Electrolyte solution and electrochemical device using same

Abstract

The invention relates to an electrolyte solution and an electrochemical device using the same. The electrolyte provided by the invention comprises a compound shown as a formula I: # imgabs0 #. The electrochemical device prepared from the electrolyte provided by the invention has improved cycle flatulence, high-temperature storage performance and hot box test performance.

Description

[0001] This application is a divisional application of a patent application with Chinese application number 202080047268.4, filing date May 22, 2020, and titled “Electrolyte and electrochemical device using the same”. Technical Field

[0002] The present application relates to the technical field of electrochemical devices, and more particularly to an electrolyte and an electrochemical device using the same. Background Art

[0003] Electrochemical devices, such as lithium-ion batteries, have attracted widespread attention due to their high energy density, low maintenance, relatively low self-discharge, long cycle life, no memory effect, high operating voltage and environmental friendliness. They are widely used in smart products (including mobile phones, notebooks, cameras and other electronic products), power tools and electric vehicles, and are gradually replacing traditional nickel-cadmium and nickel-metal hydride batteries. However, with the rapid development of technology and the diversity of market demand, people have also put forward more requirements for the power supply of electronic products, such as thinner, lighter, more diverse appearance, higher volume energy density and mass energy density, higher safety, higher power, etc.

[0004] In order to improve the energy density of the battery, the method adopted is to increase the charging voltage / increase the capacity of the active material, etc. However, these will accelerate the decomposition of the electrolyte and produce gas, causing battery bloating, battery explosion and fire and other safety issues. Therefore, it is necessary to take into account its safety issues (such as floating charge performance and hot box performance) while increasing the capacity of lithium-ion batteries. Summary of the invention

[0005] The embodiments of the present application provide an electrolyte and an electrochemical device using the same, in an attempt to solve at least one problem existing in the related field to at least some extent. The embodiments of the present application also provide an electrochemical device and an electronic device using the electrolyte.

[0006] According to one aspect of the present application, the present application provides an electrolyte comprising a compound of formula I:

[0007]

[0008] Where R 11 is selected from a covalent bond, a substituted or unsubstituted C 1 -C 20 Alkylene, substituted or unsubstituted C 2 -C 20 Alkenylene, substituted or unsubstituted C 2 -C 20 Alkyne, substituted or unsubstituted C 6 -C 20Arylene,

[0009] Substituted or unsubstituted C 3 -C 20 Heteroarylene, substituted or unsubstituted C 3 -C 20 Cycloalkylene, or a group obtained by any combination of the above groups,

[0010] Where R 12 , R 13 , R 14 are each independently selected from substituted or unsubstituted C 1 -C 20 Alkylene, substituted or unsubstituted C 2 -C 20 Alkenylene, substituted or unsubstituted C 2 -C 20 Alkyne, substituted or unsubstituted C 6 -C 20 Arylene, substituted or unsubstituted C 3 -C 20 Heteroarylene, substituted or unsubstituted C 3 -C 20 Cycloalkylene, or a group obtained by any combination of the above groups,

[0011] Among them, each R 15 , R 16 Independently selected from C 1 -C 20 Alkylene, substituted or unsubstituted C 2 -C 20 Alkenylene, substituted or unsubstituted C 2 -C 20 Alkyne, substituted or unsubstituted C 6 -C 20 Arylene, substituted or unsubstituted C 3 -C 20 Heteroarylene, substituted or unsubstituted C 3 -C 20 Cycloalkylene;

[0012] When the above groups are substituted, the substituents are independently selected from halogen, C 1 -C 20 Alkyl, C 3 -C 20 Cycloalkyl, C 2 -C 20 Alkenyl, C 6-C 20 Aryl or C 3 -C 20 heteroaryl; and

[0013] The heteroatom is selected from one or more of O, S, N and P.

[0014] In some embodiments, the compound of formula I includes at least one of the following compounds:

[0015]

[0016]

[0017]

[0018] Wherein, based on the total weight of the electrolyte, the weight percentage of the compound of formula I is 0.01 wt %-10 wt %.

[0019] In some embodiments, the electrolyte further comprises a compound containing a sulfur-oxygen double bond, wherein the compound containing a sulfur-oxygen double bond comprises a compound of formula (II-A), a compound of formula (II-B), or a combination thereof:

[0020]

[0021] Where R 21 , R 22 are each independently selected from substituted or unsubstituted C 1 -C 20 Alkyl, substituted or unsubstituted C 2 -C 20 Alkenyl, substituted or unsubstituted C 2 -C 20 Alkynyl, substituted or unsubstituted C 6 -C 20 Aryl, substituted or unsubstituted C 3 -C 20 Heteroaryl, substituted or unsubstituted C 3 -C 20 Cycloalkyl, -OR 25 or -R 26 -OR 27 ;

[0022] Where R 25 , R 27 are each independently selected from substituted or unsubstituted C 1 -C 20 Alkyl, substituted or unsubstituted C 2 -C 20 Alkenyl, substituted or unsubstituted C2 -C 20 Alkynyl, substituted or unsubstituted C 6 -C 20 Aryl, substituted or unsubstituted C 3 -C 20 Heteroaryl, substituted or unsubstituted C 3 -C 20 Cycloalkyl;

[0023] Where R 26 is selected from substituted or unsubstituted C 1 -C 20 Alkylene, substituted or unsubstituted C 2 -C 20 Alkenylene, substituted or unsubstituted C 2 -C 20 Alkyne, substituted or unsubstituted C 6 -C 20 Arylene, substituted or unsubstituted C 3 -C 20 Heteroarylene, substituted or unsubstituted C 3 -C 20 Cycloalkylene;

[0024] Where R 23 , R 24 are each independently selected from substituted or unsubstituted C 1 -C 20 Alkylene, substituted or unsubstituted C 2 -C 20 Alkenylene, substituted or unsubstituted C 2 -C 20 Alkyne, substituted or unsubstituted C 6 -C 20 Arylene, substituted or unsubstituted C 3 -C 20 Heteroarylene, -O-R'-, -R'-OR"- or a group obtained by any combination of the above groups;

[0025] wherein each R', R" is independently selected from substituted or unsubstituted C 1 -C 20 Alkylene, substituted or unsubstituted C 2 -C 20 alkenylene, or substituted or unsubstituted C 2 -C 20 Alkynylidene;

[0026] When the above groups are substituted, the substituents are independently selected from halogen, cyano, C1 -C 20 Alkyl, C 3 -C 20 Cycloalkyl, C 2 -C 20 Alkenyl, C 6 -C 20 Aryl or C 6 -C 20 heteroaryl; and

[0027] The heteroatom is selected from one or more of O, S, N, and P;

[0028] Wherein, based on the total weight of the electrolyte, the weight percentage of the compound containing sulfur-oxygen double bonds is 0.01 wt %-10 wt %.

[0029] In some embodiments, the compound containing a sulfur-oxygen double bond comprises at least one of the following compounds:

[0030]

[0031]

[0032] In some embodiments, the electrolyte further comprises a cyclic carbonate compound, wherein the cyclic carbonate compound comprises a compound of formula III:

[0033]

[0034] Where R 3 is selected from substituted or unsubstituted C 1 -C 20 Alkylene or substituted or unsubstituted C 2 -C 20 alkenylene;

[0035] Where R 3 When substituted, the substituent is selected from halogen, C 1 -C 6 Alkyl, C 2 -C 6 Alkenyl, C 6 -C 20 Aryl or C 6 -C 20 Heteroaryl, wherein the heteroatom is selected from one or more of O, S, N, and P;

[0036] In some embodiments, based on the total weight of the electrolyte, the weight percentage of the cyclic carbonate compound is 0.01 wt %-40 wt %.

[0037] In some embodiments, the cyclic carbonate compound comprises at least one of the following compounds:

[0038]

[0039] In another embodiment, the present application provides an electrochemical device, wherein the electrochemical device comprises a positive electrode, a negative electrode, a separator, and the electrolyte described in the embodiment of the present application.

[0040] In some embodiments, the positive electrode includes a current collector and a positive electrode active material layer located on the current collector, the positive electrode active material layer includes a positive electrode active material, wherein the positive electrode active material contains element A, and the element A contains at least one of Mg, Ti, Zr, Y, Zn, La, Al, W or Si.

[0041] In some embodiments, based on the total weight of the positive electrode active material, the content of the A element is 50 ppm-8000 ppm.

[0042] In some embodiments, the isolation film includes a polyolefin substrate layer and a coating located on at least one surface of the polyolefin substrate layer, and the thickness ratio of the substrate layer to the coating is 1:1-5:1.

[0043] In some embodiments, the coating includes a polymer, which includes at least one of the following compounds: polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, ethylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, perfluoroethylene-propylene copolymer, acrylic acid, methacrylic acid, itaconic acid, ethyl acrylate, butyl acrylate, acrylonitrile, methacrylonitrile.

[0044] In some embodiments, the coating further includes inorganic particles, which include at least one of the following compounds: aluminum oxide, silicon dioxide, magnesium oxide, titanium oxide, hafnium dioxide, tin oxide, cerium dioxide, nickel oxide, zinc oxide, calcium oxide, zirconium oxide, yttrium oxide, silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide or barium sulfate.

[0045] In another embodiment, the present application provides an electronic device, which includes the electrochemical device according to the embodiment of the present application.

[0046] The lithium-ion battery prepared by the electrolyte of the present application has improved cycle gassing, high temperature storage performance and hot box test performance.

[0047] Additional aspects and advantages of the embodiments of the present application will be described and shown in part in the subsequent description, or explained through the implementation of the embodiments of the present application. DETAILED DESCRIPTION

[0048] The embodiments of the present application will be described in detail below. The embodiments of the present application should not be interpreted as limiting the present application.

[0049] In the detailed description and claims, a list of items connected by the terms "one of," "one of," "a kind of," or other similar terms may mean any of the listed items. For example, if items A and B are listed, the phrase "one of A and B" means only A or only B. In another example, if items A, B, and C are listed, the phrase "one of A, B, and C" means only A; only B; or only C. Item A may include a single element or multiple elements. Item B may include a single element or multiple elements. Item C may include a single element or multiple elements.

[0050] In the detailed description and claims, a list of items connected by the terms "at least one of," "at least one of," "at least one of," or other similar terms may mean any combination of the listed items. For example, if items A and B are listed, the phrase "at least one of A and B" means only A; only B; or A and B. In another example, if items A, B, and C are listed, the phrase "at least one of A, B, and C" means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C. Item A may include a single element or multiple elements. Item B may include a single element or multiple elements. Item C may include a single element or multiple elements.

[0051] As used herein, the term "alkyl" is intended to be a straight chain saturated hydrocarbon structure having 1 to 20 carbon atoms. "Alkyl" is also intended to be a branched or cyclic hydrocarbon structure having 3 to 20 carbon atoms. For example, the alkyl group may be an alkyl group having 1 to 20 carbon atoms, an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 5 carbon atoms, an alkyl group having 5 to 20 carbon atoms, an alkyl group having 5 to 15 carbon atoms, or an alkyl group having 5 to 10 carbon atoms. When specifying an alkyl group having a specific carbon number, it is intended to cover all geometric isomers having that carbon number; therefore, for example, "butyl" means to include n-butyl, sec-butyl, isobutyl, tert-butyl and cyclobutyl; "propyl" includes n-propyl, isopropyl and cyclopropyl. Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclobutyl, n-pentyl, isopentyl, neopentyl, cyclopentyl, methylcyclopentyl, ethylcyclopentyl, n-hexyl, isohexyl, cyclohexyl, n-heptyl, octyl, cyclopropyl, cyclobutyl, norbornyl, etc. In addition, the alkyl group may be optionally substituted.

[0052] As used herein, the term "cycloalkyl" encompasses cyclic alkyl groups. The cycloalkyl group may be a cycloalkyl group of 3-20 carbon atoms, a cycloalkyl group of 6-20 carbon atoms, a cycloalkyl group of 3-12 carbon atoms, a cycloalkyl group of 3-6 carbon atoms. For example, the cycloalkyl group may be a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, etc. In addition, the cycloalkyl group may be optionally substituted.

[0053] As used herein, the term "cycloalkylene" encompasses cyclic alkylene groups. The cycloalkylene group may be a cycloalkylene group of 3-20 carbon atoms, a cycloalkylene group of 6-20 carbon atoms, a cycloalkylene group of 3-12 carbon atoms, or a cycloalkylene group of 3-6 carbon atoms. For example, the cycloalkylene group may be a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, etc. In addition, the cycloalkylene group may be optionally substituted.

[0054] As used herein, the term "alkenyl" refers to a monovalent unsaturated hydrocarbon group that can be straight or branched and has at least one and typically 1, 2 or 3 carbon-carbon double bonds. Unless otherwise defined, the alkenyl typically contains 2-20 carbon atoms, for example, an alkenyl of 2-20 carbon atoms, an alkenyl of 6-20 carbon atoms, an alkenyl of 2-12 carbon atoms, or an alkenyl of 2-6 carbon atoms. Representative alkenyls include, for example, vinyl, n-propenyl, isopropenyl, n-but-2-enyl, but-3-enyl, n-hex-3-enyl, etc. In addition, alkenyl can be optionally substituted.

[0055] The term "alkynyl" refers to a monovalent unsaturated hydrocarbon group that can be straight or branched and has at least one and typically 1, 2 or 3 carbon-carbon triple bonds. Unless otherwise defined, the alkynyl typically contains 2 to 20 carbon atoms, for example, an alkynyl of 2-20 carbon atoms, an alkynyl of 6-20 carbon atoms, an alkynyl of 2-10 carbon atoms, or an alkynyl of 2-6 carbon atoms. Representative alkynyls include, for example, ethynyl, prop-2-ynyl (n-propynyl), n-but-2-ynyl, n-hex-3-ynyl, etc. In addition, alkynyl can be optionally substituted.

[0056] As used herein, the term "alkylene" means a straight or branched divalent saturated hydrocarbon group. For example, the alkylene group can be an alkylene group of 1-20 carbon atoms, an alkylene group of 1-15 carbon atoms, an alkylene group of 1-10 carbon atoms, an alkylene group of 1-5 carbon atoms, an alkylene group of 5-20 carbon atoms, an alkylene group of 5-15 carbon atoms, or an alkylene group of 5-10 carbon atoms. Representative alkylene groups include, for example, methylene, ethane-1,2-diyl ("ethylene"), propane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, and the like. In addition, the alkylene group can be optionally substituted.

[0057] As used herein, the term "alkenylene" encompasses straight and branched alkenylene. When specifying an alkenylene with a specific carbon number, it is contemplated that all geometric isomers with that carbon number are encompassed. For example, alkenylene can be an alkenylene of 2-20 carbon atoms, an alkenylene of 2-15 carbon atoms, an alkenylene of 2-10 carbon atoms, an alkenylene of 2-5 carbon atoms, an alkenylene of 5-20 carbon atoms, an alkenylene of 5-15 carbon atoms, or an alkenylene of 5-10 carbon atoms. Representative alkenylene includes, for example, vinylene, propenylene, butenylene, etc. In addition, alkenylene can be optionally substituted.

[0058] As used herein, the term "alkynylene" encompasses straight and branched chain alkynylenes. When specifying an alkynylene with a specific carbon number, it is contemplated that all geometric isomers with that carbon number are encompassed. For example, the alkynylene may be an alkynylene of 2-20 carbon atoms, an alkynylene of 2-15 carbon atoms, an alkynylene of 2-10 carbon atoms, an alkynylene of 2-5 carbon atoms, an alkynylene of 5-20 carbon atoms, an alkynylene of 5-15 carbon atoms, or an alkynylene of 5-10 carbon atoms. Representative alkynylenes include, for example, ethynylene, propynylene, butynylene, etc. In addition, the alkynylene may be optionally substituted.

[0059] As used herein, the term "aryl" encompasses both monocyclic and polycyclic ring systems. Polycyclic rings may have two or more rings in which two carbon atoms are common to two adjacent rings (the rings are "fused"), wherein at least one of the rings is aromatic, e.g., the other rings may be cycloalkyl, cycloalkenyl, aryl, heterocyclic, and / or heteroaryl. For example, an aryl group may be C 6 -C 50 Aryl, C 6 -C 40 Aryl, C 6 -C 30 Aryl, C 6 -C 20 Aryl or C 6 -C 10 Aryl. Representative aryl groups include, for example, phenyl, methylphenyl, propylphenyl, isopropylphenyl, benzyl, and naphth-1-yl, naphth-2-yl, and the like. Additionally, aryl groups may be optionally substituted.

[0060] As used herein, "arylene" encompasses both monocyclic and polycyclic ring systems. For example, an arylene group can be C 6 -C 50 Arylene, C 6 -C 40 Arylene, C 6 -C 30 Arylene, C 6 -C 20 Arylene or C 6 -C10 Arylene. Representative arylene groups include, for example, phenylene, methylenephenyl, propylenylphenyl, isopropylenylphenyl, benzylene, and the like. Additionally, the arylene group may be optionally substituted.

[0061] As used herein, the term "heteroaryl" encompasses monocyclic heteroaromatic groups that may include one to three heteroatoms, such as pyrrole, furan, thiophene, imidazole, oxazole, thiazole, triazole, pyrazole, pyridine, pyrazine and pyrimidine, etc. The term heteroaryl also includes polycyclic heteroaromatic systems having two or more rings in which two atoms are common to two adjacent rings (the rings are "fused"), wherein at least one of the rings is a heteroaryl, and the other rings may be cycloalkyl, cycloalkenyl, aryl, heterocycle and / or heteroaryl. The heteroatoms in the heteroaryl may be, for example, O, S, N, Se, etc. For example, the heteroaryl may be C 3 -C 50 Heteroaryl, C 3 -C 40 Heteroaryl, C 3 -C 30 Heteroaryl, C 3 -C 20 Heteroaryl or C 3 -C 10 Heteroaryl. Additionally, the heteroaryl group may be optionally substituted.

[0062] As used herein, the term "heteroarylene" encompasses monocyclic or polycyclic heteroarylene groups that may include one to three heteroatoms. For example, a heteroarylene group may be C 3 -C 50 Heteroarylene, C 3 -C 40 Heteroarylene, C 3 -C 30 Heteroarylene, C 3 -C 20 Heteroarylene or C 3 -C 10 In addition, the heteroarylene group may be optionally substituted.

[0063] As used herein, the term "heteroatom" encompasses O, S, P, N, B or isosteres thereof.

[0064] As used herein, the term "halogen" encompasses F, Cl, Br, I.

[0065] As used herein, the term "covalent bond" encompasses single bonds.

[0066] When the above substituents are substituted, their substituents may be independently selected from the group consisting of: halogen, alkyl, alkenyl, aryl. As used herein, the term "substituted" or "substituted" means that it may be substituted with one or more (e.g., 2, 3) substituents.

[0067] As used herein, the content of each component is based on the total weight of the electrolyte.

[0068] 1. Electrolyte

[0069] In some embodiments, the present application provides an electrolyte comprising a compound of formula I:

[0070]

[0071] Where R 11 is selected from a covalent bond, a substituted or unsubstituted C 1 -C 20 Alkylene, substituted or unsubstituted C 2 -C 20 Alkenylene, substituted or unsubstituted C 2 -C 20 Alkyne, substituted or unsubstituted C 6 -C 20 Arylene, substituted or unsubstituted C 3 -C 20 Heteroarylene, substituted or unsubstituted C 3 -C 20 Cycloalkylene, or a group obtained by any combination of the above groups,

[0072] Where R 12 , R 13 , R 14 are each independently selected from substituted or unsubstituted C 1 -C 20 Alkylene, substituted or unsubstituted C 2 -C 20 Alkenylene, substituted or unsubstituted C 2 -C 20 Alkyne, substituted or unsubstituted C 6 -C 20 Arylene, substituted or unsubstituted C 3 -C 20 Heteroarylene, substituted or unsubstituted C 3 -C 20 Cycloalkylene, or a group obtained by any combination of the above groups,

[0073] Among them, each R 15 , R 16 Independently selected from C 1 -C 20 Alkylene, substituted or unsubstituted C 2 -C 20 Alkenylene, substituted or unsubstituted C 2 -C 20 Alkyne, substituted or unsubstituted C 6 -C 20 Arylene, substituted or unsubstituted C 3 -C 20 Heteroarylene, substituted or unsubstituted C 3 -C 20 Cycloalkylene;

[0074] When the above groups are substituted, the substituents are independently selected from halogen, C 1 -C 20 Alkyl, C 3 -C 20 Cycloalkyl, C 2 -C 20 Alkenyl, C 6 -C 20 Aryl or C 3 -C 20 heteroaryl; and

[0075] The heteroatom is selected from one or more of O, S, N and P.

[0076] In some embodiments, R 11 is selected from a covalent bond, a substituted or unsubstituted C 1 -C 10 Alkylene, or a group obtained by any combination of the above groups, wherein R 15 Selected from C 1 -C 10 Alkylene;

[0077] R 12 , R 13 , R 14 are each independently 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 Alkyne, substituted or unsubstituted C 6 -C 10 Arylene, or a group obtained by any combination of the above groups, wherein each R 15 , R 16 Independently selected from C 1 -C 10 an alkylene group; and

[0078] When the above groups are substituted, the substituents are each independently selected from halogen or C 1 -C 10 alkyl.

[0079] In some embodiments, R 11 Selected from covalent bonds, C 1 -C 6 Alkylene, or a group obtained by any combination of the above groups, wherein R 15 Selected from C 1 -C 6 Alkylene;

[0080] R 12 , R 13 , R 14 Each independently selected from C 1 -C 6 Alkylene, C 2 -C 3 Alkenylene, C 2 -C 3 Alkyne, substituted or unsubstituted phenylene, or a group obtained by any combination of the above groups, wherein each R 15 , R 16 Independently selected from C 1 -C 6 an alkylene group; and

[0081] When the above groups are substituted, the substituents are each independently selected from halogen or C 1 -C 6 alkyl.

[0082] In some embodiments, R 11 Selected from covalent bonds, ethylene or Where R 15 is ethylene;

[0083] R 12 , R 13 , R 14 Each is independently selected from methylene, ethylene, propylene, butylene, pentylene, substituted or unsubstituted phenylene, or a group obtained by any combination of the above groups, wherein each R 15 , R 16 Independently selected from methylene, ethylene, propenyl or propynyl.

[0084] In some embodiments, the compound of formula I includes or is selected from at least one of the following compounds:

[0085]

[0086]

[0087]

[0088] In some embodiments, based on the total weight of the electrolyte, the weight percentage of the compound of formula I is 0.01 wt%-10 wt%. In some embodiments, based on the total weight of the electrolyte, the weight percentage of the compound of formula I is 0.01 wt%, 0.05 wt%, 0.1 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, or a range consisting of any two of these values.

[0089] After extensive research, the present invention has found that the compound of formula I can form a nitrile protective film with excellent performance on the surface of the positive electrode active material, which can better stabilize the transition metals such as nickel, cobalt, and manganese in the positive electrode material. 11 , R 12 , R 13 , R 14 Too many short and medium chains, such as R 11 , R 12 When it is a covalent bond, it may lead to a poor stabilization effect on the positive electrode active material. The electrolyte including the compound containing the -CN functional group can significantly improve the floating charge performance, high temperature storage performance and thermal shock performance of the electrochemical device using it.

[0090] In some embodiments, the electrolyte further comprises a compound containing a sulfur-oxygen double bond, wherein the compound containing a sulfur-oxygen double bond comprises a compound of formula (II-A), a compound of formula (II-B), or a combination thereof:

[0091]

[0092] Where R 21 , R 22 are each independently selected from substituted or unsubstituted C 1 -C 20 Alkyl, substituted or unsubstituted C 2 -C 20 Alkenyl, substituted or unsubstituted C 2 -C 20 Alkynyl, substituted or unsubstituted C6 -C 20 Aryl, substituted or unsubstituted C 3 -C 20 Heteroaryl, substituted or unsubstituted C 3 -C 20 Cycloalkyl, -OR 25 or -R 26 -OR 27 ;

[0093] Where R 25 , R 27 are each independently selected from substituted or unsubstituted C 1 -C 20 Alkyl, substituted or unsubstituted C 2 -C 20 Alkenyl, substituted or unsubstituted C 2 -C 20 Alkynyl, substituted or unsubstituted C 6 -C 20 Aryl, substituted or unsubstituted C 3 -C 20 Heteroaryl, substituted or unsubstituted C 3 -C 20 Cycloalkyl;

[0094] Where R 26 is selected from substituted or unsubstituted C 1 -C 20 Alkylene, substituted or unsubstituted C 2 -C 20 Alkenylene, substituted or unsubstituted C 2 -C 20 Alkyne, substituted or unsubstituted C 6 -C 20 Arylene, substituted or unsubstituted C 3 -C 20 Heteroarylene, substituted or unsubstituted C 3 -C 20 Cycloalkylene;

[0095] Where R 23 , R 24 are each independently selected from substituted or unsubstituted C 1 -C 20 Alkylene, substituted or unsubstituted C 2 -C 20 Alkenylene, substituted or unsubstituted C 2 -C 20 Alkyne, substituted or unsubstituted C 6 -C 20Arylene, substituted or unsubstituted C 3 -C 20 Heteroarylene, -O-R'-, -R'-OR"- or a group obtained by any combination of the above groups;

[0096] wherein each R', R" is independently selected from substituted or unsubstituted C 1 -C 20 Alkylene, substituted or unsubstituted C 2 -C 20 alkenylene, or substituted or unsubstituted C 2 -C 20 Alkynylidene;

[0097] When the above groups are substituted, the substituents are independently selected from halogen, cyano, C 1 -C 20 Alkyl, C 3 -C 20 Cycloalkyl, C 2 -C 20 Alkenyl, C 6 -C 20 Aryl or C 6 -C 20 heteroaryl; and

[0098] The heteroatom is selected from one or more of O, S, N and P.

[0099] In some embodiments, R 21 , R 22 are each independently selected from substituted or unsubstituted C 1 -C 10 Alkyl, substituted or unsubstituted C 2 -C 10 Alkenyl, substituted or unsubstituted C 2 -C 10 Alkynyl, substituted or unsubstituted C 6 -C 10 Aryl, substituted or unsubstituted C 3 -C 10 Heteroaryl, substituted or unsubstituted C 3 -C 10 Cycloalkyl, -OR 25 or -R 26 -OR 27 ;

[0100] Where R 25 , R 27 are each independently selected from substituted or unsubstituted C 1 -C 10Alkyl, substituted or unsubstituted C 2 -C 10 Alkenyl, substituted or unsubstituted C 2 -C 10 Alkynyl, substituted or unsubstituted C 6 -C 10 Aryl, substituted or unsubstituted C 3 -C 10 Heteroaryl, substituted or unsubstituted C 3 -C 10 Cycloalkyl;

[0101] Where R 26 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 Alkyne, substituted or unsubstituted C 6 -C 10 Arylene, substituted or unsubstituted C 3 -C 10 Heteroarylene, substituted or unsubstituted C 3 -C 10 Cycloalkylene;

[0102] When the above groups are substituted, the substituents are independently selected from halogen, cyano, C 1 -C 10 Alkyl, C 3 -C 10 Cycloalkyl, C 2 -C 10 Alkenyl, C 6 -C 10 Aryl or C 6 -C 10 Heteroaryl.

[0103] In some embodiments, R 21 , R 22 are each independently selected from substituted or unsubstituted C 1 -C 6 Alkyl, substituted or unsubstituted C 6 -C 10 Aryl, -OR 25 or -R 26 -OR 27 ;

[0104] Where R 25 , R 27 are each independently selected from substituted or unsubstituted C1 -C 6 alkyl;

[0105] Where R 26 is selected from substituted or unsubstituted C 1 -C 6 Alkylene;

[0106] When the above groups are substituted, the substituents are each independently selected from halogen.

[0107] In some embodiments, R 23 , R 24 are each independently 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 Alkyne, substituted or unsubstituted C 6 -C 10 Arylene, substituted or unsubstituted C 3 -C 10 Heteroarylene, -O-R'-, -R'-OR"- or a group obtained by any combination of the above groups;

[0108] wherein each R', R" is independently selected from substituted or unsubstituted C 1 -C 10 Alkylene, substituted or unsubstituted C 2 -C 10 alkenylene, or substituted or unsubstituted C 2 -C 10 Alkynylidene;

[0109] When the above groups are substituted, the substituents are independently selected from halogen, cyano, C 1 -C 10 Alkyl, C 3 -C 10 Cycloalkyl, C 2 -C 10 Alkenyl, C 6 -C 10 Aryl or C 6 -C 10 Heteroaryl.

[0110] In some embodiments, R 23 , R 24 are each independently selected from substituted or unsubstituted C 1 -C 10 Alkylene, substituted or unsubstituted C2 -C 10 Alkenylene, -O-R'-, -R'-OR"- or a group obtained by any combination of the above groups;

[0111] wherein each R', R" is independently selected from substituted or unsubstituted C 1 -C 10 Alkylene, substituted or unsubstituted C 2 -C 10 alkenylene;

[0112] When the above groups are substituted, the substituents are independently selected from halogen, C 1 -C 6 alkyl.

[0113] In some embodiments, R 23 , R 24 are each independently selected from substituted or unsubstituted C 1 -C 6 Alkylene, substituted or unsubstituted C 2 -C 6 Alkenylene, -O-R'-, -R'-OR"- or a group obtained by any combination of the above groups;

[0114] wherein each R', R" is independently selected from substituted or unsubstituted C 1 -C 6 Alkylene, substituted or unsubstituted C 2 -C 6 alkenylene;

[0115] When the above groups are substituted, the substituents are each independently selected from F and methyl.

[0116] In some embodiments, based on the total weight of the electrolyte, the weight percentage of the compound containing a sulfur-oxygen double bond is 0.01 wt %-10 wt %. In some embodiments, based on the total weight of the electrolyte, the weight percentage of the compound containing a sulfur-oxygen double bond is 0.01 wt %, 1 wt %, 2 wt %, 3 wt %, 4 wt %, 5 wt %, 6 wt %, 7 wt %, 8 wt %, 9 wt %, 10 wt % or a range consisting of any two of these values.

[0117] In some embodiments, the compound containing a sulfur-oxygen double bond comprises at least one of the following compounds:

[0118]

[0119] The present application found that the compound of formula I combined with the compound containing sulfur-oxygen double bond has a strong antioxidant ability, which makes the positive electrode material not easily oxidized. On the other hand, in the case of lithium precipitation at the negative electrode, it will be reduced on the surface of metallic lithium to form a protective film, inhibiting the decomposition heat generation of metallic lithium and electrolyte, and further enhancing the protection of active materials.

[0120] In some embodiments, the electrolyte further comprises a cyclic carbonate compound, wherein the cyclic carbonate compound comprises a compound of formula III:

[0121]

[0122] Where R 3 is selected from substituted or unsubstituted C 1 -C 20 Alkylene or substituted or unsubstituted C 2 -C 20 alkenylene;

[0123] Where R 3 When substituted, the substituent is selected from halogen, C 1 -C 6 Alkyl, C 2 -C 6 Alkenyl, C 6 -C 20 Aryl or C 6 -C 20 Heteroaryl, wherein the heteroatom is selected from one or more of O, S, N, and P.

[0124] In some embodiments, R 3 is selected from substituted or unsubstituted C 1 -C 10 Alkylene or substituted or unsubstituted C 2 -C 10 alkenylene;

[0125] Where R 3 When substituted, the substituent is selected from halogen, C 1 -C 6 Alkyl, C 2 -C 6 Alkenyl.

[0126] In some embodiments, based on the gross weight of the electrolyte, the weight percentage of the cyclic carbonate compound is 0.01 wt%-40 wt%. In some embodiments, based on the gross weight of the electrolyte, the weight percentage of the cyclic carbonate compound is 0.01 wt%, 0.05 wt%, 0.01 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt% or the range composed of any two of these values.

[0127] In some embodiments, the cyclic carbonate compound comprises at least one of the following compounds:

[0128]

[0129] In some embodiments, the electrolyte further includes a polynitrile compound, which includes at least one of 1,3,5-pentanetricarboxylate, 1,2,3-propanetricarboxylate, 1,3,6-hexanetricarboxylate, 1,2,6-hexanetricarboxylate, 1,2,3-tris(2-cyanoethoxy)propane, 1,2,4-tris(2-cyanoethoxy)butane, 1,1,1-tris(cyanoethoxymethylene)ethane, 1,1,1-tris(cyanoethoxymethylene)propane, 3-methyl-1,3,5-tris(cyanoethoxy)pentane, 1,2,7-tris(cyanoethoxy)heptane, 1,2,6-tris(cyanoethoxy)hexane and 1,2,5-tris(cyanoethoxy)pentane.

[0130] In some embodiments, the electrolyte further comprises a cyclic ether, which can form a film on both the positive and negative electrodes, thereby reducing the reaction between the electrolyte and the active material.

[0131] In some embodiments, the cyclic ether includes, but is not limited to, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxolane, 2-methyl1,3-dioxolane, 4-methyl1,3-dioxolane, 1,3-dioxane, 1,4-dioxane, and dimethoxypropane.

[0132] In some embodiments, the weight percentage of the cyclic ether is 0.1wt%-10wt% based on the total weight of the electrolyte. In some embodiments, the weight percentage of the cyclic ether is not less than 0.1wt% based on the total weight of the electrolyte. In some embodiments, the weight percentage of the cyclic ether is not less than 0.5wt% based on the total weight of the electrolyte. In some embodiments, the weight percentage of the cyclic ether is not more than 2wt% based on the total weight of the electrolyte. In some embodiments, the weight percentage of the cyclic ether is not more than 5wt% based on the total weight of the electrolyte.

[0133] In some embodiments, the electrolyte further comprises a chain ether. In some embodiments, the chain ether includes, but is not limited to: dimethoxymethane, 1,1-dimethoxyethane, 1,2-dimethoxyethane, diethoxymethane, 1,1-diethoxyethane, 1,2-diethoxyethane, ethoxymethoxymethane, 1,1-ethoxymethoxyethane, 1,2-ethoxymethoxyethane.

[0134] In some embodiments, the weight percentage of the chain ether is 0.1wt%-10wt% based on the total weight of the electrolyte. In some embodiments, the weight percentage of the chain ether is not less than 0.5wt% based on the total weight of the electrolyte. In some embodiments, the weight percentage of the chain ether is not less than 2wt% based on the total weight of the electrolyte. In some embodiments, the weight percentage of the chain ether is not less than 3wt% based on the total weight of the electrolyte. In some embodiments, the weight percentage of the chain ether is not more than 10wt% based on the total weight of the electrolyte. In some embodiments, the weight percentage of the chain ether is not more than 5wt% based on the total weight of the electrolyte.

[0135] In some embodiments, the electrolyte further includes an aromatic fluorinated solvent. Aromatic fluorinated solvents can form films quickly to protect active materials, and fluorinated substances can improve the wettability of the electrolyte to active materials. In some embodiments, the aromatic fluorinated solvents include, but are not limited to: fluorobenzene, difluorobenzene, trifluorobenzene, tetrafluorobenzene, pentafluorobenzene, hexafluorobenzene, trifluoromethylbenzene.

[0136] In some embodiments, the weight percentage of the aromatic fluorine-containing solvent is about 0.1wt%-10wt% based on the total weight of the electrolyte. In some embodiments, the weight percentage of the aromatic fluorine-containing solvent is not less than 0.5wt% based on the total weight of the electrolyte. In some embodiments, the weight percentage of the aromatic fluorine-containing solvent is not less than 2wt% based on the total weight of the electrolyte. In some embodiments, the weight percentage of the aromatic fluorine-containing solvent is not more than 4wt% based on the total weight of the electrolyte. In some embodiments, the weight percentage of the aromatic fluorine-containing solvent is not more than 8wt% based on the total weight of the electrolyte.

[0137] In some embodiments, the electrolyte further comprises a lithium salt additive. In some embodiments, the lithium salt additive comprises at least one of the following compounds: lithium trifluoromethanesulfonyl imide LiN (CF 3 SO 2 ) 2 (abbreviated as LiTFSI), lithium bis(fluorosulfonyl)imide Li(N(SO 2 F) 2 )(abbreviated as LiFSI), lithium bis(oxalatoborate) LiB(C 2 O 4 ) 2 (abbreviated as LiBOB), lithium tetrafluorophosphate oxalate (LiPF 4 C 2 O 2 ), LiBF 2 (C 2 O 4 ) (abbreviated as LiDFOB), lithium hexafluorocesium oxide (LiCsF 6 ), lithium difluorophosphate (LiPO 2 F 2 ) and lithium tetrafluorooxalophosphate (LiTFOP).

[0138] In some embodiments, based on the total weight of the electrolyte, the weight percentage of the lithium salt additive is 0.01wt%-10wt%. In some embodiments, based on the total weight of the electrolyte, the weight percentage of the lithium salt additive is 0.01wt%-5wt%. In some embodiments, based on the total weight of the electrolyte, the weight percentage of the lithium salt additive is 0.01wt%-1wt%. In some embodiments, based on the total weight of the electrolyte, the weight percentage of the lithium salt additive is 0.01wt%-0.9wt%. In some embodiments, based on the total weight of the electrolyte, the weight percentage of the lithium salt additive is 0.01wt%, 0.05wt%, 0.1wt%, 0.3wt%, 0.5wt%, 0.7wt%, 0.9wt%, 1wt%, 3wt%, 5wt%, 7wt%, 9wt%, 10wt% or a range consisting of any two of these values.

[0139] 2. Electrolytes

[0140] The electrolyte used in the electrolyte solution of the present application embodiment may be an electrolyte known in the prior art, including but not limited to LiClO 4 、LiAsF 6 、LiPF 6 , LiBF 4 、LiSbF 6 、LiSO 3 F、LiN(FSO 2 ) 2 In addition, the above electrolytes can be used alone or in combination of two or more. For example, in some embodiments, the electrolyte includes LiPF 6 and LiBF 4 In some embodiments, the concentration of the electrolyte is in the range of 0.8-3 mol / L, for example, in the range of 0.8-2.5 mol / L, in the range of 0.8-2 mol / L, in the range of 1-2 mol / L, 0.5-1.5 mol / L, 0.8-1.3 mol / L, 0.5-1.2 mol / L, and for example, 1 mol / L, 1.15 mol / L, 1.2 mol / L, 1.5 mol / L, 2 mol / L or 2.5 mol / L.

[0141] 3. Electrochemical Device

[0142] The electrochemical device of the present application includes any device in which an electrochemical reaction occurs, and its specific examples include all kinds of primary batteries, secondary batteries, fuel cells, solar cells or capacitors. In particular, the electrochemical device is a lithium secondary battery, including a lithium metal secondary battery, a lithium ion secondary battery, a lithium polymer secondary battery or a lithium ion polymer secondary battery. In some embodiments, the electrochemical device of the present application is an electrochemical device having a positive electrode with a positive electrode active material capable of absorbing and releasing metal ions and a negative electrode with a negative electrode active material capable of absorbing and releasing metal ions, characterized in that it contains the electrolyte in any of the above embodiments of the present application.

[0143] 1. Electrolyte

[0144] The electrolyte used in the electrochemical device of the present application is the electrolyte of any of the above embodiments in the present application.

[0145] Furthermore, the electrolyte used in the electrochemical device of the present application may include other electrolytes within the scope not departing from the gist of the present application.

[0146] 2. Negative electrode

[0147] The material, composition and manufacturing method of the negative electrode used in the electrochemical device of the present application may include any technology disclosed in the prior art. In some embodiments, the negative electrode is a negative electrode described in US Patent Application US9812739B, which is incorporated into the present application by reference in its entirety.

[0148] In some embodiments, the negative electrode includes a current collector and a negative electrode active material layer located on the current collector. The negative electrode active material includes a material that reversibly embeds / deintercalates lithium ions. In some embodiments, the material that reversibly embeds / deintercalates lithium ions includes a carbon material. In some embodiments, the carbon material can be any carbon-based negative electrode active material commonly used in lithium-ion rechargeable batteries. In some embodiments, the carbon material includes, but is not limited to: crystalline carbon, amorphous carbon, or a mixture thereof. Crystalline carbon can be amorphous, flaky, flake-shaped, spherical or fibrous natural graphite or artificial graphite. Amorphous carbon can be soft carbon, hard carbon, mesophase pitch carbide, calcined coke, etc.

[0149] In some embodiments, the negative electrode active material layer includes a negative electrode active material. In some embodiments, the negative electrode active material includes, but is not limited to: lithium metal, structured lithium metal, natural graphite, artificial graphite, mesophase microcarbon beads (MCMB), hard carbon, soft carbon, silicon, silicon-carbon composite, Li-Sn alloy, Li-Sn-O alloy, Sn, SnO, SnO 2 , spinel-structured lithiated TiO 2 -Li 4 Ti 5 O12 , Li-Al alloy or any combination thereof.

[0150] When the negative electrode includes a silicon-carbon compound, based on the total weight of the negative electrode active material, silicon: carbon = 1:10-10:1, and the median particle size Dv50 of the silicon-carbon compound is 0.1μm-100μm. When the negative electrode includes an alloy material, a negative electrode active material layer can be formed by evaporation, sputtering, plating, and the like. When the negative electrode includes lithium metal, the negative electrode active material layer is formed, for example, with a spherical twisted conductive skeleton and metal particles dispersed in the conductive skeleton. In some embodiments, the spherical twisted conductive skeleton may have a porosity of 5%-85%. In some embodiments, a protective layer may also be provided on the lithium metal negative electrode active material layer.

[0151] In some embodiments, the negative electrode active material layer may include a binder and optionally a conductive material. The binder improves the bonding between the negative electrode active material particles and the bonding between the negative electrode active material and the current collector. In some embodiments, the binder includes, but is not limited to: polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide-containing polymers, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene 1,1-difluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin, nylon, etc.

[0152] In some embodiments, the conductive material includes, but is not limited to: a carbon-based material, a metal-based material, a conductive polymer, or a mixture thereof. In some embodiments, the carbon-based material is selected from natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, or any combination thereof. In some embodiments, the metal-based material is selected from metal powder, metal fiber, copper, nickel, aluminum, silver. In some embodiments, the conductive polymer is a polyphenylene derivative.

[0153] In some embodiments, the current collector includes, but is not limited to, copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and any combination thereof.

[0154] The negative electrode can be prepared by a preparation method known in the art. For example, the negative electrode can be obtained by mixing an active material, a conductive material, and a binder in a solvent to prepare an active material composition, and coating the active material composition on a current collector. In some embodiments, the solvent may include water, etc., but is not limited thereto.

[0155] 3. Positive electrode

[0156] The material of the positive electrode used in the electrochemical device of the present application can be prepared using materials, structures and manufacturing methods known in the art. In some embodiments, the positive electrode of the present application can be prepared using the technology described in US9812739B, which is incorporated into the present application by reference in its entirety.

[0157] In some embodiments, the positive electrode includes a current collector and a positive electrode active material layer on the current collector, wherein the positive electrode active material layer includes a positive electrode active material.

[0158] In some embodiments, the type of positive electrode active material is not particularly limited, as long as it can absorb and release metal ions (e.g., lithium ions) electrochemically. In some embodiments, the positive electrode active material is a substance containing lithium and at least one transition metal. Examples of positive electrode active materials may include, but are not limited to, lithium transition metal composite oxides and lithium-containing transition metal phosphate compounds.

[0159] In some embodiments, the lithium transition metal composite oxide includes a lithium cobalt composite oxide (eg, LiCoO 2 ), lithium nickel composite oxides (such as LiNiO 2 ), lithium manganese composite oxides (such as LiMnO 2 、LiMn 2 O 4 , Li 2 MnO 4 ), lithium nickel manganese cobalt composite oxide (such as LiNi 1 / 3 Mn 1 / 3 Co 1 / 3 O 2 、LiNi 0.5 Mn 0.3 Co 0.2 O 2 ).

[0160] In some embodiments, the positive electrode active material further comprises element A, the content of element A is 50ppm-3000ppm based on the total weight of the positive electrode active material, and the element A comprises at least one of Mg, Ti, Zr, Y, Zn, La, Al, W or Si.

[0161] In some embodiments, a portion of transition metal atoms of the host of the lithium transition metal composite oxide may be substituted with atoms of the A element.

[0162] In some embodiments, based on the total weight of the positive electrode active material, the content of the A element is 50 ppm, 100 ppm, 200 ppm, 500 ppm, 1000 ppm, 1500 ppm, 2000 ppm, 2500 ppm, 3000 ppm or a range consisting of any two of these numerical ranges.

[0163] In some embodiments, the positive electrode active material may have a coating on its surface, or may be mixed with another compound having a coating. The coating may include at least one coating element compound selected from an oxide of a coating element, a hydroxide of a coating element, an oxyhydroxide of a coating element, an oxycarbonate of a coating element, and a hydroxycarbonate of a coating element. The compound for the coating may be amorphous or crystalline.

[0164] In some embodiments, the coating element contained in the coating may include Mg, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, F or any combination thereof. The coating may be applied by any method as long as the method does not adversely affect the performance of the positive electrode active material. For example, the method may include any coating method known in the art, such as spraying, dipping, etc.

[0165] The positive electrode active material layer also includes a binder, and optionally a conductive material. The binder improves the bonding of the positive electrode active material particles to each other and also improves the bonding of the positive electrode active material to the current collector.

[0166] In some embodiments, the binder includes, but is not limited to: polyvinyl alcohol, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide-containing polymers, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin, nylon, etc.

[0167] In some embodiments, the conductive material includes, but is not limited to: carbon-based materials, metal-based materials, conductive polymers, and mixtures thereof. In some embodiments, the carbon-based material is selected from natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, or any combination thereof. In some embodiments, the metal-based material is selected from metal powder, metal fiber, copper, nickel, aluminum, silver. In some embodiments, the conductive polymer is a polyphenylene derivative.

[0168] In some embodiments, the current collector may be aluminum, but is not limited thereto.

[0169] The positive electrode can be prepared by a preparation method known in the art. For example, the positive electrode can be obtained by mixing an active material, a conductive material, and a binder in a solvent to prepare an active material composition, and coating the active material composition on a current collector. In some embodiments, the solvent may include N-methylpyrrolidone, etc., but is not limited thereto.

[0170] In some embodiments, the positive electrode is made by forming a positive electrode material using a positive electrode active material layer including a lithium transition metal compound powder and a binder on a current collector.

[0171] In some embodiments, the positive electrode active material layer can be generally prepared by dry mixing the positive electrode active material and the binder (conductive material and thickener used as needed) to form a sheet, pressing the obtained sheet to the positive electrode collector, or dissolving or dispersing these materials in a liquid medium to form a slurry, coating the slurry on the positive electrode collector and drying. In some embodiments, the material of the positive electrode active material layer includes any material known in the art.

[0172] 4. Isolation film

[0173] In some embodiments, the electrochemical device of the present application is provided with a separator between the positive electrode and the negative electrode to prevent short circuit. The material and shape of the separator used in the electrochemical device of the present application are not particularly limited, and it can be any technology disclosed in the prior art. In some embodiments, the separator includes a polymer or inorganic substance formed of a material that is stable to the electrolyte of the present application.

[0174] In some embodiments, the isolation film comprises a polyolefin substrate layer and a coating layer on at least one surface of the polyolefin substrate layer, and the thickness ratio of the substrate layer to the coating layer is 1: 1-5: 1. In some embodiments, the thickness ratio of the substrate layer to the coating layer is 1: 1, 2: 1, 3: 1, 4: 1, 5: 1, or a range consisting of any two of these numerical ranges.

[0175] In some embodiments, the thickness of the polyolefin substrate layer is 2-10 μm. In some embodiments, the thickness of the polyolefin substrate layer is 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, or a range consisting of any two of these values.

[0176] In some embodiments, the coating has a thickness of 0.5-3 μm. In some embodiments, the coating has a thickness of 0.5 μm, 0.7 μm, 1 μm, 1.2 μm, 1.4 μm, 1.7 μm, 2 μm, 2.5 μm, 3 μm, or a range consisting of any two of these values.

[0177] In some embodiments, the coating includes a polymer, and the polymer includes at least one of the following compounds: polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, ethylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, perfluoroethylene-propylene copolymer, acrylic acid, methacrylic acid, itaconic acid, ethyl acrylate, butyl acrylate, acrylonitrile, and methacrylonitrile.

[0178] In some embodiments, the coating includes inorganic particles, which contain at least one of the following compounds: aluminum oxide, silicon dioxide, magnesium oxide, titanium oxide, hafnium dioxide, tin oxide, cerium dioxide, nickel oxide, zinc oxide, calcium oxide, zirconium oxide, yttrium oxide, silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, and barium sulfate.

[0179] In some embodiments, the coating comprises both a polymer as defined above and inorganic particles.

[0180] In some embodiments, the polyolefin substrate layer is polyethylene, polypropylene, ethylene-propylene copolymer or any combination thereof.

[0181] In some embodiments, the isolation membrane is a single-layer PE porous polymer film.

[0182] In some embodiments, the isolation film is a low-temperature closed-cell isolation film. In some embodiments, the low-temperature closed-cell isolation film includes two first layers and a second layer located between the two first layers.

[0183] In some embodiments, the first layer and the second layer each independently include a polyolefin substrate layer and a coating layer located on at least one surface of the polyolefin substrate layer. In some embodiments, the polyolefin substrate layer and the coating layer are defined as described above.

[0184] In some embodiments, the closed-cell temperature of the first porous layer is 120-140° C. In some embodiments, the closed-cell temperature of the first porous layer is 120° C., 125° C., 130° C., 135° C., 140° C., or a range consisting of any two of these values.

[0185] IV. Application

[0186] The electrolyte according to the embodiment of the present application can improve the battery's cyclic flatulence, high-temperature storage performance, overcharge and hot box test performance, and is suitable for use in electronic devices including electrochemical devices.

[0187] The use of the electrochemical device of the present application is not particularly limited, and can be used for various known uses, such as laptop computers, pen-input computers, mobile computers, electronic book players, portable phones, portable fax machines, portable copiers, portable printers, head-mounted stereo headphones, video recorders, LCD televisions, portable cleaners, portable CD players, mini-discs, transceivers, electronic notepads, calculators, memory cards, portable recorders, radios, backup power supplies, motors, cars, motorcycles, power-assisted bicycles, bicycles, lighting fixtures, toys, game consoles, clocks, power tools, flashlights, cameras, large household batteries or lithium-ion capacitors, etc.

[0188] The preparation and performance of the lithium-ion battery of the present application are explained below by taking a lithium-ion battery as an example and combining a specific embodiment of preparing the electrolyte of the present application and a method of testing an electrochemical device. Those skilled in the art will understand that the preparation method described in the present application is only an example, and any other suitable preparation method is within the scope of the present application.

[0189] Although lithium ion batteries are used as examples, those skilled in the art will be able to imagine that the cathode material of the present application can be used in other suitable electrochemical devices after reading the present application. Such an electrochemical device includes any device in which an electrochemical reaction occurs, and its specific examples include all kinds of primary batteries, secondary batteries, fuel cells, solar cells or capacitors. In particular, the electrochemical device is a lithium secondary battery, including a lithium metal secondary battery, a lithium ion secondary battery, a lithium polymer secondary battery or a lithium ion polymer secondary battery.

[0190] Example

[0191] Hereinafter, the present application will be described in more detail with reference to Examples and Comparative Examples, but the present application is not limited to these Examples unless departing from the gist of the present application.

[0192] 1. Lithium-ion battery preparation

[0193] 1) Preparation of electrolyte:

[0194] In an argon atmosphere glove box with a water content of <10 ppm, ethylene carbonate (abbreviated as EC), propylene carbonate (abbreviated as PC), and diethyl carbonate (abbreviated as DEC) were mixed in a weight ratio of 3:3:4, and then the fully dried lithium salt LiPF 6 Dissolved in the above mixed solvent to obtain a basic electrolyte, wherein LiPF 6 The concentration is 1 mol / L. The electrolytes of different embodiments and comparative examples are obtained by adding substances of different contents as shown in the following tables to the basic electrolyte. The contents of each substance in the electrolyte described below are calculated based on the total weight of the electrolyte.

[0195] Examples of compounds of formula I are as follows:

[0196]

[0197] Examples of compounds containing sulfur-oxygen double bonds are shown below:

[0198]

[0199] Examples of lithium phosphate salt compounds are as follows: lithium difluorophosphate (LiPO 2 F 2 ), lithium tetrafluorooxalate phosphate (LiTFOP).

[0200] 2) Preparation of positive electrode:

[0201] Five different positive electrodes are used in the examples of this application, and the preparation methods are as follows:

[0202] Positive electrode 1: The positive electrode active material LCO (molecular formula is LiCo 0.998 Mg 0.002 O 2 ), conductive carbon black, and polyvinylidene fluoride (abbreviated as PVDF) are fully stirred and mixed in an appropriate amount of N-methylpyrrolidone (abbreviated as NMP) solvent in a weight ratio of 97:1:2 to form a uniform positive electrode slurry; the slurry is coated on the positive electrode current collector Al foil, dried, and cold pressed to obtain a positive electrode with a positive electrode compaction density of 4.15 g / cm 3 .

[0203] Positive electrode 2: The positive electrode active material NCM811 (molecular formula LiNi 0.8 Mn 0.098 Co 0.1 Mg 0.002 O 2 ), acetylene black as a conductive agent, and polyvinylidene fluoride (abbreviated as PVDF) as a binder are fully stirred and mixed in an appropriate amount of N-methylpyrrolidone (abbreviated as NMP) solvent in a weight ratio of 96:2:2 to form a uniform positive electrode slurry; the slurry is coated on the positive electrode current collector Al foil, dried, and cold pressed to obtain a positive electrode with a positive electrode compaction density of 3.50 g / cm 3 .

[0204] Positive electrode 3: The positive electrode active material NCM523 (molecular formula LiNi 0.5 Mn 0.298 Co 0.2 Mg 0.002 O 2), conductive carbon black-L, and binder polyvinylidene fluoride are fully stirred and mixed in an appropriate amount of N-methylpyrrolidone (abbreviated as NMP) solvent in a weight ratio of 96:2:2 to form a uniform positive electrode slurry; the slurry is coated on the positive electrode current collector Al foil, dried, and cold pressed to obtain a positive electrode with a positive electrode compaction density of 3.50 g / cm 3 .

[0205] Positive electrode 4: Similar to positive electrode 1, except that the positive electrode active material is LiCoO 2 .

[0206] Positive electrode 5: Similar to positive electrode 1, except that the positive electrode active material is LiCo 0.996 Mg 0.002 Al 0.001 Ti 0.001 O 2 .

[0207] 3) Preparation of negative electrode:

[0208] Three different negative electrodes are used in the examples of this application, and the preparation methods are as follows:

[0209] Negative electrode 1: The negative electrode active material graphite, the binder styrene butadiene rubber (abbreviated as SBR), and sodium carboxymethyl cellulose (abbreviated as CMC-Na) were fully stirred and mixed in an appropriate amount of deionized water solvent at a weight ratio of 97.4:1.4:1.2 to form a uniform negative electrode slurry; the slurry was coated on the negative electrode current collector Cu foil, dried, and cold pressed to obtain a negative electrode. The compaction density of the negative electrode was 1.80 g / cm 3 .

[0210] Negative electrode 2: The negative electrode active material graphite, silicon oxide material (SiO), sodium carboxymethyl cellulose (abbreviated as CMC-Na), and modified polyacrylic acid are fully stirred and mixed in an appropriate amount of deionized water solvent according to a weight ratio of 87:10:0.6:2.4 to form a uniform negative electrode slurry; the slurry is coated on the negative electrode current collector Cu foil, dried, and cold pressed to obtain a negative electrode. The compaction density of the negative electrode is 1.70g / cm 3 .

[0211] Negative electrode 3: Similar to negative electrode 2, the difference is that the surface of the silicon oxide material has an aluminum oxide layer, and the thickness of the aluminum oxide layer is 5nm.

[0212] Negative electrode 4: Similar to negative electrode 2, the difference is that the surface of the silicon oxide material has a carbon layer with a thickness of 5 nm.

[0213] 4) Isolation film:

[0214] Four different isolation membranes are used in the examples of the present application. The compositions of the isolation membranes are as follows, wherein the isolation membranes LTS-1, LTS-2 and LTS-3 are low-temperature closed-cell isolation membranes:

[0215] Separator S: A single-layer polyethylene (PE) porous polymer film is used as the separator, with a thickness of 9 μm and a porosity of 39%. A coating is provided on both sides of the polyethylene (PE) porous polymer film, and the average thickness of the coating is 1.5 μm, wherein the inorganic particles in the coating are Al 2 O 3 , the polymer is polyvinylidene fluoride.

[0216] Separator LTS-1: Separator LTS-1 is a three-layer composite membrane, that is, a second porous layer is arranged between two first porous layers; the first porous layer is a membrane prepared from a mixture of polypropylene (PP) and PE, wherein the number average molecular weight of PE is 5.0×10 3 -4.0×10 5 , the number average molecular weight of PP is 1.0×10 5 -9.0×10 5 , the content of PP is 1wt%-3wt%; the second porous layer is PE, and its number average molecular weight is 1.0×10 5 -9.0×10 5 The thickness of the first porous layer is 4 μm, the thickness of the second porous layer is 4 μm, and a coating is provided on the surface of the two first porous layers away from the second porous layer. The average thickness of the coating is 1.5 μm, and the inorganic particles on the coating are Al 2 O 3 The polymer is polyvinylidene fluoride, and the closed-cell temperature of the first porous layer is 131±2°C.

[0217] Separator LTS-2: Separator LTS-2 is a three-layer composite membrane, that is, a second porous layer is arranged between two first porous layers; the first porous layer is low molecular weight PE, and its number average molecular weight is 5.0×10 3 -4.0×10 5 The second porous layer is high molecular weight PE, with a number average molecular weight of 9.0×10 5 -4.0×10 6 ; The thickness of the first porous layer is 4μm, and the thickness of the second porous layer is 4μm; a coating is provided on the surface of the two first porous layers away from the second porous layer, the average thickness of the coating is 1.5μm, the inorganic particles on the coating are magnesium hydroxide, the polymer is polyvinylidene fluoride, and the closed-cell temperature of the first porous layer is 129±2℃.

[0218] Separator LTS-3: Separator LTS-3 is a three-layer composite membrane, that is, a second porous layer is arranged between two first porous layers; the first porous layer is low molecular weight PE, and its number average molecular weight is 5.0×10 3 -4.0×10 5 The second porous layer is a PP-PE copolymer film, wherein the PE content is 7-15wt%, and the number average molecular weight is 1.0×10 5 -9.0×10 5 ; The thickness of the first porous layer is 4μm, and the thickness of the second porous layer is 4μm; a coating is provided on the surface of the two first porous layers away from the second porous layer, the average thickness of the coating is 1.5μm, the inorganic particles on the coating are boehmite, the polymer is polyvinylidene fluoride, and the closed-cell temperature of the first porous layer is 129±2℃.

[0219] 5) Preparation of lithium-ion batteries: stack the positive electrode, separator, and negative electrode in order, so that the separator is between the positive and negative electrodes to play an isolating role, then wind and place in an outer packaging foil, inject the prepared electrolyte into the dried battery, and complete the preparation of the lithium-ion battery after vacuum packaging, standing, formation, shaping and other processes.

[0220] 2. Lithium-ion battery performance test method

[0221] A. The electrolytes and lithium ion batteries of Examples 1-31 and Comparative Examples 1-4 were prepared according to the above preparation method, wherein the positive electrode was positive electrode 1 (active material was LCO), the separator was S, and the negative electrode was negative electrode 1 (active material was graphite). The contents of various substances in the electrolyte and the test results of the relevant performance of the lithium ion battery are shown in Table 1, and the test method is as follows:

[0222] (1) Cyclic performance test process: At 25°C, the battery was charged to 4.45V at 1.5C, and then charged to 0.05C at a constant voltage at 4.45V, and then discharged to 3.0V at a current of 1C. The thickness of the lithium-ion battery was tested and recorded as d0. The process of charging at 1.5C and discharging at 1C was repeated for 800 cycles, and the thickness was tested and recorded as d. The cyclic expansion rate was calculated according to the following formula: Expansion rate (%) = (d-d0) / d0×100%.

[0223] (2) Hot box test process: Charge the battery to 4.45V at 0.5C constant current, charge to 0.05C at 4.45V constant voltage, let stand at 25±5℃ for 60 minutes, check the appearance and take photos, raise the temperature to 130℃±2℃ at a rate of 5℃ / min±2℃ / min, and keep it for 120min. After the test, check the appearance and take photos, monitor the voltage and temperature during the test, and pass the test if there is no fire or explosion. Test 10 batteries in parallel for each embodiment and comparative example, and record the number of batteries that pass the test.

[0224] (3) High temperature storage test process: Charge the battery at 25°C at a constant current of 0.5C to 4.45V, then charge at a constant voltage to a current of 0.05C, test the thickness of the lithium-ion battery and record it as d1; place it in an oven at 85°C for 24 hours, measure the thickness at this time, and record it as d2. The thickness expansion rate (%) of the lithium-ion battery after 24 hours of high temperature storage = (d2-d1) / d1×100%. In the high temperature storage test of the battery using positive electrode 1, positive electrode 3, positive electrode 4, and positive electrode 5, charge the voltage to 4.45V; in the high temperature storage test of the battery using positive electrode 2, charge the voltage to 4.25V; other test processes remain unchanged.

[0225] Table 1

[0226]

[0227]

[0228] “—” means that the substance is not added.

[0229] It can be seen from the examples and comparative examples in Table 1 that adding the compound of formula I to the electrolyte can significantly improve the cyclic flatulence, high temperature storage performance and hot box test performance of the lithium ion battery.

[0230] In addition, it can be seen that adding a compound containing a sulfur-oxygen double bond to the electrolyte containing the compound of formula I can further improve the cyclic flatulence, high temperature storage performance and hot box test performance of the lithium-ion battery.

[0231] B. The electrolytes and lithium ion batteries of Examples 32-42 and Comparative Examples 5-6 were prepared according to the above preparation method, and the batteries were subjected to high temperature storage test; the separator was separator S, and the negative electrode was negative electrode 1 (the active material was graphite). Table 2 shows the content of each substance in the electrolytes of Examples 32-42 and Comparative Examples 5-6, the type of positive electrode and the related performance test results.

[0232] Table 2

[0233]

[0234]

[0235] “—” means that the substance is not added.

[0236] It can be seen from the performance test results of the embodiments and comparative examples in Table 2 that in a lithium ion battery using positive electrode 2 (active material is NCM811) or positive electrode 3 (active material is NCM523), compared with the electrolyte using the compound of formula I-1, the electrolyte using the compound of formula I-2 can further improve the high temperature storage performance of the lithium ion battery. And when the same electrolyte is used, compared with the use of positive electrode 1, the use of positive electrode 2 (active material is NCM811) and positive electrode 3 can further improve the high temperature storage performance of the lithium ion battery.

[0237] C. The electrolytes and lithium-ion batteries of Examples 43-50 and Example 1 were prepared according to the above preparation method, wherein the positive electrode was positive electrode 1, the isolation membrane was isolation membrane S, and the negative electrode was negative electrode 1 (the active material was graphite), and the batteries were subjected to high temperature storage tests.

[0238] Table 3 shows the content of each substance in the electrolyte of Examples 43-50 and Example 1 and the related performance test results.

[0239] Table 3

[0240]

[0241] “—” means that the substance is not added.

[0242] It can be seen from the test results in Table 3 that adding a phosphate lithium salt compound to the electrolyte comprising the compound of formula I and a compound containing a sulfur-oxygen double bond can further improve the high-temperature storage performance of the lithium-ion battery. The reason may be that lithium difluorophosphate (LiPO 2 F 2 ) and lithium tetrafluorooxalophosphate (LiTFOP) can reduce the contact between the electrolyte and the positive electrode, thereby inhibiting gas production.

[0243] D. The electrolyte and lithium ion battery of Examples 51A-59B were prepared according to the above preparation method, wherein the positive electrode was positive electrode 2 (active material was NCM811), the negative electrode was negative electrode 1 (active material was graphite), and the type of the separator was shown in Table 4. The lithium ion battery of the above examples was overcharged, and the test process was as follows. The electrolyte of Examples 51A and 51B, Examples 58A and 58B, and Examples 59A and 59B were the same, but the conditions of the lithium ion battery overcharge test were different.

[0244] Overcharge test process: the battery is discharged at 0.5C to 2.8V at 25°C, then charged at a constant current of 2C (4A) to different voltages as shown in Table 4, and then charged at a constant voltage for 3 hours, and the battery surface temperature change is monitored. If there is no fire or smoke, it passes the test. Ten batteries are tested in each embodiment, and the number of batteries that pass the test is counted.

[0245] The contents of various substances in the electrolytes of Examples 51A-59B and related test results are shown in Table 4.

[0246] Table 4

[0247]

[0248] “—” means that the substance is not added.

[0249] It can be seen from the test results of Table 4 that the battery of Example 59-B using the isolation membrane S cannot pass the 8V overcharge test at all. However, when using the same electrolyte, after replacing the isolation membrane S with a low-temperature closed-cell isolation membrane (LTS-1, LTS-2 or LTS-3), the overcharge performance of the lithium-ion battery is significantly improved. The reason may be that the combination of the compound of formula I and the low-temperature closed-cell isolation membrane has a synergistic effect. The cyano-functional compound can improve the stability of the positive electrode material interface, thereby reducing the decomposition of the electrolyte on the electrode surface during the overcharge process and the hot box process, and slowing down the temperature increase. When the temperature rises to the isolation membrane closed pore, it can inhibit or completely inhibit the transmission of lithium ions, preventing further charging. The use of a low-temperature closed-cell isolation membrane can close the pores at a lower temperature, thereby preventing thermal runaway and improving overcharge and hot box performance.

[0250] E. The electrolytes and lithium-ion batteries of Examples 60-64 and Comparative Examples 7 and 8 were prepared according to the above preparation method, wherein the positive electrode was positive electrode 1 and the isolation membrane was isolation membrane S, and the batteries were subjected to high temperature storage tests.

[0251] 60℃ high temperature storage test process: Charge the battery to 4.45V at 0.5C constant current at 25℃, then charge it to 0.05C constant voltage, and test the thickness of the lithium-ion battery and record it as d 0 ; Place in a 60℃ oven for 30 days, measure the thickness at this time, and record it as d. Thickness expansion rate (%) of lithium-ion battery after high temperature storage for 24 hours = (dd 0 ) / d 0 ×100%.

[0252] The composition of each substance in the electrolyte of Examples 60-64 and Comparative Examples 7 and 8, as well as the types of negative electrodes and related performance test results are shown in Table 5.

[0253] Table 5

[0254]

[0255] “—” means that the substance is not added.

[0256] It can be seen from the test results in Table 5 that the high temperature storage performance of the lithium ion battery is significantly improved after adding the compound containing a cyano functional group to the electrolyte of Comparative Examples 7 and 8. The reason may be that the compound of formula I can improve the stability of the positive electrode material interface, while inhibiting the dissolution of transition metals and reducing the deposition of Co on the negative electrode surface, thereby slowing down the decomposition of the solid electrolyte interface (SEI) film. The two work together to reduce the decomposition of the electrolyte, inhibit gas production, and improve the high temperature storage.

[0257] References throughout the specification to "some embodiments", "some embodiments", "one embodiment", "another example", "example", "specific example" or "partial example" mean that at least one embodiment or example in the present application includes the specific features, structures, materials or characteristics described in the embodiment or example. Therefore, descriptions appearing in various places throughout the specification, such as: "in some embodiments", "in an embodiment", "in one embodiment", "in another example", "in an example", "in a specific example" or "example", do not necessarily refer to the same embodiment or example in the present application. In addition, the specific features, structures, materials or characteristics herein may be combined in one or more embodiments or examples in any suitable manner.

[0258] Although illustrative embodiments have been demonstrated and described, those skilled in the art should understand that the above embodiments should not be construed as limitations on the present application, and that changes, substitutions and modifications may be made to the embodiments without departing from the spirit, principles and scope of the present application.

Claims

1. An electrolyte, characterized in that: Including at least one of the compounds shown in the following formula I-1 to formula I-17: Wherein, based on the total weight of the electrolyte, the sum of the weight percentages of the compounds represented by Formula I-1 to Formula I-17 is 0.01 wt % to 5 wt %; The electrolyte further comprises at least one of the following compounds containing a sulfur-oxygen double bond: Wherein, based on the total weight of the electrolyte, the weight percentage of the compound containing sulfur-oxygen double bonds is 0.01 wt %-10 wt %.

2. The electrolyte according to claim 1, characterized in that The electrolyte further comprises a cyclic carbonate compound, wherein the cyclic carbonate compound comprises a compound of formula III: wherein R3 is selected from substituted or unsubstituted C1-C 20 Alkylene or substituted or unsubstituted C2-C 20 alkenylene; When R3 is substituted, the substituent is selected from halogen, C1-C6 alkyl, C2-C6 alkenyl, C6-C 20 Aryl or C6-C 20 Heteroaryl, wherein the heteroatom is selected from one or more of O, S, N, and P; Based on the total weight of the electrolyte, the weight percentage of the cyclic carbonate compound is 0.01 wt %-40 wt %.

3. The electrolyte according to claim 2, characterized in that The cyclic carbonate compound includes at least one of the following compounds:

4. An electrochemical device, characterized in that: The electrochemical device comprises a positive electrode, a negative electrode, a separator and an electrolyte according to any one of claims 1 to 3.

5. The electrochemical device according to claim 4, characterized in that The positive electrode includes a current collector and a positive electrode active material layer located on the current collector, the positive electrode active material layer includes a positive electrode active material, wherein the positive electrode active material contains element A, the element A contains at least one of Mg, Ti, Zr, Y, Zn, La, Al, W or Si, and based on the total weight of the positive electrode active material, the content of element A is 50ppm-8000ppm.

6. The electrochemical device according to claim 4, characterized in that The isolation film comprises a polyolefin substrate layer and a coating layer located on at least one surface of the polyolefin substrate layer, and the thickness ratio of the substrate layer to the coating layer is 1:1-5:

1.

7. The electrochemical device according to claim 6, characterized in that The coating includes a polymer, which includes at least one of the following compounds: polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, ethylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, perfluoroethylene-propylene copolymer, acrylic acid, methacrylic acid, itaconic acid, ethyl acrylate, butyl acrylate, acrylonitrile or methacrylonitrile.

8. The electrochemical device according to claim 6, characterized in that The coating includes inorganic particles, which contain at least one of the following compounds: aluminum oxide, silicon dioxide, magnesium oxide, titanium oxide, hafnium dioxide, tin oxide, cerium dioxide, nickel oxide, zinc oxide, calcium oxide, zirconium oxide, yttrium oxide, silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide or barium sulfate.

9. An electronic device, characterized in that: The electronic device comprises an electrochemical device according to any one of claims 4-8.

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