium ions and anions in the electrolyte, and at the same time have more advantages in ion conduction than cyclic carbonates and chain carbonates, especially in At low temperatures, it can ensure that the electrolyte has good ion conduction characteristics.
  • the mass percentage content of the cyclic carbonate can be 15% to 55%, preferably 25% to 50%; the mass percentage content of the chain carbonate can be 15% to 74 %, preferably 25% to 70%; the mass percentage content of the carboxylic acid ester may be 0.1% to 70%, preferably 5% to 50%.
  • the cyclic carbonate may be selected from one or more of ethylene carbonate, propylene carbonate, 1,2-butene carbonate, and 2,3-butanediol carbonate. Further preferably, the cyclic carbonate may be one or more selected from ethylene carbonate and propylene carbonate.
  • the chain carbonate may be one or more asymmetric chain carbonates selected from ethyl methyl carbonate, methyl propyl carbonate, methyl isopropyl carbonate, methyl butyl carbonate, and ethyl propyl carbonate.
  • the chain carbonate can also be selected from dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, one or more symmetric chain carbonate; the chain carbonate can also be the above A mixture of asymmetric chain carbonates and symmetric chain carbonates.
  • the carboxylic acid ester may be selected from methyl pivalate, ethyl pivalate, propyl pivalate, butyl pivalate, methyl butyrate, ethyl butyrate, propyl butyrate, butyric acid
  • butyl ester methyl propionate, ethyl propionate, propyl propionate, butyl propionate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate.
  • the lithium salt used in the electrolyte as an example of the present application may be selected from LiPF 6 , LiPO 2 F 2 , Li 2 PO 3 F, LiSO 3 F, lithium trifluoro((methanesulfonyl)oxy)borate, LiN( SO 2 F) 2 , LiN(SO 2 CF 3 ) 2 , LiN(SO 2 C 2 F 5 ) 2 , bis[oxalate-O,O'] lithium borate, difluorobis[oxalate-O,O' One or more of lithium phosphate, tetrafluoro[oxalate-O, O'] lithium phosphate.
  • the concentration of the lithium salt is not particularly limited, and can be adjusted reasonably according to actual needs.
  • the electrolyte has a conductivity of 4 mS/cm to 12 mS/cm at 25°C.
  • the preparation method of the electrolyte is not limited, and it can be prepared according to a conventional electrolyte method.
  • Li x1 Co y1 M1 1-y1 O 2-a Q1 a may be specifically selected from LiCo 0.9 Zr 0.1 O 2 , LiCo 0.9 Ti 0.1 O 2 , Li 1.05 Co 0.8 Mg 0.2 O 2 , Li 1.01 Co 0.98 Mg 0.01 Ti 0.005 Al 0.005 O 2 , Li 1.05 Co 0.98 Mg 0.005 Zr 0.005 Ti 0.01 O 1.9 F 0.1 , Li 1.1 Co 0.95 Mg 0.01 Zr 0.01 Al 0.03 O 2 , Li 1.04 Co 0.95 Mg 0.02 Zr 0.03 O 1.95 F 0.05 , Li 1.06 Co 0.96 Mg 0.02 Ti 0.02 O 2 , Li 1.08 Co 0.97 Mg 0.01 Zr 0.01 Al 0.01 O 1.9 S 0.1 , Li 1.09 Co 0.98 Mg 0.01 Ti 0.005 Al 0.005 O 2 , Li 1.085 Co 0.98 Zr 0.01 Ti 0.005 Al 0.005 O 1.9 Cl 0.1
  • Li l Ni m Co n M2 p M3 q O 2-b Q2 b may be specifically selected from LiNi 1/3 Co 1/3 Mn 1/3 O 2 , LiNi 0.5 Co 0.2 Mn 0.3 O 2 , LiNi 0.6 Co 0.2 Mn 0.2 O 2 , LiNi 0.8 Co 0.1 Mn 0.1 O 2 , LiNi 0.8 Co 0.1 Al 0.1 O 2 , LiNi 0.85 Co 0.15 Al 0.05 O 2 , Li 1.01 Ni 0.33 Co 0.33 Mn 0.31 Mg 0.01 Ti 0.005 Al 0.005 O 2 , Li 1.05 Ni 0.33 Co 0.33 Mn 0.31 Mg 0.005 Zr 0.005 Ti 0.01 O 1.9 F 0.1 , Li 1.1 Ni 0.33 Co 0.31 Mn 0.31 Mg 0.01 Zr 0.01 Al 0.03 O 2 , Li 1.04 Ni 0.33 Co 0.31 Mn 0.31 Mg 0.02 Zr 0.03 O 1.95 F 0.05 , Li 1.06
  • the negative electrode active material in the negative electrode sheet may be soft carbon, hard carbon, artificial graphite, natural graphite, silicon, silicon oxide compound, silicon carbon composite, lithium titanate, and Lithium alloying metals, etc. Only one type of these negative electrode active materials may be used alone, or two or more types may be used in combination.
  • the positive pole piece further includes a binder and a conductive agent.
  • the positive electrode slurry containing the positive electrode active material, the binder and the conductive agent is coated on the positive electrode current collector, and the positive electrode sheet is obtained after the positive electrode slurry is dried.
  • the types and contents of conductive agent and binder are not specifically limited, and can be selected according to actual needs.
  • the type of the positive electrode current collector is also not specifically limited, and can be selected according to actual needs, and is preferably aluminum foil.
  • the negative pole piece further includes a binder and a conductive agent.
  • the negative electrode slurry containing the negative electrode active material, the binder and the conductive agent is coated on the negative electrode current collector, and the negative electrode sheet is obtained after the negative electrode slurry is dried.
  • the types and contents of conductive agent and binder are not specifically limited, and can be selected according to actual needs.
  • the type of the negative electrode current collector is also not specifically limited, and can be selected according to actual needs, and is preferably a copper foil.
  • the separator is provided between the positive pole piece and the negative pole piece to play a role of isolation.
  • the type of the separator is not specifically limited, and may be any separator material used in existing lithium ion batteries, such as polyethylene, polypropylene, polyvinylidene fluoride, and their multilayer composite films, but not limited to These ones.
  • the charge cut-off voltage of the lithium ion battery is not less than 4.2V, that is, the lithium ion battery can be used in a high voltage state not less than 4.2V.
  • the charging cut-off voltage of the lithium ion battery is not less than 4.35V.
  • the lithium-ion battery of the present application may be either a hard-shell lithium-ion battery or a soft-package lithium-ion battery.
  • the hard shell lithium ion battery preferably uses a metal hard shell.
  • the flexible packaging lithium ion battery preferably uses a packaging bag as a battery case, and the packaging bag generally includes an accommodating portion and a sealing portion, wherein the accommodating portion is used to accommodate the electrode assembly and the electrolyte, and the sealing portion is used to seal the electrode assembly and the electrolyte.
  • the C 1 -C 12 alkyl group may be a chain alkyl group or a cyclic alkyl group.
  • the chain alkyl group may also be a linear or branched alkyl group.
  • the hydrogen on the ring of the cyclic alkyl group is also It may be further substituted with alkyl.
  • the preferred lower limit of the number of carbon atoms in the C 1 to C 12 alkyl group is 1, 2, 3, 4, and 5, and the preferred upper limit is 3, 4, 5, 6, 8, 10, and 12.
  • C 1 ⁇ C 10 alkyl is selected; further preferably, C 1 ⁇ C 6 chain alkyl, C 3 ⁇ C 8 cyclic alkyl is selected; still more preferably, C 1 ⁇ C 4 chain is selected.
  • Alkyl C 5 -C 7 cyclic alkyl.
  • Examples of the C 1 to C 12 alkyl group specifically include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, Isoamyl, neopentyl, hexyl, 2-methyl-pentyl, 3-methyl-pentyl, 1,1,2-trimethyl-propyl, 3,3-dimethyl-butyl, Heptyl, 2-heptyl, 3-heptyl, 2-methylhexyl, 3-methylhexyl, isoheptyl, octyl, nonyl, decyl.
  • C 1 -C 12 alkyl group contains an oxygen atom
  • it may be a C 1 -C 12 alkoxy group.
  • C 1 -C 10 alkoxy is selected; further preferably, C 1 -C 6 alkoxy is selected; still more preferably, C 1 -C 4 alkoxy is selected.
  • Examples of C 1 to C 12 alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, t-butoxy, N-pentyloxy, isopentyloxy, cyclopentyloxy, cyclohexyloxy.
  • the C 2 -C 12 alkenyl group may be a cyclic alkenyl group or a chain alkenyl group, and the chain alkenyl group may be a linear alkenyl group or a branched alkenyl group.
  • the number of double bonds in the C 2 to C 12 alkenyl group is preferably one.
  • the preferred lower limit of the number of carbon atoms in the C 2 to C 12 alkenyl group is 2, 3, 4, and 5, and the preferred upper limit is 3, 4, 5, 6, 8, 10, and 12.
  • C 2 -C 10 alkenyl is selected; further preferably, C 2 -C 6 alkenyl is selected; still more preferably, C 2 -C 5 alkenyl is selected.
  • Examples of C 2 to C 12 alkenyl groups include vinyl, allyl, isopropenyl, pentenyl, cyclohexenyl, cycloheptenyl, and cyclooctenyl.
  • the C 2 -C 12 alkynyl group may be a cyclic alkynyl group or a chain alkynyl group, and the chain alkynyl group may be a linear alkynyl group or a branched alkynyl group.
  • the number of triple bonds in the C 2 to C 12 alkynyl group is preferably one.
  • the preferred lower limit of the number of carbon atoms in the C 2 to C 12 alkynyl group is 2, 3, 4, and 5, and the preferred upper limit is 3, 4, 5, 6, 8, 10, and 12.
  • C 2 to C 10 alkynyl is selected; further preferably, C 2 to C 6 alkynyl is selected; still more preferably, C 2 to C 5 alkynyl is selected.
  • Examples of C 2 to C 12 alkynyl groups include ethynyl, propargyl, isopropynyl, pentynyl, cyclohexynyl, cycloheptynyl, and cyclooctynyl groups.
  • the C 1 ⁇ C 12 amino group can be selected from Wherein R ', R "is selected from C 1 ⁇ C 12 alkyl group.
  • C 6 ⁇ C 26 aryl groups can be phenyl, phenalkyl, biphenyl, fused ring aromatic hydrocarbon groups (such as naphthyl, anthracenyl, phenanthrenyl), biphenyl and fused ring aromatic hydrocarbon groups can be further alkyl Or alkenyl substitution.
  • a C 6 -C 16 aryl group is selected; further preferably, a C 6 -C 14 aryl group is selected; still more preferably, a C 6 -C 9 aryl group is selected.
  • Examples of the C 6 -C 26 aryl group include phenyl, benzyl, biphenyl, p-tolyl, o-tolyl, m-tolyl, naphthyl, anthryl, and phenanthryl.
  • the hetero atom in the C 2 -C 12 heterocyclic group may be selected from one or more of oxygen, nitrogen, sulfur, phosphorus, and boron, and the hetero ring may be an aliphatic hetero ring or an aromatic hetero ring.
  • a C 2 -C 10 heterocyclic group is selected; further preferably, a C 2 -C 7 heterocyclic group is selected; still more preferably, a five-membered aromatic heterocyclic ring, a six-membered aromatic heterocyclic ring, and a benzo heterocyclic ring are selected.
  • C 2 to C 12 heterocyclic group specific examples include ethylene oxide, propylene oxide, ethylene sulfide, aziridine, ⁇ -propiolactone, furyl, Thienyl, pyrrolyl, thiazolyl, imidazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, indolyl, quinolinyl.
  • the halogen atom as a substituent may be one or more selected from a fluorine atom, a chlorine atom, and a bromine atom, preferably a fluorine atom.
  • the compound represented by Formula I-1 is a polycyanopyrimidine compound.
  • R 1 , R 2 , R 3 , and R 4 are each independently selected from a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a substituted or unsubstituted C 1 to C 6 linear or branched alkyl group, and a substitution Or unsubstituted C 5 ⁇ C 9 cyclic alkyl, substituted or unsubstituted C 1 ⁇ C 6 alkoxy, substituted or unsubstituted C 1 ⁇ C 6 amino, substituted or unsubstituted C 2 ⁇ C 6 alkenyl, substituted or unsubstituted C 2 -C 6 alkynyl, substituted or unsubstituted C 6 -C 12 aryl, substituted or unsubstituted C 2 -C 12 heterocyclyl; further preferably, R 1 , R 2 , R 3 , and R 4 are each independently selected from a hydrogen atom, a fluorine atom,
  • x is preferably selected from integers of 0 to 6, further preferably selected from integers of 0 to 4, even more preferably selected from 0, 1, or 2.
  • y is preferably selected from integers of 0 to 6, further preferably selected from integers of 0 to 4, even more preferably selected from 0, 1 or 2.
  • m is preferably selected from 1 or 2.
  • n is preferably selected from 1 or 2.
  • R 1 and R 3 are the same group; further preferably, R 1 , R 3 and R 4 are all the same group.
  • R 1 and R 3 are all hydrogen atoms; further preferably, R 1 , R 3 and R 4 are all hydrogen atoms.
  • R 1 , R 2 , R 3 and R 4 are all hydrogen atoms, or R 1 , R 3 and R 4 are all hydrogen atoms and R 2 is selected from fluorine atom, chlorine atom, bromine atom, substituted or unsubstituted C 1 -C 6 linear or branched alkyl, substituted or unsubstituted C 1 -C 6 alkoxy.
  • the substituent is selected from one or more of halogen atoms, preferably, the substituent is selected from fluorine atoms.
  • the compound represented by Formula I-1 may be specifically selected from one or more of the following compounds, but the application is not limited thereto:
  • the compound represented by Formula I-2 is a polynitrile piperazine compound.
  • R 1 , R 2 , R 3 , and R 4 are each independently selected from a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a substituted or unsubstituted C 1 to C 6 linear or branched alkyl group, and a substitution Or unsubstituted C 5 ⁇ C 9 cyclic alkyl, substituted or unsubstituted C 1 ⁇ C 6 alkoxy, substituted or unsubstituted C 1 ⁇ C 6 amino, substituted or unsubstituted C 2 ⁇ C 6 alkenyl, substituted or unsubstituted C 2 -C 6 alkynyl, substituted or unsubstituted C 6 -C 12 aryl, substituted or unsubstituted C 2 -C 12 heterocyclyl; further preferably, R 1 , R 2 , R 3 , and R 4 are each independently selected from a hydrogen atom, a fluorine atom,
  • x is preferably selected from integers of 0 to 6, further preferably selected from integers of 0 to 4, even more preferably selected from 0, 1, or 2.
  • y is preferably selected from integers of 0 to 6, further preferably selected from integers of 0 to 4, even more preferably selected from 0, 1 or 2.
  • m is preferably selected from 1 or 2.
  • n is preferably selected from 1 or 2.
  • R 1 , R 2 , R 3 , and R 4 are the same group, and further preferably, at least three of R 1 , R 2 , R 3 , and R 4 are the same group.
  • R 1 , R 2 , R 3 , and R 4 are hydrogen atoms; further preferably, at least three of R 1 , R 2 , R 3 , and R 4 are hydrogen atoms.
  • R 1 , R 2 , R 3 and R 4 are all hydrogen atoms, or three of R 1 , R 2 , R 3 and R 4 are hydrogen atoms and the remaining one is selected from fluorine atom, chlorine atom and bromine atom , Substituted or unsubstituted C 1 -C 6 linear or branched alkyl, substituted or unsubstituted C 1 -C 6 alkoxy.
  • the substituent is selected from one or more of halogen atoms, preferably, the substituent is selected from fluorine atoms.
  • the compound represented by Formula I-2 may be specifically selected from one or more of the following compounds, but the application is not limited thereto:
  • the compound represented by Formula I-3 is a polynitrile mesitazine compound.
  • R 1 , R 2 and R 3 are each independently selected from a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a substituted or unsubstituted C 1 to C 6 linear or branched alkyl group, a substituted or unsubstituted C 5 ⁇ C 9 cyclic alkyl, substituted or unsubstituted C 1 ⁇ C 6 alkoxy, substituted or unsubstituted C 1 ⁇ C 6 amino, substituted or unsubstituted C 2 ⁇ C 6 alkenyl , Substituted or unsubstituted C 2 -C 6 alkynyl, substituted or unsubstituted C 6 -C 12 aryl, substituted or unsubstituted C 2 -C 12 heterocyclyl; further preferably, R 1 , R 2 And R 3 are each independently selected from a hydrogen atom, a fluorine atom, a chlorine atom, a
  • x is preferably selected from integers of 0 to 6, further preferably selected from integers of 0 to 4, even more preferably selected from 0, 1, or 2.
  • y is preferably selected from integers of 0 to 6, further preferably selected from integers of 0 to 4, even more preferably selected from 0, 1 or 2.
  • z is preferably selected from integers of 0 to 6, further preferably selected from integers of 0 to 4, even more preferably selected from 0, 1 or 2.
  • m is preferably selected from 1 or 2.
  • n is preferably selected from 1 or 2.
  • k is preferably selected from 1 or 2.
  • At least two of R 1 , R 2 and R 3 are the same group.
  • At least two of R 1 , R 2 and R 3 are hydrogen atoms.
  • R 1 , R 2 and R 3 are all hydrogen atoms, or two of R 1 , R 2 and R 3 are hydrogen atoms and the remaining one is selected from fluorine atom, chlorine atom, bromine atom, substituted or unsubstituted C 1 -C 6 linear or branched alkyl, substituted or unsubstituted C 1 -C 6 alkoxy.
  • the substituent is selected from one or more of halogen atoms, preferably, the substituent is selected from fluorine atoms.
  • the compound represented by Formula I-3 may be specifically selected from one or more of the following compounds, but the application is not limited thereto:
  • the additive A can be synthesized by the following method.
  • P20 aqueous solution with a concentration of 30% to 40% is added dropwise to the raw material P-1 within 20min to 60min and quickly stirred. After the completion of the dropwise addition, the solution is rapidly stirred for 15h to 30h, and stirred at 70°C to 90°C in an oil bath under reflux for 3h. 5h, to obtain colorless fuming viscous liquid intermediate product I-1-1; continue to add K 2 CO 3 , KI, anhydrous acetonitrile, quickly stir to form a solid-liquid mixed phase, quickly add raw materials at 40 °C ⁇ 60 °C P-3, continue to stir for 10h-20h, then cool to room temperature, and separate and purify to obtain the compound represented by Formula I-1.
  • the anhydrous sodium carbonate, the raw material P-4 and the raw material P-3 are mixed in absolute ethanol, and the reaction is stirred for 2h to 5h; the hot ethanol is repeatedly washed several times to obtain a crude product, and the compound represented by the formula I-2 is obtained by recrystallization.
  • the anhydrous sodium carbonate, the raw material P-5 and the raw material P-3 are mixed in absolute ethanol, and the reaction is stirred for 2h to 5h; the hot ethanol is repeatedly washed many times to obtain a crude product, and the compound represented by formula I-3 is obtained by recrystallization.
  • the lithium ion battery may include an outer package for encapsulating the positive pole piece, the negative pole piece, and the electrolyte.
  • the positive pole piece, the negative pole piece and the separator may be laminated or wound to form a laminated structure electrode assembly or a wound structure electrode assembly, and the electrode assembly is encapsulated in an outer package; the electrolyte may use an electrolyte, which is infiltrated by the electrolyte In the electrode assembly.
  • the number of electrode assemblies in a lithium ion battery can be one or several, which can be adjusted according to requirements.
  • the outer package of the lithium-ion battery may be a soft bag, such as a pouch type soft bag.
  • the material of the soft bag may be plastic, such as one or more of polypropylene PP, polybutylene terephthalate PBT, polybutylene succinate PBS, etc.
  • the outer package of the lithium ion battery can also be a hard shell, such as an aluminum shell.
  • the present application has no particular limitation on the shape of the lithium ion battery, which may be cylindrical, square, or any other shape.
  • 4 is a lithium-ion battery 5 having a square structure as an example.
  • the lithium-ion battery may be assembled into a battery module, and the number of lithium-ion batteries contained in the battery module may be multiple, and the specific number may be adjusted according to the application and capacity of the battery module.
  • FIG. 5 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. Of course, it can also be arranged in any other way. Further, the plurality of lithium ion batteries 5 can be fixed by fasteners.
  • the battery module 4 may further include a housing having an accommodation space, and a plurality of lithium ion batteries 5 are accommodated in the accommodation space.
  • the above battery modules can also be assembled into a battery pack, and the number of battery modules contained in the battery pack can be adjusted 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 provided in the battery box.
  • the battery case includes an upper case 2 and a lower case 3.
  • the upper case 2 can be covered on the lower case 3 and forms an enclosed space for accommodating the battery module 4.
  • the plurality of battery modules 4 can be arranged in the battery box in any manner.
  • a device in a second aspect of the present application, includes the lithium-ion battery of the first aspect of the present application, and the lithium-ion battery provides power for the device.
  • the device may be, but not limited to, mobile equipment (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 balls) Vehicles, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc.
  • the device can select a lithium ion battery, battery module or battery pack according to its usage requirements.
  • FIG. 8 is a device as an example.
  • the device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle.
  • battery packs or battery modules can be used.
  • the device may be a mobile phone, a tablet computer, a notebook computer, or the like.
  • the device usually requires lightness and thinness, and a lithium ion battery can be used as a power source.
  • additives A1, A2, and A3 are commercially available unless otherwise specified.
  • the specific synthesis process of additives A1, A2, and A3 is as follows.
  • Other types of additives A can be synthesized according to similar methods.
  • lithium-ion batteries were prepared according to the following methods.
  • a mixed solution of ethylene carbonate (abbreviated as EC), ethyl methyl carbonate (abbreviated as EMC) and diethyl carbonate (abbreviated as DEC) is used as an organic solvent, wherein the mass ratio of EC, EMC and DEC is 1:1 :1.
  • the lithium salt is LiPF 6 , and the content of LiPF 6 is 12.5% of the total mass of the electrolyte.
  • Each additive is added according to the electrolyte composition shown in Table 1, wherein the content of each additive component is calculated relative to the total mass of the electrolyte.
  • the positive electrode active material shown in Table 2 the binder PVDF, and the conductive agent acetylene black are mixed according to a mass ratio of 98:1:1, N-methylpyrrolidone is added, and the mixture is stirred and stabilized under the action of a vacuum mixer to obtain a positive electrode slurry. ; Evenly coat the positive electrode slurry on the aluminum foil, dry the aluminum foil at room temperature and transfer it to a 120°C blast oven to dry for 1h, and then cold press and cut to obtain the positive pole piece.
  • the lithium ion battery is first charged with a constant current of 1C to a voltage of 4.35V, further charged with a constant voltage of 4.35V to a current of 0.05C, and then discharged with a constant current of 1C to a voltage of 3.0V, which is a charge
  • the current discharge capacity is the first cycle discharge capacity.
  • the lithium-ion battery was subjected to 200 cycles of charge/discharge test according to the above method, and the discharge capacity at the 200th cycle was detected.
  • Capacity retention rate (%) after 200 cycles of the lithium ion battery (discharge capacity of the lithium ion battery after 200 cycles/discharge capacity of the first cycle of the lithium ion battery) ⁇ 100%.
  • the lithium ion battery is first charged with a constant current of 1C to a voltage of 4.35V, further charged with a constant voltage of 4.35V to a current of 0.05C, and then discharged with a constant current of 1C to a voltage of 3.0V, which is a charge
  • the current discharge capacity is the first cycle discharge capacity.
  • the lithium-ion battery was subjected to 200 cycles of charge/discharge test according to the above method, and the discharge capacity at the 200th cycle was detected.
  • Capacity retention rate (%) after 200 cycles of the lithium ion battery (discharge capacity of the lithium ion battery after 200 cycles/discharge capacity of the first cycle of the lithium ion battery) ⁇ 100%.
  • Lithium-ion battery thickness expansion rate (%) after storage at 85°C for 24 hours [(h 1 -h 0 )/h 0 ] ⁇ 100%.
  • the examples of the present application use lithium cobaltate-based materials Li x1 Co y1 M1 1-y1 O 2-a Q1 a and ternary materials Li l Ni m1 Co n1 M2 p M3 q O 2-b
  • Q2 b is used as a positive electrode active material
  • additive A is used as an electrolyte additive.
  • a certain amount of ternary material is mixed in the lithium cobalt oxide-based material, and the ternary material can be evenly distributed in the gap between the particles of the lithium cobalt oxide-based material, so the lithium cobalt oxide-based material can be effectively separated, while After mixing, it can also increase the compaction density of the positive pole piece and the energy density of the lithium ion battery; in addition, the higher thermal stability of the ternary material can not only ensure its own structural stability, but also effectively prevent local lithium cobaltate The heat transfer caused by material decomposition improves the thermal stability of the entire positive pole piece.
  • Additive A is a polynitrile six-membered nitrogen heterocyclic compound with a low oxidation potential, which can form a stable complex layer on the surface of the cathode active material when the battery is formed, effectively passivating the surface of the cathode active material and reducing the cathode active material Surface activity, the direct contact between the isolated electrolyte and the surface of the positive electrode active material makes the side reactions on the surface greatly reduced, and the lithium ions consumed in the side reactions are correspondingly reduced, that is, the consumption rate of reversible lithium ions is greatly slowed down, and finally appears
  • the actual effect is that the cycle capacity retention rate of lithium-ion batteries is greatly improved; some surface side reactions can generate gas, and the reduction of surface side reactions also means that the gas production of the battery is reduced.
  • the actual effect finally revealed is that the thickness expansion of the lithium-ion battery is significantly reduced at high temperatures. .
  • the polynitrile six-membered nitrogen heterocyclic compound of the present application has a special six-membered nitrogen heterocyclic structure, and the distance between the nitrile group and the nitrile group is closer to the surface transition metal of the positive electrode active material The distance from the transition metal can maximize the complexation of the nitrile group, and allow a greater number of nitrile groups to exert complexation.
  • the polynitrile six-membered nitrogen heterocyclic compound of the present application has a stronger covering effect on the transition metal on the surface of the positive electrode active material, a better passivation effect on the surface of the positive electrode active material, and an improvement effect on the cycle performance and storage performance of the lithium ion battery Also more outstanding.
  • an appropriate amount of the additive A needs to be added, preferably 0.1% to 10%, more preferably 0.1% to 6%, still more preferably 0.1% to 3.5%.
  • Examples 25-27 explore the effect of LiBF 4 on the performance of lithium ion batteries when the additive A addition amount is better. Compared with Example 3, Examples 25-28 have a smaller thickness expansion rate at 85°C for 24 hours. This is because the B atoms in LiBF 4 can stabilize the oxygen atoms in the positive electrode active material and inhibit the release of the positive electrode active material. The role of oxygen, so lithium-ion batteries show better storage performance.
  • Examples 28-30 explored the effect of additive A in the amount of VC, FEC, and PS on the performance of lithium-ion batteries.
  • additives help to form a surface film containing double bonds, fluorine atoms, and sulfonate groups on the surface of the positive and negative electrodes.
  • the surface film has good chemical, electrochemical, mechanical, and thermal stability, and can smoothly conduct lithium ions.
  • the direct contact between the electrolyte and the surfaces of the positive and negative electrodes is blocked, which has the effect of inhibiting the side reactions of oxidation and reduction on the surfaces of the positive and negative electrodes. Therefore, it will help to further improve the cycle performance and storage performance of lithium ion batteries.

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Abstract

一种锂离子电池（5）及装置，所述锂离子电池（5）包括电极组件以及电解液，所述电极组件包括正极极片、负极极片以及隔离膜。所述正极极片中的正极活性材料同时包含Li x1Co y1M1 1-y1O 2-aQ1 a以及Li lNi m1Co n1M2 pM3 qO 2-bQ2 b，所述Li x1Co y1M1 1-y1O 2-aQ1 a以及所述Li lNi m1Co n1M2 pM3 qO 2-bQ2 b的质量比为1:1～9:1。所述电解液中含有添加剂A，所述添加剂A为氧化电位较低的多腈基六元氮杂环化合物。锂离子电池（5）具有优异的循环性能和存储性能，尤其是在高温高电压情况下具有优异的循环性能和存储性能。

Description

锂离子电池及装置 技术领域
本申请涉及储能材料领域，具体地讲，涉及一种锂离子电池及装置。
背景技术
锂离子电池由于具备能量密度大、输出功率高、循环寿命长和环境污染小等优点而被广泛应用于电动汽车以及消费类电子产品中。目前对锂离子电池的需求是：高电压、高功率、长循环寿命、长存储寿命且安全性能优异。
锂离子电池目前广泛使用LiCoO 2作为正极活性材料，其在完全放电态的LiCoO 2和半充电态的Li 0.5CoO 2(4.2V vs.Li)之间循环时性能比较稳定，因此实际上真正被利用的锂离子只有其实际锂离子含量的1/2。而当电压大于4.2V时，LiCoO 2中剩余1/2含量的锂离子可以继续脱出，但是深度脱锂过程中，Co 3+会被氧化为很不稳定的Co 4+，与失去大量电子的表面氧共同氧化电解液，此时电池内部将会产生大量气体造成电池鼓胀。同时由于电解液中HF对正极表面的腐蚀作用，导致Co 4+溶于电解液后沉积在负极表面，催化电解液的还原，也会产生大量气体造成电池鼓胀。另外由于Co的3d能级与O的2p能级重叠程度较大，深度脱锂还会导致晶格氧失去大量电子，使LiCoO 2晶胞沿c轴方向剧烈收缩，诱发局部体相结构失稳甚至坍塌，最终引起LiCoO 2活性位点损失，锂离子电池容量迅速降低。因此LiCoO 2在大于4.2V的高电压体系中使用时的性能非常差。
鉴于此，特提出本申请。
发明内容
鉴于背景技术中存在的问题，本申请的目的在于提供一种锂离子电池及装置，所述锂离子电池具有优异的循环性能和存储性能，尤其是在高温高电压情况下具有优异的循环性能和存储性能。
为了达到上述目的，在第一方面，本申请提供了一种锂离子电池，其包括电极组件以及电解液，所述电极组件包括正极极片、负极极片以及隔离膜。所述正极极片中的正极活性材料同时包含Li x1Co y1M1 1-y1O 2-aQ1 a以及Li lNi m1Co n1M2 pM3 qO 2-bQ2 b，Li x1Co y1M1 1-y1O 2-aQ1 a以及Li lNi m1Co n1M2 pM3 qO 2-bQ2 b的质量比为1:1～9:1；其中，0.5≤x1≤1.2，0.8≤y1<1.0，0≤a≤0.1，M1选自Al、Ti、Zr、Y、Mg中的至少一种元素，Q1选自F、Cl、S中的一种或几种；0.5≤l≤1.2，0.33≤m1≤0.85、0.1≤n1≤0.33、0.1≤p≤0.33、0≤q≤0.1且m1+n1+p+q＝1，0≤b≤0.1，M2选自Mn、Al中的一种或两种，M3选自Zr、Zn、Cu、Cr、Mg、Fe、V、Ti、Y、Nb中的一种或几种，Q2选自F、Cl、S中的一种或几种。所述电解液中含有添加剂A，所述添加剂A选自式I-1、式I-2、式I-3所示的化合物中的一 种或几种。在式I-1、式I-2、式I-3中：R 1、R 2、R 3、R 4各自独立地选自氢原子、卤素原子、取代或未取代的C 1～C 12烷基、取代或未取代的C 1～C 12烷氧基、取代或未取代的C 1～C 12胺基、取代或未取代的C 2～C 12烯基、取代或未取代的C 2～C 12炔基、取代或未取代的C 6～C 26芳基、取代或未取代的C 2～C 12杂环基，其中，取代基选自卤素原子、腈基、C 1～C 6烷基、C 2～C 6烯基、C 1～C 6烷氧基中的一种或几种；x、y、z各自独立地选自0～8的整数；m、n、k各自独立地选自0～2的整数。
Figure PCTCN2019125319-appb-000001
在本申请的第二方面，本申请提供了一种装置，其包括本申请的第一方面所述的锂离子电池。
相对于现有技术，本申请至少包括如下所述的有益效果：
本申请使用包含金属离子M掺杂的钴酸锂类材料Li x1Co y1M1 1-y1O 2-aQ1 a的正极活性材料，掺杂元素M在钴酸锂类材料中充当骨架，可以减小钴酸锂类材料深度脱锂过程中的晶格形变量，延缓钴酸锂类材料体相结构的退化，改善锂离子电池在大于4.2V高电压下使用时的结构稳定性。
本申请在钴酸锂类材料Li x1Co y1M1 1-y1O 2-aQ1 a中还混合一定量的三元材料Li lNi m1Co n1M2 pM3 qO 2-bQ2 b，三元材料可以均匀分布在钴酸锂类材料颗粒与颗粒之间的间 隙中，将钴酸锂类材料有效分离开来，同时混合后还能提高正极极片的压实密度，提高锂离子电池的能量密度；此外，三元材料较高的热稳定性不仅可以保证自身的结构稳定性，而且可以有效防止局部钴酸锂类材料分解带来的热量传递，提高整个正极极片的热稳定性。
本申请使用的电解液中还含有氧化电位较低的多腈基六元氮杂环化合物，电池化成时便能在正极活性材料表面形成稳定的络合物层，有效钝化正极活性材料表面，降低正极活性材料表面活性，抑制过渡金属(尤其是钴)溶解到电解液中，从而在减少副反应的同时降低电池产气。
因此本申请的锂离子电池能具有优异的循环性能和存储性能，尤其是在高温高电压情况下具有优异的循环性能和存储性能。本申请的装置包括本申请第一方面所述的锂离子电池，因而至少具有与所述锂离子电池相同的优势。
附图说明
图1为A1化合物核磁共振碳谱。
图2为A2化合物核磁共振碳谱。
图3为A3化合物核磁共振碳谱。
图4是锂离子电池的一实施方式的示意图。
图5是电池模块的一实施方式的示意图。
图6是电池包的一实施方式的示意图。
图7是图6的分解图。
图8是锂离子电池作为电源的装置的一实施方式的示意图。
其中，附图标记说明如下：
1电池包
2上箱体
3下箱体
4电池模块
5锂离子电池
具体实施方式
下面详细说明根据本申请的锂离子电池及装置。
首先说明根据本申请第一方面的锂离子电池。
根据本申请的锂离子电池包括电极组件以及电解液，所述电极组件包括正极极片、负极极片以及隔离膜。
在本申请的锂离子电池中，所述正极极片中的正极活性材料同时包含Li x1Co y1M1 1-y1O 2-aQ1 a以及Li lNi m1Co n1M2 pM3 qO 2-bQ2 b，Li x1Co y1M1 1-y1O 2-aQ1 a以及 Li lNi m1Co n1M2 pM3 qO 2-bQ2 b的质量比为1:1～9:1。其中，0.5≤x1≤1.2，0.8≤y1<1.0，0≤a≤0.1，M1选自Al、Ti、Zr、Y、Mg中的至少一种元素，Q1选自F、Cl、S中的一种或几种；0.5≤l≤1.2，0.33≤m1≤0.85、0.1≤n1≤0.33、0.1≤p≤0.33、0≤q≤0.1且m1+n1+p+q＝1，0≤b≤0.1，M2选自Mn、Al中的一种或两种，M3选自Zr、Zn、Cu、Cr、Mg、Fe、V、Ti、Y、Nb中的一种或几种，Q2选自F、Cl、S中的一种或几种。
在本申请的锂离子电池中，所述电解液中含有添加剂A，所述添加剂A选自式I-1、式I-2、式I-3所示的化合物中的一种或几种。在式I-1、式I-2、式I-3中：R 1、R 2、R 3、R 4各自独立地选自氢原子、卤素原子、取代或未取代的C 1～C 12烷基、取代或未取代的C 1～C 12烷氧基、取代或未取代的C 1～C 12胺基、取代或未取代的C 2～C 12烯基、取代或未取代的C 2～C 12炔基、取代或未取代的C 6～C 26芳基、取代或未取代的C 2～C 12杂环基，其中，取代基(在本申请中表示“取代或未取代”中发生取代的情况)选自卤素原子、腈基、C 1～C 6烷基、C 2～C 6烯基、C 1～C 6烷氧基中的一种或几种；x、y、z各自独立地选自0～8的整数；m、n、k各自独立地选自0～2的整数。
Figure PCTCN2019125319-appb-000002
本申请的锂离子电池具有优异的循环性能和存储性能，尤其是在高温高电压情况下还具有优异的循环性能和存储性能。
具体地：
(1)本申请使用包含金属离子M掺杂的钴酸锂类材料Li x1Co y1M 1-y1O 2-z1Q z1的正极活性材料，掺杂元素M在钴酸锂类材料中充当骨架，可以减小钴酸锂类材料深度脱锂过程中的晶格形变量，延缓钴酸锂类材料体相结构的退化，改善锂离子电池在大于4.2V高电压下使用时的结构稳定性。
(2)本申请的正极活性材料同时包含钴酸锂类材料Li x1Co y1M1 1-y1O 2-aQ1 a以及三元材料Li lNi m1Co n1M2 pM3 qO 2-bQ2 b。通常在相同截止电压下，三元材料的热稳定性优于钴酸锂类材料，克容量高于钴酸锂类材料，而粒径小于钴酸锂类材料。因此通过在钴酸锂类材料Li x1Co y1M1 1-y1O 2-aQ1 a中混合一定量的三元材料Li lNi m1Co n1M2 pM3 qO 2-bQ2 b，三元材料可以均匀分布在钴酸锂类材料颗粒与颗粒之间的间隙中，将钴酸锂类材料有效分离开来，同时混合后还能提高正极极片的压实密度，提高锂离子电池的能量密度。此外，当锂离子电池在高温情况下使用时，三元材料较高的热稳定性不仅可以保证自身的结构稳定性，而且可以有效防止局部钴酸锂类材料分解带来的热量传递，提高整个正极极片的热稳定性。在混合正极活性材料中，三元材料含量过低时无法有效隔离钴酸锂类材料，起不到较好的保护作用，无法提高整个正极极片的热稳定性，而三元材料含量过高时，正极极片的压实密度不高，锂离子电池的能量密度不佳，因此，最佳混合比例为Li x1Co y1M1 1-y1O 2-aQ1 a：Li lNi m1Co n1M2 pM3 qO 2＝1:1～9:1。
(3)本申请的电解液中含有的添加剂A为氧化电位较低的多腈基六元氮杂环化合物，腈基中的氮原子含有孤对电子，与正极活性材料中的过渡金属具有较强的络合作用，应用于电解液中后，可以在电池化成过程中吸附在正极活性材料表面生成一层疏松多孔的络合物层并有效钝化正极活性材料表面。该络合物层能隔绝正极活性材料表面与电解液的直接接触以及降低正极活性材料表面活性，还能降低正极活性材料表面发生大量副反应以及抑制过渡金属(尤其是钴)溶解到电解液中，从而本申请的电解液能起到减少副反应产物并降低产气的作用。
(4)本申请的添加剂A具有特殊的六元氮杂环结构，腈基与腈基的间距更接近正极活性材料表面过渡金属与过渡金属的间距，可以最大限度地发挥腈基的络合作用，且使更多数量的腈基发挥络合作用，因此与常规线性的腈基化合物相比，本申请的多腈基六元氮杂环化合物具有更好的钝化效果。
(5)本申请的添加剂A特殊的六元氮杂环结构还能使分子的氧化电位较低，电池化成时便能在正极活性材料表面形成稳定的络合物层，改善整个电池体系的电化学性能，诸如降低产气、提高高温高电压下的循环寿命等。
在本申请的锂离子电池中，优选地，基于所述电解液的总质量计，所述添加剂A的质量百分含量为0.1％～10％。如果添加剂A含量过低，则其对电解液的改善效果不明显；如果添加剂A含量过高，则其吸附在正极活性材料表面形成的络合物层过于厚和致密，影响锂离子的扩散迁移，正极阻抗大幅增高，同时添加剂A含量过高还导致电解液整体黏度提升、离子电导率下降，因此过高的含量反而影响锂离子电池的性能发挥。优选地，所述添加剂A含量范围的上限可任选自10％、9％、8％、7％、6％、5％、4.5％、4％、3.5％、3％、2.5％、2％、1.5％、1％、0.8％，所述添加剂A含量范围的下限可任选自0.1％、0.2％、 0.3％、0.4％、0.5％、0.6％、0.7％、0.8％、0.9％、1.0％、1.2％。
进一步优选地，基于所述电解液的总质量计，所述添加剂A的质量百分含量为0.1％～6％。更进一步优选地，基于所述电解液的总质量计，所述添加剂A的质量百分含量为0.1％～3.5％。
在本申请的锂离子电池的一实施方式中，所述电解液中还可含有添加剂B，所述添加剂B为LiBF 4。在高电压锂离子电池体系中，正极活性材料容易释氧，而LiBF 4中的B原子可稳定正极活性材料中的氧原子，起到抑制正极活性材料释氧的作用，因此有助于提升高电压锂离子电池体系的寿命，尤其是存储寿命。
优选地，基于所述电解液的总质量计，所述添加剂B的质量百分含量为0.1％～10％。进一步优选地，基于所述电解液的总质量计，所述添加剂B的质量百分含量为0.1％～5％。
在本申请的锂离子电池的另一实施方式中，所述电解液中还可含有添加剂C，所述添加剂C选自碳酸亚乙烯酯(VC)、氟代碳酸乙烯酯(FEC)、1,3-丙磺酸内酯(PS)中的一种或几种。添加剂C可以在正、负极表面形成含双键、氟原子、磺酸酯基团中的一种或几种的表面膜，该表面膜的化学、电化学、机械、热稳定性好，能在顺畅导通锂离子的同时隔绝电解液与正、负极表面的直接接触，起到抑制正、负极表面的氧化、还原副反应的效果，因此可以显著抑制电池产气，提升高电压锂离子电池体系的循环寿命和存储寿命。
优选地，基于所述电解液的总质量计，所述添加剂C的质量百分含量为0.1％～10％。进一步优选地，基于所述电解液的总质量计，所述添加剂C的质量百分含量为0.1％～5％。
在本申请的锂离子电池的又一实施方式中，所述电解液中还可同时含有添加剂B以及添加剂C。优选地，基于所述电解液的总质量计，所述添加剂B和所述添加剂C的质量百分含量分别为0.1％～10％。
在本申请的锂离子电池中，所述电解液还包括有机溶剂以及锂盐。
作为本申请实施例的电解液中使用的有机溶剂，可包括环状碳酸酯以及链状碳酸酯，其可进一步提高锂离子电池高温高电压情况下的循环性能和存储性能，且易于将电解液的电导率调节至合适的范围，从而更有利于各添加剂达到更好的成膜效果。
作为本申请实施例的电解液中使用的有机溶剂还可包括羧酸酯，即根据本申请的有机溶剂可包括环状碳酸酯、链状碳酸酯以及羧酸酯的混合物。羧酸酯具有介电常数大且粘度低的特点，可有效防止锂离子和电解液中阴离子的缔合，同时在离子传导方面比环状碳酸酯和链状碳酸酯更有优势，尤其是在低温下，能可保证电解液具有良好的离子传导特性。
其中，基于有机溶剂的总质量计，环状碳酸酯的质量百分含量可为15％～55％，优选为25％～50％；链状碳酸酯的质量百分含量可为15％～74％，优选为25％～70％；羧酸酯的质量百分含量可为0.1％～70％，优选为5％～50％。
具体地，环状碳酸酯可选自碳酸乙烯酯、碳酸丙烯酯、碳酸1,2-丁烯酯、碳酸-2,3-丁二醇酯中的一种或几种。进一步优选地，环状碳酸酯可选自碳酸乙烯酯、碳酸丙烯酯中的一种或几种。
具体地，链状碳酸酯可选自碳酸甲乙酯、碳酸甲丙酯、碳酸甲基异丙酯、碳酸甲丁酯、碳酸乙丙酯中的一种或几种的非对称链状碳酸酯；链状碳酸酯还可选自碳酸二甲酯、碳酸 二乙酯、碳酸二丙酯、碳酸二丁酯中的一种或几种的对称链状碳酸酯；链状碳酸酯还可为上述非对称链状碳酸酯和对称链状碳酸酯的混合物。
具体地，羧酸酯可选自新戊酸甲酯、新戊酸乙酯、新戊酸丙酯、新戊酸丁酯、丁酸甲酯、丁酸乙酯、丁酸丙酯、丁酸丁酯、丙酸甲酯、丙酸乙酯、丙酸丙酯、丙酸丁酯、乙酸甲酯、乙酸乙酯、乙酸丙酯、乙酸丁酯中的一种或几种。
作为本申请实施例的电解液中使用的锂盐可选自LiPF 6、LiPO 2F 2、Li 2PO 3F、LiSO 3F、三氟((甲磺酰)氧基)硼酸锂、LiN(SO 2F) 2、LiN(SO 2CF 3) 2、LiN(SO 2C 2F 5) 2、双[草酸根-O,O’]硼酸锂、二氟双[草酸根-O,O’]磷酸锂、四氟[草酸根-O,O’]磷酸锂中的一种或几种。
在本申请的锂离子电池中，所述锂盐的浓度没有特别的限制，可根据实际需求进行合理调节。
在本申请的锂离子电池中，优选地，所述电解液25℃的电导率为4mS/cm～12mS/cm。
在本申请的锂离子电池中，所述电解液的制备方法不受限制，可按照常规电解液的方法制备。
在本申请的锂离子电池中，Li x1Co y1M1 1-y1O 2-aQ1 a可具体选自LiCo 0.9Zr 0.1O 2、LiCo 0.9Ti 0.1O 2、Li 1.05Co 0.8Mg 0.2O 2、Li 1.01Co 0.98Mg 0.01Ti 0.005Al 0.005O 2、Li 1.05Co 0.98Mg 0.005Zr 0.005Ti 0.01O 1.9F 0.1、Li 1.1Co 0.95Mg 0.01Zr 0.01Al 0.03O 2、Li 1.04Co 0.95Mg 0.02Zr 0.03O 1.95F 0.05、Li 1.06Co 0.96Mg 0.02Ti 0.02O 2、Li 1.08Co 0.97Mg 0.01Zr 0.01Al 0.01O 1.9S 0.1、Li 1.09Co 0.98Mg 0.01Ti 0.005Al 0.005O 2、Li 1.085Co 0.98Zr 0.01Ti 0.005Al 0.005O 1.9Cl 0.1、Li 1.03Co 0.96Mg 0.01Zr 0.01Ti 0.01Al 0.01O 2、Li 1.04Co 0.97Zr 0.01Al 0.02O 1.9F 0.1、Li 1.07Co 0.97Zr 0.01Ti 0.01Al 0.01O 1.9S 0.1、Li 1.02Co 0.96Mg 0.02Zr 0.015Ti 0.005O 1.9S 0.1、Li 1.03Co 0.98Ti 0.01Al 0.01O 1.9Cl 0.1、Li 1.05Co 0.97Mg 0.01Zr 0.01Al 0.01O 1.9Cl 0.1、Li 1.04Co 0.95Zr 0.02Ti 0.03O 1.9F 0.1、Li 1.09Co 0.97Mg 0.02Ti 0.01O 1.95F 0.05、Li 1.03Co 0.95Mg 0.03Ti 0.02O 1.9S 0.1、Li 1.04Co 0.97Zr 0.01Ti 0.01Al 0.01O 1.9S 0.1中的一种或几种。
在本申请的锂离子电池中，Li lNi mCo nM2 pM3 qO 2-bQ2 b可具体选自LiNi 1/3Co 1/3Mn 1/3O 2、LiNi 0.5Co 0.2Mn 0.3O 2、LiNi 0.6Co 0.2Mn 0.2O 2、LiNi 0.8Co 0.1Mn 0.1O 2、LiNi 0.8Co 0.1Al 0.1O 2、LiNi 0.85Co 0.15Al 0.05O 2、Li 1.01Ni 0.33Co 0.33Mn 0.31Mg 0.01Ti 0.005Al 0.005O 2、Li 1.05Ni 0.33Co 0.33Mn 0.31Mg 0.005Zr 0.005Ti 0.01O 1.9F 0.1、Li 1.1Ni 0.33Co 0.31Mn 0.31Mg 0.01Zr 0.01Al 0.03O 2、Li 1.04Ni 0.33Co 0.31Mn 0.31Mg 0.02Zr 0.03O 1.95F 0.05、Li 1.06Ni 0.33Co 0.32Mn 0.31Mg 0.02Ti 0.02O 2、Li 1.08Ni 0.33Co 0.32Mn 0.31Mg 0.01Zr 0.01Al 0.01O 1.9S 0.1、Li 1.09Ni 0.33Co 0.33Mn 0.32Mg 0.01Ti 0.005Al 0.005O 2、Li 1.085Ni 0.33Co 0.33Mn 0.32Zr 0.01Ti 0.005Al 0.005O 1.9Cl 0.1、Li 1.03Ni 0.33Co 0.32Mn 0.31Mg 0.01Zr 0.01Ti 0.01Al 0.01O 2、Li 1.04Ni 0.33Co 0.32Mn 0.32Zr 0.01Al 0.02O 1.9F 0.1、Li 1.07Ni 0.33Co 0.32Mn 0.32Zr 0.01Ti 0.01Al 0.01O 1.9S 0.1、Li 1.02Ni 0.33Co 0.32Mn 0.31Mg 0.02Zr 0.015Ti 0.005O 1.9S 0.1、Li 1.03Ni 0.33Co 0.33Mn 0.32Ti 0.01Al 0.01O 1.9Cl 0.1、Li 1.05Ni 0.33Co 0.32Mn 0.32Mg 0.01Zr 0.01Al 0.01O 1.9Cl 0.1、Li 1.04Ni 0.33Co 0.31Mn 0.31Zr 0.02Ti 0.03O 1.9F 0.1、Li 1.09Ni 0.33Co 0.32Mn 0.32Mg 0.02Ti 0.01O 1.95F 0.05、Li 1.03Ni 0.33Co 0.31Mn 0.31Mg 0.03Ti 0.02O 1.9S 0.1、Li 1.04Ni 0.33Co 0.31Mn 0.31Zr 0.01Ti 0.01Al 0.01O 1.9S 0.1、Li 1.01Ni 0.50Co 0.20Mn 0.28Mg 0.01Ti 0.005Al 0.005O 2、Li 1.05Ni 0.50Co 0.20Mn 0.28Mg 0.005Zr 0.005Ti 0.01O 1.9F 0.1、Li 1.1Ni 0.50Co 0.20Mn 0.25Mg 0.01Zr 0.01Al 0.03O 2、 Li 1.04Ni 0.50Co 0.20Mn 0.25Mg 0.02Zr 0.03O 1.95F 0.05、Li 1.06Ni 0.50Co 0.20Mn 0.26Mg 0.02Ti 0.02O 2、Li 1.08Ni 0.50Co 0.20Mn 0.27Mg 0.01Zr 0.01Al 0.01O 1.9S 0.1、Li 1.09Ni 0.60Co 0.20Mn 0.18Mg 0.01Ti 0.005Al 0.005O 2、Li 1.085Ni 0.60Co 0.20Mn 0.18Zr 0.01Ti 0.005Al 0.005O 1.9Cl 0.1、Li 1.03Ni 0.60Co 0.20Mn 0.16Mg 0.01Zr 0.01Ti 0.01Al 0.01O 2、Li 1.04Ni 0.60Co 0.20Mn 0.17Zr 0.01Al 0.02O 1.9F 0.1、Li 1.07Ni 0.60Co 0.20Mn 0.17Zr 0.01Ti 0.01Al 0.01O 1.9S 0.1、Li 1.02Ni 0.60Co 0.20Mn 0.16Mg 0.02Zr 0.015Ti 0.005O 1.9S 0.1、Li 1.03Ni 0.60Co 0.20Mn 0.18Ti 0.01Al 0.01O 1.9Cl 0.1、Li 1.05Ni 0.60Co 0.20Mn 0.17Mg 0.01Zr 0.01Al 0.01O 1.9Cl 0.1、Li 1.04Ni 0.60Co 0.20Mn 0.15Zr 0.02Ti 0.03O 1.9F 0.1、Li 1.09Ni 0.60Co 0.20Mn 0.17Mg 0.02Ti 0.01O 1.95F 0.05、Li 1.03Ni 0.60Co 0.20Mn 0.15Mg 0.03Ti 0.02O 1.9S 0.1、Li 1.04Ni 0.60Co 0.20Mn 0.17Zr 0.01Ti 0.01Al 0.01O 1.9S 0.1、Li 1.01Ni 0.60Co 0.20Mn 0.18Mg 0.01Ti 0.005Al 0.005O 2、Li 1.05Ni 0.60Co 0.20Mn 0.18Mg 0.005Zr 0.005Ti 0.01O 1.9F 0.1、Li 1.10Ni 0.60Co 0.20Mn 0.15Mg 0.01Zr 0.01Al 0.03O 2、Li 1.04Ni 0.60Co 0.20Mn 0.15Mg 0.02Zr 0.03O 1.95F 0.05、Li 1.06Ni 0.60Co 0.20Mn 0.15Mg 0.02Ti 0.02O 2、Li 1.08Ni 0.60Co 0.20Mn 0.17Mg 0.01Zr 0.01Al 0.01O 1.9S 0.1、Li 1.09Ni 0.60Co 0.20Mn 0.18Mg 0.01Ti 0.005Al 0.005O 2、Li 1.085Ni 0.60Co 0.20Mn 0.18Zr 0.01Ti 0.005Al 0.005O 1.9Cl 0.1、Li 1.03Ni 0.60Co 0.2Mn 0.16Mg 0.01Zr 0.01Ti 0.01Al 0.01O 2、Li 1.04Ni 0.60Co 0.2Mn 0.17Zr 0.01Al 0.02O 1.9F 0.1、Li 1.07Ni 0.60Co 0.2Mn 0.17Zr 0.01Ti 0.01Al 0.01O 1.9S 0.1、Li 1.02Ni 0.60Co 0.20Mn 0.16Mg 0.02Zr 0.015Ti 0.005O 1.9S 0.1、Li 1.03Ni 0.60Co 0.20Mn 0.18Ti 0.01Al 0.01O 1.9Cl 0.1、Li 1.05Ni 0.60Co 0.20Mn 0.17Mg 0.01Zr 0.01Al 0.01O 1.9Cl 0.1、Li 1.04Ni 0.60Co 0.20Mn 0.15Zr 0.02Ti 0.03O 1.9F 0.1、Li 1.09Ni 0.60Co 0.20Mn 0.17Mg 0.02Ti 0.01O 1.95F 0.05、Li 1.03Ni 0.60Co 0.20Mn 0.15Mg 0.03Ti 0.02O 1.9S 0.1、Li 1.04Ni 0.60Co 0.20Mn 0.17Zr 0.01Ti 0.01Al 0.01O 1.9S 0.1、Li 1.09Ni 0.80Co 0.10Mn 0.08Mg 0.01Ti 0.005Al 0.005O 2、Li 1.085Ni 0.80Co 0.10Mn 0.08Zr 0.01Ti 0.005Al 0.005O 1.9Cl 0.1、Li 1.03Ni 0.80Co 0.10Mn 0.06Mg 0.01Zr 0.01Ti 0.01Al 0.01O 2、Li 1.04Ni 0.80Co 0.10Mn 0.07Zr 0.01Al 0.02O 1.9F 0.1、Li 1.07Ni 0.80Co 0.10Mn 0.07Zr 0.01Ti 0.01Al 0.01O 1.9S 0.1、Li 1.02Ni 0.80Co 0.10Mn 0.06Mg 0.02Zr 0.015Ti 0.005O 1.9S 0.1、Li 1.03Ni 0.80Co 0.10Mn 0.08Ti 0.01Al 0.01O 1.9Cl 0.1、Li 1.05Ni 0.80Co 0.10Mn 0.07Mg 0.01Zr 0.01Al 0.01O 1.9Cl 0.1、Li 1.04Ni 0.80Co 0.10Mn 0.05Zr 0.02Ti 0.03O 1.9F 0.1、Li 1.09Ni 0.80Co 0.10Mn 0.07Mg 0.02Ti 0.01O 1.95F 0.05、Li 1.03Ni 0.80Co 0.10Mn 0.05Mg 0.03Ti 0.02O 1.9S 0.1、Li 1.04Ni 0.80Co 0.10Mn 0.07Zr 0.01Ti 0.01Al 0.01O 1.9S 0.1、Li 1.01Ni 0.80Co 0.10Mn 0.08Mg 0.01Ti 0.005Al 0.005O 2、Li 1.05Ni 0.80Co 0.10Mn 0.08Mg 0.005Zr 0.005Ti 0.01O 1.9F 0.1、Li 1.1Ni 0.80Co 0.10Mn 0.05Mg 0.01Zr 0.01Al 0.03O 2、Li 1.04Ni 0.80Co 0.10Mn 0.05Mg 0.02Zr 0.03O 1.95F 0.05、Li 1.06Ni 0.80Co 0.10Mn 0.06Mg 0.02Ti 0.02O 2、Li 1.08Ni 0.80Co 0.10Mn 0.07Mg 0.01Zr 0.01Al 0.01O 1.9S 0.1、Li 1.09Ni 0.80Co 0.10Mn 0.08Mg 0.01Ti 0.005Al 0.005O 2、Li 1.085Ni 0.80Co 0.10Mn 0.08Zr 0.01Ti 0.005Al 0.005O 1.9Cl 0.1、Li 1.03Ni 0.80Co 0.10Mn 0.06Mg 0.01Zr 0.01Ti 0.01Al 0.01O 2、Li 1.04Ni 0.80Co 0.10Mn 0.07Zr 0.01Al 0.02O 1.9F 0.1、Li 1.07Ni 0.80Co 0.10Mn 0.07Zr 0.01Ti 0.01Al 0.01O 1.9S 0.1、Li 1.02Ni 0.80Co 0.10Mn 0.06Mg 0.02Zr 0.015Ti 0.005O 1.9S 0.1、Li 1.03Ni 0.80Co 0.10Mn 0.08Ti 0.01Al 0.01O 1.9Cl 0.1、Li 1.05Ni 0.80Co 0.10Mn 0.07Mg 0.01Zr 0.01Al 0.01O 1.9Cl 0.1、Li 1.04Ni 0.80Co 0.10Mn 0.05Zr 0.02Ti 0.03O 1.9F 0.1、Li 1.09Ni 0.80Co 0.10Mn 0.07Mg 0.02Ti 0.01O 1.95F 0.05、Li 1.03Ni 0.80Co 0.10Mn 0.05Mg 0.03Ti 0.02O 1.9S 0.1、Li 1.04Ni 0.80Co 0.10Mn 0.07Zr 0.01Ti 0.01Al 0.01O 1.9S 0.1中的一种或几种。
在本申请的锂离子电池中，所述负极极片中的负极活性材料可为软碳、硬碳、人造石墨、天然石墨、硅、硅氧化合物、硅碳复合物、钛酸锂、能与锂形成合金的金属等。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。
在本申请的锂离子电池中，所述正极极片还包括粘结剂和导电剂。将包含有正极活性材料、粘结剂和导电剂的正极浆料涂覆在正极集流体上，待正极浆料干燥后获得正极极片。导电剂以及粘结剂的种类和含量不受具体的限制，可根据实际需求进行选择。正极集流体的种类也不受具体的限制，可根据实际需求进行选择，优选可为铝箔。
同样的，所述负极极片还包括粘结剂和导电剂。将包含有负极活性材料、粘结剂和导电剂的负极浆料涂覆在负极集流体上，待负极浆料干燥后获得负极极片。导电剂以及粘结剂的种类和含量不受具体的限制，可根据实际需求进行选择。负极集流体的种类也不受具体的限制，可根据实际需求进行选择，优选可为铜箔。
在本申请的锂离子电池中，所述隔离膜设置在正极极片和负极极片之间，起到隔离作用。所述隔离膜的种类并不受到具体的限制，可以是现有锂离子电池中使用的任何隔离膜材料，例如聚乙烯、聚丙烯、聚偏氟乙烯以及它们的多层复合膜，但不仅限于这些。
在本申请的锂离子电池中，所述锂离子电池的充电截止电压不小于4.2V，即锂离子电池可在不小于4.2V的高电压状态下使用。优选地，所述锂离子电池的充电截止电压不小于4.35V。
本申请的锂离子电池既可为硬壳锂离子电池，也可为软包装锂离子电池。硬壳锂离子电池优选使用金属材质的硬壳。软包装锂离子电池优选使用包装袋作为电池壳体，所述包装袋通常包括容纳部和密封部，其中容纳部用于容纳电极组件和电解液，而密封部用于将电极组件和电解液密封。本申请对于软包装锂离子电池性能的改善更明显，原因在于软包装锂离子电池在使用时很容易发生鼓胀，而本申请可以极大降低电池产气量，避免软包装锂离子电池鼓胀造成寿命缩短。
在本申请的锂离子电池中，在式I-1、式I-2、式I-3所示的化合物中：
C 1～C 12烷基可为链状烷基，也可为环状烷基，链状烷基又可为直链烷基或支链烷基，位于环状烷基的环上的氢还可进一步被烷基取代。C 1～C 12烷基中碳原子数优选的下限值为1、2、3、4、5，优选的上限值为3、4、5、6、8、10、12。优选地，选择C 1～C 10烷基；进一步优选地，选择C 1～C 6链状烷基、C 3～C 8环状烷基；更进一步优选地，选择C 1～C 4链状烷基、C 5～C 7环状烷基。作为C 1～C 12烷基的实例，具体可以举出：甲基、乙基、正丙基、异丙基、正丁基、异丁基、仲丁基、叔丁基、正戊基、异戊基、新戊基、己基、2-甲基-戊基、3-甲基-戊基、1,1,2-三甲基-丙基、3,3-二甲基-丁基、庚基、2-庚基、3-庚基、2-甲基己基、3-甲基己基、异庚基、辛基、壬基、癸基。
当前述所提到的C 1～C 12烷基中含有氧原子时，可为C 1～C 12烷氧基。优选地，选择C 1～C 10烷氧基；进一步优选地，选择C 1～C 6烷氧基；更进一步优选地，选择C 1～C 4烷氧基。作为C 1～C 12烷氧基的实例，具体可以举出：甲氧基、乙氧基、正丙氧基、异丙氧基、正丁氧基、仲丁氧基、叔丁氧基、正戊氧基、异戊氧基、环戊氧基、环己氧基。
C 2～C 12烯基可为环状烯基，也可为链状烯基，链状烯基又可为直链烯基或支链烯基。另外，C 2～C 12烯基中双键的个数优选为1个。C 2～C 12烯基中碳原子数优选的下限值为2、3、4、5，优选的上限值为3、4、5、6、8、10、12。优选地，选择C 2～C 10烯基；进一步优选地，选择C 2～C 6烯基；更进一步优选地，选择C 2～C 5烯基。作为C 2～C 12烯基的 实例，具体可以举出：乙烯基、烯丙基、异丙烯基、戊烯基、环己烯基、环庚烯基、环辛烯基。
C 2～C 12炔基可为环状炔基，也可为链状炔基，链状炔基又可为直链炔基或支链炔基。另外，C 2～C 12炔基中三键的个数优选为1个。C 2～C 12炔基中碳原子数优选的下限值为2、3、4、5，优选的上限值为3、4、5、6、8、10、12。优选地，选择C 2～C 10炔基；进一步优选地，选择C 2～C 6炔基；更进一步优选地，选择C 2～C 5炔基。作为C 2～C 12炔基的实例，具体可以举出：乙炔基、炔丙基、异丙炔基、戊炔基、环己炔基、环庚炔基、环辛炔基。
C 1～C 12胺基可选自
Figure PCTCN2019125319-appb-000003
其中R’、R”选自C 1～C 12烷基。
C 6～C 26芳基可为苯基、苯烷基、联苯基、稠环芳烃基(例如萘基、蒽基、菲基)，联苯基和稠环芳烃基还可进一步被烷基或烯基取代。优选地，选择C 6～C 16芳基；进一步优选地，选择C 6～C 14芳基；更进一步优选地，选择C 6～C 9芳基。作为C 6～C 26芳基的实例，具体可以举出：苯基、苄基、联苯基、对甲苯基、邻甲苯基、间甲苯基、萘基、蒽基、菲基。
C 2～C 12杂环基中杂原子可选自氧、氮、硫、磷、硼中的一种或几种，杂环可为脂杂环或芳杂环。优选地，选择C 2～C 10杂环基；进一步优选地，选择C 2～C 7杂环基；更进一步优选地，选择五元芳杂环、六元芳杂环以及苯并杂环。作为C 2～C 12杂环基的实例，具体可以举出：环氧乙烷基、环氧丙烷基、环硫乙烷基、氮杂环丙烷基、β-丙内酯基、呋喃基、噻吩基、吡咯基、噻唑基、咪唑基、吡啶基、吡嗪基、嘧啶基、哒嗪基、吲哚基、喹啉基。
作为取代基的卤素原子可选自氟原子、氯原子、溴原子中的一种或几种，优选为氟原子。
(1)具体地，式I-1所示的化合物为多腈基嘧啶类化合物。
在式I-1中：
优选地，R 1、R 2、R 3、R 4各自独立地选自氢原子、氟原子、氯原子、溴原子、取代或未取代的C 1～C 6直链或支链烷基、取代或未取代的C 5～C 9环状烷基、取代或未取代的C 1～C 6烷氧基、取代或未取代的C 1～C 6胺基、取代或未取代的C 2～C 6烯基、取代或未取代的C 2～C 6炔基、取代或未取代的C 6～C 12芳基、取代或未取代的C 2～C 12杂环基；进一步优选地，R 1、R 2、R 3、R 4各自独立地选自氢原子、氟原子、氯原子、溴原子、取代或未取代的C 1～C 3直链或支链烷基、取代或未取代的C 5～C 7环状烷基、取代或未取代的C 1～C 3烷氧基、取代或未取代的C 1～C 3胺基、取代或未取代的C 2～C 3烯基、取代或未取代的C 2～C 3炔基、取代或未取代的C 6～C 8芳基、取代或未取代的C 2～C 7杂环基。其中，取代基选自卤素原子中的一种或几种。
x优选地选自0～6的整数，进一步优选地选自0～4的整数，更进一步优选地选自0、1或2。
y优选地选自0～6的整数，进一步优选地选自0～4的整数，更进一步优选地选自0、1或2。
m优选地选自1或2。
n优选地选自1或2。
优选地，R 1、R 3为相同的基团；进一步优选地，R 1、R 3、R 4均为相同的基团。
优选地，R 1、R 3均为氢原子；进一步优选地，R 1、R 3、R 4均为氢原子。
优选地，R 1、R 2、R 3、R 4均为氢原子，或者R 1、R 3、R 4均为氢原子而R 2选自氟原子、氯原子、溴原子、取代或未取代的C 1～C 6直链或支链烷基、取代或未取代的C 1～C 6烷氧基。其中，取代基选自卤素原子中的一种或几种，优选地，取代基选自氟原子。
优选地，式I-1所示的化合物可具体选自以下化合物中的一种或几种，但本申请不限于此：
Figure PCTCN2019125319-appb-000004
(2)具体地，式I-2所示的化合物为多腈基哌嗪类化合物。
在式I-2中：
优选地，R 1、R 2、R 3、R 4各自独立地选自氢原子、氟原子、氯原子、溴原子、取代或未取代的C 1～C 6直链或支链烷基、取代或未取代的C 5～C 9环状烷基、取代或未取代的C 1～C 6烷氧基、取代或未取代的C 1～C 6胺基、取代或未取代的C 2～C 6烯基、取代或未取代的C 2～C 6炔基、取代或未取代的C 6～C 12芳基、取代或未取代的C 2～C 12杂环基；进一步优选地，R 1、R 2、R 3、R 4各自独立地选自氢原子、氟原子、氯原子、溴原子、取代 或未取代的C 1～C 3直链或支链烷基、取代或未取代的C 5～C 7环状烷基、取代或未取代的C 1～C 3烷氧基、取代或未取代的C 1～C 3胺基、取代或未取代的C 2～C 3烯基、取代或未取代的C 2～C 3炔基、取代或未取代的C 6～C 8芳基、取代或未取代的C 2～C 7杂环基。其中，取代基选自卤素原子中的一种或几种。
x优选地选自0～6的整数，进一步优选地选自0～4的整数，更进一步优选地选自0、1或2。
y优选地选自0～6的整数，进一步优选地选自0～4的整数，更进一步优选地选自0、1或2。
m优选地选自1或2。
n优选地选自1或2。
优选地，R 1、R 2、R 3、R 4中至少有两个为相同的基团，进一步优选地，R 1、R 2、R 3、R 4中至少有三个为相同的基团。
优选地，R 1、R 2、R 3、R 4中至少有两个为氢原子；进一步优选地，R 1、R 2、R 3、R 4中至少有三个为氢原子。
优选地，R 1、R 2、R 3、R 4均为氢原子，或者R 1、R 2、R 3、R 4中有三个为氢原子且剩余一个选自氟原子、氯原子、溴原子、取代或未取代的C 1～C 6直链或支链烷基、取代或未取代的C 1～C 6烷氧基。其中，取代基选自卤素原子中的一种或几种，优选地，取代基选自氟原子。
优选地，式I-2所示的化合物可具体选自以下化合物中的一种或几种，但本申请不限于此：
Figure PCTCN2019125319-appb-000005
(3)具体地，式I-3所示的化合物为多腈基均三嗪类化合物。
在式I-3中：
优选地，R 1、R 2、R 3各自独立地选自氢原子、氟原子、氯原子、溴原子、取代或未 取代的C 1～C 6直链或支链烷基、取代或未取代的C 5～C 9环状烷基、取代或未取代的C 1～C 6烷氧基、取代或未取代的C 1～C 6胺基、取代或未取代的C 2～C 6烯基、取代或未取代的C 2～C 6炔基、取代或未取代的C 6～C 12芳基、取代或未取代的C 2～C 12杂环基；进一步优选地，R 1、R 2、R 3各自独立地选自氢原子、氟原子、氯原子、溴原子、取代或未取代的C 1～C 3直链或支链烷基、取代或未取代的C 5～C 7环状烷基、取代或未取代的C 1～C 3烷氧基、取代或未取代的C 1～C 3胺基、取代或未取代的C 2～C 3烯基、取代或未取代的C 2～C 3炔基、取代或未取代的C 6～C 8芳基、取代或未取代的C 2～C 7杂环基。其中，取代基选自卤素原子中的一种或几种。
x优选地选自0～6的整数，进一步优选地选自0～4的整数，更进一步优选地选自0、1或2。
y优选地选自0～6的整数，进一步优选地选自0～4的整数，更进一步优选地选自0、1或2。
z优选地选自0～6的整数，进一步优选地选自0～4的整数，更进一步优选地选自0、1或2。
m优选地选自1或2。
n优选地选自1或2。
k优选地选自1或2。
优选地，R 1、R 2、R 3中至少有两个为相同的基团。
优选地，R 1、R 2、R 3中至少有两个为氢原子。
优选地，R 1、R 2、R 3均为氢原子，或者R 1、R 2、R 3中有两个为氢原子且剩余一个选自氟原子、氯原子、溴原子、取代或未取代的C 1～C 6直链或支链烷基、取代或未取代的C 1～C 6烷氧基。其中，取代基选自卤素原子中的一种或几种，优选地，取代基选自氟原子。
优选地，式I-3所示的化合物可具体选自以下化合物中的一种或几种，但本申请不限于此：
Figure PCTCN2019125319-appb-000006
Figure PCTCN2019125319-appb-000007
在本申请的锂离子电池中，所述添加剂A可通过下述方法合成。
(1)式I-1所示的化合物的制备
反应方程式为：
Figure PCTCN2019125319-appb-000008
具体制备工艺为：
在20min～60min内向原料P-1中滴加浓度为30％～40％的P-2水溶液并快速搅拌，滴加完毕后快速搅拌15h～30h，于70℃～90℃油浴回流搅拌3h～5h，得到无色发烟粘稠状液体中间产物I-1-1；继续加入K 2CO 3、KI、无水乙腈，快速搅拌成固液混合相，于40℃～60℃下快速加入原料P-3，继续搅拌10h～20h后冷却至室温，分离提纯得到式I-1所示的化合物。
(2)式I-2所示的化合物的制备
反应方程式为：
Figure PCTCN2019125319-appb-000009
具体制备工艺为：
将无水碳酸钠、原料P-4与原料P-3在无水乙醇中混合，反应搅拌2h～5h；热乙醇反复多次冲洗得到粗产物，重结晶得到式I-2所示的化合物。
(3)式I-3所示的化合物的制备
反应方程式为：
Figure PCTCN2019125319-appb-000010
具体制备工艺为：
将无水碳酸钠、原料P-5与原料P-3在无水乙醇中混合，反应搅拌2h～5h；热乙醇反复多次冲洗得到粗产物，重结晶得到式I-3所示的化合物。
在一些实施例中，锂离子电池可以包括外包装，用于封装正极极片、负极极片和电解质。作为一个示例，正极极片、负极极片和隔离膜可经叠片或卷绕形成叠片结构电极组件或卷绕结构电极组件，电极组件封装在外包装内；电解质可采用电解液，电解液浸润于电极组件中。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，锂离子电池的外包装可以是软包，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。锂离子电池的外包装也可以是硬壳，例如铝壳等。
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。如图4是作为一个示例的方形结构的锂离子电池5。
在一些实施例中，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多个，具体数量可根据电池模块的应用和容量来调节。
图5是作为一个示例的电池模块4。参照图5，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壳体，多个锂离子电池5容纳于该容纳空间。
在一些实施例中，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根据电池包的应用和容量进行调节。
图6和图7是作为一个示例的电池包1。参照图6和图7，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。
接下来说明本申请第二方面的装置。
在本申请的第二方面提供一种装置，所述装置包括本申请第一方面的锂离子电池，所述锂离子电池为所述装置提供电源。所述装置可以但不限于是移动设备(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。
所述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8是作为一个示例的装置。该装置为纯电动车、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。
为了使本申请的目的、技术方案和有益技术效果更加清晰，以下结合实施例，对本申请进行进一步详细说明。应当理解的是，本说明书中描述的实施例仅仅是为了解释本申请，并非为了限定本申请，实施例的配方、比例等可因地制宜做出选择而对结果并无实质性影响。
在实施例、对比例中，所使用到的试剂、材料以及仪器如没有特殊的说明，均可商购获得。其中添加剂A1、A2、A3的具体合成过程如下，其它种类的添加剂A均可根据类似的方法合成。
添加剂A1的合成：
Figure PCTCN2019125319-appb-000011
在0.5h内向1,3-丙二胺中滴加37％甲醛水溶液并快速搅拌，滴加完毕后继续快速搅拌20h，之后于80℃油浴回流搅拌4h，得到无色发烟粘稠状液体中间产物六氢嘧啶；继续加入K 2CO 3、KI、无水乙腈，快速搅拌成固液混合相，之后于60℃下0.5h内加入β-氯 丙腈，继续搅拌17h后冷却至室温，分离提纯得到A1。核磁共振碳谱如图1所示。
添加剂A2的合成：
Figure PCTCN2019125319-appb-000012
将无水碳酸钠、哌嗪与β-氯丙腈在无水乙醇中混合，反应搅拌4h；热乙醇反复多次冲洗得到粗产物，重结晶得到A2。核磁共振碳谱如图2所示。
添加剂A3的合成：
Figure PCTCN2019125319-appb-000013
将无水碳酸钠、1,3,5-均三嗪与氯乙腈在无水乙醇中混合，反应搅拌4h；热乙醇反复多次冲洗得到粗产物，重结晶得到A3。核磁共振碳谱如图3所示。
在实施例1-30和对比例1-2中，锂离子电池均按照下述方法制备。
(1)电解液的制备
采用碳酸乙烯酯(简称为EC)、碳酸甲乙酯(简称为EMC)和碳酸二乙酯(简称为DEC)的混合液为有机溶剂，其中，EC、EMC和DEC的质量比为1:1:1。锂盐为LiPF 6，LiPF 6的含量为电解液总质量的12.5％。按照如表1所示的电解液组成加入各添加剂，其中各添加剂组分的含量均为相对于电解液的总质量计算得到。
其中，在实施例和对比例中所使用的添加剂A分别简写如下：
Figure PCTCN2019125319-appb-000014
Figure PCTCN2019125319-appb-000015
(2)正极极片的制备
将表2所示的正极活性材料、粘结剂PVDF、导电剂乙炔黑按照质量比98:1:1混合，加入N-甲基吡咯烷酮，在真空搅拌机作用下搅拌至稳定均一，获得正极浆料；将正极浆料均匀涂覆于铝箔上，将铝箔在室温晾干后转移至120℃的鼓风烘箱中干燥1h，然后经过冷压、分切得到正极极片。
(3)负极极片的制备
将负极活性材料石墨、导电剂乙炔黑、增稠剂羧甲基纤维素钠、粘结剂丁苯橡胶按照 质量比97:1:1:1混合，加入去离子水，在真空搅拌机作用下搅拌至稳定均一，获得负极浆料；将负极浆料均匀涂覆于铜箔上，将铜箔在室温晾干后转移至120℃的鼓风烘箱中干燥1h，然后经过冷压、分切得到负极极片。
(4)锂离子电池的制备
将正极极片、负极极片以及PP/PE/PP隔离膜进行卷绕得到电极组件，将电极组件放入包装袋铝塑膜中，之后注入电解液，再依次经过封口、静置、热冷压、化成、排气、测试容量等工序，获得锂离子电池。
表1 实施例1-30和对比例1-2的电解液参数
Figure PCTCN2019125319-appb-000016
Figure PCTCN2019125319-appb-000017
表2 实施例1-30和对比例1-2的正极活性材料参数
Figure PCTCN2019125319-appb-000018
Figure PCTCN2019125319-appb-000019
下面说明锂离子电池的测试过程。
(1)锂离子电池在常温、高电压情况下的循环性能测试
在25℃下，将锂离子电池先以1C恒流充电至电压为4.35V，进一步以4.35V恒压充电至电流为0.05C，然后以1C恒流放电至电压为3.0V，此为一个充放电循环过程，此次的放电容量为首次循环的放电容量。将锂离子电池按照上述方法进行200次循环充电/放电测试，检测得到第200次循环的放电容量。
锂离子电池循环200次后的容量保持率(％)＝(锂离子电池循环200次的放电容量/锂离子电池首次循环的放电容量)×100％。
(2)锂离子电池在高温、高电压情况下的循环性能测试
在45℃下，将锂离子电池先以1C恒流充电至电压为4.35V，进一步以4.35V恒压充电至电流为0.05C，然后以1C恒流放电至电压为3.0V，此为一个充放电循环过程，此次的放电容量为首次循环的放电容量。将锂离子电池按照上述方法进行200次循环充电/放电测试，检测得到第200次循环的放电容量。
锂离子电池循环200次后的容量保持率(％)＝(锂离子电池循环200次的放电容量/锂离子电池首次循环的放电容量)×100％。
(3)锂离子电池在高温情况下的存储性能测试
在25℃下，将锂离子电池以0.5C恒流充电至电压为4.35V，然后以4.35V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h 0；之后将锂离子电池放入85℃的恒温箱，存储24h后取出，测试此时锂离子电池的厚度并记为h 1。
锂离子电池85℃存储24h后的厚度膨胀率(％)＝[(h 1-h 0)/h 0]×100％。
表3 实施例1-30和对比例1-2的性能测试结果
Figure PCTCN2019125319-appb-000020
Figure PCTCN2019125319-appb-000021
从实施例1-30和对比例1-2的对比中可以看出：本申请的锂离子电池在高温高电压情况下具有优异的循环性能和存储性能。
与对比例1相比，本申请的实施例使用钴酸锂类材料Li x1Co y1M1 1-y1O 2-aQ1 a和三元材料Li lNi m1Co n1M2 pM3 qO 2-bQ2 b的混合物作为正极活性材料、使用添加剂A作为电解液添加剂。在钴酸锂类材料中混合一定量的三元材料，三元材料可以均匀分布在钴酸锂类材料颗粒与颗粒之间的间隙中，因此能将钴酸锂类材料有效分离开来，同时混合后还能提高正极极片的压实密度，提高锂离子电池的能量密度；此外，三元材料较高的热稳定性不仅可以保证自身的结构稳定性，而且可以有效防止局部钴酸锂类材料分解带来的热量传递，提高整个正极极片的热稳定性。添加剂A为氧化电位较低的多腈基六元氮杂环化合物，其在电池化成时便能在正极活性材料表面形成稳定的络合物层，有效钝化正极活性材料表面，降低正极活性材料表面活性，隔绝电解液与正极活性材料表面的直接接触，使得表面副反应大大减少，副反应中消耗的锂离子也就相应减少，也就是可逆锂离子的消耗速度大 大减慢，最终显现出来的实际效果是锂离子电池循环容量保持率大幅提升；部分表面副反应可产生气体，表面副反应的减少还意味着电池产气量减少，最终显现出来的实际效果是高温下锂离子电池厚度膨胀明显减轻。
与对比例2采用线性的腈基化合物相比，本申请的多腈基六元氮杂环化合物具有特殊的六元氮杂环结构，腈基与腈基的间距更接近正极活性材料表面过渡金属与过渡金属的间距，可以最大限度地发挥腈基的络合作用，且使更多数量的腈基发挥络合作用。因此本申请的多腈基六元氮杂环化合物对正极活性材料表面过渡金属的覆盖作用更强，对正极活性材料表面的钝化效果更好，对锂离子电池循环性能和存储性能的改善效果也更加出众。
从实施例1-7还可以看出，随着添加剂A加入量的增加(0.1％增至10％)，在充电截止电压固定为4.35V的情况下，锂离子电池在25℃和45℃时的循环容量保持率达到最佳后又出现了下降的趋势，85℃存储24h厚度膨胀率一直减小。这是由于当添加剂A的加入量较多时，首先添加剂A吸附在正极活性材料表面形成的络合物层容易更厚和致密，影响锂离子的扩散迁移，正极阻抗大幅增高；其次添加剂A在形成络合物层的同时会消耗锂离子，导致可用于循环的锂离子减少；最后添加剂A加入量较高时会引起电解液整体黏度提升、离子电导率下降，最终锂离子电池在25℃和45℃时的循环容量保持率达到最佳后出现了下降的趋势。因此，添加剂A的加入量需要适量，优选为0.1％～10％，进一步优选为0.1％～6％，更进一步优选为0.1％～3.5％。
实施例25-27探索了添加剂A加入量在较优的情况下LiBF 4对锂离子电池性能的影响。与实施例3相比，实施例25-28在85℃存储24h的厚度膨胀率更小，这是由于LiBF 4中的B原子可稳定正极活性材料中的氧原子，起到抑制正极活性材料释氧的作用，因此锂离子电池表现出更好的存储性能。
实施例28-30探索了添加剂A加入量在较优的情况下VC、FEC、PS对锂离子电池性能的影响。这些添加剂有助于在正、负极表面形成含双键、氟原子、磺酸酯基团的表面膜，该表面膜的化学、电化学、机械、热稳定性好，能在顺畅导通锂离子的同时隔绝电解液与正、负极表面的直接接触，起到抑制正、负极表面的氧化、还原副反应的效果。因此加入后有助于进一步改善锂离子电池的循环性能和存储性能。
根据上述说明书的揭示和教导，本申请所属领域的技术人员还可以对上述实施方式进行适当的变更和修改。因此，本申请并不局限于上面揭示和描述的具体实施方式，对本申请的一些修改和变更也应当落入本申请的权利要求的保护范围内。此外，尽管本说明书中使用了一些特定的术语，但这些术语只是为了方便说明，并不对本申请构成任何限制。

Claims (11)

  1. 一种锂离子电池，包括电极组件以及电解液，所述电极组件包括正极极片、负极极片以及隔离膜；
    其特征在于，
    所述正极极片中的正极活性材料同时包含Li x1Co y1M1 1-y1O 2-aQ1 a以及Li lNi m1Co n1M2 pM3 qO 2-bQ2 b，
    所述Li x1Co y1M1 1-y1O 2-aQ1 a以及所述Li lNi m1Co n1M2 pM3 qO 2-bQ2 b的质量比为1:1～9:1；
    其中，0.5≤x1≤1.2，0.8≤y1<1.0，0≤a≤0.1，M1选自Al、Ti、Zr、Y、Mg中的至少一种元素，Q1选自F、Cl、S中的一种或几种；0.5≤l≤1.2，0.33≤m1≤0.85、0.1≤n1≤0.33、0.1≤p≤0.33、0≤q≤0.1且m1+n1+p+q＝1，0≤b≤0.1，M2选自Mn、Al中的一种或两种，M3选自Zr、Zn、Cu、Cr、Mg、Fe、V、Ti、Y、Nb中的一种或几种，Q2选自F、Cl、S中的一种或几种；
    所述电解液中含有添加剂A，所述添加剂A选自式I-1、式I-2、式I-3所示的化合物中的一种或几种；
    Figure PCTCN2019125319-appb-100001
    在所述的式I-1、式I-2、式I-3中：R 1、R 2、R 3、R 4各自独立地选自氢原子、卤素原子、取代或未取代的C 1～C 12烷基、取代或未取代的C 1～C 12烷氧基、取代或未取代的C 1～C 12胺基、取代或未取代的C 2～C 12烯基、取代或未取代的C 2～C 12炔基、取代或未取代的C 6～C 26芳基、取代或未取代的C 2～C 12杂环基，其中，取代基选自卤素原子、腈基、C 1～C 6烷基、C 2～C 6烯基、C 1～C 6烷氧基中的一种或几种；x、y、z各自独立地选自0～8的整数；m、n、k各自独立地选自0～2的整数。
  2. 根据权利要求1所述的锂离子电池，其特征在于，
    在所述的式I-1、式I-2、式I-3中：R 1、R 2、R 3和R 4各自独立地选自氢原子、卤素原子、取代或未取代的C 1～C 3直链或支链烷基、取代或未取代的C 5～C 7环状烷基、取代或未取代的C 1～C 3烷氧基、取代或未取代的C 1～C 3胺基、取代或未取代的C 2～C 3烯基、取代或未取代的C 2～C 3炔基、取代或未取代的C 6～C 8芳基、取代或未取代的C 2～C 7杂环基，其中，取代基选自卤素原子；
    x、y、z各自独立地选自0、1或2；
    m、n、k各自独立地选自1或2。
  3. 根据权利要求1所述的锂离子电池，其特征在于，
    在所述的式I-1中，R 1、R 3为相同的基团，优选地，R 1、R 3、R 4均为相同的基团；
    在所述的式I-2中，R 1、R 2、R 3、R 4中至少有两个为相同的基团，优选地，R 1、R 2、R 3、R 4中至少有三个为相同的基团；
    在所述的式I-3中，R 1、R 2、R 3中至少有两个为相同的基团。
  4. 根据权利要求3所述的锂离子电池，其特征在于，
    在所述的式I-1中，R 1、R 3均为氢原子；优选地，R 1、R 3、R 4均为氢原子；
    在所述的式I-2中，R 1、R 2、R 3、R 4中至少有两个为氢原子；优选地，R 1、R 2、R 3、R 4中至少有三个为氢原子；
    在所述的式I-3中，R 1、R 2、R 3中至少有两个为氢原子。
  5. 根据权利要求1所述的锂离子电池，其特征在于，所述添加剂A选自如下化合物中的一种或几种：
    Figure PCTCN2019125319-appb-100002
    Figure PCTCN2019125319-appb-100003
    Figure PCTCN2019125319-appb-100004
  6. 根据权利要求1所述的锂离子电池，其特征在于，基于所述电解液的总质量计，所述添加剂A的质量百分含量为0.1％～10％，优选为0.1％～6％，更优选为0.1％～3.5％。
  7. 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添加剂B，所述添加剂B为LiBF 4；优选地，基于所述电解液的总质量计，所述添加剂B的质量百分含量为0.1％～10％，优选为0.1％～5％。
  8. 根据权利要求1或7所述的锂离子电池，其特征在于，所述电解液中还含有添加剂C，所述添加剂C选自碳酸亚乙烯酯、氟代碳酸乙烯酯、1,3-丙磺酸内酯中的一种或几种；优选地，基于所述电解液的总质量计，所述添加剂C的质量百分含量为0.1％～10％，优选为0.1％～5％。
  9. 根据权利要求1所述的锂离子电池，其特征在于，所述锂离子电池为硬壳锂离子电池或软包装锂离子电池。
  10. 根据权利要求1所述的锂离子电池，其特征在于，所述锂离子电池的充电截止电压不小于4.2V，优选不小于4.35V。
  11. 一种装置，其特征在于，包括根据权利要求1～10中任一项所述的锂离子电池。
PCT/CN2019/125319 2018-12-14 2019-12-13 锂离子电池及装置 WO2020119802A1 (zh)

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