WO2022143191A1 - 一种锂离子电池 - Google Patents

一种锂离子电池 Download PDF

Info

Publication number
WO2022143191A1
WO2022143191A1 PCT/CN2021/138677 CN2021138677W WO2022143191A1 WO 2022143191 A1 WO2022143191 A1 WO 2022143191A1 CN 2021138677 W CN2021138677 W CN 2021138677W WO 2022143191 A1 WO2022143191 A1 WO 2022143191A1
Authority
WO
WIPO (PCT)
Prior art keywords
cyclic
group
positive electrode
groups
lithium
Prior art date
Application number
PCT/CN2021/138677
Other languages
English (en)
French (fr)
Inventor
胡时光
钱韫娴
曹朝伟
郭鹏凯
向晓霞
王驰
向书槐
陈群
邓永红
Original Assignee
深圳新宙邦科技股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 深圳新宙邦科技股份有限公司 filed Critical 深圳新宙邦科技股份有限公司
Priority to JP2023537202A priority Critical patent/JP2024500789A/ja
Priority to EP21913932.6A priority patent/EP4270574A1/en
Priority to KR1020237020445A priority patent/KR20230109704A/ko
Publication of WO2022143191A1 publication Critical patent/WO2022143191A1/zh

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—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
    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H01M10/0568—Liquid materials characterised by the solutes
    • H—ELECTRICITY
    • 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
    • H01M10/0569—Liquid materials characterised by the solvents
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/485—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/028—Positive electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0025—Organic electrolyte
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the invention belongs to the technical field of secondary batteries, and in particular relates to a lithium ion battery.
  • Lithium-ion batteries are widely used in life and production due to their excellent performance.
  • people have put forward higher requirements for the performance of lithium-ion batteries, especially under high temperature conditions.
  • the cycle performance needs to be further improved.
  • the cycle process of lithium-ion batteries especially in high-nickel high-voltage ternary battery systems, when the nickel content and working voltage in the ternary cathode material are high, the cycle gas generation of lithium-ion batteries is more serious.
  • the oxidative decomposition of the electrolyte on the surface of the cathode material with high nickel content is easier and faster, which further increases the cycle gas production and deteriorates the high temperature cycle performance.
  • the present invention provides a lithium ion battery.
  • the present invention provides a lithium ion battery, comprising a positive electrode, a negative electrode and a non-aqueous electrolyte, the positive electrode comprises a positive electrode material layer, the positive electrode material layer comprises a positive electrode active material, and the positive electrode active material comprises LiNi x Co y Mn z L (1-xyz) O 2 , where L is Al, Sr, Mg, Ti, Ca, Zr, Zn, Si, Cu, V or Fe, 0.5 ⁇ x ⁇ 1, 0 ⁇ y ⁇ 0.5, 0 ⁇ z ⁇ 0.5, 0 ⁇ x+y+z ⁇ 1, the upper limit voltage of the lithium-ion battery is ⁇ 4.2V;
  • the non-aqueous electrolyte solution includes a solvent, an electrolyte salt and a compound represented by structural formula 1:
  • A, B and C are each independently selected from the group consisting of cyclic carbonate group, cyclic sulfate group, cyclic sulfite group, cyclic sulfonate group, cyclic sulfone group, cyclic sulfoxide group, A cyclic carboxylate group or a cyclic acid anhydride group;
  • D and E are each independently selected from a single bond, or a group containing a hydrocarbylene group, an ether bond, a sulfur-oxygen double bond or a carbon-oxygen double bond;
  • the addition amount of the compound represented by the structural formula 1 is 0.01 to 5.0%.
  • A, B, and C independently contain a cyclic carbonate group, a cyclic sulfate group, a cyclic sulfite group, a cyclic sulfonate group, a cyclic sulfone group, and a cyclic sulfoxide group.
  • the number of cyclic carboxylate groups or cyclic acid anhydride groups is 1 to 5, and A, B, C cyclic carbonate groups, cyclic sulfate groups, cyclic sulfite groups, cyclic sulfonate groups
  • the total number of cyclic sulfone group, cyclic sulfone group, cyclic sulfoxide group, cyclic carboxylate group or cyclic acid anhydride group is less than or equal to 10.
  • a and C are independently selected from the groups shown in structural formula 2:
  • n is selected from an integer of 0-4, R 1 is selected from hydrogen, halogen or halogenated hydrocarbon group of C1-C5; R 2 , R 3 , R 4 , R 5 , R 6 , R 7 are each independently selected from C1 ⁇ C3 alkylene group, C1 ⁇ C3 alkoxy group, oxygen atom, At least one of R 2 , R 3 and R 4 is selected from And at least one of R 2 , R 3 and R 4 is selected from oxygen atoms, and at least one of R 5 , R 6 and R 7 is selected from And at least one of R 5 , R 6 and R 7 is selected from oxygen atoms.
  • B is selected from the group shown in structural formula 3:
  • m is selected from an integer of 1 to 4
  • R 8 , R 9 and R 10 are each independently selected from C1-C3 hydrocarbylene, C1-C3 alkoxy, oxygen atom, At least one of R 8 , R 9 and R 10 is selected from And at least one of R 8 , R 9 and R 10 is selected from oxygen atoms.
  • D and E are each independently selected from the groups shown in structural formula 4:
  • z is selected from an integer from 0 to 4
  • R 11 and R 13 are each independently selected from a single bond or a C1-C5 hydrocarbylene group
  • R 12 is selected from a single bond
  • D and E are each independently selected from single bonds or C1-C5 alkylene groups
  • A, B, and C are each independently selected from substituted or unsubstituted cyclic carbonate groups, cyclic sulfate groups, cyclic sulfite group, cyclic sulfonate group, cyclic sulfone group, cyclic sulfoxide group, cyclic carboxylate group or cyclic acid anhydride group;
  • the substituent is selected from halogen, hydrocarbyl or halogenated hydrocarbyl.
  • the substituents are selected from halogen, alkyl or haloalkyl.
  • a and C are the same as each other, A and B are the same or different from each other, and D and E are the same as each other.
  • the compound shown in the structural formula 1 is selected from one or more of the following compounds:
  • the positive electrode active material is selected from LiNi 0.5 Co 0.2 Mn 0.3 O 2 , LiNi 0.6 Co 0.2 Mn 0.2 O 2 , LiNi 0.7 Co 0.1 Mn 0.2 O 2 , LiNi 0.8 Co 0.15 Al 0.05 O 2 , LiNi 0.8 Co One or more of 0.1 Mn 0.1 O 2 , LiNi 0.6 Mn 0.4 O 2 and LiNi 0.8 Mn 0.2 O 2 .
  • the non-aqueous electrolyte further includes auxiliary additives, and the auxiliary additives include unsaturated cyclic carbonate compounds, fluorinated cyclic carbonate compounds, aromatic additives, fluorinated anisole compounds, dicarboxylic acid At least one of acid anhydride, lithium difluorophosphate, and lithium bisfluorosulfonimide (LiFSI).
  • auxiliary additives include unsaturated cyclic carbonate compounds, fluorinated cyclic carbonate compounds, aromatic additives, fluorinated anisole compounds, dicarboxylic acid At least one of acid anhydride, lithium difluorophosphate, and lithium bisfluorosulfonimide (LiFSI).
  • the inventors found that when the compound represented by the structural formula 1 is used in combination with a high-nickel ternary material, a ternary high-nickel ternary material with high high-temperature cycle capacity retention rate and small cycle gas production can be obtained Lithium-ion batteries, in which the compound represented by structural formula 1 decomposes on the surface of the positive electrode to form a protective film, which covers the surface of the positive electrode material uniformly. On the other hand, it can well protect the stability of the positive electrode structure. It is speculated that the decomposition product of structural formula 1 on the surface of the positive electrode is complexed with nickel ions to form a relatively stable protective film to limit its dissolution. At the same time, the formed film has a certain elasticity and will Corresponding expansion and contraction occurs with the expansion and contraction of the positive electrode material, so as to realize the protection of the positive electrode, and it is not easy to crack during the charge-discharge cycle.
  • Example 1 is a TEM image of a positive electrode after the cycle provided by Example 7 of the present invention.
  • FIG. 2 is a TEM image of the positive electrode after cycling provided by Comparative Example 1 of the present invention.
  • An embodiment of the present invention provides a lithium ion battery, including a positive electrode, a negative electrode and a non-aqueous electrolyte, the positive electrode includes a positive electrode material layer, the positive electrode material layer includes a positive electrode active material, and the positive electrode active material includes LiNi x Co y Mn z L (1-xyz) O 2 , where L is Al, Sr, Mg, Ti, Ca, Zr, Zn, Si, Cu, V or Fe, 0.5 ⁇ x ⁇ 1, 0 ⁇ y ⁇ 0.5, 0 ⁇ z ⁇ 0.5, 0 ⁇ x+y+z ⁇ 1, the upper limit voltage of the lithium-ion battery is ⁇ 4.2V;
  • the non-aqueous electrolyte solution includes a solvent, an electrolyte salt and a compound represented by structural formula 1:
  • A, B and C are each independently selected from the group consisting of cyclic carbonate group, cyclic sulfate group, cyclic sulfite group, cyclic sulfonate group, cyclic sulfone group, cyclic sulfoxide group, A cyclic carboxylate group or a cyclic acid anhydride group;
  • D and E are each independently selected from a single bond, or a group containing a hydrocarbylene group, an ether bond, a sulfur-oxygen double bond or a carbon-oxygen double bond;
  • the addition amount of the compound represented by the structural formula 1 is 0.01 to 5.0%.
  • the compound represented by the structural formula 1 is decomposed on the surface of the positive electrode to form a protective film, which uniformly covers the surface of the positive electrode material, and on the one hand, inhibits the decomposition of the original lithium carbonate and other alkaline oxides on the surface of the positive electrode material. , reducing the generation of gas, and on the other hand, it can well protect the stability of the positive electrode structure. It is speculated that the decomposition product of structural formula 1 on the surface of the positive electrode is complexed with nickel ions to form a relatively stable protective film to limit its dissolution. At the same time, the formed film has With a certain elasticity, the corresponding expansion and contraction will occur with the expansion and contraction of the positive electrode material, so as to realize the protection of the positive electrode, and it is not easy to rupture during the charge-discharge cycle.
  • the performance of the battery is related to the nickel content in the positive electrode active material and the content of the compound represented by the structural formula 1 in the non-aqueous electrolyte.
  • the compound represented by the structural formula 1 is added. Although it can improve the high-temperature cycle performance of the battery to a certain extent, its improvement effect is relatively low, and when the nickel content in the positive electrode active material is high (0.5 ⁇ x ⁇ 1), the compound represented by structural formula 1 Then it has an extremely excellent improvement effect on the high temperature cycle performance of the battery, indicating that the presence of nickel in the positive electrode active material has a clear relationship with the compound represented by structural formula 1. With the increase of nickel content, the compound represented by structural formula 1 is more effective.
  • x is selected from 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.83, 0.85, 0.88, 0.90, 0.95.
  • the positive active material is selected from LiNi 0.5 Co 0.2 Mn 0.3 O 2 , LiNi 0.6 Co 0.2 Mn 0.2 O 2 , LiNi 0.7 Co 0.1 Mn 0.2 O 2 , LiNi 0.8 Co 0.15 Al 0.05 O 2 , LiNi 0.8 Co 0.15 Al 0.05 O 2 , One or more of 0.8 Co 0.1 Mn 0.1 O 2 , LiNi 0.6 Mn 0.4 O 2 and LiNi 0.8 Mn 0.2 O 2 .
  • element L is introduced into the positive electrode active material by doping, L is Al, Sr, Mg, Ti, Ca, Zr, Zn, Si, Cu, V or Fe, and the doped element L may be It provides stronger A-O chemical bonds than active transition metals such as Ni, Co, and Mn, inhibits the precipitation of lattice oxygen under high voltage, and improves the stability of the material structure.
  • A, B, and C each independently contain a cyclic carbonate group, a cyclic sulfate group, a cyclic sulfite group, a cyclic sulfonate group, a cyclic sulfone group, a cyclic sulfite group
  • the number of sulfone groups, cyclic carboxylate groups or cyclic acid anhydride groups is 1 to 5, and A, B, and C are cyclic carbonate groups, cyclic sulfate groups, cyclic sulfite groups, and cyclic sulfonic acid groups.
  • the total number of ester groups, cyclic sulfone groups, cyclic sulfoxide groups, cyclic carboxylate groups or cyclic acid anhydride groups is less than or equal to 10.
  • a and C are each independently selected from groups represented by structural formula 2:
  • n is selected from an integer of 0-4, R 1 is selected from hydrogen, halogen or halogenated hydrocarbon group of C1-C5; R 2 , R 3 , R 4 , R 5 , R 6 , R 7 are each independently selected from C1 ⁇ C3 alkylene group, C1 ⁇ C3 alkoxy group, oxygen atom, At least one of R 2 , R 3 and R 4 is selected from And at least one of R 2 , R 3 and R 4 is selected from oxygen atoms, and at least one of R 5 , R 6 and R 7 is selected from And at least one of R 5 , R 6 and R 7 is selected from oxygen atoms.
  • the combined group of -R 3 -R 2 -R 4 - and the combined group of -R 7 -R 5 -R 6 - are each independently selected from
  • B is selected from the group represented by Structural Formula 3:
  • m is selected from an integer of 1 to 4
  • R 8 , R 9 and R 10 are each independently selected from C1-C3 hydrocarbylene, C1-C3 alkoxy, oxygen atom, At least one of R 8 , R 9 and R 10 is selected from And at least one of R 8 , R 9 and R 10 is selected from oxygen atoms.
  • the combined groups of -R 9 -R 8 -R 10 - are each independently selected from
  • D and E are each independently selected from groups represented by structural formula 4:
  • z is selected from an integer from 0 to 4
  • R 11 and R 13 are each independently selected from a single bond or a C1-C5 hydrocarbylene group
  • R 12 is selected from a single bond
  • a and C are the same as each other, A and B are the same or different from each other, and D and E are the same as each other.
  • the compound represented by the structural formula 1 is a symmetrical structure, and the compound represented by the structural formula 1 of the symmetrical structure is more convenient in synthesis than the asymmetrical structure, The yield of the product is higher, which is beneficial to reduce the production cost.
  • D and E are each independently selected from single bonds or C1-C5 hydrocarbylene groups
  • A, B, and C are each independently selected from substituted or unsubstituted cyclic carbonate groups, cyclic sulfate groups , cyclic sulfite group, cyclic sulfonate group, cyclic sulfone group, cyclic sulfoxide group, cyclic carboxylate group or cyclic acid anhydride group.
  • the substituent when A, B or C is substituted, is selected from halogen, hydrocarbyl or halogenated hydrocarbyl, more preferably, when A, B or C is substituted, the substituent is selected from halogen, alkyl or haloalkyl.
  • the compound represented by structural formula 1 can be selected from one or more of the following compounds:
  • D and E are each independently selected from groups represented by structural formula 4:
  • z is selected from an integer of 1-4
  • R 11 and R 13 are each independently selected from a single bond or a C1-C5 hydrocarbylene group
  • R 12 is selected from
  • A, B and C are each independently selected from substituted or unsubstituted cyclic carbonate groups, cyclic sulfate groups, cyclic sulfite groups, cyclic sulfonate groups, cyclic sulfone groups, cyclic sulfoxide groups group, cyclic carboxylate group or cyclic acid anhydride group.
  • the substituent is selected from halogen, hydrocarbyl or halogenated hydrocarbyl, more preferably, when A, B or C is substituted, the substituent is selected from halogen, alkyl or haloalkyl.
  • the compound represented by structural formula 1 can be selected from one or more of the following compounds:
  • the compound represented by the structural formula 1 can also be selected from one or more of the following compounds:
  • Compound 1 can be prepared by the following methods:
  • the organic solvents such as sorbitol, dimethyl carbonate, methanol alkaline substance catalyst potassium hydroxide and DMF are placed in the reaction vessel, and after reacting for several hours under heating conditions, a certain amount of oxalic acid is added to adjust the pH to neutrality, and the solution is filtered. After recrystallization, intermediate product 1 can be obtained, and then intermediate product 1, carbonate, thionyl chloride, etc. are esterified under high temperature conditions to obtain intermediate product 2, and then intermediate product 2 is obtained by using an oxidant such as sodium periodate. Compound 1 can be obtained by oxidation.
  • Compound 2 can be made by:
  • the solvent includes one or more of ether-based solvents, nitrile-based solvents, carbonate-based solvents, and carboxylate-based solvents.
  • the ether solvent includes cyclic ether or chain ether.
  • cyclic ethers examples include 1,3-dioxolane (DOL), 1,4-dioxoxane (DX), crown ethers, tetrahydrofuran (THF), 2-methyltetrahydrofuran (2 -CH3 -THF), one or more of 2-trifluoromethyltetrahydrofuran (2- CF3 -THF).
  • DOL 1,3-dioxolane
  • DX 1,4-dioxoxane
  • crown ethers examples include tetrahydrofuran (THF), 2-methyltetrahydrofuran (2 -CH3 -THF), one or more of 2-trifluoromethyltetrahydrofuran (2- CF3 -THF).
  • chain ethers examples include one or more of dimethoxymethane (DMM), 1,2-dimethoxyethane (DME), and diglyme (TEGDME) .
  • DDM dimethoxymethane
  • DME 1,2-dimethoxyethane
  • TEGDME diglyme
  • nitrile-based solvent one or more of acetonitrile, glutaronitrile, and malononitrile can be mentioned.
  • carbonate-based solvents include cyclic carbonates or chain carbonates.
  • cyclic carbonates include one or more of ethylene carbonate (EC), propylene carbonate (PC), ⁇ -butyrolactone (GBL), and butylene carbonate (BC).
  • EC ethylene carbonate
  • PC propylene carbonate
  • GBL ⁇ -butyrolactone
  • BC butylene carbonate
  • chain carbonates examples include dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), methyl-n-propyl carbonate, ethyl-n-propyl carbonate One or more of ester, dipropyl carbonate (DPC).
  • DMC dimethyl carbonate
  • EMC ethyl methyl carbonate
  • DEC diethyl carbonate
  • methyl-n-propyl carbonate ethyl-n-propyl carbonate
  • DPC dipropyl carbonate
  • the carboxylate solvent includes cyclic carboxylate or chain carbonate.
  • cyclic carboxylic acid esters include one or more of ⁇ -butyrolactone, ⁇ -valerolactone, and ⁇ -valerolactone.
  • chain carbonates examples include methyl acetate (MA), ethyl acetate (EA), propyl acetate (EP), butyl acetate, propyl propionate (PP), and butyl propionate. one or more of.
  • the electrolyte salt is selected from lithium salts.
  • the electrolyte salt is selected from LiPF 6 , LiBF 4 , LiBOB, LiDFOB, LiN(SO 2 CF 3 ) 2 , LiN(SO 2 C 2 F 5 ) 2 , LiC(SO 2 CF 3 ) 3.
  • the concentration of the electrolyte salt is 0.1 mol/L-8 mol/L.
  • the concentration of the electrolyte salt is 0.5mol/L-4mol/L.
  • the concentration of the electrolyte salt may be 0.5 mol/L, 1 mol/L, 1.5 mol/L, 2 mol/L, 2.5 mol/L, 3 mol/L, 3.5 mol/L or 4 mol/L.
  • the non-aqueous electrolyte further includes auxiliary additives
  • the auxiliary additives include unsaturated cyclic carbonate compounds, fluorinated cyclic carbonate compounds, aromatic additives, fluorine-containing anisole compounds, At least one of dicarboxylic anhydride, lithium difluorophosphate, and lithium bisfluorosulfonimide (LiFSI).
  • the unsaturated cyclic carbonate compounds include vinylene carbonate (VC), vinylethylene carbonate (VEC), 4,5-dimethyl vinylene carbonate, phenylene carbonate At least one of vinyl ester and 4,5-divinyl ethylene carbonate;
  • the non-aqueous electrolyte contains unsaturated cyclic carbonate compounds, based on the total mass of the non-aqueous electrolyte as 100%, the content of unsaturated cyclic carbonate compounds is 0.1-5%;
  • the fluorinated cyclic carbonate compounds include fluoroethylene carbonate (FEC), 4,4-difluoroethylene carbonate, 4,5-difluoroethylene carbonate, 4- Fluoro-4-methylethylene carbonate, 4,5-difluoro-4-methylethylene carbonate, 4-fluoro-5-methylethylene carbonate, 4,4-difluoro-5-methyl Ethylene carbonate, 4-(fluoromethyl) ethylene carbonate, 4-(difluoromethyl) ethylene carbonate, 4-(trifluoromethyl) ethylene carbonate, 4-(fluoromethyl) )-4-fluoroethylene carbonate, 4-(fluoromethyl)-5-fluoroethylene carbonate, 4-fluoro-4,5-dimethylethylene carbonate, 4,5-difluoro-4 , one or more of 5-dimethyl ethylene carbonate and 4,4-difluoro-5,5-dimethyl ethylene carbonate.
  • FEC fluoroethylene carbonate
  • the non-aqueous electrolyte contains fluorinated cyclic carbonate compounds, based on the total mass of the non-aqueous electrolyte as 100%, the content of the fluorinated cyclic carbonate compounds is 0.1-30% ;
  • the aromatic additives include biphenyls, alkyl biphenyls, terphenyls, partial hydrides of terphenyls, cyclohexylbenzene, tert-butylbenzene, tert-amylbenzene, diphenyl ether, diphenyl Aromatic compounds such as furan; one or more of 2-fluorobiphenyl, o-cyclohexyl fluorobenzene and p-cyclohexyl fluorobenzene.
  • the mass percentage content of the aromatic additives is 0.1-5% based on the total mass of the non-aqueous electrolyte as 100%.
  • the fluoroanisole compound includes one or more of 2,4-difluoroanisole, 2,5-difluoroanisole, and 2,6-difluoroanisole.
  • the non-aqueous electrolyte contains a fluorine-containing anisole compound, based on the total mass of the non-aqueous electrolyte as 100%, the mass percentage of the fluorine-containing anisole compound is 0.1-5%.
  • the dicarboxylic acid anhydride includes one or more of succinic acid, maleic acid, and phthalic acid.
  • the mass percentage of the dicarboxylic anhydride is 0.1-5% based on the total mass of the non-aqueous electrolyte as 100%.
  • the mass percentage of the lithium difluorophosphate is 0.1- 2%;
  • the non-aqueous electrolyte contains lithium bis(fluorosulfonyl)imide (LiFSI), based on 100% of the total mass of the non-aqueous electrolyte, the bis(fluorosulfonyl) The mass percentage content of lithium imide (LiFSI) is 0.1-5%.
  • the auxiliary additives further include 1-methyl-2-pyrrolidone, 1-methyl-2-piperidone, 3-methyl-2-oxazolidinone, 1,3-dimethylone Nitrogen-containing compounds such as base-2-imidazolidinone and N-methylsuccinimide; hydrocarbon compounds such as heptane, octane, and cycloheptane; fluorine-containing aromatic compounds such as fluorobenzene, difluorobenzene, and trifluorotoluene Wait.
  • Nitrogen-containing compounds such as base-2-imidazolidinone and N-methylsuccinimide
  • hydrocarbon compounds such as heptane, octane, and cycloheptane
  • fluorine-containing aromatic compounds such as fluorobenzene, difluorobenzene, and trifluorotoluene Wait.
  • the mass percentage content of any optional substance in the auxiliary additives in the non-aqueous electrolyte solution is in the range of 10% or less, preferably, the mass percentage content is 0.1% -5%.
  • the positive active material is selected from LiNi 0.5 Co 0.2 Mn 0.3 O 2 , LiNi 0.6 Co 0.2 Mn 0.2 O 2 , LiNi 0.7 Co 0.1 Mn 0.2 O 2 , LiNi 0.8 Co 0.1 Mn 0.1 O 2 , One or more of LiNi 0.6 Mn 0.4 O 2 and LiNi 0.8 Mn 0.2 O 2 .
  • the positive electrode further includes a positive electrode current collector, and the positive electrode material layer covers the surface of the positive electrode current collector.
  • the positive electrode current collector is selected from metal materials that can conduct electrons.
  • the positive electrode current collector includes one or more of Al, Ni, and stainless steel.
  • the positive electrode current collector is selected from the group consisting of: aluminum foil.
  • the positive electrode material layer further includes a positive electrode binder and a positive electrode conductive agent, and the positive electrode active material, the positive electrode binder and the positive electrode conductive agent are blended to obtain the positive electrode material layer.
  • the positive electrode binder includes polyvinylidene fluoride, vinylidene fluoride copolymer, polytetrafluoroethylene, vinylidene fluoride-hexafluoropropylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene- Perfluoroalkyl vinyl ether copolymer, ethylene-tetrafluoroethylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, vinylidene fluoride-trifluoroethylene copolymer, vinylidene fluoride-trichloroethylene copolymer Copolymers, vinylidene fluoride-vinyl fluoride copolymers, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymers, thermoplastic polyimides, thermoplastic resins such as polyethylene and polypropylene; acrylic resins;
  • the positive electrode conductive agent includes one or more of conductive carbon black, conductive carbon balls, conductive graphite, conductive carbon fibers, carbon nanotubes, graphene or reduced graphene oxide.
  • the negative electrode includes a negative electrode material layer, the negative electrode material layer includes a negative electrode active material, and the negative electrode active material includes one or more of a silicon-based negative electrode, a carbon-based negative electrode, a tin-based negative electrode, and a lithium negative electrode kind.
  • the silicon-based negative electrode includes one or more of silicon material, silicon oxide, silicon-carbon composite material and silicon alloy material;
  • the carbon-based negative electrode includes graphite, hard carbon, soft carbon, graphene, intermediate One or more of phase carbon microspheres;
  • the tin-based negative electrode includes one or more of tin, tin carbon, tin oxygen, and tin metal compounds;
  • the lithium negative electrode includes one or more of metallic lithium or lithium alloys. one or more.
  • the lithium alloy may be at least one of a lithium-silicon alloy, a lithium-sodium alloy, a lithium-potassium alloy, a lithium-aluminum alloy, a lithium-tin alloy, and a lithium-indium alloy.
  • the negative electrode further includes a negative electrode current collector, and the negative electrode material layer covers the surface of the negative electrode current collector.
  • the negative electrode current collector is selected from metal materials that can conduct electrons.
  • the negative electrode current collector includes one or more of Cu, Ni, and stainless steel.
  • the negative electrode current collector is selected from the group consisting of: copper foil.
  • the negative electrode material layer further includes a negative electrode binder and a negative electrode conductive agent, and the negative electrode material layer is obtained by blending the negative electrode active material, the negative electrode binder and the negative electrode conductive agent.
  • the negative electrode binder includes polyvinylidene fluoride, vinylidene fluoride copolymer, polytetrafluoroethylene, vinylidene fluoride-hexafluoropropylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene- Perfluoroalkyl vinyl ether copolymer, ethylene-tetrafluoroethylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, vinylidene fluoride-trifluoroethylene copolymer, vinylidene fluoride-trichloroethylene copolymer Copolymers, vinylidene fluoride-vinyl fluoride copolymers, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymers, thermoplastic polyimides, thermoplastic resins such as polyethylene and polypropylene; acrylic resins;
  • the negative electrode conductive agent includes one or more of conductive carbon black, conductive carbon ball, conductive graphite, conductive carbon fiber, carbon nanotube, graphene or reduced graphene oxide.
  • the battery further includes a separator located between the positive electrode and the negative electrode.
  • the separator can be an existing conventional separator, which can be a ceramic separator, a polymer separator, a non-woven fabric, an inorganic-organic composite separator, etc., including but not limited to single-layer PP (polypropylene), single-layer PE (polyethylene), Diaphragms such as double-layer PP/PE, double-layer PP/PP and triple-layer PP/PE/PP.
  • PP polypropylene
  • PE polyethylene
  • Diaphragms such as double-layer PP/PE, double-layer PP/PP and triple-layer PP/PE/PP.
  • the concentration is 1 mol/L, and then each additive is added according to the following tables. The amount of the additive is calculated as a percentage of the total mass of the electrolyte.
  • the cathode active material, conductive carbon black Super-P, and binder polyvinylidene fluoride (PVDF) were mixed in a mass ratio of 93:4:3, and then dispersed in N-methyl-2-pyrrolidone (NMP) , to obtain a positive electrode slurry.
  • NMP N-methyl-2-pyrrolidone
  • the positive electrode active material is shown in the following tables.
  • the positive electrode slurry is uniformly coated on both sides of the aluminum foil, and the positive electrode plate is obtained after drying, calendering and vacuum drying, and welding the aluminum lead wire with an ultrasonic welder.
  • the thickness is 120-150 ⁇ m.
  • a three-layer separator with a thickness of 20 ⁇ m is placed between the positive plate and the negative plate, and then the sandwich structure composed of the positive plate, the negative plate and the separator is wound, and then the rolled body is flattened and placed in an aluminum foil packaging bag. Vacuum bake at 75°C for 48h to obtain the cell to be injected.
  • the electrolyte prepared above was injected into the cells, sealed in vacuum, and left at 45°C for 24 hours.
  • the routine formation of the first charging is carried out according to the following steps: 0.05C constant current charging for 180min, 0.1C constant current charging for 180min, 0.2C constant current charging for 120min, aging at 45°C for 48h, secondary vacuum sealing, and then further charging with 0.2C Constant current charging to 4.4V (LiNi 0.5 Co 0.2 Mn 0.3 O 2 /AG) or 4.2V (LiNi 0.8 Co 0.15 Al 0.05 O 2 /AG) or 4.2V (LiNi 0.8 Co 0.1 Mn 0.1 O 2 /AG) or 4.25V (LiNi 0.7 Co 0.1 Mn 0.2 O 2 /AG) or 4.35V (LiNi 0.6 Co 0.2 Mn 0.2 O 2 /AG), discharge to 3.0V at a constant current of 0.2C.
  • the prepared lithium-ion battery was placed in an oven with a constant temperature of 45 °C and charged to 4.4V (LiNi 0.5 Co 0.2 Mn 0.3 O 2 /AG) or 4.2V (LiNi 0.8 Co 0.15 Al 0.05 O 2 / AG) at a constant current of 1 C. AG) or 4.2V (LiNi 0.8 Co 0.1 Mn 0.1 O 2 /AG) or 4.25V (LiNi 0.7 Co 0.1 Mn 0.2 O 2 /AG) or 4.35V (LiNi 0.6 Co 0.2 Mn 0.2 O 2 /AG), then constant Charge the battery at a constant voltage until the current drops to 0.05C, and then discharge it at a constant current of 1C to 3.0V. This cycle records the first discharge capacity and the last discharge capacity, and measures the initial battery volume and after 1000 cycles. volume of.
  • the capacity retention rate for high temperature cycling is calculated as follows:
  • Capacity retention rate last discharge capacity/first discharge capacity ⁇ 100%.
  • Volume expansion rate (%) (battery volume after cycling-initial battery volume)/initial battery volume ⁇ 100%.
  • Example 7 The lithium ion batteries obtained in Example 7 and Comparative Example 1 were placed in an oven with a constant temperature of 45°C, charged to 4.4V (LiNi 0.5 Co 0.2 Mn 0.3 O 2 /AG) at a constant current of 1 C, and then charged at a constant current Constant voltage charge until the current drops to 0.05C, and then discharge to 3.0V with a constant current of 1C. After 1000 cycles in this way, the lithium ion battery is disassembled, and the positive electrode is taken out for transmission electron microscope observation.
  • the positive electrode TEM image of Example 7 is as follows As shown in FIG. 1 , the TEM image of the positive electrode of Comparative Example 1 is shown in FIG. 2 .

Landscapes

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

Abstract

为克服现有高镍高压锂离子电池存在产气严重以及高温循环性能差的问题，本发明提供了一种锂离子电池，包括正极、负极和非水电解液，所述正极包括正极材料层，所述正极材料层包括正极活性材料，所述正极活性材料包括LiNi xCo yMn zL (1-x-y-z)O 2，其中，L为Al、Sr、Mg、Ti、Ca、Zr、Zn、Si、Cu、V或Fe，0.5≤x≤1，0≤y≤0.5，0≤z≤0.5，0≤x+y+z≤1，所述锂离子电池的上限电压≥4.2V；所述非水电解液包括溶剂、电解质盐和结构式1所示的化合物： A-D-B-E-C 结构式1 以所述非水电解液的总质量为100％计，所述结构式1所示的化合物的添加量为0.01～5.0％。本发明采用结构式1所示的化合物与高镍三元材料合用，得到了一种高温循环容量保持率较高且循环产气较小的三元高镍锂离子电池。

Description

一种锂离子电池 技术领域
本发明属于二次电池技术领域，具体涉及一种锂离子电池。
背景技术
锂离子电池因其优良的性能广泛应用于生活生产中，近年来，随着消费类电子产品和新能源汽车的发展，人们对锂离子电池的性能提出了更高的要求，尤其是高温条件下的循环性能有待进一步提升。在锂离子电池循环过程中，尤其是高镍高压三元电池体系，当三元正极材料中的镍含量和工作电压都较高时，锂离子电池的循环产气现象更为严重，可能的原因为：一方面，随着镍含量的提升，正极材料表面原有的碱性化合物含量增加，尤其是碳酸锂的含量，在电池循环过程中，碳酸锂会发生分解产生气体；另一方面，高镍三元材料中锂离子能脱嵌的比例更多，此时正极材料的结构极易发生变化甚至坍塌，这会造成正极保护膜的破裂，导致正极材料直接暴露在电解液中发生副反应产生大量气体，同时镍离子活性较高，电解液在含镍量高的正极材料表面发生氧化分解更容易并且更快，进一步增大循环产气并劣化高温循环性能。
发明内容
针对现有高镍锂离子电池存在产气严重以及高温循环性能差的问题，本发明提供了一种锂离子电池。
本发明解决上述技术问题所采用的技术方案如下：
本发明提供了一种锂离子电池，包括正极、负极和非水电解液，所述正极包括正极材料层，所述正极材料层包括正极活性材料，所述正极活性材料包括LiNi xCo yMn zL (1-x-y-z)O 2，其中，L为Al、Sr、Mg、Ti、Ca、Zr、Zn、Si、Cu、V或Fe，0.5≤x≤1，0≤y≤0.5，0≤z≤0.5，0≤x+y+z≤1，所述锂离子电池的上限电压≥4.2V；
所述非水电解液包括溶剂、电解质盐和结构式1所示的化合物：
A-D-B-E-C
结构式1
其中，A、B、C各自独立地选自含有环状碳酸酯基、环状硫酸酯基、环状亚硫酸酯基、环状磺酸酯基、环状砜基、环状亚砜基、环状羧酸酯基或环状酸酐基的基团；
D、E各自独立地选自单键、或含有亚烃基、醚键、硫氧双键或碳氧双键的基团；
以所述非水电解液的总质量为100％计，所述结构式1所示的化合物的添加量为0.01～5.0％。
可选的，A、B、C各自独立地含有的环状碳酸酯基、环状硫酸酯基、环状亚硫酸酯基、环状磺酸酯基、环状砜基、环状亚砜基、环状羧酸酯基或环状酸酐基的数量为1～5，且A、B、C的环状碳酸酯基、环状硫酸酯基、环状亚硫酸酯基、环状磺酸酯基、环状砜基、环状亚砜基、环状羧酸酯基或环状酸酐基的总数量小于等于10。
可选的，A、C各自独立地选自结构式2所示的基团：
Figure PCTCN2021138677-appb-000001
结构式2
其中，n选自0～4的整数，R 1选自氢、卤素或C1～C5的卤代烃基；R 2、R 3、R 4、R 5、R 6、R 7各自独立地选自C1～C3的亚烃基、C1～C3的烷氧基、氧原子、
Figure PCTCN2021138677-appb-000002
R 2、R 3、R 4中至少一个选自
Figure PCTCN2021138677-appb-000003
且R 2、R 3、R 4中至少一个选自氧原子，R 5、R 6、R 7中至少一个选自
Figure PCTCN2021138677-appb-000004
且R 5、R 6、R 7中至少一个选自氧原子。
可选的，B选自结构式3所示的基团：
Figure PCTCN2021138677-appb-000005
结构式3
其中，m选自1～4的整数，R 8、R 9、R 10各自独立地选自C1～C3的亚烃基、C1～C3的烷氧基、氧原子、
Figure PCTCN2021138677-appb-000006
R 8、R 9、R 10中至少一个选自
Figure PCTCN2021138677-appb-000007
且R 8、R 9、R 10中至少一个选自氧原子。
可选的，D、E各自独立地选自结构式4所示的基团：
Figure PCTCN2021138677-appb-000008
结构式4
其中，z选自0～4的整数，R 11和R 13各自独立地选自单键或C1～C5的亚烃基，R 12选自单键、
Figure PCTCN2021138677-appb-000009
Figure PCTCN2021138677-appb-000010
可选的，D、E各自独立地选自单键或C1～C5的亚烃基，A、B、C各自独立地选自取代或未取代的环状碳酸酯基、环状硫酸酯基、环状亚硫酸酯基、环状磺酸酯基、环状砜基、环状亚砜基、环状羧酸酯基或环状酸酐基；
可选的，A、B或C经取代时，取代基选自卤素、烃基或卤代烃基。
可选的，A、B或C经取代时，取代基选自卤素、烷基或卤代烷基。
可选的，A与C彼此相同，A与B彼此相同或不同，D与E彼此相同。
可选的，所述结构式1所示的化合物选自以下化合物中的一种或多种：
Figure PCTCN2021138677-appb-000011
Figure PCTCN2021138677-appb-000012
Figure PCTCN2021138677-appb-000013
Figure PCTCN2021138677-appb-000014
可选的，所述正极活性材料选自LiNi 0.5Co 0.2Mn 0.3O 2、LiNi 0.6Co 0.2Mn 0.2O 2、LiNi 0.7Co 0.1Mn 0.2O 2、LiNi 0.8Co 0.15Al 0.05O 2、LiNi 0.8Co 0.1Mn 0.1O 2、LiNi 0.6Mn 0.4O 2和LiNi 0.8Mn 0.2O 2的一种或多种。
可选的，所述非水电解液还包括辅助添加剂，所述辅助添加剂包括不饱和环状碳酸酯类化合物、氟代环状碳酸酯类化合物、芳香族添加剂、含氟茴香醚化合物、二羧酸酐、二氟磷酸锂、双氟磺酰亚胺锂(LiFSI)中的至少一种。
根据本发明提供的锂离子电池，发明人发现，结构式1所示的化合物与高镍三元材料合用时，能够得到一种高温循环容量保持率较高且循环产气较小的三元高镍锂离子电池，其中，结构式1所示的化合物在正极表面分解形成保护膜，均一的覆盖在正极材料表面，一方面抑制正极材料表面原有的碳酸锂等碱性氧化物的分解，减少气体的生成，另一方面可以很好的保护正极结构稳定，推测是结构式1在正极表面的分解产物与镍离子络合形成了较为稳固的保护膜，限制其溶出，同时形成的膜具有一定弹性，会随着正极材料的膨胀收缩而发生对应的膨胀收缩，实现对正极的保护，且在充放电循环中不易发生破裂。
附图说明
图1是本发明实施例7提供的循环后正极TEM图；
图2是本发明对比例1提供的循环后正极TEM图。
具体实施方式
为了使本发明所解决的技术问题、技术方案及有益效果更加清楚明白，以下结合附图及实施例，对本发明进行进一步详细说明。应当理解，此处所描述的具体实施例仅仅用以解释本发明，并不用于限定本发明。
本发明一实施例提供了一种锂离子电池，包括正极、负极和非水电解液，所述正极包括正极材料层，所述正极材料层包括正极活性材料，所述正极活性材料包括LiNi xCo yMn zL (1-x-y-z)O 2，其中，L为Al、Sr、Mg、Ti、Ca、Zr、Zn、Si、Cu、V或Fe，0.5≤x≤1，0≤y≤0.5，0≤z≤0.5，0≤x+y+z≤1，所述锂离子电池的上限电压≥4.2V；
所述非水电解液包括溶剂、电解质盐和结构式1所示的化合物：
A-D-B-E-C
结构式1
其中，A、B、C各自独立地选自含有环状碳酸酯基、环状硫酸酯基、环状亚硫酸酯基、环状磺酸酯基、环状砜基、环状亚砜基、环状羧酸酯基或环状酸酐基的基团；
D、E各自独立地选自单键、或含有亚烃基、醚键、硫氧双键或碳氧双键的基团；
以所述非水电解液的总质量为100％计，所述结构式1所示的化合物的添加量为0.01～5.0％。
在本发明提供的锂离子电池中，结构式1所示的化合物在正极表面分解形成保护膜，均一的覆盖在正极材料表面，一方面抑制正极材料表面原有的碳酸锂等碱性氧化物的分解，减少气体的生成，另一方面可以很好的保护正极结构稳定，推测是结构式1在正极表面的分解产物与镍离子络合形成了较为稳固的保护膜，限制其溶出，同时形成的膜具有一定弹性，会随着正极材料的膨胀收缩而发生对应的膨胀收缩，实现对正极的保护，且在充放电循环中不易发生破裂。
需要说明的是，电池的性能与正极活性材料中的镍含量以及非水电解液中的结构式1所示的化合物含量相关，当正极活性材料中的镍含量过少时，添加结构式1所示的化合物虽然能够对电池的高温循环性能起到一定的改善作用，但其改善效果相对较低，而正极活性材料中的镍含量较高(0.5≤x≤1)的情况下，结构式1所示的化合物则对电池的高温循环性能起到极其优异的改善效果，说明正极活性材料中镍的存在与结构式1所示的化合物存在明确的关联，随着镍含量的提高，结构式1所示的化合物越能发挥其对电池的改善作用。同时，在所述结构式1所示的化合物的添加量过少时，起不到成膜保护作用，对电池性能的改善效果不明显；当所述结构式1所示的化合物的添加量过多时，不仅会成膜太厚造成阻抗增大，还会显著提高电解液的黏度，影响电池性能的发挥，因此，添加适量的结构式1所示的化合物才能与高镍三元材料具有较好的配合效果。
当锂离子电池的充电上限电压较高时，其电解液更容易发生分解，而结构式1所示的化合物能够有效抑制在高电压条件下电解液的分解，因此特别适用于上限电压≥4.2V的高电压锂离子电池。
在一些实施例中，x选自0.5、0.55、0.6、0.65、0.7、0.75、0.8、0.83、0.85、0.88、0.90、0.95。
在一些实施例中，所述正极活性材料选自LiNi 0.5Co 0.2Mn 0.3O 2、LiNi 0.6Co 0.2Mn 0.2O 2、LiNi 0.7Co 0.1Mn 0.2O 2、LiNi 0.8Co 0.15Al 0.05O 2、LiNi 0.8Co 0.1Mn 0.1O 2、LiNi 0.6Mn 0.4O 2和LiNi 0.8Mn 0.2O 2的一种或多种。
在一些实施例中，所述正极活性材料通过掺杂的方式引入元素L，L为Al、Sr、Mg、Ti、Ca、Zr、Zn、Si、Cu、V或Fe，掺杂的元素L可以提供较Ni、Co、Mn等活性过渡金属更强的A-O化学键，抑制高电压下晶格氧的析出，提高材料结构的稳定性。
在一些实施例中，A、B、C各自独立地含有的环状碳酸酯基、环状硫酸酯基、环状亚硫酸酯基、环状磺酸酯基、环状砜基、环状亚砜基、环状羧酸酯基或环状酸酐基的数量为1～5，且A、B、C的环状碳酸酯基、环状硫酸酯基、环状亚硫酸酯基、环状磺酸酯基、环状砜基、环状亚砜基、环状羧酸酯基或环状酸酐基的总数量小于等于10。
在一些实施例中，A、C各自独立地选自结构式2所示的基团：
Figure PCTCN2021138677-appb-000015
结构式2
其中，n选自0～4的整数，R 1选自氢、卤素或C1～C5的卤代烃基；R 2、R 3、R 4、R 5、R 6、R 7各自独立地选自C1～C3的亚烃基、C1～C3的烷氧基、氧原子、
Figure PCTCN2021138677-appb-000016
R 2、R 3、R 4中至少一个选自
Figure PCTCN2021138677-appb-000017
且R 2、R 3、R 4中至少一个选自氧原子，R 5、R 6、R 7中至少一个选自
Figure PCTCN2021138677-appb-000018
且R 5、R 6、R 7中至少一个选自氧原子。
在优选的实施例中，-R 3-R 2-R 4-的组合基团和-R 7-R 5-R 6-的组合基团各自独立地选自
Figure PCTCN2021138677-appb-000019
在一些实施例中，B选自结构式3所示的基团：
Figure PCTCN2021138677-appb-000020
结构式3
其中，m选自1～4的整数，R 8、R 9、R 10各自独立地选自C1～C3的亚烃基、C1～C3的烷氧基、氧原子、
Figure PCTCN2021138677-appb-000021
R 8、R 9、R 10中至少一个选自
Figure PCTCN2021138677-appb-000022
且R 8、R 9、R 10中至少一个选自氧原子。
在优选的实施例中，-R 9-R 8-R 10-的组合基团各自独立地选自
Figure PCTCN2021138677-appb-000023
Figure PCTCN2021138677-appb-000024
在一些实施例中，D、E各自独立地选自结构式4所示的基团：
Figure PCTCN2021138677-appb-000025
结构式4
其中，z选自0～4的整数，R 11和R 13各自独立地选自单键或C1～C5的亚烃基，R 12选自单键、
Figure PCTCN2021138677-appb-000026
Figure PCTCN2021138677-appb-000027
在一些实施例中，A与C彼此相同，A与B彼此相同或不同，D与E彼此相同。
当A与C彼此相同，以及D与E彼此相同时，所述结构式1所示的化合物为对称结构，相比于非对称结构，对称结构的结构式1所示的化合物在合成上更为便捷，产品的收率更高，有利于降低生产成本。
在一些实施例中，D、E各自独立地选自单键或C1～C5的亚烃基，A、B、C各自独立地选自取代或未取代的环状碳酸酯基、环状硫酸酯基、环状亚硫酸酯基、环状磺酸酯基、环状砜基、环状亚砜基、环状羧酸酯基或环状酸酐基。优选的，A、B或C经取代时，取代基选自卤素、烃基或卤代烃基，更优选地，A、B或C经取代时，取代基选自卤素、烷基或卤代烷基。
作为示例，结构式1所示的化合物可选自以下化合物中的一种或多种：
Figure PCTCN2021138677-appb-000028
Figure PCTCN2021138677-appb-000029
在一些实施例中，D、E各自独立地选自结构式4所示的基团：
Figure PCTCN2021138677-appb-000030
结构式4
其中，z选自1～4的整数，R 11和R 13各自独立地选自单键或C1～C5的亚烃基，R 12选自
Figure PCTCN2021138677-appb-000031
Figure PCTCN2021138677-appb-000032
Figure PCTCN2021138677-appb-000033
A、B、C各自独立地选自取代或未取代的环状碳酸酯基、环状硫酸酯基、环状亚硫酸酯基、环状磺酸酯基、环状砜基、环状亚砜基、环状羧酸酯基或环状酸酐基。优选的，A、B或C经取代时，取代基选自卤素、烃基或卤代烃基，更优选地，A、B或C经取代时，取代基选自卤素、烷基或卤代烷基。
作为示例，结构式1所示的化合物可选自以下化合物中的一种或多种：
Figure PCTCN2021138677-appb-000034
Figure PCTCN2021138677-appb-000035
在一些实施例中，所述结构式1所示的化合物还可选自以下化合物中的一种或多种：
Figure PCTCN2021138677-appb-000036
Figure PCTCN2021138677-appb-000037
需要说明的是，以上是本发明所要求保护的部分化合物，但不限于此，不应理解为对本发明的限制。
本领域技术人员在知晓结构式1的化合物的结构式的情况下，根据化学合成领域的公知常识可以知晓上述化合物的制备方法。例如：
化合物1可通过以下方法制成：
将山梨醇、碳酸二甲酯、甲醇碱性物质催化剂氢氧化钾以及DMF等有机溶剂置于反应容器中，在加热条件下进行反应数小时后，加入一定量的草酸调节pH至中性，过滤、重结晶后即可得到中间产物1，接着将中间产物1、碳酸酯、二氯亚砜等在高温条件下发生酯化反应得到中间产物2，再使用高碘酸钠等氧化剂将中间产物2氧化即可得到化合物1。
化合物2可通过以下方法制成：
将双丙酮-D-甘露醇、碳酸二甲酯、甲醇、碳酸钾和二氧六环等在加热、搅拌下进行反应数小时后，加入一定量的草酸调节溶液pH到中性，过滤、浓缩后获得中间产物3；在中间产物3中加入适量的纯水、碳酸酯、酸等进行水解反应获得中间产物4；然后将中间产物4、二氯亚砜和碳酸酯溶剂在加热的条件下制备得到中间产物5；最后使用高碘酸钠等氧化剂将中间产物5氧化即可得到化合物2。
在一些实施例中，所述溶剂包括醚类溶剂、腈类溶剂、碳酸酯类溶剂和羧酸酯类溶剂中的一种或多种。
其中，醚类溶剂包括环状醚或链状醚。
作为环状醚的例子，可以列举如：1,3-二氧戊烷(DOL)、1,4-二氧惡烷(DX)、冠醚、四氢呋喃(THF)、2-甲基四氢呋喃(2-CH 3-THF)，2-三氟甲基四氢呋喃(2-CF 3-THF)中的一种或多种。
作为链状醚的例子，可以列举如：二甲氧基甲烷(DMM)、1,2-二甲氧基乙烷(DME)、二甘醇二甲醚(TEGDME)中的一种或多种。
其中，作为腈类溶剂的例子，可以列举如：乙腈、戊二腈、丙二腈中的一种或多种。
其中，碳酸酯类溶剂包括环状碳酸酯或链状碳酸酯。
作为环状碳酸酯的例子，可以列举如：碳酸乙烯酯(EC)、碳酸丙烯酯(PC)、γ-丁内酯(GBL)、碳酸亚丁酯(BC)中的一种或多种。
作为链状碳酸酯的例子，可以列举如：碳酸二甲酯(DMC)、碳酸甲乙酯(EMC)、碳酸二乙酯(DEC)、碳酸甲基正丙基酯、碳酸乙基正丙基酯、碳酸二丙酯(DPC)中的一种或多种。
其中，羧酸酯类溶剂包括环状羧酸酯或链状碳酸酯。
作为环状羧酸酯的例子，可以列举如：γ-丁内酯、γ-戊内酯、δ-戊内酯中的一种或多种。
作为链状碳酸酯的例子，可以列举如：乙酸甲酯(MA)、乙酸乙酯(EA)、乙酸丙酯(EP)、乙酸丁酯、丙酸丙酯(PP)、丙酸丁酯中的一种或多种。
在一些实施例中，所述电解质盐选自锂盐。在优选的实施例中，所述电解质盐选自LiPF 6、LiBF 4、LiBOB、LiDFOB、LiN(SO 2CF 3) 2、LiN(SO 2C 2F 5) 2、LiC(SO 2CF 3) 3、LiN(SO 2F) 2、LiClO 4、LiAsF 6、LiSbF 6、LiCF 3SO 3、Li 2B 10Cl 10、低级脂肪族羧酸锂盐、LiAlCl 4中的一种或多种。
在一些实施例中，所述非水电解液中，所述电解质盐的浓度为0.1mol/L-8mol/L。
在优选的实施例中，所述非水电解液中，所述电解质盐的浓度为0.5mol/L-4mol/L。具体的，所述电解质盐的浓度可以为0.5mol/L、1mol/L、1.5mol/L、2mol/L、2.5mol/L、3mol/L、3.5mol/L或4mol/L。
在一些实施例中，所述非水电解液还包括辅助添加剂，所述辅助添加剂包括不饱和环状碳酸酯类化合物、氟代环状碳酸酯类化合物、芳香族添加剂、含氟茴香醚化合物、二羧酸酐、二氟磷酸锂、双氟磺酰亚胺锂(LiFSI)中的至少一种。
在一些实施例中，所述不饱和环状碳酸酯类化合物包括碳酸亚乙烯酯(VC)、碳酸乙烯亚乙酯(VEC)、4，5-二甲基碳酸亚乙烯酯、苯基碳酸亚乙烯酯、4，5-二乙烯基碳酸亚乙酯中的至少一种；
当所述非水电解液中含有不饱和环状碳酸酯类化合物时，以所述非水电解液的总质量为100％计，不饱和环状碳酸酯类化合物含量为0.1-5％；
在一些实施例中，所述氟代环状碳酸酯类化合物包括氟代碳酸乙烯酯(FEC)、4，4-二氟碳酸亚乙酯、4，5-二氟碳酸亚乙酯、4-氟-4-甲基碳酸亚乙酯、4，5-二氟-4-甲基碳酸亚乙酯、4-氟-5-甲基碳酸亚乙酯、4，4-二氟-5-甲基碳酸亚乙酯、4-(氟甲基)碳酸亚乙酯、4-(二氟甲基)碳酸亚乙酯、4-(三氟甲基)碳酸亚乙酯、4-(氟甲基)-4-氟碳酸亚乙酯、4-(氟甲基)-5-氟碳酸亚乙酯、4-氟-4，5-二甲基碳酸亚乙酯、4，5-二氟-4，5-二甲基碳酸亚乙酯、4，4-二氟-5，5-二甲基碳酸亚乙酯中的一种或多种。
当所述非水电解液中含有氟代环状碳酸酯类化合物时，以所述非水电解液的总质量为100％计，所述氟代环状碳酸酯类化合物含量为0.1-30％；
在一些实施例中，所述芳香族添加剂包括联苯、烷基联苯、三联苯、三联苯的部分氢化物、环己基苯、叔丁基苯、叔戊基苯、二苯醚、二苯并呋喃等芳香族化合物；2-氟联苯、邻环己基氟苯、对环己基氟苯中的一种或多种。
当所述非水电解液中含有芳香族添加剂时，以所述非水电解液的总质量为100％计，所述芳香族添加剂的质量百分含量为0.1-5％。
在一些实施例中，所述含氟茴香醚化合物包括2，4-二氟茴香醚、2，5-二氟茴香醚、2，6-二氟茴香醚中的一种或多种。当所述非水电解液中含有含氟茴香醚化合物时，以所述非水电解液的总质量为100％计，所述含氟茴香醚化合物的质量百分含量为0.1-5％。
在一些实施例中，所述二羧酸酐包括琥珀酸、马来酸、苯二甲酸中的一种或多种。当所述非水电解液中含有二羧酸酐时，以所述非水电解液的总质量为100％计，所述二羧酸酐的质量百分含量为0.1-5％。
在一些实施例中，当所述非水电解液中含有二氟磷酸锂时，以所述非水电解液的总质量为100％计，所述二氟磷酸锂的质量百分含量为0.1-2％；
在一些实施例中，当所述非水电解液中含有双(氟磺酰)亚胺锂(LiFSI)时，以所述非水电解液的总质量为100％计，所述双(氟磺酰)亚胺锂(LiFSI)的质量百分含量为0.1-5％。
在一些实施例中，所述辅助添加剂还包括1-甲基-2-吡咯烷酮、1-甲基-2-哌啶酮、3-甲基-2-噁唑烷酮、1，3-二甲基-2-咪唑烷酮、N-甲基琥珀酰亚胺等含氮化合物；庚烷、辛烷、环庚烷等烃化合物；氟苯、二氟苯、三氟甲苯等含氟芳香族化合物等。
需要说明的是，除非特殊说明，一般情况下，所述辅助添加剂中任意一种可选物质在非水电解液中的质量百分含量范围为10％以下，优选的，质量百分含量为0.1-5％。
在优选的实施例中，所述正极活性材料选自LiNi 0.5Co 0.2Mn 0.3O 2、LiNi 0.6Co 0.2Mn 0.2O 2、LiNi 0.7Co 0.1Mn 0.2O 2、LiNi 0.8Co 0.1Mn 0.1O 2、LiNi 0.6Mn 0.4O 2和LiNi 0.8Mn 0.2O 2中的一种或多种。
在一些实施例中，所述正极还包括正极集流体，所述正极材料层覆盖于所述正极集流体的表面。所述正极集流体选自可传导电子的金属材料，优选的，所述正极集流体包括Al、Ni、不锈钢的一种或多种，在更优选的实施例中，所述正极集流体选自铝箔。
在一些实施例中，所述正极材料层还包括有正极粘结剂和正极导电剂，所述正极活性材料、所述正极粘结剂和所述正极导电剂共混得到所述正极材料层。
所述正极粘结剂包括聚偏氟乙烯、偏氟乙烯的共聚物、聚四氟乙烯、偏氟乙烯-六氟丙烯的共聚物、四氟乙烯-六氟丙烯的共聚物、四氟乙烯-全氟烷基乙烯基醚的共聚物、乙烯-四氟乙烯的共聚物、偏氟乙烯-四氟乙烯的共聚物、偏氟乙烯-三氟乙烯的共聚物、偏氟乙烯-三氯乙烯的共聚物、偏氟乙烯-氟代乙烯的共聚物、偏氟乙烯-六氟丙烯-四氟乙烯的共聚物、热塑性聚酰亚胺、聚乙烯及聚丙烯等热塑性树脂；丙烯 酸类树脂；以及苯乙烯丁二烯橡胶中的一种或多种。
所述正极导电剂包括导电炭黑、导电碳球、导电石墨、导电碳纤维、碳纳米管、石墨烯或还原氧化石墨烯中的一种或多种。
在一些实施例中，所述负极包括负极材料层，所述负极材料层包括负极活性材料，所述负极活性材料包括硅基负极、碳基负极、锡基负极、锂负极中的一种或多种。其中，所述硅基负极包括硅材料、硅的氧化物、硅碳复合材料以及硅合金材料中的一种或多种；所述碳基负极包括石墨、硬碳、软碳、石墨烯、中间相碳微球中的一种或多种；所述锡基负极包括锡、锡碳、锡氧、锡金属化合物中的一种或多种；所述锂负极包括金属锂或锂合金中的一种或多种。所述锂合金具体可以是锂硅合金、锂钠合金、锂钾合金、锂铝合金、锂锡合金和锂铟合金中的至少一种。
在一些实施例中，所述负极还包括负极集流体，所述负极材料层覆盖于所述负极集流体的表面。所述负极集流体选自可传导电子的金属材料，优选的，所述负极集流体包括Cu、Ni、不锈钢的一种或多种，在更优选的实施例中，所述负极集流体选自铜箔。
在一些实施例中，所述负极材料层还包括有负极粘结剂和负极导电剂，所述负极活性材料、所述负极粘结剂和所述负极导电剂共混得到所述负极材料层。
所述负极粘结剂包括聚偏氟乙烯、偏氟乙烯的共聚物、聚四氟乙烯、偏氟乙烯-六氟丙烯的共聚物、四氟乙烯-六氟丙烯的共聚物、四氟乙烯-全氟烷基乙烯基醚的共聚物、乙烯-四氟乙烯的共聚物、偏氟乙烯-四氟乙烯的共聚物、偏氟乙烯-三氟乙烯的共聚物、偏氟乙烯-三氯乙烯的共聚物、偏氟乙烯-氟代乙烯的共聚物、偏氟乙烯-六氟丙烯-四氟乙烯的共聚物、热塑性聚酰亚胺、聚乙烯及聚丙烯等热塑性树脂；丙烯酸类树脂；以及苯乙烯丁二烯橡胶中的一种或多种。
所述负极导电剂包括导电炭黑、导电碳球、导电石墨、导电碳纤维、碳纳米管、石墨烯或还原氧化石墨烯中的一种或多种。
在一些实施例中，所述电池中还包括有隔膜，所述隔膜位于所述正极和所述负极之间。
所述隔膜可为现有常规隔膜，可以是陶瓷隔膜、聚合物隔膜、无纺布、无机-有机复合隔膜等，包括但不限于单层PP(聚丙烯)、单层PE(聚乙烯)、双层PP/PE、双层PP/PP和三层PP/PE/PP等隔膜。以下通过实施例对本发明进行进一步的说明。
一、实施例1～42和对比例1～9
1)电解液的制备
将碳酸乙烯酯(EC)、碳酸二乙酯(DEC)和碳酸甲乙酯(EMC)按质量比为EC:DEC:EMC＝1:1:1进行混合，然后加入六氟磷酸锂(LiPF 6)至摩尔浓度为1mol/L，然后按照以下各表格添加各添加剂。添加剂的用量，按照占电解液的总质量的百分比计。
2)正极板的制备
按93:4:3的质量比混合正极活性材料、导电碳黑Super-P和粘结剂聚偏二氟乙烯(PVDF)，然后将它们分散在N-甲基-2-吡咯烷酮(NMP)中，得到正极浆料。正极活性材料如以下各表格所示，将正极浆料均匀涂布在铝箔的两面上，经过烘干、压延和真空干燥，并用超声波焊机焊上铝制引出线后得到正极板，极板的厚度在120-150μm。
3)负极板的制备
按94:1:2.5:2.5的质量比混合负极活性材料石墨、导电碳黑Super-P，粘结剂丁苯橡胶(SBR)和羧甲基纤维素(CMC)，然后将它们分散在去离子水中，得到负极浆料。将负极浆料涂布在铜箔的两面上，经过烘干、压延和真空干燥，并用超声波焊机焊上镍制引出线后得到负极板，极板的厚度在120-150μm。
4)电芯的制备
在正极板和负极板之间放置厚度为20μm的三层隔离膜，然后将正极板、负极板和隔膜组成的三明治结构进行卷绕，再将卷绕体压扁后放入铝箔包装袋，在75℃下真空烘烤48h，得到待注液的电芯。
5)电芯的注液和化成
在水氧含量分别20ppm、50ppm以下的手套箱中，将上述制备的电解液注入电芯中，经真空封装，45℃搁置24h。
然后按以下步骤进行首次充电的常规化成：0.05C恒流充电180min,0.1C恒流充电180min，0.2C恒流充电120min，在45℃老化48h后，二次真空封口，然后进一步以0.2C的电流恒流充电至4.4V(LiNi 0.5Co 0.2Mn 0.3O 2/AG)或4.2V(LiNi 0.8Co 0.15Al 0.05O 2/AG)或4.2V(LiNi 0.8Co 0.1Mn 0.1O 2/AG)或4.25V(LiNi 0.7Co 0.1Mn 0.2O 2/AG)或4.35V(LiNi 0.6Co 0.2Mn 0.2O 2/AG)，以0.2C的电流恒流放电至3.0V。
二、性能测试
对实施例1～42和对比例1～9制备得到的锂离子电池进行如下性能测试：
高温循环性能测试
将制备的锂离子电池置于恒温45℃的烘箱中，以1C的电流恒流充电至4.4V(LiNi 0.5Co 0.2Mn 0.3O 2/AG)或4.2V(LiNi 0.8Co 0.15Al 0.05O 2/AG)或4.2V(LiNi 0.8Co 0.1Mn 0.1O 2/AG)或4.25V(LiNi 0.7Co 0.1Mn 0.2O 2/AG)或4.35V(LiNi 0.6Co 0.2Mn 0.2O 2/AG)，再恒流恒压充电至电流下降至0.05C，然后以1C的电流恒流放电至3.0V，如此循环，记录第1次的放电容量和最后一次的放电容量，测量电池初始电池体积及1000次循环后的体积。
按下式计算高温循环的容量保持率：
容量保持率＝最后一次的放电容量/第1次的放电容量×100％。
按下式计算高温循环的体积膨胀率：
体积膨胀率(％)＝(循环后电池体积-初始电池体积)/初始电池体积×100％。
以下数据测试所用电池除各表中所列出的区别外其它条件相同。
1、将实施例1～10和对比例1～4得到的测试结果填入表1。
表1
Figure PCTCN2021138677-appb-000038
由表1的测试结果可知，当正极活性材料为LiNi 0.5Co 0.2Mn 0.3O 2时，对比实施例1-10和对比例1可知，添加结构式1所示的化合物可以明显抑制高温循环产气，且当结构式1所示化合物的含量为1％～2％时，电池的高温循环体积膨胀率最小为7.2％-8.2％，并且此时拥有最优的高温循环容量保持率75.2％-77.2％；对比实施例1-10和对比例2-3可知，当结构式1所示的化合物的含量小于0.01％或大于5％时，电池的循环产气量出现明显上升，并且高温循环性能也出现明显下降，说明在高镍三元锂离子电池中，结构式1所示的化合物的合理添加量为0.01％-5％，过多或过少均不利于电池性能的提高。
2、将实施例7、11～14和对比例1、4～9得到的测试结果填入表2。
表2
Figure PCTCN2021138677-appb-000039
Figure PCTCN2021138677-appb-000040
对比实施例7、11-14和对比例1、4-9可以发现，当正极活性材料的镍含量较低时，对比例5中的循环体积膨胀率仍为48.4％，与对比例4之间的改善幅度远小于实施例7与对比例1之间的改善幅度，同时也明显小于实施例11-14和对比例6-9之间的改善幅度，并且对比例5中低镍电池体系的循环性能也没有明显提升，即结构式1所示的化合物对电池性能的提升作用与正极活性材料中的镍含量明显相关，当正极活性材料中镍含量高于一定值时，结构式1所示化合物才能发挥较好的配合作用。
3、将实施例15～24和对比例6得到的测试结果填入表3。
表3
Figure PCTCN2021138677-appb-000041
由表3的测试数据可知，当正极活性材料为LiNi 0.6Co 0.2Mn 0.2O 2时，对比实施例15-24和对比例6可知，添加结构式1所示的化合物均可以明显降低电池的循环产气并且提高高温循环性能，同时采用结构式1所示的不同化合物对于电池的高温循环性能均有不同程度的提升。
4、将实施例25～31和对比例7得到的测试结果填入表4。
表4
Figure PCTCN2021138677-appb-000042
由表4的测试数据可知，当正极活性材料为LiNi 0.7Co 0.1Mn 0.2O 2时，对比实施例25-30和对比例7可知，添加结构式1所示的化合物均可以明显降低电池的循环产气并且改善高温循环性能，同时采用结构式1所示的不同化合物对于电池的高温循环性能均有不同程度的提升。
5、将实施例32～35和对比例8得到的测试结果填入表5。
表5
Figure PCTCN2021138677-appb-000043
Figure PCTCN2021138677-appb-000044
由表5的测试数据可知，当正极活性材料为LiNi 0.8Co 0.15Al 0.05O 2时，对比实施例32-35和对比例8可知，添加结构式1所示的不同化合物均可以明显降低电池的循环产气，同时高温循环容量保持率也有明显的提升。
6、将实施例36～42和对比例9得到的测试结果填入表6。
表6
Figure PCTCN2021138677-appb-000045
由表6的测试数据可知，当正极活性材料为LiNi 0.8Co 0.1Al 0.1O 2时，对比实施例36-42和对比例9可知，添加结构式1所示的不同化合物均可以明显降低电池的循环产气，同时高温循环容量保持率也有明显的提升。
7、将实施例7和对比例1得到的锂离子电池置于恒温45℃的烘箱中，以1C的电流恒流充电至4.4V(LiNi 0.5Co 0.2Mn 0.3O 2/AG)，再恒流恒压充电至电流下降至0.05C，然后以1C的电流恒流放电至3.0V，如此循环1000次后，将锂离子电池拆解，取出正极进行透射电镜观察，实施例7的正极TEM图如图1所示，对比例1的正极TEM图如图2所示。
对比图1和图2的透射电镜图，当电解液中不含结构式1所示的化合物时，观察到对比例1中循环后的正极材料发现晶格条纹明显变的杂乱无序，即正极材料的结构发生了变化，结合表1中电池性能数据可知，对比例1的循环后体积膨胀率为57.4％；而图2中实施例7的正极材料的晶格条纹仍然有序分布，而且实施例7的循环后体积膨胀率只有7.2％，说明添加结构式1所示的添加剂的确可以保护正极材料，并且抑制循环过程中的产气。
以上所述仅为本发明的较佳实施例而已，并不用以限制本发明，凡在本发明的精神和原则之内所作的任何修改、等同替换和改进等，均应包含在本发明的保护范围之内。

Claims (10)

  1. 一种锂离子电池，其特征在于，包括正极、负极和非水电解液，所述正极包括正极材料层，所述正极材料层包括正极活性材料，所述正极活性材料包括LiNi xCo yMn zL (1-x-y-z)O 2，其中，L为Al、Sr、Mg、Ti、Ca、Zr、Zn、Si、Cu、V或Fe，0.5≤x≤1，0≤y≤0.5，0≤z≤0.5，0≤x+y+z≤1，所述锂离子电池的上限电压≥4.2V；
    所述非水电解液包括溶剂、电解质盐和结构式1所示的化合物：
    A-D-B-E-C
    结构式1
    其中，A、B、C各自独立地选自含有环状碳酸酯基、环状硫酸酯基、环状亚硫酸酯基、环状磺酸酯基、环状砜基、环状亚砜基、环状羧酸酯基或环状酸酐基的基团；
    D、E各自独立地选自单键、或含有亚烃基、醚键、硫氧双键或碳氧双键的基团；
    以所述非水电解液的总质量为100％计，所述结构式1所示的化合物的添加量为0.01～5.0％。
  2. 根据权利要求1所述的锂离子电池，其特征在于，A、B、C各自独立地含有的环状碳酸酯基、环状硫酸酯基、环状亚硫酸酯基、环状磺酸酯基、环状砜基、环状亚砜基、环状羧酸酯基或环状酸酐基的数量为1～5，且A、B、C的环状碳酸酯基、环状硫酸酯基、环状亚硫酸酯基、环状磺酸酯基、环状砜基、环状亚砜基、环状羧酸酯基或环状酸酐基的总数量小于等于10。
  3. 根据权利要求1所述的锂离子电池，其特征在于，A、C各自独立地选自结构式2所示的基团：
    Figure PCTCN2021138677-appb-100001
    其中，n选自0～4的整数，R 1选自氢、卤素、C1～C5的烃基或卤代烃基；R 2、R 3、R 4、R 5、R 6、R 7各自独立地选自C1～C3的亚烃基、C1～C3的烷氧基、氧原子、
    Figure PCTCN2021138677-appb-100002
    R 2、R 3、R 4中至少一个选自
    Figure PCTCN2021138677-appb-100003
    且R 2、R 3、R 4中至少一个选自氧原子，R 5、R 6、R 7中至少一个选自
    Figure PCTCN2021138677-appb-100004
    且R 5、R 6、R 7中至少一个选自氧原子。
  4. 根据权利要求1所述的锂离子电池，其特征在于，B选自结构式3所示的基团：
    Figure PCTCN2021138677-appb-100005
    其中，m选自1～4的整数，R 8、R 9、R 10各自独立地选自C1～C3的亚烃基、C1～C3的烷氧基、氧原子、
    Figure PCTCN2021138677-appb-100006
    R 8、R 9、R 10中至少一个选自
    Figure PCTCN2021138677-appb-100007
    且R 8、R 9、R 10中至少一个选自氧原子。
  5. 根据权利要求1所述的锂离子电池，其特征在于，D、E各自独立地选自结构式4所示的基团：
    Figure PCTCN2021138677-appb-100008
    其中，z选自0～4的整数，R 11和R 13各自独立地选自单键或C1～C5的亚烃基，R 12选自单键、
    Figure PCTCN2021138677-appb-100009
    Figure PCTCN2021138677-appb-100010
  6. 根据权利要求1所述的锂离子电池，其特征在于，D、E各自独立地选自单键或C1～C5的亚烃基，A、B、C各自独立地选自取代或未取代的环状碳酸酯基、环状硫酸酯基、环状亚硫酸酯基、环状磺酸酯基、环状砜基、环状亚砜基、环状羧酸酯基或环状酸酐基；
    优选的，A、B或C经取代时，取代基选自卤素、烃基或卤代烃基，更优选的，A、B或C经取代时，取代基选自卤素、烷基或卤代烷基。
  7. 根据权利要求1-6任一项所述的锂离子电池，其特征在于，
    A与C彼此相同，A与B彼此相同或不同，D与E彼此相同。
  8. 根据权利要求1所述的锂离子电池，其特征在于，所述结构式1所示的化合物选自以下化合物中的一种或多种：
    Figure PCTCN2021138677-appb-100011
    Figure PCTCN2021138677-appb-100012
    Figure PCTCN2021138677-appb-100013
    Figure PCTCN2021138677-appb-100014
  9. 根据权利要求1所述的锂离子电池，其特征在于，所述正极活性材料选自LiNi 0.5Co 0.2Mn 0.3O 2、LiNi 0.6Co 0.2Mn 0.2O 2、LiNi 0.7Co 0.1Mn 0.2O 2、LiNi 0.8Co 0.15Al 0.05O 2、LiNi 0.8Co 0.1Mn 0.1O 2、LiNi 0.6Mn 0.4O 2和LiNi 0.8Mn 0.2O 2的一种或多种。
  10. 根据权利要求1所述的锂离子电池，其特征在于，所述非水电解液还包括辅助添加剂，所述辅助添加剂包括不饱和环状碳酸酯类化合物、氟代环状碳酸酯类化合物、芳香族添加剂、含氟茴香醚化合物、二羧酸酐、二氟磷酸锂、双氟磺酰亚胺锂(LiFSI)中的至少一种。
PCT/CN2021/138677 2020-12-28 2021-12-16 一种锂离子电池 WO2022143191A1 (zh)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP2023537202A JP2024500789A (ja) 2020-12-28 2021-12-16 リチウムイオン電池
EP21913932.6A EP4270574A1 (en) 2020-12-28 2021-12-16 Lithium-ion battery
KR1020237020445A KR20230109704A (ko) 2020-12-28 2021-12-16 리튬 이온 배터리

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
CN202011606717.2 2020-12-28
CN202011606717 2020-12-28
CN202110392954.1 2021-04-13
CN202110392954.1A CN114695944A (zh) 2020-12-28 2021-04-13 一种锂离子电池

Publications (1)

Publication Number Publication Date
WO2022143191A1 true WO2022143191A1 (zh) 2022-07-07

Family

ID=82135512

Family Applications (2)

Application Number Title Priority Date Filing Date
PCT/CN2021/138674 WO2022143190A1 (zh) 2020-12-28 2021-12-16 一种非水电解液及电池
PCT/CN2021/138677 WO2022143191A1 (zh) 2020-12-28 2021-12-16 一种锂离子电池

Family Applications Before (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/138674 WO2022143190A1 (zh) 2020-12-28 2021-12-16 一种非水电解液及电池

Country Status (6)

Country Link
US (1) US20240055659A1 (zh)
EP (2) EP4270574A1 (zh)
JP (1) JP2024500789A (zh)
KR (1) KR20230109704A (zh)
CN (2) CN114695956A (zh)
WO (2) WO2022143190A1 (zh)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115513528B (zh) * 2022-11-21 2023-05-05 广州天赐高新材料股份有限公司 非水电解液及二次电池
CN115663286B (zh) * 2022-12-08 2023-09-08 深圳新宙邦科技股份有限公司 一种锂离子电池

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013038842A1 (ja) * 2011-09-12 2013-03-21 日本電気株式会社 二次電池
CN103098290A (zh) * 2010-10-22 2013-05-08 三井化学株式会社 环状硫酸酯化合物、含有其的非水电解液、及锂二次电池
CN108258311A (zh) * 2016-12-29 2018-07-06 深圳新宙邦科技股份有限公司 锂离子电池非水电解液及锂离子电池
CN109428120A (zh) * 2017-08-30 2019-03-05 深圳新宙邦科技股份有限公司 锂离子电池用非水电解液及锂离子电池
CN110100336A (zh) * 2016-12-22 2019-08-06 株式会社村田制作所 二次电池
CN110931863A (zh) * 2019-11-12 2020-03-27 深圳市比克动力电池有限公司 电池电解液用添加剂、锂离子电池电解液、锂离子电池

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109119598B (zh) * 2017-06-22 2021-09-21 微宏动力系统（湖州）有限公司 一种非水电解液及二次电池
CN107508000A (zh) * 2017-08-31 2017-12-22 广州鹏辉能源科技股份有限公司 锂离子电池电解液和锂离子电池
CN110265625B (zh) * 2018-11-12 2020-12-04 宁德时代新能源科技股份有限公司 负极极片及锂离子二次电池
CN109942534A (zh) * 2019-03-06 2019-06-28 珠海市赛纬电子材料股份有限公司 一种联三碳酸乙烯酯及其制备方法
CN111755753B (zh) * 2020-07-09 2021-09-28 香河昆仑化学制品有限公司 一种锂离子电池电解液添加剂环碳酸硫酸乙烯酯及其制备方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103098290A (zh) * 2010-10-22 2013-05-08 三井化学株式会社 环状硫酸酯化合物、含有其的非水电解液、及锂二次电池
WO2013038842A1 (ja) * 2011-09-12 2013-03-21 日本電気株式会社 二次電池
CN110100336A (zh) * 2016-12-22 2019-08-06 株式会社村田制作所 二次电池
CN108258311A (zh) * 2016-12-29 2018-07-06 深圳新宙邦科技股份有限公司 锂离子电池非水电解液及锂离子电池
CN109428120A (zh) * 2017-08-30 2019-03-05 深圳新宙邦科技股份有限公司 锂离子电池用非水电解液及锂离子电池
CN110931863A (zh) * 2019-11-12 2020-03-27 深圳市比克动力电池有限公司 电池电解液用添加剂、锂离子电池电解液、锂离子电池

Also Published As

Publication number Publication date
CN114695944A (zh) 2022-07-01
KR20230109704A (ko) 2023-07-20
WO2022143190A1 (zh) 2022-07-07
EP4270574A1 (en) 2023-11-01
CN114695956A (zh) 2022-07-01
JP2024500789A (ja) 2024-01-10
US20240055659A1 (en) 2024-02-15
EP4270583A1 (en) 2023-11-01

Similar Documents

Publication Publication Date Title
US20200313237A1 (en) Non-Aqueous Electrolyte for Lithium Ion Battery and Lithium Ion Battery
JP6963068B2 (ja) リチウムイオン電池用非水電解液
CN114497692B (zh) 二次电池
WO2022143191A1 (zh) 一种锂离子电池
JPWO2014050877A1 (ja) 非水電解液、電気化学デバイス、リチウムイオン二次電池、及び、モジュール
CN105895958A (zh) 一种电解液及锂离子电池
WO2023124604A1 (zh) 二次电池
WO2024037187A1 (zh) 一种锂离子电池
WO2024032173A1 (zh) 一种锂离子电池
JP5590192B2 (ja) 電気化学デバイス及び電気化学デバイス用非水電解液
WO2024045816A1 (zh) 一种锂离子电池
CN116435595A (zh) 一种锂离子电池
WO2024114206A1 (zh) 一种锂离子电池
WO2023016411A1 (zh) 一种非水电解液及电池
WO2022218145A1 (zh) 一种非水电解液及锂离子电池
WO2023279953A1 (zh) 一种非水电解液及电池
WO2023016412A1 (zh) 一种非水电解液及电池
CN105336991B (zh) 锂离子电池用高电压电解液
WO2022218143A1 (zh) 一种磷酸铁锂电池
WO2022042374A1 (zh) 锂离子电池非水电解液以及锂离子电池
JP6143410B2 (ja) 電気化学デバイス及び電気化学デバイス用非水電解液
CN115207442A (zh) 一种富锰锂离子电池
WO2022218144A1 (zh) 一种锂离子电池
JP2012216391A (ja) 電気化学デバイス及び電気化学デバイス用非水電解液
WO2023000889A1 (zh) 一种非水电解液及锂离子电池

Legal Events

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

Ref document number: 21913932

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 20237020445

Country of ref document: KR

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 2023537202

Country of ref document: JP

WWE Wipo information: entry into national phase

Ref document number: 2021913932

Country of ref document: EP

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 2021913932

Country of ref document: EP

Effective date: 20230728