WO2020119809A1 - 电解液、电池及装置 - Google Patents

电解液、电池及装置 Download PDF

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WO2020119809A1
WO2020119809A1 PCT/CN2019/125330 CN2019125330W WO2020119809A1 WO 2020119809 A1 WO2020119809 A1 WO 2020119809A1 CN 2019125330 W CN2019125330 W CN 2019125330W WO 2020119809 A1 WO2020119809 A1 WO 2020119809A1
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substituted
unsubstituted
formula
electrolyte
additive
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PCT/CN2019/125330
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English (en)
French (fr)
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伊天成
胡春华
蒋耀
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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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H01M10/0567—Liquid materials characterised by the additives
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • 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 an electrolyte, 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.
  • Lithium ion batteries are currently widely used electrolyte systems using lithium hexafluorophosphate as a conductive lithium salt and cyclic carbonate and/or chain carbonate as a solvent.
  • lithium hexafluorophosphate as a conductive lithium salt
  • cyclic carbonate and/or chain carbonate as a solvent.
  • the purpose of this application is to provide an electrolyte, a battery and a device, the electrolyte can improve the cycle performance and storage performance of the battery, especially improve the cycle performance and high-voltage cycle performance of the battery Storage performance.
  • the present application provides an electrolyte solution containing an organic solvent and an electrolyte salt, and the electrolyte solution further includes additive A, additive B, and additive C, the additive A One or more selected from the compounds represented by Formula I-1, Formula I-2, and Formula I-3, and the additive B is selected from one of the compounds represented by Formula II-1, Formula II-2 One or more kinds, the additive C is selected from one or more of the compounds represented by formula III-1 and formula III-2.
  • R 5 is selected from substituted or unsubstituted C 1 to C 12 alkylene, substituted or unsubstituted C 2 to C 12 alkenylene, substituted or unsubstituted C 2 to C 12 alkynylene
  • R 6 , R 7 and R 8 are each independently selected from substituted or unsubstituted C 0 to C 12 alkylene, substituted or unsubstituted C 2 to C 12 alkenylene, substituted Or an unsubstituted C 2 -C 12 alkynylene group, wherein the substituent is selected from halogen atoms, nitrile groups, C 1 -C 6 alkyl groups, C 2 -C 6 alkenyl groups, C 1 -C 6 alkoxy groups One or more.
  • a, b, c and d are each independently selected from integers within 1 to 5
  • R 9 , R 10 , R 11 , R 12 , R 13 , R 14 and R 15 , R 16 and R 17 are each independently selected from a substituted or unsubstituted C 1 to C 10 alkylene group, a substituted or unsubstituted C 2 to C 10 alkenylene group, wherein the substituent is selected from a halogen atom and a nitrile One or more of a group, a C 1 -C 6 alkyl group, a C 2 -C 6 alkenyl group, and a C 1 -C 6 alkoxy group.
  • the present application provides a battery including the electrolyte described in the first aspect of the present application.
  • the present application provides an apparatus including the battery described in the second aspect of the present application.
  • the present application includes at least the following beneficial effects: the electrolyte of the present application contains a polynitrile six-membered nitrogen heterocyclic compound with a low oxidation potential, which can be formed on the surface of the positive electrode active material when the battery is formed
  • the stable complex layer effectively passivates the surface of the positive electrode active material, inhibits its oxidation of the electrolyte, and reduces battery gas production;
  • the electrolyte of the present application also contains aliphatic dinitriles or polynitriles with higher oxidation potential
  • the compound which can exist in the electrolyte for a long time and stably, repairs the complex layer that is damaged during cycling or high temperature storage at any time, reduces the dissolution of transition metal ions, and greatly reduces the damage of the SEI film deposited on the negative electrode after the transition metal dissolves.
  • the electrolyte of this application also contains dinitrile or polynitrile compounds with ether bonds.
  • the oxygen (-O-) in the ether group of this molecule will react with trace amounts of PF 5 and HF in the electrolyte to prevent
  • the corrosion of the surface of the positive electrode active material directly exposed to the electrolyte environment without forming a complex layer by PF 5 and HF makes the surface of the positive electrode active material more durable during cycling and storage; therefore, the electrolyte of the present application It can improve the cycle performance and storage performance of the battery, especially the cycle performance and storage performance of the battery under high temperature and high voltage.
  • the device of the present application includes the aforementioned battery, and therefore has at least the same advantages as the aforementioned 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 perspective view of an embodiment of a battery.
  • FIG. 5 is a perspective view of an embodiment of a battery module.
  • FIG. 6 is a perspective view 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 with a battery as a power source.
  • the electrolytic solution according to the first aspect of the present application contains an organic solvent and an electrolyte salt, and the electrolytic solution further contains additive A, additive B, and additive C.
  • 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 group, substituted or unsubstituted C 6 to C 26 aryl group, substituted or unsubstituted C 2 to C 12 heterocyclic group, wherein the substituent (here means substitution in “substituted or unsubstituted or unsubstituted
  • Additive A 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. It has a strong complexation with the transition metal in the positive electrode active material and is used in the electrolyte. After that, it can be adsorbed on the surface of the positive electrode active material during the formation of the battery to form a loose porous protective film and effectively passivate the surface of the positive electrode active material.
  • the porous protective film not only can isolate the surface of the cathode active material from direct contact with the electrolyte without affecting the normal transmission of ions, but also can reduce the surface activity of the cathode active material while inhibiting a large number of side reactions on the surface of the cathode active material, thereby achieving Reduce the side reaction products and reduce the role of gas production.
  • Additive A 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. It can maximize the complexation of the nitrile group and increase the number.
  • the nitrile group has a complexing effect, so compared with the conventional linear nitrile compound, the polynitrile six-membered nitrogen heterocyclic compound of the present application can have a better passivation effect.
  • the special six-membered nitrogen heterocyclic structure of Additive A 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 electrochemical performance of the entire battery system, such as reducing production. Gas, improve the cycle life under high temperature and high voltage, etc.
  • the mass percentage content of the additive A in the electrolyte is 0.1% to 10%. 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 ions.
  • the positive electrode impedance is greatly increased, and at the same time, the overall viscosity of the electrolyte is increased, and the ionic conductivity is reduced, which affects the performance of the battery.
  • the upper limit of the content range of the additive A can be selected from 10%, 9%, 8%, 7%, 6%, 5%, 4.5%, 4%, 3.5%, 3%, 2%, 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 in the electrolyte is 0.1% to 3.5%.
  • 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.
  • 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.
  • 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.
  • 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 B is selected from one or more of the compounds represented by Formula II-1 and Formula II-2.
  • R 5 is selected from substituted or unsubstituted C 1 to C 12 alkylene, substituted or unsubstituted C 2 to C 12 alkenylene, substituted or unsubstituted C 2 to C 12 alkynylene
  • R 6 , R 7 and R 8 are each independently selected from substituted or unsubstituted C 0 to C 12 alkylene, substituted or unsubstituted C 2 to C 12 alkenylene, substituted Or an unsubstituted C 2 -C 12 alkynylene group, wherein the substituent (in this case, a substitution occurs in “substituted or unsubstituted”) is selected from a halogen atom, a nitrile group, a C 1 -C 6 alkyl group, and C 2 One or more of -C 6
  • Additive B is an aliphatic dinitrile or polynitrile compound.
  • the aliphatic skeleton has strong oxidation resistance and can exist stably for a long time after being added to the electrolyte.
  • the nitrogen atom in the molecule of Additive B contains a lone pair of electrons and has a strong complexation with the transition metal in the positive electrode active material. It can repair the complex layer (formed by Additive A) that is damaged during cycling or high-temperature storage at any time ), reducing the dissolution of transition metal ions, greatly reducing the damage of the SEI film deposited on the negative electrode after the transition metal dissolution. Therefore, when the additive B is applied to the electrolyte, the battery can have better high-temperature and high-voltage cycle performance and storage performance.
  • the mass percentage content of the additive B in the electrolyte is 0.1% to 10%. If the content of the additive B is too low, its repairing effect on the complex layer formed by the additive A is not obvious; if the content of the additive B is too high, the complex layer formed on the surface of the positive electrode active material is too thick and dense. The negative electrode impedance is greatly increased, which affects the performance of the battery.
  • the upper limit of the content range of the additive B can be selected from 10%, 9%, 8%, 7%, 6%, 5%, 4.5%, 4%, 3.5%, 3%, 2%, 1%, 0.8%
  • the lower limit of the content range of the additive B can be selected from 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%.
  • the mass percentage content of the additive B in the electrolyte is 0.1% to 5%.
  • the C 0 to C 12 alkylene group may be a linear alkylene group or a branched chain alkylene group.
  • the preferred lower limit of the number of carbon atoms in the C 0 to C 12 alkylene group is 1, 2, 3, 4 , 5, the preferred upper limit is 3, 4, 5, 6, 7, 8, 9, 10, 11, 12.
  • C 0 to C 10 alkylene is selected; further preferably, C 1 to C 6 alkylene is selected; still more preferably, C 2 to C 4 alkylene is selected.
  • specific examples of C 0 to C 12 alkylene groups specific examples include methylene, ethylene, propylene, isopropylene, butylene, isobutylene, sec-butylene, and pentylene. , Akilidene.
  • the C 2 to C 12 alkenylene group may be a linear alkenylene group or a branched alkenylene group, and the number of double bonds in the C 2 to C 12 alkenylene group is preferably one.
  • the preferable lower limit of the number of carbon atoms in the C 2 to C 12 alkenylene group is 2, 3, 4, and 5, and the preferable upper limit is 4, 5, 6, 7, 8, 9, 10, 11, 12, and 12 .
  • C 2 -C 10 alkenylene is selected; further preferably, C 2 -C 6 alkenylene is selected; still more preferably, C 2 -C 4 alkenylene is selected.
  • specific examples include vinylidene, allylidene, isopropenylene, allylene, and pentenylene.
  • the C 2 to C 12 alkynylene group may be a linear alkynylene group or a branched alkynylene 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 C 2 to C 12 alkynylene is 2, 3, 4, and 5, and the preferred upper limit is 4, 5, 6, 7, 8, 9, 10, 11, 12, and 12 .
  • C 2 to C 10 alkynylene is selected; further preferably, C 2 to C 6 alkynylene is selected; still more preferably, C 2 to C 4 alkynylene is selected.
  • specific examples include ethynylene, propargylene, isopropynylene, and pentynylene groups.
  • 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 II-1 is an aliphatic dinitrile compound.
  • R 5 is selected from substituted or unsubstituted C 1 -C 10 alkylene, substituted or unsubstituted C 2 -C 10 alkenylene, substituted or unsubstituted C 2 -C 10 alkynylene; wherein The substituent is selected from halogen atoms, preferably fluorine atoms. More preferably, R 5 is selected from C 1 to C 6 alkylene, C 2 to C 6 alkenylene, and C 2 to C 6 alkynylene. Even more preferably, R 5 is selected from C 2 to C 4 alkylene, C 2 to C 4 alkenylene, C 2 to C 4 alkynylene.
  • the compound represented by Formula II-1 can be selected from succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, suberonitrile, azelanitrile, sebaconitrile, undecanedinitrile, twelve Alkane dinitrile, tetramethyl succinonitrile, methylglutaronitrile, butadiene dinitrile, 2-pentene dinitrile, hex-2-ene dinitrile, hex-3-ene dinitrile, oct-4-ene dinitrile One or more of nitrile and oct-4-yne dinitrile.
  • the compound represented by Formula II-1 may be selected from one of succinonitrile, glutaronitrile, adiponitrile, butene dinitrile, 2-pentene dinitrile, and hex-3-ene dinitrile Or several, the specific structure is as follows:
  • the compound represented by Formula II-2 is an aliphatic polynitrile compound.
  • R 6 , R 7 and R 8 are each independently selected from substituted or unsubstituted C 0 to C 10 alkylene, substituted or unsubstituted C 2 to C 10 alkenylene, substituted or unsubstituted C 2 to C 10 alkynylene; wherein the substituent is selected from halogen atoms, preferably fluorine atoms. More preferably, R 6 , R 7 , and R 8 are each independently selected from C 0 to C 6 alkylene, C 2 to C 6 alkenylene, and C 2 to C 6 alkynylene. More preferably, R 6 is selected from C 0 to C 1 alkylene, and R 7 and R 8 are each independently selected from C 2 to C 4 alkylene, C 2 to C 4 alkenylene, C 2 to C 4 Alkynylene.
  • the compound represented by formula II-2 may be selected from one or more of 1,2,3-propanetricarbonitrile, 1,3,5-pentanetricarbonitrile, 1,3,6-hexanetrinitrile
  • the specific structure is as follows:
  • the additive C is selected from one or more of the compounds represented by Formula III-1 and Formula III-2.
  • a, b, c, and d are each independently selected from integers within 1 to 5
  • R 9 , R 10 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 and R 17 are each independently selected from a substituted or unsubstituted C 1 -C 10 alkylene group, a substituted or unsubstituted C 2 -C 10 alkenylene group, wherein the substituent (here means “substituted or In the case of unsubstituted, substitution occurs) one or more selected from halogen atoms, nitrile groups, C 1 to C 6 alkyl groups, C 2 to C 6 alkenyl groups, and C 1 to C 6 alkoxy groups.
  • Additive C is a dinitrile or polynitrile compound with an ether bond.
  • the oxygen (-O-) in the ether group of this molecule will react with trace amounts of PF 5 and HF in the electrolyte to prevent PF 5 and HF from
  • the corrosion of the surface of the positive electrode active material formed by forming the complex layer and directly exposed to the electrolyte environment makes the surface of the positive electrode active material more durable during cycling and storage. Therefore, when the additive C is applied to the electrolyte, the battery can have better high temperature and high voltage cycle performance and storage performance.
  • the mass percentage content of the additive C in the electrolyte is 0.1% to 10%. If the content of additive C is too low, the effect of PF 5 and HF absorption is not obvious, and the surface of the bare positive electrode active material covered by the complex layer will still be corroded; if the content of additive C is too high, the surface of the positive electrode active material will form The complex layer is too thick and dense, and the positive and negative electrode impedances are greatly increased, which affects the performance of the battery.
  • the upper limit of the range of the additive C content may be selected from 10%, 9%, 8%, 7%, 6%, 5%, 4.5%, 4%, 3.5%, 3%, 2%, 1%, 0.8%
  • the lower limit of the content range of the additive C can be optionally selected from 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, and 0.6%.
  • the mass percentage content of the additive C in the electrolyte is 0.1% to 5%.
  • the C 1 -C 10 alkylene group may be a linear alkylene group or a branched chain alkylene group.
  • the preferred lower limit of the number of carbon atoms in the C 1 -C 10 alkylene group is 1, 2, 3, preferably The upper limit of is 4, 5, 6, 7, 8, 9, 10.
  • C 1 to C 6 alkylene is selected; further preferably, C 2 to C 4 alkylene is selected.
  • Examples of C 1 to C 10 alkylene groups include methylene, ethylene, propylene, isopropylene, butylene, isobutylene, sec-butylene, and pentylene. , Akilidene.
  • the C 2 to C 10 alkenylene group may be a straight chain alkenylene group or a branched alkenylene group, and the number of double bonds in the C 2 to C 10 alkenylene group is preferably one.
  • the preferable lower limit of the number of carbon atoms in C 2 to C 12 alkenylene is 2, 3, 4, and 5, and the preferable upper limit is 4, 5, 6, 7, 8, 9, and 10.
  • C 2 to C 6 alkenylene is selected.
  • specific examples of the C 2 to C 10 alkenylene group specific examples include vinylidene group, allylene group, isopropenylene group, allylene group, and alkenylene group.
  • 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 III-1 is a dinitrile compound having an ether bond.
  • a is selected from 1 or 2.
  • R 9 , R 10 , and R 11 are each independently selected from substituted or unsubstituted C 1 -C 6 alkylene, substituted or unsubstituted C 2 -C 6 alkenylene, wherein the substituent is selected from
  • the halogen atom is preferably a fluorine atom. More preferably, R 9 , R 10 , and R 11 are each independently selected from C 1 to C 6 alkylene and C 2 to C 6 alkenylene. Even more preferably, R 9 , R 10 , and R 11 are each independently selected from C 2 to C 4 alkylene.
  • the compound represented by Formula III-1 may be selected from 1,2-bis(cyanoethoxy)ethane, 1,2-bis(cyanopropoxy)ethane, 1,2-bis(cyanobutyl) Oxy)ethane, 1,3-bis(cyanoethoxy)propane, 1,3-bis(cyanopropoxy)propane, 1,3-bis(cyanobutoxy)propane, 1,4-bis (Cyanoethoxy)butane, 1,4-bis(cyanopropoxy)butane, 1,4-bis(cyanobutoxy)butane, 1,5-bis(cyanopropoxy)pentane , 1,6-bis (cyanopropyloxy) hexane in one or more.
  • the compound represented by Formula III-1 may be selected from 1,2-bis(cyanoethoxy)ethane, 1,2-bis(cyanopropoxy)ethane, 1,3-bis(cyano Ethoxy)propane, 1,4-bis(cyanopropoxy)butane, 1,5-bis(cyanopropoxy)pentane, 1,6-bis(cyanopropoxy)hexane Species or several species, the specific structure is as follows:
  • the compound represented by Formula III-2 is a polynitrile compound having an ether bond.
  • b, c, and d are each independently selected from 1 or 2.
  • R 12 , R 13 , R 14 , R 15 , R 16 and R 17 are each independently selected from substituted or unsubstituted C 1 ⁇ C 16 alkylene, substituted or unsubstituted C 2 ⁇ C 6 sub Alkenyl; wherein, the substituent is selected from halogen atoms, preferably fluorine atoms. Further preferably, R 12 , R 13 , R 14 , R 15 , R 16 and R 17 are each independently selected from C 1 to C 6 alkylene and C 2 to C 6 alkenylene. Even more preferably, R 12 , R 13 , R 14 , R 15 , R 16 , and R 17 are each independently selected from C 2 to C 4 alkylene.
  • the compound represented by Formula III-2 may be selected from 1,2,3-tris(cyanoethoxy)propane, 1,2,3-tris(cyanopropoxy)propane, 1,3,5- Tris(cyanoethoxy)pentane, 1,3,5-tris(cyanopropoxy)pentane, 1,2,6-tris(cyanoethoxy)hexane, 1,4,7-tri( One or more of cyanoethoxy) heptane, the specific structure is as follows:
  • the electrolyte may further contain an additive D.
  • the additive D may be selected from cyclic carbonate compounds containing carbon-carbon unsaturated bonds, halogen-substituted cyclic carbonate compounds, sulfate compounds, sultone compounds, disulfonate compounds, sulfite compounds, aromatic compounds , Isocyanate compound, phosphazene compound, acid anhydride compound, phosphite compound, phosphate compound, borate compound one or more.
  • the mass percentage content of the additive D in the electrolyte is 0.01% to 30%.
  • the cyclic carbonate compound containing a carbon-carbon unsaturated bond may be selected from one or more of the compounds represented by Formula IV-0.
  • R 20 is selected from a C 1 -C 6 alkylene group substituted with an alkenyl or alkynyl group on the branch, a substituted or unsubstituted C 2 -C 6 linear alkenylene group, wherein The group is selected from one or more of halogen atoms, C 1 to C 6 alkyl groups, and C 2 to C 6 alkenyl groups.
  • the cyclic carbonate compound containing a carbon-carbon unsaturated bond may be specifically selected from one or more of the following compounds, but the application is not limited thereto:
  • the halogen-substituted cyclic carbonate compound may be selected from one or more of the compounds represented by Formula IV-1.
  • R 21 is selected from halogen-substituted C 1 -C 6 alkylene and halogen-substituted C 2 -C 6 alkenylene.
  • the halogen-substituted cyclic carbonate compound may be selected from fluoroethylene carbonate (abbreviated as FEC), fluoropropylene carbonate (abbreviated as FPC), trifluoropropylene carbonate (abbreviated as TFPC), trans Or one or more of cis-4,5-difluoro-1,3-dioxolane-2-one (hereinafter both are collectively referred to as "DFEC").
  • FEC fluoroethylene carbonate
  • FPC fluoropropylene carbonate
  • TFPC trifluoropropylene carbonate
  • DFEC trans Or one or more of cis-4,5-difluoro-1,3-dioxolane-2-one (hereinafter both are collectively referred to as "DFEC").
  • the sulfate compound is preferably a cyclic sulfate compound, and the cyclic sulfate compound may be selected from one or more of the compounds represented by Formula IV-2.
  • R 22 is selected from substituted or unsubstituted C 1 -C 6 alkylene, substituted or unsubstituted C 2 -C 6 alkenylene, wherein the substituent is selected from halogen atom, C 1 One or more of -C 3 alkyl and C 2 -C 4 alkenyl.
  • R 22 is selected from substituted or unsubstituted C 1 to C 4 alkylene, substituted or unsubstituted C 2 to C 4 alkenylene, wherein the substituent is selected from halogen atoms , C 1 ⁇ C 3 alkyl, C 2 ⁇ C 4 alkenyl one or more.
  • the sulfate compound may be specifically selected from one or more of the following compounds, but the application is not limited thereto:
  • the sulfate compound is selected from one or more of vinyl sulfate (abbreviated as DTD), propylene sulfate (abbreviated as TMS), 4-methylethylene sulfate (abbreviated as PLS), specific structure as follows:
  • the sultone compound may be selected from one or more of the compounds represented by formula IV-3.
  • R 23 is selected from a substituted or unsubstituted C 1 to C 6 alkylene group, a substituted or unsubstituted C 2 to C 6 alkenylene group, wherein the substituent is selected from a halogen atom, C 1 One or more of -C 3 alkyl and C 2 -C 4 alkenyl.
  • R 23 is selected from a substituted or unsubstituted C 1 to C 4 alkylene group, a substituted or unsubstituted C 2 to C 4 alkenylene group, wherein the substituent is selected from a halogen atom , C 1 ⁇ C 3 alkyl, C 2 ⁇ C 4 alkenyl one or more.
  • the sultone compound may be specifically selected from one or more of the following compounds, but the application is not limited thereto:
  • the sultone compound may be selected from one or more of 1,3-propane sultone (abbreviated as PS) and 1,3-propene sultone (abbreviated as PES), specifically
  • PS 1,3-propane sultone
  • PES 1,3-propene sultone
  • R 24 , R 25 , R 26 , and R 27 are each independently selected from a hydrogen atom, a halogen atom, a substituted or unsubstituted C 1 to C 10 alkyl group, and a substituted or unsubstituted C 2 to C 10 alkenyl, wherein the substituent is one or more selected from halogen atoms, C 1 to C 3 alkyl, and C 2 to C 4 alkenyl.
  • R 24 , R 25 , R 26 , and R 27 are each independently selected from a hydrogen atom, a halogen atom, a substituted or unsubstituted C 1 to C 4 alkyl group, a substituted or unsubstituted C 2 -C 6 alkenyl group, wherein the substituent is one or more selected from halogen atom, C 1 -C 3 alkyl group, C 2 -C 4 alkenyl group.
  • the disulfonate compound may be specifically selected from one or more of the following compounds, but the application is not limited thereto:
  • the disulfonate compound may be selected from methylene disulfonate (abbreviated as MMDS), and the specific structure is as follows:
  • the sulfite compound is preferably a cyclic sulfite compound, and specifically can be selected from one or more of the compounds represented by Formula IV-5.
  • R 28 is selected from substituted or unsubstituted C 1 -C 6 alkylene, substituted or unsubstituted C 2 -C 6 alkenylene, wherein the substituent is selected from halogen atom, C 1 One or more of -C 3 alkyl and C 2 -C 4 alkenyl.
  • R 28 is selected from a substituted or unsubstituted C 1 to C 4 alkylene group, a substituted or unsubstituted C 2 to C 4 alkenylene group, wherein the substituent is selected from a halogen atom , C 1 ⁇ C 3 alkyl, C 2 ⁇ C 4 alkenyl one or more.
  • the sulfite compound may be selected from one or more of vinyl sulfite (abbreviated as ES), propylene sulfite (abbreviated as PS), and butylene sulfite (abbreviated as BS).
  • ES vinyl sulfite
  • PS propylene sulfite
  • BS butylene sulfite
  • the aromatic compound may be selected from cyclohexylbenzene, fluorocyclohexylbenzene compound (1-fluoro-2-cyclohexylbenzene, 1-fluoro-3-cyclohexylbenzene, 1-fluoro-4-cyclohexylbenzene), tert-butyl Benzene, tert-amylbenzene, 1-fluoro-4-tert-butylbenzene, biphenyl, terphenyl (ortho, meta, para), diphenyl ether, fluorobenzene, difluorobenzene (ortho Position, meta position, para position), anisole, 2,4-difluoroanisole, partial hydride of terphenyl (1,2-dicyclohexylbenzene, 2-phenylbicyclohexyl, 1,2 -One or more of diphenylcyclohexane and o-cyclohexylbiphenyl
  • the aromatic compound may be selected from one or more of biphenyl, terphenyl (ortho, meta, para), fluorobenzene, cyclohexylbenzene, t-butylbenzene, t-pentylbenzene Further preferably, the aromatic compound may be selected from one or more of biphenyl, o-terphenyl, fluorobenzene, cyclohexylbenzene, and tert-amylbenzene.
  • the isocyanate compound may be selected from methyl isocyanate, ethyl isocyanate, butyl isocyanate, phenyl isocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, octamethylene diisocyanate, 1,4-phenylene diisocyanate
  • isocyanate 2-isocyanatoethyl acrylate, and 2-isocyanatoethyl methacrylate.
  • the isocyanate compound may be selected from one or more of hexamethylene diisocyanate, octamethylene diisocyanate, 2-isocyanatoethyl acrylate, 2-isocyanatoethyl methacrylate .
  • the phosphazene compound is preferably a cyclic phosphazene compound.
  • the cyclic phosphazene compound can be selected from one of methoxypentafluorocyclotriphosphazene, ethoxypentafluorocyclotriphosphazene, phenoxypentafluorocyclotriphosphazene, and ethoxyheptafluorocyclotetraphosphazenekind or several.
  • the cyclic phosphazene compound may be selected from one or more of methoxypentafluorocyclotriphosphazene, ethoxypentafluorocyclotriphosphazene, and phenoxypentafluorocyclotriphosphazene.
  • the cyclic phosphazene compound may be selected from methoxypentafluorocyclotriphosphazene or ethoxypentafluorocyclotriphosphazene.
  • the acid anhydride compound may be a linear acid anhydride or a cyclic acid anhydride.
  • the acid anhydride compound may be selected from one or more of acetic anhydride, propionic anhydride, succinic anhydride, maleic anhydride, 2-allyl succinic anhydride, glutaric anhydride, itaconic anhydride, 3-sulfo-propionic anhydride Species.
  • the acid anhydride compound may be selected from one or more of succinic anhydride, maleic anhydride, and 2-allyl succinic anhydride. Further preferably, the acid anhydride compound may be selected from one or both of succinic anhydride and 2-allyl succinic anhydride.
  • the phosphite compound may be selected from silane phosphite compounds, and specifically may be selected from one or more of the compounds represented by Formula IV-6.
  • R 31 , R 32 , R 33 , R 34 , R 35 , R 36 , R 37 , R 38 , and R 39 are each independently selected from halogen-substituted or unsubstituted C 1 -C 6 alkane base.
  • the silane phosphite compound may be specifically selected from one or more of the following compounds, but the application is not limited thereto:
  • the phosphate compound may be selected from silane phosphate compounds, specifically one or more of the compounds represented by Formula IV-7.
  • R 41 , R 42 , R 43 , R 44 , R 45 , R 46 , R 47 , R 48 , R 49 are each independently selected from halogen-substituted or unsubstituted C 1 -C 6 alkyl base.
  • the silane phosphate compound may be specifically selected from one or more of the following compounds, but the application is not limited thereto:
  • the borate compound can be selected from silane borate compounds, specifically one or more of the compounds represented by formula IV-8.
  • R 51 , R 52 , R 53 , R 54 , R 55 , R 56 , R 57 , R 58 , and R 59 are each independently selected from halogen-substituted or unsubstituted C 1 -C 6 alkane base.
  • the silane borate compound may be specifically selected from one or more of the following compounds, but the application is not limited thereto:
  • the organic solvent used as the electrolyte in the embodiments of the present application is preferably a non-aqueous organic solvent.
  • the organic solvent used in the electrolyte as an embodiment of the present application may include cyclic carbonate and chain carbonate, which can further improve the cycle performance and storage performance under high temperature and high voltage, and it is easy to
  • the electrical conductivity 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 ions and anions in the electrolyte, and at the same time have more advantages in ion conduction than cyclic carbonates and chain carbonates, especially at low temperatures The following can ensure that the electrolyte has good ion conduction characteristics.
  • the mass percentage content of the cyclic carbonate may be 15% to 55%, preferably 25% to 50%; the mass percentage content of the chain carbonate may 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.
  • Li salts-2 suitably selected from (CF 2 ) 2 (SO 2 ) 2 NLi (cyclic), (CF 2 ) 3 (SO 2 ) 2 NLi (cyclic) and LiC (SO one or more of the 2 CF 3) 3 "methyl imide or lithium salts.”
  • [Li salt-5] suitably selected from bis[oxalate-O,O'] lithium borate (LiBOB), difluoro[oxalate-O,O'] lithium borate, difluorobis[oxalic acid Root-O,O']Lithium Phosphate (LiPFO) and tetrafluoro[oxalate-O,O']Lithium Phosphate, one or more "lithium salt with oxalate ligand as positive ion", Among them, it is more preferably selected from LiBOB and LiPFO.
  • the lithium salt can be used alone or in combination.
  • the lithium salt is selected from LiPF 6 , LiPO 2 F 2 , Li 2 PO 3 F, LiBF 4 , LiSO 3 F, trifluoro((methanesulfonyl)oxy) lithium borate (LiTFMSB), bis[oxalic acid One or more of lithium-O,O'] lithium borate (LiBOB), difluorobis[oxalate-O,O'] lithium phosphate (LiPFO) and tetrafluoro[oxalate-O,O'] lithium phosphate Species.
  • the lithium salt is selected from LiPF 6 , LiBF 4 , LiSO 3 F, trifluoro((methanesulfonyl)oxy) lithium borate (LiTFMSB), LiPO 2 F 2 , bis[oxalate-O,O'] One or more of lithium borate (LiBOB) and difluorobis[oxalate-O,O'] lithium phosphate (LiPFO). Further preferably, the lithium salt is LiPF 6 .
  • the preparation method of the electrolyte is not limited, and can be prepared according to a conventional electrolyte method.
  • the electrolyte of the first aspect of the present application preferably, has a conductivity of 4 mS/cm to 12 mS/cm at 25°C.
  • 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 battery according to the second aspect of the present application includes an electrode assembly and the electrolyte according to the first aspect of the present application, the electrode assembly includes a positive pole piece, a negative pole piece and a separator. It should be noted that the battery according to the second aspect of the present application may be a lithium ion battery, a sodium ion battery, or a magnesium ion battery.
  • the positive pole piece contains a positive electrode active material capable of detaching and intercalating lithium ions
  • the negative pole piece contains a negative electrode active material capable of intercalating and detaching lithium ions
  • the positive electrode active material includes Li x1 Co y1 M 1-y1 O 2-z1 Q z1 , 0.5 ⁇ x1 ⁇ 1.2, 0.8 ⁇ y1 ⁇ 1.0, 0 ⁇ z1 ⁇ 0.1, M is selected From one or more of Al, Ti, Zr, Y, and Mg, Q is selected from one or more of F, Cl, and S.
  • the doping element M acts as a skeleton in the lithium cobalt oxide material, which can reduce cobalt
  • the lattice shape variation during the deep delithiation of the lithium acid material delays the degradation of the bulk structure of the lithium cobaltate material and improves the structural stability of the lithium ion battery when it is used at a high voltage greater than 4.2V.
  • the positive electrode active material may also include lithium nickel oxide, lithium manganese oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, the foregoing oxides obtained by adding other transition metals or non-transition metals One or more of the compounds.
  • the negative electrode active material includes soft carbon, hard carbon, artificial graphite, natural graphite, Si, SiO x2 , Si/C composite material, Si alloy, lithium titanate, and can form an alloy with lithium One or more of the metals, 0 ⁇ x2 ⁇ 2.
  • the positive pole piece contains a positive active material that can be extracted and inserted into sodium ions
  • the negative pole piece contains a negative active material that can be inserted and extracted from sodium ions
  • the positive electrode active material may be selected from sodium iron composite oxide (NaFeO 2 ), sodium cobalt composite oxide (NaCoO 2 ), sodium chromium composite oxide (NaCrO 2 ), sodium manganese composite oxide (NaMnO 2 ), sodium Nickel composite oxide (NaNiO 2 ), sodium nickel titanium composite oxide (NaNi 1/2 Ti 1/2 O 2 ), sodium nickel manganese composite oxide (NaNi 1/2 Mn 1/2 O 2 ), sodium iron manganese Composite oxide (Na 2/3 Fe 1/3 Mn 2/3 O 2 ), sodium nickel cobalt manganese composite oxide (NaNi 1/3 Co 1/3 Mn 1/3 O 2 ), sodium iron phosphate compound (NaFePO 4 ), sodium manganese phosphate compound (NaMnPO 4 ), sodium cobalt phosphate compound (NaCoPO 4 ), etc.
  • this application is not limited to these materials, and this application may also use other conventionally known materials that can be used as positive electrode active materials for sodium ion batteries.
  • the negative electrode active material may be selected from hard carbon, natural graphite, artificial graphite, soft carbon, carbon black, acetylene black, carbon nanotubes, graphene, carbon nanofibers, and other carbon materials.
  • examples of other negative electrode active materials include elements such as Si, Ge, Pb, In, Zn, H, Ca, Sr, Ba, Ru, and Rh which are alloyed with sodium, and oxidation containing these elements And carbides.
  • the positive pole piece contains a positive active material that can be extracted and inserted into magnesium ions
  • the negative pole piece contains a negative active material that can be inserted and extracted from magnesium ions.
  • the positive electrode active material may be selected from V 2 O 5 , MoO 3 , MnO 2 , TiS 2 , MoS 2 and the like
  • the negative electrode active material may be selected from metal magnesium, magnesium alloy, graphite and the like.
  • the separator is provided between the positive pole piece and the negative pole piece to play a role of isolation.
  • the specific type of the separator is not specifically limited, and may be any separator material used in existing batteries, such as polyethylene, polypropylene, polyvinylidene fluoride, and their multilayer composite films, but not limited to these .
  • 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 positive electrode current collector is also not subject to specific restrictions, and can be selected according to actual needs.
  • 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 negative electrode current collector is not subject to specific restrictions, and can be selected according to actual needs.
  • the charge cut-off voltage of the battery may be not less than 4.2V, that is, the battery may be used in a high voltage state not less than 4.2V.
  • the higher the valence state of the transition metal on the surface of the positive electrode active material the stronger the Coulomb interaction with the nitrile group in the additive A, that is, the greater the degree of additive A's corresponding protection.
  • the battery can operate in the range of 4.2V to 4.9V, and further preferably, the battery can operate in the range of 4.3V to 4.8V.
  • the battery of the second aspect of the present application may include an outer package for encapsulating the positive pole piece, the negative pole piece and the electrolyte.
  • the positive electrode sheet, the negative electrode sheet, and the separator may be laminated or wound to form a laminated structure electrode assembly or a wound structure electrode assembly.
  • the electrode assembly is packaged in an outer package; the electrolyte is infiltrated into the electrode assembly.
  • the number of electrode assemblies in the battery can be one or several, which can be adjusted according to requirements.
  • the battery outer packaging of the second aspect of the present application may be either a hard shell or a flexible packaging. It is preferable to use a metal hard shell (for example, aluminum shell, steel shell, etc.) for the hard shell outer packaging.
  • the flexible packaging preferably uses a packaging bag as the battery outer packaging.
  • 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 electrolyte described in the first aspect of the present application improves the performance of the flexible package battery more obviously, because the flexible package battery is prone to swell when in use, and this application can greatly reduce the gas production of the battery and avoid the shortening of the life of the flexible package battery.
  • FIG. 4 is a battery 5 of a square structure as an example.
  • the battery may be assembled into a battery module, and the number of 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 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 batteries 5 can be fixed by fasteners.
  • the battery module 4 may further include a housing having an accommodating space, and a plurality of batteries 5 are accommodated in the accommodating 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.
  • an apparatus in a third aspect of the present application, includes the battery of the second aspect of the present application, and the battery provides power for the apparatus.
  • 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 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.
  • a battery pack or battery module may be used.
  • the device may be a mobile phone, a tablet computer, a notebook computer, or the like.
  • the device is usually required to be thin and light, and a battery can be used as a power source.
  • 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 1, 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 to a 120°C blast oven for 1 hour, 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 electrolyte of the present application contains a combined additive of additive A, additive B, and additive C.
  • 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.
  • Additive B is an aliphatic dinitrile or polynitrile compound with a high oxidation potential, which can be stably present in the electrolyte for a long time, and can repair the complex layer (formed by additive A) that is damaged during cycling or high-temperature storage at any time ), reducing the dissolution of transition metal ions, greatly reducing the damage of the SEI film deposited on the negative electrode after the transition metal dissolution.
  • Additive C is a dinitrile or polynitrile compound with an ether bond.
  • the oxygen (-O-) in the ether group of this molecule will react with trace amounts of PF 5 and HF in the electrolyte to prevent PF 5 and HF from
  • the corrosion of the surface of the positive electrode active material formed by forming the complex layer and directly exposed to the electrolyte environment makes the surface of the positive electrode active material more durable during cycling and storage. Therefore, the electrolyte of the present application can significantly improve the cycle performance and storage performance of the lithium ion battery under high temperature and high voltage.
  • 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 positive electrode The distance between the transition metal and the transition metal on the surface of the active material can maximize the complexation of the nitrile group, and allow a greater number of nitrile groups to perform the 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.
  • the examples of the present application also use the metal ion M-doped lithium cobaltate material Li x1 Co y1 M 1-y1 O 2-z1 Q z1 as the positive electrode active material, doped with the element M Acts as a skeleton in the positive electrode active material, which can reduce the lattice deformation of the positive electrode active material during deep delithiation, delay the degradation of the bulk structure of the positive electrode active material, and greatly improve the structural stability of the lithium ion battery when used under high voltage conditions Sex.
  • additive A When the addition amount of additive A is large, first, the complex layer formed by additive A adsorbed on the surface of the positive electrode active material is easy to be thicker and denser, which affects the diffusion and migration of lithium ions, and the impedance of the positive electrode is greatly increased; secondly, additive A is formed At the same time, the complex layer will consume lithium ions, resulting in the reduction of lithium ions that can be used for recycling. Finally, the higher amount of additive A will cause the overall viscosity of the electrolyte to increase and the ion conductivity to decrease. Finally, the lithium ion battery is at 25 °C and 45 After the cycle capacity retention rate at °C reached the optimum, a downward trend appeared. Therefore, an appropriate amount of the additive A needs to be added, preferably 0.1% to 10.0%, and more preferably 0.1% to 3.5%.
  • the addition amount of the additive B also needs to be an appropriate amount, and the addition is 0.1% to 10.0%, more preferably 0.1% to 5.0%.
  • the addition amount of the additive C also needs to be an appropriate amount, and the addition is 0.1% to 10.0%, and more preferably 0.1% to 5.0%.

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Abstract

一种电解液、电池（5）及装置，所述电解液含有有机溶剂以及电解质盐，所述电解液中还含有添加剂A、添加剂B以及添加剂C，添加剂A为氧化电位较低的多腈基六元氮杂环化合物，添加剂B为氧化电位较高的脂族二腈或多腈类化合物，添加剂C为具有醚键的二腈或多腈类化合物。所述电解液能提高电池（5）的循环性能和存储性能，尤其是提高电池（5）高温高电压情况下的循环性能和存储性能。

Description

电解液、电池及装置 技术领域
本申请涉及储能材料领域，具体地讲，涉及一种电解液、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的是以六氟磷酸锂为导电锂盐以及以环状碳酸酯和/或链状碳酸酯为溶剂的电解液体系。然而上述电解液体系尚存在诸多不足，例如在高电压和高温情况下，上述电解液体系的循环性能和存储性能有待提高。
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电解液、电池及装置，所述电解液能提高电池的循环性能和存储性能，尤其是提高电池高温高电压情况下的循环性能和存储性能。
为了达到上述目的，在本申请的第一方面，本申请提供了一种电解液，其含有有机溶剂以及电解质盐，所述电解液中还含有添加剂A、添加剂B以及添加剂C，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，所述添加剂B选自式II-1、式II-2所示的化合物中的一种或几种，所述添加剂C选自式III-1、式III-2所示的化合物中的一种或几种。
Figure PCTCN2019125330-appb-000001
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 PCTCN2019125330-appb-000002
在式II-1、式II-2中：R 5选自取代或未取代的C 1～C 12亚烷基、取代或未取代的C 2～C 12亚烯基、取代或未取代的C 2～C 12亚炔基，R 6、R 7、R 8各自独立地选自取代或未取代的C 0～C 12亚烷基、取代或未取代的C 2～C 12亚烯基、取代或未取代的C 2～C 12亚炔基，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。
Figure PCTCN2019125330-appb-000003
在式III-1、式III-2中：a、b、c、d各自独立地选自1～5内的整数，R 9、R 10、R 11、R 12、R 13、R 14、R 15、R 16、R 17各自独立地选自取代或未取代的C 1～C 10亚烷基、取代或未取代的C 2～C 10亚烯基，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。
在本申请的第二方面，本申请提供了一种电池，其包括本申请第一方面所述的电解液。
在本申请的第三方面，本申请提供了一种装置，其包括本申请的第二方面所述的电池。
相对于现有技术，本申请至少包括如下所述的有益效果：本申请的电解液中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，抑制其对电解液的氧化作用、降低电池产气；本申请的电解液中还含有氧化电位较高的脂族二腈或多腈类化合物，其能长久稳定地存在于电解液中，随时修补循环或高温存储过程中遭到破坏的络合物层，减少过渡金属离子溶出，大大降低过渡金属溶出后沉积在负极对SEI膜的破坏；本申请的电解液中还含有具有醚键的二腈或多腈类化合物，该类分子醚基中的氧(-O-)会与电解液中痕量的PF 5、HF发生反应，阻止PF 5、HF对未形成络合物层而直接暴露于电解液环境中的正极活性材料表面的腐蚀，使正极活性材料表面在循环和存储过程中的耐久度更佳；因此本申请的电解液能提高电池的循环性能和存储性能，尤其是能提高电池高温高电压情况下的循环性能和存储性能。本申请的装置包括所述的电池，因而至少具有与所述电池相同的优势。
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是电池的一实施方式的立体图。
图5是电池模块的一实施方式的立体图。
图6是电池包的一实施方式的立体图。
图7是图6的分解图。
图8是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电池
具体实施方式
下面详细说明根据本申请的电解液、电池及装置。
首先说明根据本申请第一方面的电解液。
根据本申请第一方面的电解液含有有机溶剂以及电解质盐，且所述电解液中还含有添加剂A、添加剂B以及添加剂C。
〔添加剂A〕
在本申请第一方面的电解液中，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(这里表示“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 PCTCN2019125330-appb-000004
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的多孔保护膜并有效钝化正极活性材料表面。该多孔保护膜不仅能在隔绝正极活性材料表面与电解液直接接触的同时不影响离子的正常传输，而且能在降低正极活性材料表面活性的同时抑制正极活性材料表面发生大量副反应，从而能达到减少副反应产物并降低产气的作用。
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可具有更好的钝化效果。
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。
在本申请第一方面的电解液中，优选地，所述添加剂A在所述电解液中的质量百分含量为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，影响离子的扩散迁移，正极阻抗大幅增高，同时还导致了电解液整体黏度提升、离子电导率下降， 因此反而影响了电池的性能发挥。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％、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，所述添加剂A在所述电解液中的质量百分含量为0.1％～3.5％。
在本申请第一方面的电解液中，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 PCTCN2019125330-appb-000005
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 PCTCN2019125330-appb-000006
(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 PCTCN2019125330-appb-000007
(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 PCTCN2019125330-appb-000008
Figure PCTCN2019125330-appb-000009
〔添加剂B〕
在本申请第一方面的电解液中，所述添加剂B选自式II-1、式II-2所示的化合物中的一种或几种。在式II-1、式II-2中，R 5选自取代或未取代的C 1～C 12亚烷基、取代或未取代的C 2～C 12亚烯基、取代或未取代的C 2～C 12亚炔基，R 6、R 7、R 8各自独立地选自取代或未取代的C 0～C 12亚烷基、取代或未取代的C 2～C 12亚烯基、取代或未取代的C 2～C 12亚炔基，其中，取代基(这里表示“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。
Figure PCTCN2019125330-appb-000010
添加剂B为脂族二腈或多腈类化合物，脂族骨架耐氧化性很强，加入电解液中后可长久稳定地存在。添加剂B分子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，可随时修补循环或高温存储过程中遭到破坏的络合物层(由添加剂A形成)，减少过渡金属离子溶出，大大降低过渡金属溶出后沉积在负极对SEI膜的破坏。因此当添加剂B应用于电解液后，电池能具有较好的高温高电压循环性能和存储性能。
在本申请第一方面的电解液中，优选地，所述添加剂B在所述电解液中的质量百分含量为0.1％～10％。如果添加剂B含量过低，则其对添加剂A形成的络合物层破坏后的修补作用不明显；如果添加剂B含量过高，则正极活性材料表面形成的络合物层过于厚和致密，正负极阻抗大幅增高，反而影响了电池的性能发挥。所述添加剂B含量范围的上限可任选自10％、9％、8％、7％、6％、5％、4.5％、4％、3.5％、3％、2％、1％、0.8％，所述添加剂B含量范围的下限可任选自0.1％、0.2％、0.3％、0.4％、0.5％、0.6％。
进一步优选地，所述添加剂B在所述电解液中的质量百分含量为0.1％～5％。
在本申请第一方面的电解液中，在式II-1、式II-2所示的化合物中：
C 0～C 12亚烷基可为直链亚烷基，也可为支链亚烷基，C 0～C 12亚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、7、8、9、10、11、12。优选地，选择C 0～C 10亚烷基；进一步优选地，选择C 1～C 6亚烷基；更进一步优选地，选择C 2～C 4亚烷基。作为C 0～C 12亚烷基的实例，具体可以举出：亚甲基、亚乙基、亚丙基、亚异丙基、亚丁基、亚异丁基、亚仲丁基、亚戊基、亚己基。
C 2～C 12亚烯基可为直链亚烯基，也可为支链亚烯基，C 2～C 12亚烯基中双键的个数优选为1个。C 2～C 12亚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4、5、6、7、8、9、10、11、12。优选地，选择C 2～C 10亚烯基；进一步优选地，选择C 2～C 6亚烯基；更进一步优选地，选择C 2～C 4亚烯基。作为C 2～C 12亚烯基的实例，具体可以举出：亚乙烯基、亚烯丙基、亚异丙烯基、亚烯丁基、亚烯戊基。
C 2～C 12亚炔基可为直链亚炔基，也可为支链亚炔基，C 2～C 12炔基中叁键的个数优选为1个。C 2～C 12亚炔基中碳 原子数优选的下限值为2、3、4、5，优选的上限值为4、5、6、7、8、9、10、11、12。优选地，选择C 2～C 10亚炔基；进一步优选地，选择C 2～C 6亚炔基；更进一步优选地，选择C 2～C 4亚炔基。作为C 2～C 12亚炔基的实例，具体可以举出：亚乙炔基、亚炔丙基、亚异丙炔基、亚戊炔基。
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II-1所示的化合物为脂族二腈类化合物。
在式II-1中：
优选地，R 5选自取代或未取代的C 1～C 10亚烷基、取代或未取代的C 2～C 10亚烯基、取代或未取代的C 2～C 10亚炔基；其中，取代基选自卤素原子，优选为氟原子。进一步优选地，R 5选自C 1～C 6亚烷基、C 2～C 6亚烯基、C 2～C 6亚炔基。更进一步优选地，R 5选自C 2～C 4亚烷基、C 2～C 4亚烯基、C 2～C 4亚炔基。
优选地，式II-1所示的化合物可选自丁二腈、戊二腈、己二腈、庚二腈、辛二腈、壬二腈、癸二腈、十一烷二腈、十二烷二腈、四甲基琥珀腈、甲基戊二腈、丁烯二腈、2-戊烯二腈、己-2-烯二腈、己-3-烯二腈、辛-4-烯二腈、辛-4-炔二腈中的一种或几种。
进一步优选地，式II-1所示的化合物可选自丁二腈、戊二腈、己二腈、丁烯二腈、2-戊烯二腈、己-3-烯二腈中的一种或几种，具体结构如下：
Figure PCTCN2019125330-appb-000011
(2)具体地，式II-2所示的化合物为脂族多腈类化合物。
在式II-2中：
优选地，R 6、R 7、R 8各自独立地选自取代或未取代的C 0～C 10亚烷基、取代或未取代的C 2～C 10亚烯基、取代或未取代的C 2～C 10亚炔基；其中，取代基选自卤素原子，优选为氟原子。进一步优选地，R 6、R 7、R 8各自独立地选自C 0～C 6亚烷基、C 2～C 6亚烯基、C 2～C 6亚炔基。更进一步优选地，R 6选自C 0～C 1亚烷基，R 7、R 8各自独立地选自C 2～C 4亚烷基、C 2～C 4亚烯基、C 2～C 4亚炔基。
优选地，式II-2所示的化合物可选自1,2,3-丙三甲腈、1,3,5-戊三甲腈、1,3,6-己烷三腈中的一种或几种，具体结构如下：
Figure PCTCN2019125330-appb-000012
〔添加剂C〕
在本申请第一方面的电解液中，所述添加剂C选自式III-1、式III-2所示的化合物中的一种或几种。在式III-1、式III-2中，a、b、c、d各自独立地选自1～5内的整数，R 9、R 10、R 11、R 12、R 13、R 14、R 15、R 16、R 17各自独立地选自取代或未取代的C 1～C 10亚烷基、取代或未取代的C 2～C 10亚烯基，其中，取代基(这里表示“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。
Figure PCTCN2019125330-appb-000013
Figure PCTCN2019125330-appb-000014
添加剂C为具有醚键的二腈或多腈类化合物，该类分子醚基中的氧(-O-)会与电解液中痕量的PF 5、HF发生反应，阻止PF 5、HF对未形成络合物层而直接暴露于电解液环境中的正极活性材料表面的腐蚀，使正极活性材料表面在循环和存储过程中的耐久度更佳。因此当添加剂C应用于电解液后，电池能具有较好的高温高电压循环性能和存储性能。
在本申请第一方面的电解液中，优选地，所述添加剂C在所述电解液中的质量百分含量为0.1％～10％。如果添加剂C含量过低，则其吸收PF 5、HF的作用不明显，无络合物层覆盖的裸露正极活性材料表面依然会遭到腐蚀；如果添加剂C含量过高，则正极活性材料表面形成的络合物层过于厚和致密，正负极阻抗大幅增高，反而影响了电池的性能发挥。所述添加剂C含量范围的上限可任选自10％、9％、8％、7％、6％、5％、4.5％、4％、3.5％、3％、2％、1％、0.8％，所述添加剂C含量范围的下限可任选自0.1％、0.2％、0.3％、0.4％、0.5％、0.6％。
进一步优选地，所述添加剂C在所述电解液中的质量百分含量为0.1％～5％。
在本申请第一方面的电解液中，在式III-1、式III-2所示的化合物中：
C 1～C 10亚烷基可为直链亚烷基，也可为支链亚烷基，C 1～C 10亚烷基中碳原子数优选的下限值为1、2、3，优选的上限值为4、5、6、7、8、9、10。优选地，选择C 1～C 6亚烷基；进一步优选地，选择C 2～C 4亚烷基。作为C 1～C 10亚烷基的实例，具体可以举出：亚甲基、亚乙基、亚丙基、亚异丙基、亚丁基、亚异丁基、亚仲丁基、亚戊基、亚己基。
C 2～C 10亚烯基可为直链亚烯基，也可为支链亚烯基，C 2～C 10亚烯基中双键的个数优选为1个。C 2～C 12亚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4、5、6、7、8、9、10。优选地，选择C 2～C 6亚烯基。作为C 2～C 10亚烯基的实例，具体可以举出：亚乙烯基、亚烯丙基、亚异丙烯基、亚烯丁基、亚烯戊基。
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III-1所示的化合物为具有醚键的二腈类化合物。
在式III-1中：
优选地，a选自1或2。
优选地，R 9、R 10、R 11各自独立地选自取代或未取代的C 1～C 6亚烷基、取代或未取代的C 2～C 6亚烯基，其中，取代基选自卤素原子，优选为氟原子。进一步优选地，R 9、R 10、R 11各自独立地选自C 1～C 6亚烷基、C 2～C 6亚烯基。更进一步优选地，R 9、R 10、R 11各自独立地选自C 2～C 4亚烷基。
优选地，式III-1所示的化合物可选自1,2-二(氰乙氧基)乙烷、1,2-二(氰丙氧基)乙烷、1,2-二(氰丁氧基)乙烷、1,3-二(氰乙氧基)丙烷、1,3-二(氰丙氧基)丙烷、1,3-二(氰丁氧基)丙烷、1,4-二(氰乙氧基)丁烷、1,4-二(氰丙氧基)丁烷、1,4-二(氰丁氧基)丁烷、1,5-二(氰丙氧基)戊烷、1,6-二(氰丙氧基)己烷中的一种或几种。
进一步优选地，式III-1所示的化合物可选自1,2-二(氰乙氧基)乙烷、1,2-二(氰丙氧基)乙烷、1,3-二(氰乙氧基)丙烷、1,4-二(氰丙氧基)丁烷、1,5-二(氰丙氧基)戊烷、1,6-二(氰丙氧基)己烷中的一种或几种，具体结构如下：
Figure PCTCN2019125330-appb-000015
Figure PCTCN2019125330-appb-000016
(2)具体地，式III-2所示的化合物为具有醚键的多腈类化合物。
在式III-2中：
优选地，b、c、d各自独立地选自1或2。
优选地，R 12、R 13、R 14、R 15、R 16、R 17各自独立地选自取代或未取代的C 1～C 16亚烷基、取代或未取代的C 2～C 6亚烯基；其中，取代基选自卤素原子，优选为氟原子。进一步优选地，R 12、R 13、R 14、R 15、R 16、R 17各自独立地选自C 1～C 6亚烷基、C 2～C 6亚烯基。更进一步优选地，R 12、R 13、R 14、R 15、R 16、R 17各自独立地选自C 2～C 4亚烷基。
优选地，式III-2所示的化合物可选自1,2,3-三(氰乙氧基)丙烷、1,2,3-三(氰丙氧基)丙烷、1,3,5-三(氰乙氧基)戊烷、1,3,5-三(氰丙氧基)戊烷、1,2,6-三(氰乙氧基)己烷、1,4,7-三(氰乙氧基)庚烷中的一种或几种，具体结构如下：
Figure PCTCN2019125330-appb-000017
〔添加剂D〕
在本申请第一方面的电解液中，所述电解液还可含有添加剂D。添加剂D可选自含有碳碳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、二磺酸酯化合物、亚硫酸酯化合物、芳香化合物、异氰酸酯化合物、磷腈化合物、酸酐化合物、亚磷酸酯化合物、磷酸酯化合物、硼酸酯化合物中的一种或几 种。
在本申请第一方面的电解液中，优选地，所述添加剂D在所述电解液中的质量百分含量为0.01％～30％。
(a)含有碳碳不饱和键的环状碳酸酯化合物
含有碳碳不饱和键的环状碳酸酯化合物可选自式IV-0所示的化合物中的一种或几种。在式IV-0中，R 20选自支链上有烯基或炔基取代的C 1～C 6亚烷基、取代或未取代的C 2～C 6直链亚烯基，其中，取代基选自卤素原子、C 1～C 6烷基、C 2～C 6烯基中的一种或几种。
Figure PCTCN2019125330-appb-000018
优选地，含有碳碳不饱和键的环状碳酸酯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 PCTCN2019125330-appb-000019
(b)卤素取代的环状碳酸酯化合物
卤素取代的环状碳酸酯化合物可选自式IV-1所示的化合物中的一种或几种。在式IV-1中，R 21选自卤素取代的C 1～C 6亚烷基、卤素取代的C 2～C 6亚烯基。
Figure PCTCN2019125330-appb-000020
具体地，卤素取代的环状碳酸酯化合物可选自氟代碳酸乙烯酯(简称为FEC)、氟代碳酸丙烯酯(简称为FPC)、三氟代碳酸丙烯酯(简称为TFPC)、反式或顺式-4,5-二氟-1,3-二氧杂环戊烷-2-酮(以下将两者统称为“DFEC”)中的一种或几种。
(c)硫酸酯化合物
硫酸酯化合物优选为环状硫酸酯化合物，环状硫酸酯化合物可选自式IV-2所示的化合物中的一种或几种。在式IV-2中，R 22选自取代或未取代的C 1～C 6亚烷基、取代或未取代的C 2～C 6亚烯基，其中，取代基选自卤素原子、C 1～C 3烷基、C 2～C 4烯基中的一种或几种。
Figure PCTCN2019125330-appb-000021
在式IV-2中，优选地，R 22选自取代或未取代的C 1～C 4亚烷基、取代或未取代的C 2～C 4亚烯基，其中，取代基选自卤素原子、C 1～C 3烷基、C 2～C 4烯基中的一种或几种。
优选地，硫酸酯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 PCTCN2019125330-appb-000022
进一步优选地，硫酸酯化合物选自硫酸乙烯酯(简称为DTD)、硫酸丙烯酯(简称为TMS)、4-甲基硫酸亚乙酯(简称为PLS)中的一种或几种，具体结构如下：
Figure PCTCN2019125330-appb-000023
(d)磺酸内酯化合物
磺酸内酯化合物可选自式IV-3所示的化合物中的一种或几种。在式IV-3中，R 23选自取代或未取代的C 1～C 6亚烷基、取代或未取代的C 2～C 6亚烯基，其中，取代基选自卤素原子、C 1～C 3烷基、C 2～C 4烯基中的一种或几种。
Figure PCTCN2019125330-appb-000024
在式IV-3中，优选地，R 23选自取代或未取代的C 1～C 4亚烷基、取代或未取代的C 2～C 4亚烯基，其中，取代基选自卤素原子、C 1～C 3烷基、C 2～C 4烯基中的一种或几种。
优选地，磺酸内酯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 PCTCN2019125330-appb-000025
进一步优选地，磺酸内酯化合物可选自1,3-丙烷磺酸内酯(简称为PS)、1,3-丙烯磺酸内酯(简称为PES)中的一种或几种，具体结构如下：
Figure PCTCN2019125330-appb-000026
(e)二磺酸酯化合物
二磺酸酯化合物为含有两个磺酸基(-S(＝O) 2O-)的化合物，优选选自二磺酸亚甲酯化合物，二磺酸亚甲酯化合物可选自式IV-4所示的化合物中的一种或几种。在式IV-4中，R 24、R 25、R 26、R 27各自独立地选自氢原子、卤素原子、取代或未取代的C 1～C 10烷基、取代或未取代的C 2～C 10烯基，其中，取代基选自卤素原子、C 1～C 3烷基、C 2～C 4烯基 中的一种或几种。
Figure PCTCN2019125330-appb-000027
在式IV-4中，优选地，R 24、R 25、R 26、R 27各自独立地选自氢原子、卤素原子、取代或未取代的C 1～C 4烷基、取代或未取代的C 2～C 6烯基，其中，取代基选自卤素原子、C 1～C 3烷基、C 2～C 4烯基中的一种或几种。
优选地，二磺酸酯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 PCTCN2019125330-appb-000028
进一步优选地，二磺酸酯化合物可选自甲烷二磺酸亚甲酯(简称为MMDS)，具体结构如下：
Figure PCTCN2019125330-appb-000029
(f)亚硫酸酯化合物
亚硫酸酯化合物优选为环状亚硫酸酯化合物，具体可选自式IV-5所示的化合物中的一种或几种。在式IV-5中，R 28选自取代或未取代的C 1～C 6亚烷基、取代或未取代的C 2～C 6亚烯基，其中，取代基选自卤素原子、C 1～C 3烷基、C 2～C 4烯基中的一种或几种。
Figure PCTCN2019125330-appb-000030
在式IV-5中，优选地，R 28选自取代或未取代的C 1～C 4亚烷基、取代或未取代的C 2～C 4亚烯基，其中，取代基选自卤素原子、C 1～C 3烷基、C 2～C 4烯基中的一种或几种。
优选地，亚硫酸酯化合物可选自亚硫酸乙烯酯(简称为ES)、亚硫酸丙烯酯(简称为PS)、亚硫酸丁烯酯(简称为BS)中的一种或几种。
(g)芳香化合物
芳香化合物可选自环己基苯、氟代环己基苯化合物(1-氟-2-环己基苯、1-氟-3-环己基苯、1-氟-4-环己基苯)、叔丁基苯、叔戊基苯、1-氟-4-叔丁基苯、联苯、三联苯(邻位体、间位体、对位体)、二苯基醚、氟苯、二氟苯(邻位体、间位体、对位体)、茴香醚、2,4-二氟茴香醚、三联苯的部分氢化物(1,2-二环己基苯、2-苯基双环己基、1,2-二苯基环己烷、邻环己基联苯)中的一种或几种。
优选地，芳香化合物可选自联苯、三联苯(邻位体、间位体、对位体)、氟苯、环己基苯、叔丁基苯、叔戊基苯中的一种或几种，进一步优选地，芳香化合物可选自联苯、邻三联苯、氟苯、环己基苯、叔戊基苯中的一种或几种。
(h)异氰酸酯化合物
异氰酸酯化合物可选自甲基异氰酸酯、乙基异氰酸酯、丁基异氰酸酯、苯基异氰酸酯、四亚甲基二异氰酸酯、六亚甲基二异氰酸酯、八亚甲基二异氰酸酯、1,4-亚苯基二异氰酸酯、丙烯酸2-异氰酸根合乙酯、甲基丙烯酸2-异氰酸根合乙酯中的一种或几种。
优选地，异氰酸酯化合物可选自六亚甲基二异氰酸酯、八亚甲基二异氰酸酯、丙烯酸2-异氰酸根合乙酯、甲基丙烯酸2-异氰酸根合乙酯中的一种或几种。
(i)磷腈化合物
磷腈化合物优选为环状磷腈化合物。环状磷腈化合物可选自甲氧基五氟环三磷腈、乙氧基五氟环三磷腈、苯氧基五氟环三磷腈、乙氧基七氟环四磷腈中的一种或几种。
优选地，环状磷腈化合物可选自甲氧基五氟环三磷腈、乙氧基五氟环三磷腈、苯氧基五氟环三磷腈中的一种或几种。
进一步优选地，环状磷腈化合物可选自甲氧基五氟环三磷腈或乙氧基五氟环三磷腈。
(j)酸酐化合物
酸酐化合物可为链状酸酐或环状酸酐。具体地，酸酐化合物可选自乙酸酐、丙酸酐、琥珀酸酐、马来酸酐、2-烯丙基琥珀酸酐、戊二酸酐、衣康酸酐、3-磺基-丙酸酐中的一种或几种。
优选地，酸酐化合物可选自琥珀酸酐、马来酸酐、2-烯丙基琥珀酸酐中的一种或几种。进一步优选地，酸酐化合物可选自琥珀酸酐、2-烯丙基琥珀酸酐中的一种或两种。
(k)亚磷酸酯化合物
亚磷酸酯化合物可选自硅烷亚磷酸酯化合物，具体可选自式IV-6所示的化合物中的一种或几种。在式IV-6中，R 31、R 32、R 33、R 34、R 35、R 36、R 37、R 38、R 39各自独立地选自卤素取代或未取代的C 1～C 6烷基。
Figure PCTCN2019125330-appb-000031
优选地，硅烷亚磷酸酯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 PCTCN2019125330-appb-000032
(l)磷酸酯化合物
磷酸酯化合物可选自硅烷磷酸酯化合物，具体可选自式IV-7所示的化合物中的一种或几种。在式IV-7中，R 41、R 42、R 43、R 44、R 45、R 46、R 47、R 48、R 49各自独立地选自卤素取代或未取代的C 1～C 6烷基。
Figure PCTCN2019125330-appb-000033
优选地，硅烷磷酸酯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 PCTCN2019125330-appb-000034
(m)硼酸酯化合物
硼酸酯化合物可选自硅烷硼酸酯化合物，具体可选自式IV-8所示的化合物中的一种或几种。在式IV-8中，R 51、R 52、R 53、R 54、R 55、R 56、R 57、R 58、R 59各自独立地选自卤素取代或未取代的C 1～C 6烷基。
Figure PCTCN2019125330-appb-000035
优选地，硅烷硼酸酯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 PCTCN2019125330-appb-000036
〔有机溶剂〕
在本申请第一方面的电解液中，作为本申请实施例的电解液中使用的有机溶剂优选为非水有机溶剂。
优选地，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进一步包括羧酸酯，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。
〔电解质盐〕
在本申请第一方面的电解液中，作为本申请中使用的电解质盐，可以合适地列举出下述的锂盐。
〔Li盐－1类〕：可以合适地列举出选自LiPF 6、LiBF 4、LiAsF 6、LiSbF 6、LiPF 4(CF 3) 2、LiPF 3(C 2F 5) 3、LiPF 3(CF 3) 3、LiPF 3(异-C 3F 7) 3和LiPF 5(异-C 3F 7)中的一种或几种的“路易斯酸与LiF的络盐”，其中优选选自LiPF 6、LiBF 4、LiAsF 6，更优选选自LiPF 6、LiBF 4。
〔Li盐－2类〕：可以合适地列举出选自(CF 2) 2(SO 2) 2NLi(环状)、(CF 2) 3(SO 2) 2NLi(环状)和LiC(SO 2CF 3) 3中的一种或几种的“亚胺或甲基化锂盐”。
〔Li盐－3类〕：可以合适地列举出选自LiSO 3F、LiCF 3SO 3、CH 3SO 4Li、C 2H 5SO 4Li、C 3H 7SO 4Li、三氟((甲磺酰)氧基)硼酸锂(LiTFMSB)、五氟((甲磺酰)氧基)磷酸锂(LiPFMSP)中的一种或几种的“含有S(＝O) 2O结构的锂盐”，其中更优选选自LiSO 3F、CH 3SO 4Li、C 2H 5SO 4Li或LiTFMSB。
〔Li盐－4类〕：可以合适地列举出选自LiPO 2F 2、Li 2PO 3F和LiClO 4中的一种或几种的“含有P＝O或Cl＝O结构的锂盐”，其中优选选自LiPO 2F 2、Li 2PO 3F。
〔Li盐－5类〕：可以合适地列举出选自双[草酸根-O,O’]硼酸锂(LiBOB)、二氟[草酸根-O,O’]硼酸锂、二氟双[草酸根-O,O’]磷酸锂(LiPFO)和四氟[草酸根-O,O’]磷酸锂中的一种或几种的“以草酸盐配位体为正离子的锂盐”，其中更优选选自LiBOB、LiPFO。
上述锂盐可以单独使用或混合使用。其中，优选地，锂盐选自LiPF 6、LiPO 2F 2、Li 2PO 3F、LiBF 4、LiSO 3F、三氟((甲磺酰)氧基)硼酸锂(LiTFMSB)、双[草酸根-O,O’]硼酸锂(LiBOB)、二氟双[草酸根-O,O’]磷酸锂(LiPFO)和四氟[草酸根-O,O’]磷酸锂中的一种或几种。更优选地，锂盐选自LiPF 6、LiBF 4、LiSO 3F、三氟((甲磺酰)氧基)硼酸锂(LiTFMSB)、LiPO 2F 2、双[草酸根-O,O’]硼酸锂(LiBOB)和二氟双[草酸根-O,O’]磷酸锂(LiPFO)中的一种或几种。进一步优选地，锂盐为LiPF 6。
在本申请第一方面的电解液中，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。
在本申请第一方面的电解液中，优选地，所述电解液25℃的电导率为4mS/cm～12mS/cm。
在本申请第一方面的电解液中，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 PCTCN2019125330-appb-000037
Figure PCTCN2019125330-appb-000038
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 PCTCN2019125330-appb-000039
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 PCTCN2019125330-appb-000040
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。
其次说明根据本申请第二方面的电池。
根据本申请第二方面的电池包括电极组件以及根据本申请第一方面所述的电解液，所述电极组件包括正极极片、 负极极片以及隔离膜。需要说明的是，根据本申请第二方面的电池可为锂离子电池、钠离子电池或镁离子电池。
当电池为锂离子电池时，正极极片包含能脱出、嵌入锂离子的正极活性材料，负极极片包含能嵌入、脱出锂离子的负极活性材料。
具体的，当电池为锂离子电池时，正极活性材料包括Li x1Co y1M 1-y1O 2-z1Q z1，0.5≤x1≤1.2，0.8≤y1<1.0，0≤z1≤0.1，M选自Al、Ti、Zr、Y、Mg中的一种或几种，Q选自F、Cl、S中的一种或几种。当使用包含金属离子M掺杂的钴酸锂材料Li x1Co y1M 1-y1O 2-z1Q z1的正极活性材料时，掺杂元素M在钴酸锂材料中充当骨架，可以减小钴酸锂材料深度脱锂过程中的晶格形变量，延缓钴酸锂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。正极活性材料还可包括锂镍氧化物、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、前述这些氧化物添加其他过渡金属或非过渡金属得到的化合物中的一种或几种。
具体的，当电池为锂离子电池时，负极活性材料包括软碳、硬碳、人造石墨、天然石墨、Si、SiO x2、Si/C复合材料、Si合金、钛酸锂、能与锂形成合金的金属中的一种或几种，0<x2≤2。
当电池为钠离子电池时，正极极片包含能脱出、嵌入钠离子的正极活性材料，负极极片包含能嵌入、脱出钠离子的负极活性材料。
具体地，正极活性材料可以选自钠铁复合氧化物(NaFeO 2)、钠钴复合氧化物(NaCoO 2)、钠铬复合氧化物(NaCrO 2)、钠锰复合氧化物(NaMnO 2)、钠镍复合氧化物(NaNiO 2)、钠镍钛复合氧化物(NaNi 1/2Ti 1/2O 2)、钠镍锰复合氧化物(NaNi 1/2Mn 1/2O 2)、钠铁锰复合氧化物(Na 2/3Fe 1/3Mn 2/3O 2)、钠镍钴锰复合氧化物(NaNi 1/3Co 1/3Mn 1/3O 2)、钠铁磷酸化合物(NaFePO 4)、钠锰磷酸化合物(NaMnPO 4)、钠钴磷酸化合物(NaCoPO 4)等。但本申请并不限定于这些材料，本申请还可以使用其他可被用作钠离子电池正极活性材料的传统公知的材料。这些正极活性材料可以仅单独使用一种，也可以将两种以上组合使用。
具体地，负极活性材料可以选自硬碳、天然石墨、人造石墨、软碳、炭黑、乙炔黑、碳纳米管、石墨烯、碳纳米纤维等碳材料。此外，作为其他负极活性材料，还可以列举出例如Si、Ge、Pb、In、Zn、H、Ca、Sr、Ba、Ru、Rh等与钠发生合金化的元素的单质、含这些元素的氧化物以及碳化物等。但并不限定于这些材料，本申请还可以使用其他可被用作钠离子电池负极活性材料的传统公知的材料。这些负极活性材料可以仅单独使用一种，也可以将两种以上组合使用。
当电池为镁离子电池时，正极极片包含能脱出、嵌入镁离子的正极活性材料，负极极片包含能嵌入、脱出镁离子的负极活性材料。例如，正极活性材料可以选自V 2O 5、MoO 3、MnO 2、TiS 2、MoS 2等，负极活性材料可以选自金属镁、镁合金、石墨等。但并不限定于这些材料，本申请还可以使用其他可被用作镁离子电池正负极活性材料的传统公知的材料。这些正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。
在本申请第二方面的电池中，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。所述隔离膜的具体种类并不受到具体的限制，可以是现有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。
在本申请第二方面的电池中，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。
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。
在本申请第二方面的电池中，电池的充电截止电压可不小于4.2V，即电池可在不小于4.2V的高电压状态下使用。在高电压状态下，正极活性材料表面过渡金属的价态越高，与添加剂A中腈基的库仑相互作用便越强，也即添加剂A能够越大程度地发挥相应的保护作用。优选地，电池可在4.2V～4.9V范围内工作，进一步优选地，电池可在4.3V～4.8V范围内工作。
本申请第二方面的电池可以包括外包装，用于封装正极极片、负极极片和电解液。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；电解液浸润于电极组件中。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。
本申请第二方面的电池外包装既可为硬壳，也可为软包装。硬壳外包装优选使用金属材质的硬壳(例如铝壳、钢壳等)。软包装优选使用包装袋作为电池外包装，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。
本申请第一方面所述的电解液对于软包装电池性能的改善更明显，原因在于软包装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，避免软包装电池鼓胀造成寿命缩短。
本申请对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电池5。
在一些实施例中，电池可以组装成电池模块，电池模块所含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三方面的装置。
在本申请第三方面提供一种装置，所述装置包括本申请第二方面的电池，所述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。
在本申请的下述具体实施例中，仅示出电池为锂离子电池的实施例，但本申请不限于此。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 PCTCN2019125330-appb-000041
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 PCTCN2019125330-appb-000042
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 PCTCN2019125330-appb-000043
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1-32和对比例1-3中，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1-32和对比例1-3中所使用的添加剂A、添加剂B以及添加剂C分别简写为：
Figure PCTCN2019125330-appb-000044
Figure PCTCN2019125330-appb-000045
Figure PCTCN2019125330-appb-000046
(2)正极极片的制备
将表1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1-32和对比例1-3的电解液参数
Figure PCTCN2019125330-appb-000047
Figure PCTCN2019125330-appb-000048
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2 实施例1-32和对比例1-3的性能测试结果
Figure PCTCN2019125330-appb-000049
Figure PCTCN2019125330-appb-000050
从实施例1-32和对比例1-3的对比中可以看出：在电解液中加入本申请的组合添加剂后可显著提高锂离子电池在高温高电压情况下的循环性能和存储性能。
与对比例1未加入任何添加剂相比，本申请的电解液包含添加剂A、添加剂B和添加剂C的组合添加剂。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。添加剂B为氧化电位较高的脂族二腈或多腈类化合物，其能长久稳定地存在于电解液中，随时修补循环或高温存储过程中遭到破坏的络合物层(由添加剂A形成)，减少过渡金属离子溶出，大大降低过渡金属溶出后沉积在负极对SEI膜的破坏。添加剂C为具有醚键的二腈或多腈类化合物，该类分子醚基中的氧(-O-)会与电解液中痕量的PF 5、HF发生反应，阻止PF 5、HF对未形成络合物层而直接暴露于电解液环境中的正极活性材料表面的腐蚀，使正极活性材料表面在循环和存储过程中的耐久度更佳。由此，本申请的电解液能显著提高锂离子电池在高温高电压情况下的循环性能和存储性能。
与对比例2、对比例3仅加入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。
与对比例1-3相比，本申请的实施例还使用了金属离子M掺杂的钴酸锂材料Li x1Co y1M 1-y1O 2-z1Q z1作为正极活性材料，掺杂元素M在正极活性材料中充当骨架，可以减小正极活性材料深度脱锂过程中的晶格形变量，延缓正极活性材料体相结构的退化，大大改善锂离子电池在高电压情况下使用时的结构稳定性。
从实施例1-7可以看出，随着添加剂A加入量的增加(0.1％增至10.0％)，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。这充电截当添加剂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较高的加入量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％～10.0％，进一步优选为0.1％～3.5％。
从实施例8-14可以看出，随着添加剂B加入量的增加(0.1％增至10.0％)，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。这是由于添加剂B的加入量较多时，其对正极活性材料表面的络合物层的修补作用较强烈，最终正极活性材料表面形成的络合物层容易更厚和致密，正负极阻抗大幅增高，从而锂离子电池在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B的加入量也需要适量，添加为0.1％～10.0％，进一步优选为0.1％～5.0％。
从实施例15-21可以看出，随着添加剂C加入量的增加(0.1％增至10.0％)，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。这是由于添加剂C的加入量较多时，其对正极活性材料表面的络合物层的保护作用较强烈，最终正极活性材料表面形成的络合物层容易更厚和致密，正负极阻抗大幅增高，从而锂离子电池在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C的加入量也需要适量，添加为0.1％～10.0％，进一步优选为0.1％～5.0％。
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. 一种电解液，含有有机溶剂以及电解质盐；
    其特征在于，
    所述电解液中还含有添加剂A、添加剂B以及添加剂C；
    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 PCTCN2019125330-appb-100001
    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；
    所述添加剂B选自式II-1、式II-2所示的化合物中的一种或几种；
    Figure PCTCN2019125330-appb-100002
    在式II-1、式II-2中，R 5选自取代或未取代的C 1～C 12亚烷基、取代或未取代的C 2～C 12亚烯基、取代或未取代的C 2～C 12亚炔基，R 6、R 7、R 8各自独立地选自取代或未取代的C 0～C 12亚烷基、取代或未取代的C 2～C 12亚烯基、取代或未取代的C 2～C 12亚炔基，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；
    所述添加剂C选自式III-1、式III-2所示的化合物中的一种或几种；
    Figure PCTCN2019125330-appb-100003
    在式III-1、式III-2中，a、b、c、d各自独立地选自1～5内的整数，R 9、R 10、R 11、R 12、R 13、R 14、R 15、R 16、R 17各自独立地选自取代或未取代的C 1～C 10亚烷基、取代或未取代的C 2～C 10亚烯基，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。
  2. 根据权利要求1所述的电解液，其特征在于，
    在式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；和/或，
    在式II-1、式II-2中：R 5选自取代或未取代的C 1～C 10亚烷基、取代或未取代的C 2～C 10亚烯基、取代或未取代的C 2～C 10亚炔基，R 6、R 7、R 8各自独立地选自取代或未取代的C 0～C 10亚烷基、取代或未取代的C 2～C 10亚烯基、取代或未取代的C 2～C 10亚炔基，其中，取代基选自卤素原子；和/或，
    在式III-1、式III-2中：R 9、R 10、R 11、R 12、R 13、R 14、R 15、R 16、R 17各自独立地选自取代或未取代的C 1～C 6亚烷基、取代或未取代的C 2～C 6亚烯基，其中，取代基选自卤素原子；a、b、c、d各自独立地选自1或2。
  3. 根据权利要求1所述的电解液，其特征在于，
    在式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；
    在式I-3中，R 1、R 2、R 3中至少有两个为氢原子；
    在式II-1中，R 5选自C 1～C 6亚烷基、C 2～C 6亚烯基、C 2～C 6亚炔基，优选地，R 5选自C 2～C 4亚烷基、C 2～C 4亚烯基、C 2～C 4亚炔基；
    在式II-2中，R 6、R 7、R 8各自独立地选自C 0～C 6亚烷基、C 2～C 6亚烯基、C 2～C 6亚炔基，优选地，R 6选自C 0～C 1亚烷基，R 7、R 8各自独立地选自C 2～C 4亚烷基、C 2～C 4亚烯基、C 2～C 4亚炔基；
    在式III-1中，R 9、R 10、R 11各自独立地选自C 1～C 6亚烷基、C 2～C 6亚烯基，优选地，R 9、R 10、R 11各自独立地选自C 2～C 4亚烷基；
    在式III-2中，R 12、R 13、R 14、R 15、R 16、R 17各自独立地选自C 1～C 6亚烷基、C 2～C 6亚烯基，优选地，R 12、R 13、R 14、R 15、R 16、R 17各自独立地选自C 2～C 4亚烷基。
  4. 根据权利要求1所述的电解液，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 PCTCN2019125330-appb-100004
    Figure PCTCN2019125330-appb-100005
  5. 根据权利要求1所述的电解液，其特征在于，
    所述添加剂B选自丁二腈、戊二腈、己二腈、庚二腈、辛二腈、壬二腈、癸二腈、十一烷二腈、十二烷二腈、四甲基琥珀腈、甲基戊二腈、丁烯二腈、2-戊烯二腈、己-2-烯二腈、己-3-烯二腈、辛-4-烯二腈、辛-4-炔二腈、1,2,3-丙三甲腈、1,3,5-戊三甲腈、1,3,6-己烷三腈中的一种或几种。
  6. 根据权利要求1所述的电解液，其特征在于，
    所述添加剂C选自1,2-二(氰乙氧基)乙烷、1,2-二(氰丙氧基)乙烷、1,2-二(氰丁氧基)乙烷、1,3-二(氰乙氧基)丙烷、1,3-二(氰丙氧基)丙烷、1,3-二(氰丁氧基)丙烷、1,4-二(氰乙氧基)丁烷、1,4-二(氰丙氧基)丁烷、1,4-二(氰丁氧基)丁烷、1,5-二(氰丙氧基)戊烷、1,6-二(氰丙氧基)己烷、1,2,3-三(氰乙氧基)丙烷、1,2,3-三(氰丙氧基)丙烷、1,3,5-三(氰乙氧基)戊烷、1,3,5-三(氰丙氧基)戊烷、1,2,6-三(氰乙氧基)己烷、1,4,7-三(氰乙氧基)庚烷中的一种或几种。
  7. 根据权利要求1所述的电解液，其特征在于，
    所述添加剂A在所述电解液中的质量百分含量为0.1％～10％，优选为0.1％～3.5％；和/或，
    所述添加剂B在所述电解液中的质量百分含量为0.1％～10％，优选为0.1％～5％；和/或，
    所述添加剂C在所述电解液中的质量百分含量为0.1％～10％，优选为0.1％～5％。
  8. 根据权利要求1所述的电解液，其特征在于，所述电解液中还含有添加剂D，所述添加剂D选自含有碳碳不饱 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、二磺酸酯化合物、亚硫酸酯化合物、芳香化合物、异氰酸酯化合物、磷腈化合物、酸酐化合物、亚磷酸酯化合物、磷酸酯化合物、硼酸酯化合物中的一种或几种。
  9. 一种电池，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，
    所述电解液为根据权利要求1-8中任一项所述的电解液。
  10. 根据权利要求9所述的电池，其特征在于，所述正极极片中的正极活性材料包括Li x1Co y1M 1-y1O 2-z1Q z1，0.5≤x1≤1.2，0.8≤y1<1.0，0≤z1≤0.1，M选自Al、Ti、Zr、Y、Mg中的一种或几种，Q选自F、Cl、S中的一种或几种。
  11. 一种装置，其特征在于，包括根据权利要求9或10所述的电池。
PCT/CN2019/125330 2018-12-14 2019-12-13 电解液、电池及装置 WO2020119809A1 (zh)

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