Electrolyte, battery monomer, battery and electric device

Abstract

The invention provides an electrolyte, a battery monomer, a battery and a power utilization device, the electrolyte comprises a first anion shown in a formula (I), and X, a, b, R1 and R2 are respectively defined in the description. # imgabs0 #

Description

Electrolyte, battery cells, batteries and electrical devices Technical Field

[0001] The present application relates to an electrolyte, a battery cell, a battery and an electrical device. Background Art

[0002] In recent years, batteries have been widely used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, as well as in multiple fields such as power tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, aerospace, etc. With the application and promotion of batteries, the energy density of traditional batteries with carbon-based materials as negative electrodes can no longer meet the demand, so there is a need for battery systems with higher energy density. Batteries with materials such as lithium metal as negative electrodes have high energy density, but the cycle life of the battery is short. The above statements are only used to provide background technical information related to this application and do not necessarily constitute prior art.

[0003] Summary of the Invention

[0004] The present application provides an electrolyte, a battery cell, a battery, and an electrical device, which can improve the cycle performance of the battery.

[0005] In a first aspect, the present application provides an electrolyte comprising a first anion represented by formula (I),

[0006] X includes one or more elements selected from N, B, P, Al, Si, S, Cl, As, and Se; a represents an integer greater than or equal to 1; b represents an integer greater than or equal to 1; R 1 Each independently includes one or more of a halogen atom, a halosulfonyl group, a haloalkylsulfonyl group, and an ester group -O-(C=O)-, and optionally two adjacent R 1 It can also form a ring with X; R 2 Each independently includes one or more of C1-C10 chain alkyl, C1-C10 oxo chain alkyl, C3-C10 cyclic alkyl, C1-C10 oxo heterocyclic alkyl, C1-C10 halogenated chain alkyl, C1-C10 oxohalogenated chain alkyl, C3-C10 halogenated cyclic alkyl, and C1-C10 oxohalogenated cyclic alkyl, and optionally two adjacent R 2 It can also form a ring with X.

[0007] On the one hand, the first anion can form a high-quality SEI film on the negative electrode surface, inducing dense metal deposition and improving the battery's cycling stability. On the other hand, it can also reduce its own decomposition and consumption, delaying the onset of electrolyte dry-up. As a result, the electrolyte provided by the embodiments of the present application can have high reduction resistance and low consumption rate, thereby improving the battery's cycling performance.

[0008] In any embodiment of the present application, R 1 Each independently includes one or more of a fluorine atom, a fluorosulfonyl group, a fluoroalkylsulfonyl group, and an ester group -O-(C=O)-, and optionally two adjacent R 1 It can also form a ring with X.

[0009] In any embodiment of the present application, R 1 Including fluorine atoms, one or more of the following groups,

[0010] # indicates the connection location.

[0011] R 1 When the above groups are included, it helps to form a higher quality SEI film on the surface of the negative electrode, which can induce dense metal deposition and further extend the battery cycle life.

[0012] In any embodiment of the present application, R 2 Each independently includes one or more of C1-C10 oxo-chain alkyl, C1-C10 oxo-cyclic alkyl, C1-C10 oxo-halogenated chain alkyl, and C1-C10 oxo-halogenated cyclic alkyl, and optionally two adjacent R 2 It can also form a ring with X. Oxygen atoms have a better binding effect with metal ions. 2 When containing oxygen heteroatoms, R 2 It can also provide a second reaction site for complexing with metal ions to increase the reaction rate of metal ions; at the same time, it can further improve the overall stability and reduction resistance of the first anion, further reduce the decomposition consumption of the first anion, delay the occurrence of electrolyte drying up, and thus further extend the cycle life of the battery.

[0013] In any embodiment of the present application, R 2 Each independently includes one or more of C1-C10 oxo-chain alkyl and C1-C10 oxo-heterocyclic alkyl, and optionally two adjacent R 2 It can also form a ring with X. Halogen atoms will slightly reduce R 2 Therefore, R 2 When halogen atoms are not present, the overall stability and reduction resistance of the first anion can be further improved, the decomposition consumption of the first anion can be further reduced, and the time for the electrolyte to dry up can be delayed, thereby further extending the cycle life of the battery.

[0014] In any embodiment of the present application, R 2 Each independently includes one or more of the following groups,

[0015] # indicates the connection location.

[0016] In any embodiment of the present application, R 2 Each independently includes one or more of B-31, B-32, B-40, B-41, B-60, and B-61. 2 Containing two oxygen atoms with a suitable distance between the two oxygen atoms is conducive to better combination with metal lithium ions and can further extend the cycle life of the battery.

[0017] In any embodiment of the present application, X includes one or more elements of N, B, and P, and optionally includes one or more elements of N and B.

[0018] In any embodiment of the present application, X includes N; a is 1, b is 1; R 1 including halosulfonyl or haloalkylsulfonyl, and optionally including fluorosulfonyl or fluoroalkylsulfonyl; R 2 Including one or more of C1-C10 chain alkyl, C1-C10 oxo chain alkyl, C3-C10 cyclic alkyl, C1-C10 oxo heterocyclic alkyl, C1-C10 halogenated chain alkyl, C1-C10 oxohalogenated chain alkyl, C3-C10 halogenated cyclic alkyl, C1-C10 oxohalogenated cyclic alkyl, optionally including one or more of C1-C10 oxo chain alkyl, C1-C10 oxo heterocyclic alkyl, C1-C10 oxohalogenated chain alkyl, C1-C10 oxohalogenated cyclic alkyl, more optionally including one or more of C1-C10 oxo chain alkyl and C1-C10 oxohalogenated cyclic alkyl.

[0019] In any embodiment of the present application, X includes B; a represents an integer greater than or equal to 1, b represents an integer greater than or equal to 1, and a+b is 4, optionally, a is 2, and b is 2; R 1 Each independently includes one or more of a halogen atom, an ester group -O-(C=O)-, and optionally two adjacent R 1 It can also form a ring with X, optionally, R 1 Each independently includes one or more of a fluorine atom and an ester group, and optionally two adjacent R 1 It can also form a ring with X; R 2 Each independently includes one or more of C1-C10 chain alkyl, C1-C10 oxo chain alkyl, C3-C10 cyclic alkyl, C1-C10 oxo heterocyclic alkyl, C1-C10 halogenated chain alkyl, C1-C10 oxohalogenated chain alkyl, C3-C10 halogenated cyclic alkyl, and C1-C10 oxohalogenated cyclic alkyl, and optionally two adjacent R 2It can also form a ring with X, optionally, R 2 Each independently includes one or more of C1-C10 oxo-chain alkyl, C1-C10 oxo-cyclic alkyl, C1-C10 oxo-halogenated chain alkyl, and C1-C10 oxo-halogenated cyclic alkyl, and R 2 The oxygen atom in is directly connected to X, more preferably, R 2 Each independently includes one or more of C1-C10 oxo-chain alkyl and C1-C10 oxo-heterocyclic alkyl, and R 2 The oxygen atom in is directly connected to X.

[0020] In any embodiment of the present application, X includes P; a represents an integer greater than or equal to 1, b represents an integer greater than or equal to 1, and a+b is 6, optionally, a is 4 or 5, and b is 1 or 2; R 1 Each independently includes one or more of a halogen atom, an ester group -O-(C=O)-, and optionally two adjacent R 1 It can also form a ring with X, optionally, R 1 Each independently includes one or more of a fluorine atom, an ester group -O-(C=O)-, and optionally two adjacent R 1 It can also form a ring with X; R 2 Each independently includes one or more of C1-C10 chain alkyl, C1-C10 oxo chain alkyl, C3-C10 cyclic alkyl, C1-C10 oxo heterocyclic alkyl, C1-C10 halogenated chain alkyl, C1-C10 oxohalogenated chain alkyl, C3-C10 halogenated cyclic alkyl, and C1-C10 oxohalogenated cyclic alkyl, and optionally two adjacent R 2 It can also form a ring with X, optionally, R 2 Each independently includes one or more of C1-C10 oxo-chain alkyl, C1-C10 oxo-cyclic alkyl, C1-C10 oxo-halogenated chain alkyl, and C1-C10 oxo-halogenated cyclic alkyl, and R 2 The oxygen atom in is directly connected to X, more preferably, R 2 Each independently includes one or more of C1-C10 oxo-chain alkyl and C1-C10 oxo-heterocyclic alkyl, and R 2 The oxygen atom in is directly connected to X.

[0021] In any embodiment of the present application, the first anion includes one or more of the following,

[0022] In any embodiment of the present application, the first anion includes one or more of I-3, I-4, I-8, and I-9. In this case, the group R in the first anion 2Containing two oxygen atoms with a suitable distance between the two oxygen atoms is conducive to better combination with metal lithium ions, and can further improve the overall stability and reduction resistance of the first anion, thereby further reducing the decomposition consumption of the first anion, delaying the time for the electrolyte to dry up, and further extending the cycle life of the battery.

[0023] In any embodiment of the present application, the molar concentration of the first anion in the electrolyte is 0.5-4 mol / L, optionally 1-3.5 mol / L, and more preferably 1.5-3 mol / L. This can improve the reduction resistance of the electrolyte, reduce the consumption rate of the electrolyte, and further extend the cycle life of the battery.

[0024] In any embodiment of the present application, the electrolyte further includes a second anion, the second anion including one or more of a bisfluorosulfonyl imide anion, a bistrifluoromethanesulfonyl imide anion, a dioxalatoborate anion, a difluorooxalatoborate anion, a difluorodioxalatophosphate anion, a tetrafluorooxalatophosphate anion, a difluorophosphate anion, a hexafluorophosphate anion, a tetrafluoroborate anion, a hexafluoroarsenate anion, and a trifluoromethanesulfonate anion; optionally, the second anion includes one or more of a bisfluorosulfonyl imide anion, a bistrifluoromethanesulfonyl imide anion, a difluorooxalatoborate anion, and a tetrafluorooxalatophosphate anion. These second anions have good compatibility with the first anion, can promote metal ion transport, and also decompose on the negative electrode surface to form an SEI film rich in inorganic fluorine components, promote dense metal deposition, thereby helping the battery have a longer cycle life.

[0025] In any embodiment of the present application, the molar concentration of the second anion in the electrolyte is less than or equal to 4 mol / L, optionally less than or equal to 2 mol / L, and more optionally less than or equal to 1 mol / L. By adjusting the concentration of the second anion within the above range, neither the ion transport performance of the electrolyte nor the stability of the electrolyte to the positive and negative electrodes is affected, thereby helping the battery to have a longer cycle life.

[0026] In any embodiment of the present application, the electrolyte includes a first cation, which includes one or more of alkali metal ions, alkaline earth metal ions, zinc ions, and aluminum ions, and can optionally include one or more of lithium ions, sodium ions, potassium ions, and magnesium ions, and can more optionally include lithium ions.

[0027] In any embodiment of the present application, the electrolyte includes a solvent, the solvent includes a first solvent, and the first solvent includes one or more of an ester and halogenated ester solvent, a sulfone solvent, a nitrile solvent, an ether solvent, and an ionic liquid. The first solvent can provide the electrolyte with high ionic conductivity and high reduction resistance, while having good compatibility with the first anion.

[0028] In any embodiment of the present application, the first solvent comprises dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene carbonate, propylene carbonate, fluoroethylene carbonate, difluoroethylene carbonate, methyl trifluoroethyl carbonate, ethyl trifluoroethyl carbonate, di(2,2,2-trifluoroethyl) carbonate, methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl 2,2,2-trifluoroacetate, ethyl 2,2,2-trifluoroacetate, methyl ether, ethyl ether, propyl ether, butyl ether, methyl ethyl ether, methyl propyl ether, methyl butyl ether, ethyl propyl ether, ethyl butyl ether, propyl butyl ether, dimethoxymethane, diethoxy One or more of methane, dipropoxymethane, 1,2-dimethoxyethane, dimethoxypropane, 1,2-diethoxyethane, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, tetrahydrofuran, 1,3-dioxolane, tetrahydropyran, 1,3-dioxane, 1,4-dioxane, dimethyl sulfone, dimethyl sulfoxide, sulfolane, ethyl methyl sulfone, tetramethylene sulfoxide, ethyl methyl sulfoxide, diethyl sulfone, diethyl sulfoxide, methyl phenyl sulfone, methyl phenyl sulfoxide, ethyl phenyl sulfone, ethyl phenyl sulfoxide, vinyl phenyl sulfone, vinyl phenyl sulfoxide, acetonitrile, propionitrile, butyronitrile, succinonitrile, and 2-butenenitrile.

[0029] In any embodiment of the present application, the first solvent includes one or more of dimethoxymethane, diethoxymethane, dipropoxymethane, 1,2-dimethoxyethane, dimethoxypropane, 1,2-diethoxyethane, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether.

[0030] In any embodiment of the present application, the solvent further includes a second solvent, wherein the second solvent includes one or more of a hydrocarbon, a halogenated hydrocarbon solvent, and a fluoroether solvent. The second solvent has a high electrochemical window, good compatibility with the first solvent, and can also reduce the viscosity of the electrolyte and promote the transport of metal ions.

[0031] In any embodiment of the present application, the second solvent includes cyclohexane, benzene, toluene, p-xylene, m-xylene, o-xylene, fluorobenzene, p-difluorobenzene, m-difluorobenzene, o-difluorobenzene, trifluorotoluene, trifluoromethoxybenzene, decafluoropentane, perfluoropentanone, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, 1,2-bis(1,1,2,2-tetrafluoroethoxy)ethane, bis(2,2,2-trifluoroethyl)ether, 1,1,2,3,3,3-hexafluoropropyl ethyl ether, 1H,1H,5 One or more of H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether, ethyl trifluoromethyl ether, difluoromethyl-2,2,3,3,3-pentafluoropropyl ether, heptafluoropropyl-1,2,2,2-tetrafluoroethyl ether, difluoromethyl 2,2,3,3-tetrafluoropropyl ether, perfluoroisopropyl methyl ether, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, ethyl-1,1,2,2-tetrafluoroethyl ether, ethyl-2,2,2-tetrafluoroethyl ether, and bis(1,1,2,2-tetrafluoroethyl) ether.

[0032] In any embodiment of the present application, the second solvent includes one or more of trifluoromethoxybenzene, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, and 1,2-bis(1,1,2,2-tetrafluoroethoxy)ethane.

[0033] In any embodiment of the present application, the solvent includes a first solvent and a second solvent, and the weight ratio of the first solvent to the second solvent is (0.1-10):1, optionally (0.3-3):1, and more optionally (0.5-1.5):1. This can provide the electrolyte with high ionic conductivity and low viscosity, thereby improving the coulombic efficiency and cycle life of the battery.

[0034] In any embodiment of the present application, the electrolyte further includes an additive, and the additive includes one or more of propane sultone, vinyl sulfate, vinyl sulfite, tris(trimethylsilane) phosphate, tris(trimethylsilane) phosphite, tris(trifluoroethyl) phosphate, tris(trifluoroethyl) phosphite, tris(trimethylsilane) borate, dimethylmaleic anhydride, and 1,4-diisocyanate.

[0035] In any embodiment of the present application, the weight proportion of the additive in the electrolyte is less than or equal to 5 wt %, optionally less than or equal to 3 wt %, and more optionally less than or equal to 1 wt %.

[0036] A second aspect of the present application provides a battery cell, comprising the electrolyte of the first aspect of the present application.

[0037] In any embodiment of the present application, the battery cells include metal battery cells, metal-air battery cells, metal-sulfur battery cells and negative electrode-free metal battery cells, and can optionally include lithium metal battery cells, negative electrode-free lithium metal battery cells, lithium-air battery cells and lithium-sulfur battery cells.

[0038] A third aspect of the present application provides a battery, comprising the battery cell of the second aspect of the present application.

[0039] A fourth aspect of the present application provides an electrical device comprising the battery of the third aspect of the present application.

[0040] The electric device of the present application includes the battery provided by the present application, and thus has at least the same advantages as the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] To more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on the drawings without inventive effort.

[0042] FIG1 is a schematic diagram of a battery cell according to an embodiment of the present application.

[0043] FIG2 is an exploded schematic diagram of an embodiment of a battery cell of the present application.

[0044] FIG3 is a schematic diagram of an embodiment of a battery module of the present application.

[0045] FIG4 is a schematic diagram of an embodiment of a battery pack of the present application.

[0046] FIG. 5 is an exploded schematic diagram of the embodiment of the battery pack shown in FIG. 4 .

[0047] FIG6 is a schematic diagram of an embodiment of an electric device including the battery of the present application as a power source.

[0048] In the accompanying drawings, which are not necessarily drawn to scale, reference numerals are as follows: 1 battery pack, 2 upper housing, 3 lower housing, 4 battery module, 5 battery cell, 51 housing, 52 electrode assembly, 53 cover plate. DETAILED DESCRIPTION

[0049] Below, the embodiments of the electrolyte, battery cells, batteries, and electrical devices of the present application are described in detail with appropriate reference to the accompanying drawings. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there may be cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0050] " range " disclosed in the present application is limited in the form of lower limit and upper limit, and given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of special range. The scope limited in this way can be to include end value or not include end value, and can be arbitrarily combined, that is, any lower limit can form a range with any upper limit combination. For example, if the scope of 60-120 and 80-110 is listed for specific parameters, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range value 1 and 2 are listed, and if the maximum range value 3,4 and 5 are listed, then the following range can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In this application, unless otherwise specified, the numerical range " ab " represents the abbreviation of any real number combination between a and b, wherein a and b are all real numbers. For example, a numerical range of "0-5" indicates that all real numbers between "0-5" are listed herein, and "0-5" is simply an abbreviation for these numerical combinations. Furthermore, when a parameter is expressed as an integer ≥ 2, this is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0051] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions, and such technical solutions should be considered to be included in the disclosure of the present application.

[0052] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form new technical solutions, and such technical solutions should be deemed to be included in the disclosure of this application.

[0053] Unless otherwise specified, all steps of the present application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), indicating that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0054] Unless otherwise specified, the terms "include" and "comprising" used in this application may be open-ended or closed-ended. For example, "include" and "comprising" may mean that other components not listed may also be included or that only the listed components are included.

[0055] Unless otherwise specified, the term "or" is used in this application to be inclusive. For example, the phrase "A or B" means "A, B, or both A and B." More specifically, the condition "A or B" is satisfied if any of the following conditions are met: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0056] Unless otherwise specified, in this application, the terms "first", "second", etc. are used to distinguish different objects rather than to describe a specific order or a primary-secondary relationship.

[0057] Unless otherwise specified, the terms used in this application have the common meanings that are commonly understood by those skilled in the art.

[0058] Unless otherwise stated, the numerical values ​​of the various parameters mentioned in this application can be measured using various test methods commonly used in the art, for example, they can be measured according to the test methods given in the examples of this application. Unless otherwise stated, the test temperature of each parameter is 25°C.

[0059] The term "chain alkyl" encompasses both straight-chain and branched alkyl groups. Examples of chain alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, isopentyl, and the like. In various embodiments, a C1-C10 chain alkyl group, i.e., a chain alkyl group, may contain 1-10 carbon atoms.

[0060] The term "oxoalkyl" refers to an alkyl group containing oxygen atoms in the backbone. The number of oxygen atoms in the oxoalkyl group can be one or more. In various embodiments, the C1-C10 oxoalkyl group, i.e., the oxoalkyl group, can contain 1-10 carbon atoms.

[0061] The term "cyclic alkyl" refers to a closed alicyclic ring system. Examples of cyclic alkyl groups include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. In various embodiments, a C3-C10 cyclic alkyl group, i.e., a cyclic alkyl group, may contain 3-10 carbon atoms. The cyclic alkyl group may or may not contain alkyl substituents on the ring.

[0062] The term "oxocyclic alkyl" refers to a cyclic alkyl group containing an oxygen atom. The number of oxygen atoms in the oxocyclic alkyl group may be one or more. Examples of oxocyclic alkyl groups include, but are not limited to, tetrahydrofuranyl, tetrahydropyranyl, 1,3-dioxolane, 1,3-dioxanyl, 1,4-dioxanyl, and the like. In various embodiments, a C1-C10 oxocyclic alkyl group, i.e., an oxocyclic alkyl group, may contain 1-10 carbon atoms. The oxocyclic alkyl group may or may not contain alkyl substituents on the ring.

[0063] The term "halogenated chain alkyl group" refers to a chain alkyl group in which at least one hydrogen atom is replaced by a halogen atom. The number of halogen atoms in the halogenated chain alkyl group may be one or more. When the number of halogen atoms in the halogenated chain alkyl group is more than one, the multiple halogen atoms may be the same or different.

[0064] The term "oxohalogenated chain alkyl group" refers to an oxohalogenated chain alkyl group in which at least one hydrogen atom is replaced by a halogen atom. The number of halogen atoms in the oxohalogenated chain alkyl group may be one or more. When the number of halogen atoms in the oxohalogenated chain alkyl group is more than one, the multiple halogen atoms may be the same or different.

[0065] The term "halogenated cyclic alkyl group" refers to a cyclic alkyl group in which at least one hydrogen atom is replaced by a halogen atom. The number of halogen atoms in the halogenated cyclic alkyl group may be one or more. When the number of halogen atoms in the halogenated cyclic alkyl group is more than one, the multiple halogen atoms may be the same or different.

[0066] The term "oxahalogenated cyclic alkyl group" refers to an oxahalogenated cyclic alkyl group in which at least one hydrogen atom is replaced by a halogen atom. The number of halogen atoms in the oxahalogenated cyclic alkyl group may be one or more. When the number of halogen atoms in the oxahalogenated cyclic alkyl group is more than one, the multiple halogen atoms may be the same or different.

[0067] The term "halogen atom" refers to a fluorine atom, a chlorine atom, a bromine atom or the like.

[0068] Throughout this manual, “#” indicates a link location.

[0069] Throughout this specification, substituents of compounds are disclosed in groups or ranges. It is expressly contemplated that this description includes each individual subcombination of members of these groups and ranges. For example, it is expressly contemplated that the term "C1-C6 alkyl" individually discloses C1, C2, C3, C4, C5, C6, C1-C6, C1-C5, C1-C4, C1-C3, C1-C2, C2-C6, C2-C5, C2-C4, C2-C3, C3-C6, C3-C5, C3-C4, C4-C6, C4-C5, C5-C6 alkyl. As another example, integers ranging from 3 to 10 are expressly contemplated to individually disclose 3, 4, 5, 6, 7, 8, 9, and 10. Accordingly, other groups or ranges may be expressly contemplated.

[0070] The battery mentioned in the embodiments of the present application may be a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in the present application may include a battery cell, a battery module, or a battery pack.

[0071] A battery cell is the smallest unit of a battery, independently capable of charging and discharging. A battery cell can be cylindrical, flat, rectangular, or in other shapes, though this is not a limitation in the present invention. Figure 1 shows a battery cell 5 with a rectangular structure as an example.

[0072] When there are multiple battery cells, the multiple battery cells are connected in series, in parallel, or in mixed series via a busbar. In some embodiments, the battery may be a battery module; when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module. In some embodiments, the battery may be a battery pack, which includes a housing and battery cells, with the battery cells or battery modules housed in the housing. In some embodiments, the housing may serve as part of the vehicle's chassis structure. For example, a portion of the housing may form at least a portion of the vehicle's floor, or a portion of the housing may form at least a portion of the vehicle's crossbeam or longitudinal beam.

[0073] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0074] The battery cells provided in the embodiments of the present application include battery cells using alkali metals, alkaline earth metals, zinc, aluminum, and alloys thereof as negative electrode active materials. For example, the battery cells provided in the embodiments of the present application include metal battery cells, metal-air battery cells, metal-sulfur battery cells, and negative electrode-free metal battery cells. As examples, the battery cells may be lithium metal battery cells, negative electrode-free lithium metal battery cells, lithium-air battery cells, lithium-sulfur battery cells, sodium metal battery cells, negative electrode-free sodium metal battery cells, sodium-air battery cells, sodium-sulfur battery cells, potassium metal battery cells, negative electrode-free potassium metal battery cells, potassium-air battery cells, potassium-sulfur battery cells, magnesium metal battery cells, negative electrode-free magnesium metal battery cells, magnesium-air battery cells, magnesium-sulfur battery cells, and the like.

[0075] A battery cell generally includes an electrode assembly. The electrode assembly generally includes a positive electrode sheet, a negative electrode sheet, and a separator located between the positive and negative electrode sheets. The electrode assembly can be a wound structure or a laminated structure, which is not limited in the present embodiment.

[0076] The battery cell may also include an outer packaging, which can be used to encapsulate the electrode assembly and electrolyte. The outer packaging can be a hard shell, such as a hard plastic shell, aluminum shell, steel shell, etc. The outer packaging can also be a soft package, such as a bag-type soft package. The soft package can be made of plastic, such as one or more of polypropylene (PP), polybutylene terephthalate (PBT), and polybutylene succinate (PBS).

[0077] In some embodiments, as shown in Figure 2, the outer packaging may include a housing 51 and a cover plate 53. The housing 51 may include a base plate and side plates connected to the base plate, which together form a receiving cavity. The housing 51 has an opening communicating with the receiving cavity, and the cover plate 53 is used to cover the opening, thereby sealing the receiving cavity. The electrode assembly 52 is enclosed in the receiving cavity. The number of electrode assemblies 52 contained in the battery cell 5 can be one or more, and can be adjusted according to needs.

[0078] In some embodiments, battery cells can be assembled into a battery module. The number of battery cells contained in a battery module can be multiple, and the specific number can be adjusted according to the application and capacity of the battery module. Figure 3 is a schematic diagram of a battery module 4 as an example. As shown in Figure 3, in the battery module 4, multiple battery cells 5 can be arranged in sequence along the length of the battery module 4. Of course, they can also be arranged in any other manner. The multiple battery cells 5 can further be fixed by fasteners.

[0079] Optionally, the battery module 4 may further include a housing having an accommodation space, and the plurality of battery cells 5 are accommodated in the accommodation space.

[0080] In some embodiments, the battery modules described above may also be assembled into a battery pack, and the number of battery modules contained in the battery pack may be adjusted according to the application and capacity of the battery pack.

[0081] Figures 4 and 5 are schematic diagrams of an exemplary battery pack 1. As shown in Figures 4 and 5, the battery pack 1 may include a housing and multiple battery modules 4 disposed within the housing. The housing comprises an upper housing 2 and a lower housing 3. The upper housing 2 covers the lower housing 3 and forms an enclosed space for accommodating the battery modules 4. The multiple battery modules 4 may be arranged in any manner within the housing.

[0082] High energy density is an irreversible trend in future battery development. Batteries using alkali metals, alkaline earth metals, zinc, aluminum, and their alloys as negative electrode active materials have attracted widespread attention due to their high energy density. However, large-scale application of these batteries faces many challenges. For example, the solid electrolyte interface film (SEI) formed on the negative electrode surface is generally not reusable. As the battery charges and discharges, the thickness of the SEI film accumulates, causing the electrolyte to continuously decompose and consume, which can easily lead to electrolyte dryness and a shorter battery cycle life.

[0083] In view of this, the inventors improved the electrolyte.

[0084] The electrolyte provided in the embodiment of the present application includes a first anion represented by formula (I),

[0085] X includes one or more elements selected from N, B, P, Al, Si, S, Cl, As, and Se; a represents an integer greater than or equal to 1; b represents an integer greater than or equal to 1; R 1 Each independently includes one or more of a halogen atom, a halosulfonyl group, a haloalkylsulfonyl group, and an ester group -O-(C=O)-, and optionally two adjacent R 1 It can also form a ring with X; R 2 Each independently includes one or more of C1-C10 chain alkyl, C1-C10 oxo chain alkyl, C3-C10 cyclic alkyl, C1-C10 oxo heterocyclic alkyl, C1-C10 halogenated chain alkyl, C1-C10 oxohalogenated chain alkyl, C3-C10 halogenated cyclic alkyl, and C1-C10 oxohalogenated cyclic alkyl, and optionally two adjacent R 2 It can also form a ring with X.

[0086] The specific value of a+b is related to the specific type of element X. For example, when X is N, a can be 1 and b can be 1; when X is B, a+b can be 4; and when X is P, a+b can be 6.

[0087] The electrolyte provided in the embodiment of the present application includes a first anion, wherein the first anion has X as a central atom, and at least one group R is connected to the central atom. 1 and at least one group R 2 .

[0088] Multiple R 1 Each independently includes one or more of a halogen atom, a halosulfonyl group, a haloalkylsulfonyl group, and an ester group -O-(C=O)-, and optionally two adjacent R 1 It can also form a ring with X. Thus, R 1 It helps to form a high-quality SEI film on the surface of the negative electrode, which induces dense metal deposition and improves the cycle stability of the battery.

[0089] Multiple R 2 Each independently includes one or more of C1-C10 chain alkyl, C1-C10 oxo chain alkyl, C3-C10 cyclic alkyl, C1-C10 oxo heterocyclic alkyl, C1-C10 halogenated chain alkyl, C1-C10 oxohalogenated chain alkyl, C3-C10 halogenated cyclic alkyl, and C1-C10 oxohalogenated cyclic alkyl, and optionally two adjacent R 2 It can also form a ring with X. Thus, R 2 It can have higher reduction resistance, which helps to improve the overall stability and reduction resistance of the first anion, thereby reducing the decomposition consumption of the first anion and delaying the time when the electrolyte drys out.

[0090] Therefore, the first anion can form a high-quality SEI film on the negative electrode surface, inducing dense metal deposition and improving the battery's cycling stability. It can also reduce its own decomposition and consumption, delaying the onset of electrolyte dry-up. As a result, the electrolyte provided by the embodiments of the present application can have high reduction resistance and a low consumption rate, thereby improving the battery's cycling performance.

[0091] In some embodiments, R 1 It may independently include one or more of a fluorine atom, a fluorosulfonyl group, a fluoroalkylsulfonyl group, and an ester group -O-(C=O)-, and optionally two adjacent R 1 It can also form a ring with X.

[0092] In some embodiments, R 1 It may include fluorine atoms, one or more of the following groups,

[0093] # indicates the connection location.

[0094] When group A-4 appears, it means at least two R 1Connected to the central atom X, and two adjacent R 1 Together they form the structure shown in group A-4 (i.e., oxalate group), and group A-4 also forms a ring structure with the central atom X.

[0095] R 1 When fluorine atoms, fluorosulfonyl groups, fluoroalkylsulfonyl groups, or oxalate groups are included, it helps to form a higher quality SEI film on the surface of the negative electrode, which plays a role in inducing dense metal deposition and further extending the battery cycle life.

[0096] In some embodiments, R 2 Can independently include one or more of C1-C10 oxo-chain alkyl, C1-C10 oxo-cyclic alkyl, C1-C10 oxo-halogenated chain alkyl, C1-C10 oxo-halogenated cyclic alkyl, and optionally two adjacent R 2 It can also form a ring with X.

[0097] Oxygen atoms have a better binding effect with metal ions. 2 When containing oxygen heteroatoms, R 2 It can also provide a second reaction site for complexing with metal ions to increase the reaction rate of metal ions; at the same time, it can further improve the overall stability and reduction resistance of the first anion, further reduce the decomposition consumption of the first anion, delay the occurrence of electrolyte drying up, and thus further extend the cycle life of the battery.

[0098] In some embodiments, the number of oxygen heteroatoms in the C1-C10 oxo-chain alkyl group may be 1-4, optionally 2 or 3, and more optionally 2.

[0099] In some embodiments, the number of oxygen heteroatoms in the C1-C10 oxygen heterocyclic alkyl group may be 1-4, optionally 2 or 3, and more optionally 2.

[0100] In some embodiments, the number of oxygen heteroatoms in the C1-C10 oxohalogenated chain alkyl group may be 1-4, optionally 2 or 3, and more optionally 2.

[0101] In some embodiments, the number of oxygen heteroatoms in the C1-C10 oxahalogenated cyclic alkyl group may be 1-4, optionally 2 or 3, and more optionally 2.

[0102] In some embodiments, R 2 Can independently include one or more of C1-C10 oxo-chain alkyl, C1-C10 oxo-heterocyclic alkyl, and optionally two adjacent R 2 It can also form a ring with X.

[0103] Halogen atoms will slightly reduce R 2 Therefore, R 2 When halogen atoms are not present, the overall stability and reduction resistance of the first anion can be further improved, the decomposition consumption of the first anion can be further reduced, and the time for the electrolyte to dry up can be delayed, thereby further extending the cycle life of the battery.

[0104] In some embodiments, R 2 Can independently include one or more of the following groups,

[0105] # indicates the connection location.

[0106] When groups B-55, B-56, B-57, and B-58 appear, they represent at least two R 2 Connected to the central atom X, and two adjacent R 2 Together they form the structure shown by groups B-55, B-56, B-57, and B-58. At the same time, groups B-55, B-56, B-57, and B-58 also form a ring structure with the central atom X.

[0107] In some embodiments, R 2 One or more of B-8 to B-63 may be included independently. 2 When containing oxygen heteroatoms, R 2 It can also provide a second reaction site for complexing with metal ions to increase the reaction rate of metal ions.

[0108] In some embodiments, R 2 It may independently include one or more of B-8 to B-11, B-18 to B-21, B-31 to B-33, B-40 to B-42, B-46 to B-48, B-51 to B-57, B-59 to B-61. 2 When halogen atoms are not present, the overall stability and reduction resistance of the first anion can be further improved, the decomposition consumption of the first anion can be further reduced, and the time for the electrolyte to dry up can be delayed, thereby further extending the cycle life of the battery.

[0109] In some embodiments, R 2 Can include one or more of B-31, B-32, B-40, B-41, B-60, B-61 independently. 2 Containing two oxygen atoms with a suitable distance between the two oxygen atoms is conducive to better combination with metal lithium ions and can further extend the cycle life of the battery.

[0110] In some embodiments, X may include one or more elements of N, B, and P. Alternatively, X includes one or more elements of N and B.

[0111] In some embodiments, X includes N, a is 1, b is 1, R 1 Including halosulfonyl or haloalkylsulfonyl, R 2 Including one or more of C1-C10 chain alkyl, C1-C10 oxo chain alkyl, C3-C10 cyclic alkyl, C1-C10 oxo heterocyclic alkyl, C1-C10 halogenated chain alkyl, C1-C10 oxohalogenated chain alkyl, C3-C10 halogenated cyclic alkyl, and C1-C10 oxohalogenated cyclic alkyl.

[0112] In some embodiments, X includes N, R 1 This includes fluorosulfonyl or fluoroalkylsulfonyl.

[0113] In some embodiments, X includes N, R 1 Including A-1, A-2 or A-3. Optionally, R 1 Including A-1.

[0114] In some embodiments, X includes N, R 2 Including one or more of C1-C10 oxo-chain alkyl, C1-C10 oxo-cyclic alkyl, C1-C10 oxo-halogenated chain alkyl, and C1-C10 oxo-halogenated cyclic alkyl. 2 It includes one or more of C1-C10 oxo-chain alkyl and C1-C10 oxo-cyclic alkyl.

[0115] In some embodiments, X includes N, R 2 Including one or more of B-8, B-10, B-12 to B-14, B-18, B-20, B-22 to B-24, B-31 to B-39, B-46 to B-54, B-59 to B-63. Optionally, R 2 Including one or more of B-8, B-10, B-18, B-20, B-31 to B-33, B-46 to B-48, B-51 to B-54, B-59 to B-61. More optionally, R 2 Including one or more of B-31, B-32, B-60, and B-61. This can further improve the overall stability and reduction resistance of the first anion, further reduce the decomposition and consumption of the first anion, delay the occurrence of electrolyte drying up, and thus further extend the cycle life of the battery.

[0116] In some embodiments, X includes B, a represents an integer greater than or equal to 1, b represents an integer greater than or equal to 1, and a+b is 4, R 1Each independently includes one or more of a halogen atom, an ester group -O-(C=O)-, and optionally two adjacent R 1 It can also form a ring with X, for example, it can form an oxalate group (group A-4); R 2 Each independently includes one or more of C1-C10 chain alkyl, C1-C10 oxo chain alkyl, C3-C10 cyclic alkyl, C1-C10 oxo heterocyclic alkyl, C1-C10 halogenated chain alkyl, C1-C10 oxohalogenated chain alkyl, C3-C10 halogenated cyclic alkyl, and C1-C10 oxohalogenated cyclic alkyl, and optionally two adjacent R 2 It can also form a ring with X.

[0117] When X includes B, a+b is 4. For example, in some embodiments, a is 1 and b is 3. In some embodiments, a is 2 and b is 2. In some embodiments, a is 3 and b is 1. Alternatively, a is 2 and b is 2.

[0118] In some embodiments, X includes B, R 1 Each independently includes one or more of a fluorine atom, an ester group -O-(C=O)-, and optionally two adjacent R 1 It can also form a ring with X, for example, it can form an oxalate group.

[0119] In some embodiments, X comprises B, a is 1, R 1 Including fluorine atoms.

[0120] In some embodiments, X comprises B, a is 2, R 1 Contains fluorine atoms or oxalate groups.

[0121] In some embodiments, X comprises B, a is 3, R 1 Contains fluorine atoms and / or oxalate groups.

[0122] In some embodiments, X includes B, R 2 Each independently includes one or more of C1-C10 oxo-chain alkyl, C1-C10 oxo-cyclic alkyl, C1-C10 oxo-halogenated chain alkyl, and C1-C10 oxo-halogenated cyclic alkyl, and optionally two adjacent R 2 It can also form a ring with X. Optionally, R 2 Each independently includes one or more of C1-C10 oxo-chain alkyl and C1-C10 oxo-heterocyclic alkyl, and optionally two adjacent R 2 It can also form a ring with X.

[0123] In some embodiments, X includes B, R 2Each independently includes one or more of C1-C10 oxo-chain alkyl, C1-C10 oxo-cyclic alkyl, C1-C10 oxo-halogenated chain alkyl, and C1-C10 oxo-halogenated cyclic alkyl, and R 2 The oxygen atom in is directly connected to X. 2 Each independently includes one or more of C1-C10 oxo-chain alkyl and C1-C10 oxo-heterocyclic alkyl, and R 2 The oxygen atom in is directly connected to X. This can further improve the overall stability and reduction resistance of the first anion, further reduce the decomposition and consumption of the first anion, delay the time for the electrolyte to dry out, and thus further extend the cycle life of the battery.

[0124] In some embodiments, X includes B, R 2 Each independently includes one or more of B-9, B-11, B-15 to B-17, B-19, B-21, B-25 to B-30, B-40 to B-45, B-55 to B-58. 2 Each independently includes one or more of B-9, B-11, B-19, B-21, B-40 to B-42, B-55 to B-57. More preferably, R 2 The first anion is independently composed of one or more of B-40 and B-41. This can further improve the overall stability and reduction resistance of the first anion, further reduce the decomposition and consumption of the first anion, delay the occurrence of electrolyte drying up, and thus further extend the cycle life of the battery.

[0125] In some embodiments, X includes P, a represents an integer greater than or equal to 1, b represents an integer greater than or equal to 1, and a+b is 6, R 1 Each independently includes one or more of a halogen atom, an ester group -O-(C=O)-, and optionally two adjacent R 1 It can also form a ring with X, for example, it can form an oxalate group (group A-4); R 2 Each independently includes one or more of C1-C10 chain alkyl, C1-C10 oxo chain alkyl, C3-C10 cyclic alkyl, C1-C10 oxo heterocyclic alkyl, C1-C10 halogenated chain alkyl, C1-C10 oxohalogenated chain alkyl, C3-C10 halogenated cyclic alkyl, and C1-C10 oxohalogenated cyclic alkyl, and optionally two adjacent R 2 It can also form a ring with X.

[0126] When X includes P, a+b is 6. For example, in some embodiments, a is 1 and b is 5. In some embodiments, a is 2 and b is 4. In some embodiments, a is 3 and b is 3. In some embodiments, a is 4 and b is 2. In some embodiments, a is 5 and b is 1. Alternatively, a is 4 or 5, and b is 1 or 2.

[0127] In some embodiments, X includes P, R 1 Each independently includes one or more of a fluorine atom, an ester group -O-(C=O)-, and optionally two adjacent R 1 It can also form a ring with X, for example, it can form an oxalate group.

[0128] In some embodiments, X comprises P, a is 1, R 1 Including fluorine atoms.

[0129] In some embodiments, X comprises P, a is 2, R 1 Contains fluorine atoms or oxalate groups.

[0130] In some embodiments, X comprises P, a is 3 or 4 or 5, R 1 Contains fluorine atoms and / or oxalate groups.

[0131] In some embodiments, X includes P, R 2 Each independently includes one or more of C1-C10 oxo-chain alkyl, C1-C10 oxo-cyclic alkyl, C1-C10 oxo-halogenated chain alkyl, and C1-C10 oxo-halogenated cyclic alkyl, and optionally two adjacent R 2 It can also form a ring with X. Optionally, R 2 Each independently includes one or more of C1-C10 oxo-chain alkyl and C1-C10 oxo-heterocyclic alkyl, and optionally two adjacent R 2 It can also form a ring with X.

[0132] In some embodiments, X includes P, R 2 Each independently includes one or more of C1-C10 oxo-chain alkyl, C1-C10 oxo-cyclic alkyl, C1-C10 oxo-halogenated chain alkyl, and C1-C10 oxo-halogenated cyclic alkyl, and R 2 The oxygen atom in is directly connected to X. 2 Each independently includes one or more of C1-C10 oxo-chain alkyl and C1-C10 oxo-heterocyclic alkyl, and R 2 The oxygen atom in is directly connected to X. This can further improve the overall stability and reduction resistance of the first anion, further reduce the decomposition and consumption of the first anion, delay the time for the electrolyte to dry out, and thus further extend the cycle life of the battery.

[0133] In some embodiments, X includes P, R 2 Each independently includes one or more of B-9, B-11, B-15 to B-17, B-19, B-21, B-25 to B-30, B-40 to B-45, B-55 to B-58. 2 Each independently includes one or more of B-9, B-11, B-19, B-21, B-40 to B-42, B-55 to B-57. More preferably, R 2 The first anion is independently composed of one or more of B-40 and B-41. This can further improve the overall stability and reduction resistance of the first anion, further reduce the decomposition and consumption of the first anion, delay the occurrence of electrolyte drying up, and thus further extend the cycle life of the battery.

[0134] In some embodiments, the first anion may include one or more of the following,

[0135] Optionally, the first anion includes one or more of I-2, I-3, I-4, I-5, I-8, I-9, I-10, and I-11.

[0136] More optionally, the first anion includes one or more of I-3, I-4, I-8, and I-9. In this case, the group R 2 Containing two oxygen atoms with a suitable distance between the two oxygen atoms is conducive to better combination with metal lithium ions, and can further improve the overall stability and reduction resistance of the first anion, thereby further reducing the decomposition consumption of the first anion, delaying the time for the electrolyte to dry up, and further extending the cycle life of the battery.

[0137] In some embodiments, the molar concentration of the first anion in the electrolyte can be 0.5-4 mol / L, optionally 1-3.5 mol / L, and more preferably 1.5-3 mol / L. This can improve the reduction resistance of the electrolyte and reduce the consumption rate of the electrolyte, thereby further extending the cycle life of the battery.

[0138] In some embodiments, the electrolyte may include a second anion, and the second anion may include a bis(fluorosulfonyl)imide anion (FSI - ), bis(trifluoromethanesulfonyl)imide anion (TFSI - ), dioxalatoborate anion (BOB - ), difluorooxalatoborate anion (DFOB - ), difluorobis(oxaloyl)phosphate anion (DFOP- ), tetrafluorooxalophosphate anion (TFOP - ), difluorophosphate anion (PO2F2 - ), hexafluorophosphate anion (PF6 - ), tetrafluoroborate anion (BF4 - ), hexafluoroarsenate anion (AsF6 - ), trifluoromethanesulfonate anion (CF3SO3 - )

[0139] In some embodiments, the second anion may include a bis(fluorosulfonyl)imide anion (FSI - ), bis(trifluoromethanesulfonyl)imide anion (TFSI - ), difluorooxalatoborate anion (DFOB - ), tetrafluorooxalophosphate anion (TFOP - ) in one or more of the following. These second anions have good compatibility with the first anions, can promote metal ion transport, and also decompose on the negative electrode surface to form an SEI film rich in inorganic fluorine components, promoting dense metal deposition, thereby helping the battery have a longer cycle life.

[0140] In some embodiments, the molar concentration of the second anion in the electrolyte can be less than or equal to 4 mol / L, optionally less than or equal to 2 mol / L, and more optionally less than or equal to 1 mol / L. By adjusting the concentration of the second anion within the above range, neither the ion transport performance of the electrolyte nor the stability of the electrolyte to the positive and negative electrodes is affected, thereby helping the battery have a longer cycle life.

[0141] In some embodiments, the electrolyte includes a first cation, which may include one or more of alkali metal ions, alkaline earth metal ions, zinc ions, and aluminum ions, and may optionally include one or more of lithium ions, sodium ions, potassium ions, and magnesium ions, and may more optionally include lithium ions.

[0142] In some embodiments, the electrolyte includes a solvent, which may include a first solvent, wherein the first solvent includes one or more of an ester and halogenated ester solvent, a sulfone solvent, a nitrile solvent, an ether solvent, and an ionic liquid. The first solvent can impart high ionic conductivity and high reduction resistance to the electrolyte, while also exhibiting good compatibility with the first anion.

[0143] In some embodiments, the first solvent may include an ether solvent. Ether solvents have higher reduction resistance and help the battery have a longer cycle life.

[0144] In some embodiments, the first solvent may include dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), ethylene carbonate (EC), propylene carbonate (PC), fluoroethylene carbonate (FEC), difluoroethylene carbonate, methyl trifluoroethyl carbonate, ethyl trifluoroethyl carbonate, bis(2,2,2-trifluoroethyl) carbonate, methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl 2,2,2-trifluoroacetate, ethyl 2,2,2-trifluoroacetate, methyl ether, ethyl ether, propyl ether, butyl ether, methyl ethyl ether, methyl propyl ether, methyl butyl ether, ethyl propyl ether, ethyl butyl ether, propyl butyl ether , dimethoxymethane, diethoxymethane, dipropoxymethane, 1,2-dimethoxyethane, dimethoxypropane, 1,2-diethoxyethane, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, tetrahydrofuran, 1,3-dioxolane, tetrahydropyran, 1,3-dioxane, 1,4-dioxane, dimethyl sulfone, dimethyl sulfoxide, sulfolane, ethyl methyl sulfone, tetramethylene sulfoxide, ethyl methyl sulfoxide, diethyl sulfone, diethyl sulfoxide, methyl phenyl sulfone, methyl phenyl sulfoxide, ethyl phenyl sulfoxide, ethyl phenyl sulfoxide, vinyl phenyl sulfone, vinyl phenyl sulfoxide, acetonitrile, propionitrile, butyronitrile, succinonitrile, 2-butenenitrile or one or more.

[0145] In some embodiments, the first solvent may include one or more of dimethoxymethane, diethoxymethane, dipropoxymethane, 1,2-dimethoxyethane, dimethoxypropane, 1,2-diethoxyethane, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether.

[0146] In some embodiments, the first solvent may include one or more of 1,2-dimethoxyethane (DME) and 1,2-diethoxyethane (DEE).

[0147] In some embodiments, the weight percentage of the first solvent is W1, and based on the total weight of the solvent, 70 wt% ≤ W1 ≤ 100 wt%, optionally 75 wt% ≤ W1 ≤ 100 wt%, 80 wt% ≤ W1 ≤ 100 wt%, 85 wt% ≤ W1 ≤ 100 wt%, and 90 wt% ≤ W1 ≤ 100 wt%. When the content of the first solvent is within the above range, the electrolyte can have high ionic conductivity and high reduction resistance, while having better compatibility with the first anion, thereby helping the battery have a longer cycle life.

[0148] In some embodiments, W1 may be 100 wt %.

[0149] In some embodiments, the solvent may further include a second solvent, which may include one or more of a hydrocarbon, a halogenated hydrocarbon, or a fluoroether solvent. The second solvent has a high electrochemical window, good compatibility with the first solvent, and can also reduce the viscosity of the electrolyte, thereby facilitating the transport of metal ions.

[0150] In some embodiments, the second solvent may include cyclohexane, benzene, toluene, p-xylene, m-xylene, o-xylene, fluorobenzene, p-difluorobenzene, m-difluorobenzene, o-difluorobenzene, trifluorotoluene, trifluoromethoxybenzene, decafluoropentane, perfluoropentanone, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, 1,2-bis(1,1,2,2-tetrafluoroethoxy)ethane, bis(2,2,2-trifluoroethyl)ether, 1,1,2,3,3,3-hexafluoropropyl ethyl ether, 1H,1H,5H- One or more of octafluoropentyl-1,1,2,2-tetrafluoroethyl ether, ethyl trifluoromethyl ether, difluoromethyl-2,2,3,3,3-pentafluoropropyl ether, heptafluoropropyl-1,2,2,2-tetrafluoroethyl ether, difluoromethyl 2,2,3,3-tetrafluoropropyl ether, perfluoroisopropyl methyl ether, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, ethyl-1,1,2,2-tetrafluoroethyl ether, ethyl-2,2,2-tetrafluoroethyl ether, and bis(1,1,2,2-tetrafluoroethyl) ether.

[0151] In some embodiments, the second solvent may include one or more of trifluoromethoxybenzene, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, and 1,2-bis(1,1,2,2-tetrafluoroethoxy)ethane. The second solvent may thus have a higher electrochemical window, good compatibility with the first solvent, and promote the formation of an inorganic fluorine-rich SEI film on the negative electrode surface, thereby promoting dense metal deposition and thus contributing to a longer cycle life for the battery.

[0152] In some embodiments, the weight percentage of the second solvent is recorded as W2, based on the total weight of the solvent, then 0<W2≤30wt%, optionally, 0<W2≤25wt%, 0<W2≤20wt%, 0<W2≤15wt%, 0<W2≤10wt%.

[0153] In some embodiments, the weight ratio of the first solvent to the second solvent may be (0.1-10):1, optionally (0.3-3):1, and more optionally (0.5-1.5):1. This can provide the electrolyte with high ionic conductivity and low viscosity, thereby improving the coulombic efficiency and cycle life of the battery.

[0154] In some embodiments, the electrolyte may further include an additive. The present application has no particular restrictions on the type of additive, as long as it does not damage the subject matter of the present application. As an example, the additive may include propane sultone (PS), vinyl sulfate (DTD), vinyl sulfite (ES), tris(trimethylsilane) phosphate (TMSP), tris(trimethylsilane) phosphite, tris(trifluoroethyl) phosphate, tris(trifluoroethyl) phosphite, tris(trimethylsilane) borate, dimethyl maleic anhydride, or one or more of 1,4-diisocyanate.

[0155] In some embodiments, the weight proportion of the additive in the electrolyte may be less than or equal to 5 wt %, optionally less than or equal to 3 wt %, and more optionally less than or equal to 1 wt %.

[0156] [Preparation method]

[0157] Methods for preparing an electrolyte are well known. For example, a first electrolyte salt (composed of a first anion and a first cation), an optional second electrolyte salt (composed of a second anion and a first cation), a solvent, and optional additives can be uniformly mixed to obtain an electrolyte. During the preparation process, the order in which the materials are added is not particularly limited; they can be added simultaneously or in batches.

[0158] The components and their contents in the electrolyte can be determined by conventional methods in the art. For example, gas chromatography-mass spectrometry (GC-MS), ion chromatography (IC), liquid chromatography (LC), inductively coupled plasma optical emission spectroscopy (ICP-OES), and the like can be used for detection.

[0159] A battery cell includes a positive electrode sheet and a negative electrode sheet.

[0160] The structure and / or composition of each of the positive electrode sheet and the negative electrode sheet can be selected according to the type of battery cell, and the embodiments of the present application are not limited to this. The battery cells of the embodiments of the present application may include metal battery cells, metal-air battery cells, metal-sulfur battery cells, and metal battery cells without negative electrodes, etc. As an example, the battery cells may include lithium metal battery cells, lithium metal battery cells without negative electrodes, lithium-air battery cells, lithium-sulfur battery cells, sodium metal battery cells, sodium metal battery cells without negative electrodes, sodium-air battery cells, sodium-sulfur battery cells, potassium metal battery cells, potassium metal battery cells without negative electrodes, potassium-air battery cells, potassium-sulfur battery cells, magnesium metal battery cells, magnesium metal battery cells without negative electrodes, magnesium-air battery cells, magnesium-sulfur battery cells, etc. In some embodiments, the battery cells may include lithium metal battery cells, lithium metal battery cells without negative electrodes, lithium-air battery cells, and lithium-sulfur battery cells.

[0161] [Positive electrode]

[0162] In some embodiments, the positive electrode sheet includes a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode current collector, wherein the positive electrode film layer includes a positive electrode active material. For example, the positive electrode current collector has two opposing surfaces in its thickness direction, and the positive electrode film layer is disposed on either or both of the two opposing surfaces of the positive electrode current collector.

[0163] The type of positive electrode active material can be selected according to the type of battery cell, which is not limited in the embodiments of the present application.

[0164] For example, when the battery cell is a lithium metal battery cell or a negative electrode-free lithium metal battery cell, the positive electrode active material may include, but is not limited to, one or more of lithium transition metal oxides, lithium-containing phosphates, and their respective modified compounds. Examples of lithium transition metal oxides may include, but are not limited to, one or more of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and their respective modified compounds. Examples of lithium-containing phosphates may include, but are not limited to, one or more of lithium iron phosphate, a composite material of lithium iron phosphate and carbon, lithium manganese phosphate, a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, a composite material of lithium manganese iron phosphate and carbon, and their respective modified compounds. In some embodiments, in order to further improve the energy density of the battery, the positive electrode active material may include a general formula of Li a Ni b Co c M d O e A f One or more lithium transition metal oxides and modified compounds thereof. 0.8≤a≤1.2, 0.5≤b<1, 0<c<1, 0<d<1, 1≤e≤2, 0≤f≤1, M includes one or more of Mn, Al, Zr, Zn, Cu, Cr, Mg, Fe, V, Ti and B, and A includes one or more of N, F, S and Cl.

[0165] As an example, the positive electrode active material may include LiCoO2, LiNiO2, LiMnO2, LiMn2O4, LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (abbreviated as NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2 (abbreviated as NCM523), LiNi 0.5 Co 0.25 Mn 0.25 O2 (abbreviated as NCM211), LiNi 0.6 Co 0.2 Mn 0.2O2 (abbreviated as NCM622), LiNi 0.8 Co 0.1 Mn 0.1 O2 (abbreviated as NCM811), LiNi 0.96 Co 0.02 Mn 0.02 O2 (abbreviated as Ni96), LiNi 0.85 Co 0.15 Al 0.05 One or more of O2, LiFePO4, LiMnPO4.

[0166] When the battery cell is a sodium metal battery cell or a sodium metal battery cell without a negative electrode, the positive electrode active material may include but is not limited to one or more of sodium-containing transition metal oxides, polyanion materials (such as phosphates, fluorophosphates, pyrophosphates, sulfates, etc.), and Prussian blue materials. As an example, the positive electrode active material may include NaFeO2, NaCoO2, NaCrO2, NaMnO2, NaNiO2, NaNi 1 / 2 Ti 1 / 2 O2、NaNi 1 / 2 Mn 1 / 2 O2、Na 2 / 3 Fe 1 / 3 Mn 2 / 3 O2、NaNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2, NaFePO4, NaMnPO4, NaCoPO4, Prussian blue materials, general formula X p M' q (PO4) r O x Y 3-x One or more materials. p M' q (PO4) r O x Y 3-x , 0<p≤4, 0<q≤2, 1≤r≤3, 0≤x≤2, X includes H + 、Li + 、Na + , K + and NH4 + One or more of, M' comprises a transition metal, optionally comprising one or more of V, Ti, Mn, Fe, Co, Ni, Cu and Zn, and Y comprises a halogen atom, optionally comprising one or more of F, Cl and Br.

[0167] The modified compounds of the above-mentioned positive electrode active materials may be used to perform doping modification and / or surface coating modification on the positive electrode active materials.

[0168] When the battery cell is a lithium-sulfur battery cell or a sodium-sulfur battery cell, the positive electrode active material may include but is not limited to one or more of elemental sulfur, sulfur-carbon composite materials, sulfur-conductive polymer composite materials, and sulfur-metal oxide composite materials.

[0169] In some embodiments, the positive electrode film layer may further include a positive electrode conductive agent. The present application does not particularly limit the type of the positive electrode conductive agent. For example, the positive electrode conductive agent may include one or more of superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0170] In some embodiments, the positive electrode film layer may further optionally include a positive electrode binder. This application does not particularly limit the type of positive electrode binder. As an example, the positive electrode binder may include one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorine-containing acrylic resin.

[0171] In some embodiments, the positive electrode current collector may be a metal foil or a composite current collector. As an example of a metal foil, aluminum foil may be used. The composite current collector may include a polymer material base layer and a metal material layer formed on at least one surface of the polymer material base layer. As an example, the metal material may include one or more of aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy. As an example, the polymer material base layer may include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0172] The positive electrode film layer can be formed by coating a positive electrode slurry onto a positive electrode current collector, drying it, and cold pressing it. The positive electrode slurry is typically formed by dispersing the positive electrode active material, an optional conductive agent, an optional binder, and any other components in a solvent and stirring them uniformly. The solvent can be, but is not limited to, N-methylpyrrolidone (NMP).

[0173] [Negative electrode]

[0174] In some embodiments, the negative electrode plate may include a negative electrode current collector and a first metal layer disposed on at least one surface of the negative electrode current collector. The metal elements in the first metal layer may include one or more of alkali metal elements, alkaline earth metal elements, zinc, and aluminum.

[0175] In some embodiments, the metal material in the first metal layer may include one or more of lithium, lithium alloy, sodium, sodium alloy, potassium, potassium alloy, magnesium, magnesium alloy, zinc, zinc alloy, aluminum, and aluminum alloy.

[0176] A lithium alloy may be an alloy of metallic lithium and other metallic elements or non-metallic elements. For example, the other metallic elements in the lithium alloy may include one or more of tin, zinc, aluminum, magnesium, silver, gold, gallium, indium, and platinum, and the non-metallic elements in the lithium alloy may include one or more of boron, carbon, and silicon.

[0177] The sodium alloy may be an alloy of metallic sodium and other metallic elements or non-metallic elements. For example, the other metallic elements in the sodium alloy may include one or more of tin, zinc, aluminum, magnesium, silver, gold, gallium, indium, and platinum, and the non-metallic elements in the sodium alloy may include one or more of boron, carbon, and silicon.

[0178] Potassium alloys may be alloys of magnesium with other metal elements or non-metal elements. For example, the other metal elements in the magnesium alloy may include one or more of tin, zinc, aluminum, sodium, lithium, silver, gold, gallium, indium, and platinum, and the non-metal elements in the potassium alloy may include one or more of boron, carbon, and silicon.

[0179] A magnesium alloy may be an alloy of magnesium with other metal elements or non-metal elements. For example, the other metal elements in the magnesium alloy may include one or more of tin, zinc, aluminum, sodium, lithium, silver, gold, gallium, indium, and platinum. The non-metal elements in the magnesium alloy may include one or more of boron, carbon, and silicon.

[0180] A zinc alloy may be an alloy of metallic zinc and other metallic elements or non-metallic elements. For example, the other metallic elements in the zinc alloy may include one or more of tin, lithium, sodium, aluminum, magnesium, silver, gold, gallium, indium, and platinum, and the non-metallic elements in the zinc alloy may include one or more of boron, carbon, and silicon.

[0181] An aluminum alloy may be an alloy of aluminum with other metal elements or non-metal elements. For example, the other metal elements in the aluminum alloy may include one or more of tin, zinc, lithium, sodium, magnesium, silver, gold, gallium, indium, and platinum. The non-metal elements in the aluminum alloy may include one or more of boron, carbon, and silicon.

[0182] In some embodiments, the negative electrode sheet may include a negative electrode current collector but not the first metal layer, so as to be assembled into a negative electrode metal-free battery cell.

[0183] In some embodiments, the negative electrode current collector may include a metal foil, a three-dimensional porous current collector, or a composite current collector. As examples of metal foils, copper foil, copper alloy foil, nickel foil, and nickel alloy foil may be used. As examples of three-dimensional porous current collectors, copper mesh, nickel mesh, copper foam, and nickel foam may be used. The composite current collector may include a polymer material base layer and a metal material layer formed on at least one surface of the polymer material base layer. As an example, the metal material may include one or more of copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy. As an example, the polymer material base layer may include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0184] In some embodiments, the surface of the negative electrode current collector may further include a conductive coating to promote uniform metal deposition. The conductive coating may include conductive carbon, which may include one or more of carbon fibers, carbon nanotubes, graphene, and fullerene.

[0185] [Isolation film]

[0186] Battery cells may include a separator. This separator can be positioned between the positive and negative electrode sheets, primarily to prevent internal short circuits. This application does not specifically limit the type of separator; any known porous membrane with good chemical and mechanical stability can be used.

[0187] In some embodiments, the material of the isolation membrane can include one or more of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and polyimide. The isolation membrane can be a single-layer film or a multi-layer composite film. When the isolation membrane is a multi-layer composite film, the materials of each layer can be the same or different.

[0188] The preparation method of battery cells is well known. In some embodiments, the positive electrode sheet, separator, negative electrode sheet and electrolyte can be assembled to form a battery cell. As an example, the positive electrode sheet, separator, and negative electrode sheet can be formed into an electrode assembly through a winding process and / or a lamination process, and the electrode assembly is placed in an outer package, dried and injected with the above-mentioned electrolyte, and then subjected to vacuum packaging, standing, formation, shaping and other processes to obtain a battery cell. Multiple battery cells can also be further connected in series, in parallel or in a mixed connection to form a battery module. Multiple battery modules can also be connected in series, in parallel or in a mixed connection to form a battery pack. In some embodiments, multiple battery cells can also directly form a battery pack.

[0189] Electrical devices

[0190] The embodiments of the present application also provide an electrical device, which includes one or more of the battery cells, battery modules, or battery packs provided in the embodiments of the present application. The battery cells, battery modules, or battery packs can be used as power sources for the electrical device, or as energy storage units for the electrical device. The electrical device can be, but is not limited to, a mobile device (such as a mobile phone, a tablet computer, a laptop computer, etc.), an electric vehicle (such as a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck, etc.), an electric train, a ship, a satellite, an energy storage system, etc.

[0191] The electrical device can select battery cells, battery modules or battery packs according to its usage requirements.

[0192] Figure 6 is a schematic diagram of an exemplary electric device. This device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. To meet the high power and high energy density requirements of this device, a battery pack or battery module may be used.

[0193] As another example, an electric device may be a mobile phone, a tablet computer, a laptop computer, etc. Such an electric device is usually required to be lightweight and thin, and may use a battery cell as a power source.

[0194] Example

[0195] The following examples describe the present disclosure in more detail and are intended to be illustrative only, as various modifications and variations within the scope of the present disclosure will be apparent to those skilled in the art. Unless otherwise indicated, all parts, percentages, and ratios reported in the following examples are by weight, and all reagents used in the examples are commercially available or synthesized according to conventional methods and used directly without further processing, and all instruments used in the examples are commercially available.

[0196] Synthesis of the first electrolyte salt (composed of the first anion and the first cation)

[0197] The present application illustratively provides several methods for preparing the first electrolyte salt. Other first electrolyte salts can be prepared with reference to this exemplary method. According to the exemplary compound preparation method, those skilled in the art can easily obtain the specific method for implementing each synthesis step from the relevant scientific literature or standard textbooks in this field. Unless otherwise specified, commercially available or known compounds in the literature are used as raw materials for synthesis. Those skilled in the art of organic synthesis will recognize that, for the purpose of optimizing the generation of the compounds described herein, the nature and order of the proposed synthesis steps can be changed.

[0198] The processes described herein can be monitored by any suitable method known in the art. For example, product formation can be monitored by spectroscopic means, such as nuclear magnetic resonance spectroscopy (NMR, e.g., 1 H or 13 C or 19 F or 11 B or 31 P), infrared spectroscopy (IR), mass spectrometry (MS), etc.

[0199] Synthesis of the first electrolyte salt I-3

[0200] 1-(2-Aminoethoxy)-2-methoxyethane (10.0 g, 83.92 mmol) and 1-(fluorosulfonyl)-2,3-dimethyl-1H-imidazol-3-ium trifluoromethanesulfonate (27.55 g, 83.92 mmol) were weighed and added to a 500 mL single-necked flask. 300 mL of acetonitrile was then added and stirred at 25°C for 2 h. After the reaction, the acetonitrile was removed by concentration under reduced pressure. Water (30 mL) and ethyl acetate (30 mL x 2) were then added for extraction. The organic phase obtained from the extraction was washed with water (20 mL) and saturated brine (10 mL x 2), separated, dried over anhydrous magnesium sulfate, filtered, and finally concentrated under reduced pressure to yield 16.87 g of the intermediate product. The yield was approximately 100%.

[0201] 1 H NMR (DMSO-d6, 400MHz), δ (ppm): 3.63 (m, 2H), 3.54 (m, 4H), 3.24 (s, 3H), 2.28 (m, 2H).

[0202] 13 C NMR (DMSO-d6, 100MHz), δ (ppm): 73.1, 70.4, 70.3, 53.9, 37.2.

[0203] 19 F NMR (DMSO-d6, 376MHz), δ (ppm): -69.7.

[0204] HRMS(ESI + )m / z[M] + calcd.for C5H 12 FNO4S:201.0471,found:201.0465.

[0205] The intermediate product (2.0 g, 9.95 mmol) was weighed and placed in a 25 mL single-necked flask, followed by 10 mL of methanol. After cooling to below 10°C, a lithium hydroxide aqueous solution (0.238 g, 9.95 mmol of LiOH and 0.5 mL of water) was added dropwise. After the addition was complete, the mixture was heated to 55°C and stirred for 5 hours until no NH chemical shift was observed. After the reaction was complete, the mixture was concentrated under reduced pressure to remove the methanol, filtered, and dried to yield 1.31 g of the first electrolyte salt I-3. The yield was 63.52%.

[0206] 1 H NMR (DMSO-d6, 400MHz), δ (ppm): 3.54 (m, 4H), 3.40 (m, 2H), 3.24 (s, 3H), 1.50 (m, 2H).

[0207] Synthesis of the first electrolyte salt I-5

[0208] 1-(2-Aminoethoxy)-2-methoxyethane (10.0 g, 83.92 mmol) and triethylamine (8.5 g, 83.92 mmol) were weighed and added to a 250 mL three-necked flask, followed by 100 mL of ultra-dry dichloromethane (DCM). After cooling to 0°C, trifluoromethanesulfonyl chloride (14.2 g, 83.92 mmol) was added dropwise. The temperature was raised to 25°C and stirred overnight. After the reaction, the dichloromethane was removed by concentration under reduced pressure. Water (30 mL) and ethyl acetate (30 mL x 2) were then added for extraction. The organic phase obtained from the extraction was washed with water (20 mL) and saturated brine (10 mL x 2), separated, dried over anhydrous magnesium sulfate, filtered, and finally concentrated under reduced pressure to obtain 21.0 g of the intermediate product. The yield was approximately 100%.

[0209] 1 H NMR (DMSO-d6, 400MHz), δ (ppm): 9.51 (s, 1H), 3.65 (m, 2H), 3.58 (m, 4H), 3.26 (s, 3H), 2.24 (m, 2H).

[0210] 13 C NMR (DMSO-d6, 100MHz), δ (ppm): 149.4, 73.1, 70.7, 70.3, 53.9, 41.5.

[0211] 19 F NMR (DMSO-d6, 376MHz), δ (ppm): -77.37.

[0212] HRMS(ESI + )m / z[M] +calcd.for C6H 12 F3NO4S:251.0439,found:251.0443.

[0213] The intermediate product (2.0 g, 7.96 mmol) was weighed and placed in a 25 mL single-necked flask, followed by 10 mL of methanol. After cooling to below 10°C, a lithium hydroxide aqueous solution (0.19 g, 7.96 mmol of LiOH and 0.4 mL of water) was added dropwise. After the addition was complete, the mixture was heated to 55°C and stirred for 3 hours until no NH chemical shift was observed. After the reaction was complete, the mixture was concentrated under reduced pressure to remove methanol, filtered, and dried to yield 1.48 g of the first electrolyte salt I-5. The yield was 72.38%.

[0214] 1 H NMR (DMSO-d6, 400MHz), δ (ppm): 3.58 (m, 4H), 3.42 (m, 2H), 3.26 (s, 3H), 1.52 (m, 2H).

[0215] Synthesis of the first electrolyte salt I-8

[0216] Weigh boron trifluoride etherate (9.51 g, 67.0 mmol) and 100 mL of ether, add to a 250 mL three-necked flask under argon protection, and then add another 100 mL of ether; after cooling to 0°C, add ethylene glycol monomethyl ether (10.0 g, 131.42 mmol) dropwise; after the addition is completed, heat to 25°C and stir for 40 h; after the reaction is completed, concentrate under reduced pressure to remove the ether, and then distill under reduced pressure to obtain the intermediate product.

[0217] 1 H NMR (DMSO-d6, 400MHz), δ (ppm): 3.70 (m, 4H), 3.56 (m, 4H), 3.24 (s, 6H).

[0218] 13 C NMR (DMSO-d6, 100MHz), δ (ppm): 75.8, 63.6, 53.9.

[0219] 11 B NMR (DMSO-d6, 128MHz), δ (ppm): 3.7.

[0220] HRMS(ESI + )m / z[M] + calcd.for C6H 15 BO4:162.1063,found:162.1048.

[0221] The intermediate product (3 g, 18.51 mmol) and lithium fluoride (0.72 g, 27.76 mol) were weighed and added to a 50 mL polytetrafluoroethylene autoclave. The mixture was dissolved in 20 mL of hydrofluoric acid and stirred at 50°C for 18 h. After the reaction, the mixture was neutralized with lithium carbonate and dissolved in ethylene glycol dimethyl ether. The mixture was filtered and concentrated. Finally, the mixture was slurried with ethyl acetate and petroleum ether (1:25, m:m), filtered, and dried under vacuum at 45°C to obtain 2.72 g of the first electrolyte salt I-8. The yield was 71.30%.

[0222] 1 H NMR (DMSO-d6, 400MHz), δ (ppm): 3.70 (m, 4H), 3.56 (m, 4H), 3.24 (s, 6H).

[0223] 13 C NMR (DMSO-d6, 100MHz), δ (ppm): 76.0, 53.9, 44.0.

[0224] 19 F NMR (DMSO-d6, 376MHz), δ (ppm): -148.7.

[0225] 11 B NMR (DMSO-d6, 128MHz), δ (ppm): 3.37.

[0226] HRMS(ESI + )m / z[M] + calcd.for C6H 14 BF2LiO4:206.1113,found:206.1149.

[0227] Synthesis of the first electrolyte salt I-9

[0228] Lithium difluorooxalatoborate (3.0 g, 20.87 mmol) and 2-methoxyethyl p-toluenesulfonate (10.1 g, 43.82 mmol) were weighed and added to a 250 mL three-necked flask. The mixture was dissolved in 100 mL of acetonitrile and stirred at 50°C under argon for 28 h. After the reaction, the acetonitrile was removed by concentration under reduced pressure and recrystallization to yield 2.37 g of the first electrolyte salt I-9. The yield was 44.39%.

[0229] 1 H NMR (DMSO-d6, 400MHz), δ (ppm): 3.70 (m, 4H), 3.56 (m, 4H), 3.24 (s, 6H).

[0230] 13C NMR (DMSO-d6, 100MHz), δ (ppm): 161.0, 76.0, 53.9, 46.0.

[0231] HRMS(ESI + )m / z[M] + calcd.for C8H 14 BLiO8:256.0942,found:256.0931.

[0232] Synthesis of the first electrolyte salt I-11

[0233] Lithium hexafluorophosphate (10.0 g, 65.83 mmol) was weighed and added to a 250 mL three-necked flask. 140 mL of acetonitrile was then added to dissolve the product. Under argon, a solution of bis(trimethylsilyl) oxalate (15.74 g, 67.14 mmol) in acetonitrile was added dropwise at 40-45°C. The mixture was stirred at 40-45°C for 30 h. After the reaction, the acetonitrile was removed by concentration under reduced pressure, and the mixture was dried under vacuum at 40-45°C to yield 12.52 g of the intermediate product. The yield was 94.21%.

[0234] 19 F NMR (DMSO-d6, 376MHz), δ (ppm): -78.3.

[0235] 31 P NMR (DMSO-d6, 160MHz), δ (ppm): -143.7.

[0236] HRMS(ESI + )m / z[M] + calcd.for C2F4LiO4P:201.9630,found:201.9659.

[0237] The intermediate product (3.0 g, 14.85 mmol) and 2-methoxyethyl p-toluenesulfonate (7.18 g, 31.19 mmol) were weighed into a 250 mL three-necked flask, dissolved in 100 mL of acetonitrile, and stirred at 50°C under argon for 20 h. After the reaction, the acetonitrile was removed by concentration under reduced pressure and recrystallization to yield 1.95 g of the first electrolyte salt I-11. The yield was 40.18%.

[0238] 1 H NMR (DMSO-d6, 400MHz), δ (ppm): 3.70 (m, 4H), 3.56 (m, 4H), 3.24 (s, 6H).

[0239] 13C NMR (DMSO-d6, 100MHz), δ (ppm): 161.0, 76.0, 53.9, 32.0.

[0240] 19 F NMR (DMSO-d6, 376MHz), δ (ppm): -64.8.

[0241] 31 P NMR (DMSO-d6, 160MHz), δ (ppm): -139.2.

[0242] HRMS(ESI + )m / z[M] + calcd.for C8H 14 F2LiO8P:314.0554,found:314.0528.

[0243] Example 1

[0244] (1) Preparation of electrolyte

[0245] A first solvent, 1,2-dimethoxyethane (DME), and a second solvent, trifluoromethoxybenzene, were thoroughly mixed in a 1:1 weight ratio to form a solvent. 1.77 g of a first electrolyte salt containing the anion shown in I-3 and lithium ions, and 0.4675 g of a second electrolyte salt, lithium bis(fluorosulfonyl)imide (LiFSI), were added to 5 ml of the solvent and stirred thoroughly to form a colorless, transparent electrolyte solution.

[0246] (2) Preparation of positive electrode sheet

[0247] The positive electrode active material NCM811, the conductive agent acetylene black, and the binder PVDF were mixed in a weight ratio of 98:1:1, added to the solvent NMP and stirred until the system became uniform to obtain a positive electrode slurry with a solid content of 70%; the positive electrode slurry was evenly coated on both surfaces of the positive electrode current collector aluminum foil, dried, and then transferred to an oven for further drying, and then cut into 40mm×50mm rectangles as positive electrode sheets for later use.

[0248] (3) Preparation of negative electrode sheet

[0249] A 50 μm thick lithium foil was laminated to a 12 μm thick copper foil by roller pressing, and then cut into a 41 mm × 51 mm rectangle as a negative electrode sheet for later use.

[0250] (4) Preparation of isolation membrane

[0251] The polyethylene porous film was cut into a rectangle of 45 mm × 55 mm and used as a separator for later use.

[0252] (5) Preparation of batteries

[0253] A pre-cut positive electrode sheet was stacked with two pre-cut negative electrode sheets, separated by a separator to form an electrode assembly. The electrode assembly was placed in an aluminum-plastic film bag, and 0.30 g of the prepared electrolyte was injected. The battery was then vacuum-pressed and allowed to stand for at least 6 hours to produce a rated capacity of 140 mAh.

[0254] Cycle life test

[0255] At 25°C, the prepared battery was charged at a constant current of 0.2C (28mA) to 4.3V. It was then charged at a constant voltage to a current of 0.1C (14mA). At this point, the battery was fully charged. The charge capacity at this point was recorded as the first cycle charge capacity. After the battery rested for 5 minutes, it was discharged at a constant current of 1C (140mA) to 2.8V. This constituted a cycle charge and discharge process. The discharge capacity at this point was recorded as the first cycle discharge capacity. The battery was subjected to a cyclic charge and discharge test according to the above method, and the discharge capacity after each cycle was recorded until the battery's discharge capacity decayed to 80% of the first cycle discharge capacity. The number of cycles at this point was used to characterize the battery's cycle life.

[0256] Electrolyte consumption rate test

[0257] The above cycle life test was conducted with the electrolyte injection volume set to 0.15g, 0.20g, 0.25g, and 0.30g, respectively, to obtain the cycle life of the battery at different electrolyte injection volumes. The battery cycle life (as the vertical axis) was plotted against the electrolyte injection volume (as the horizontal axis, measured in g) and a linear fit was performed to obtain the slope k (cycles / g).

[0258] The consumption rate r of the electrolyte can be calculated according to the following formula: r (mg / Ah / circuit) = 1000 / (k×0.14).

[0259] Example 2-49

[0260] The battery preparation and testing methods were similar to those of Example 1, except for the different electrolyte compositions, as detailed in Table 1. The first electrolyte salts were each composed of the corresponding first anion and lithium ions. PS represents propane sultone, DTD represents vinyl sulfate, ES represents vinyl sulfite, and TMSP represents tris(trimethylsilyl)phosphate. The additive content is based on the total weight of the electrolyte.

[0261] Comparative Example 1

[0262] The preparation and testing methods of the battery are similar to those of Example 1, except that the composition of the electrolyte is different.

[0263] Take 1.52g of lithium hexafluorophosphate and add it to 5ml of a mixed solvent of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) in a weight ratio of 1:1, and stir thoroughly to form a colorless and transparent electrolyte.

[0264] Comparative Example 2

[0265] The preparation and testing methods of the battery are similar to those of Example 1, except that the composition of the electrolyte is different.

[0266] Take 0.4675g of lithium bis(fluorosulfonyl)imide salt, add it into 5ml of a mixed solvent of 1,2-dimethoxyethane (DME) and trifluoromethoxybenzene in a weight ratio of 1:1, stir thoroughly to form a colorless and transparent electrolyte.

[0267] Table 1

[0268] Based on the test results of Examples 1-49 and Comparative Examples 1-2, it can be seen that the electrolyte provided by Examples 1-49 can reduce the consumption rate of the electrolyte and extend the cycle life of the battery.

[0269] Based on the test results of Examples 1-8, it can be seen that when the first anion includes I-3, I-4, I-8, and I-9, the consumption rate of the electrolyte can be further reduced and the cycle life of the battery can be further extended. 2 Containing two oxygen atoms with a suitable distance between the two oxygen atoms is conducive to better combination with metal lithium ions, and can further improve the overall stability and reduction resistance of the first anion, thereby further reducing the decomposition consumption of the first anion, delaying the time for the electrolyte to dry up, and further extending the cycle life of the battery.

[0270] Based on the test results of Examples 1 and 9-16, it can be seen that when the molar concentration of the first anion is between 0.5 mol / L and 4 mol / L, optionally 1 mol / L to 3.5 mol / L, and more optionally 1.5 mol / L to 3 mol / L, the consumption rate of the electrolyte can be further reduced and the cycle life of the battery can be further extended.

[0271] It can be seen from the test results of Examples 1 and 17-19 that when the first anion includes a bis(trifluoromethanesulfonyl)imide anion (TFSI - ), difluorooxalatoborate anion (DFOB - ), the consumption rate of the electrolyte can be further reduced and the cycle life of the battery can be further extended.

[0272] Based on the test results of Examples 1 and 20-25, it can be seen that when the electrolyte further includes a second anion, and the molar concentration of the second anion is less than or equal to 4 mol / L, and can be optionally less than or equal to 2 mol / L, and can be more optionally less than or equal to 1 mol / L, the consumption rate of the electrolyte can be further reduced and the cycle life of the battery can be further extended.

[0273] Based on the test results of Examples 1 and 26-29, it can be seen that when the first solvent includes 1,2-dimethoxyethane or 1,2-diethoxyethane, the consumption rate of the electrolyte can be further reduced and the cycle life of the battery can be further extended.

[0274] Based on the test results of Examples 1 and 30-38, it can be seen that when the solvent includes a mixture of a first solvent and a second solvent, optionally, the weight ratio of the first solvent to the second solvent is (0.1-10):1, optionally (0.3-3):1, and more optionally (0.5-1.5):1, the consumption rate of the electrolyte can be further reduced and the cycle life of the battery can be further extended.

[0275] Based on the test results of Examples 1 and 39-42, it can be seen that when the second solvent includes trifluoromethoxybenzene, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, and 1,2-bis(1,1,2,2-tetrafluoroethoxy)ethane, the consumption rate of the electrolyte can be further reduced and the cycle life of the battery can be further extended.

[0276] Based on the test results of Examples 1 and 43-49, it can be seen that when the electrolyte includes an appropriate amount of additives, the cycle life of the battery can be further extended.

[0277] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and within the scope of the technical solution of the present application, embodiments having substantially the same structure as the technical idea and exerting the same effects are all included in the technical scope of the present application. In addition, within the scope of the subject matter of the present application, various modifications that can be conceived by those skilled in the art to the embodiments, and other methods constructed by combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. An electrolyte comprising a first anion represented by formula (I), X includes one or more elements selected from N, B, P, Al, Si, S, Cl, As, and Se; a represents an integer greater than or equal to 1; b represents an integer greater than or equal to 1; R 1 Each independently includes one or more of a halogen atom, a halosulfonyl group, a haloalkylsulfonyl group, and an ester group -O-(C=O)-, and optionally two adjacent R 1 It can also form a ring with X; R 2 Each independently includes one or more of C1-C10 chain alkyl, C1-C10 oxo chain alkyl, C3-C10 cyclic alkyl, C1-C10 oxo cyclic alkyl, C1-C10 halogenated chain alkyl, C1-C10 oxo halogenated chain alkyl, C3-C10 halogenated cyclic alkyl, C1-C10 oxo halogenated cyclic alkyl, and optionally two adjacent R 2 It can also form a ring with X.

2. The electrolyte according to claim 1, in, R 1 Each independently includes one or more of a fluorine atom, a fluorinated sulfonyl group, a fluorinated alkylsulfonyl group, and an ester group -O-(C=O)-, and optionally two adjacent R 1 It can also form a ring with X; Optionally, R 1 Including fluorine atoms, one or more of the following groups, # indicates the connection location.

3. The electrolyte according to claim 1 or 2, in, R 2 Each independently includes one or more of C1-C10 oxo-chain alkyl, C1-C10 oxo-cyclic alkyl, C1-C10 oxo-halogenated chain alkyl, and C1-C10 oxo-halogenated cyclic alkyl, and optionally two adjacent R 2 It can also form a ring with X; Optionally, R 2 Each independently includes one or more of C1-C10 oxygen heterocyclic alkyl and C1-C10 oxygen heterocyclic alkyl, and optionally two adjacent R 2 It can also form a ring with X.

4. The electrolyte according to any one of claims 1 to 3, in, R 2 Each independently includes one or more of the following groups, # indicates the connection position; Optionally, R 2 Each independently includes one or more of B-31, B-32, B-40, B-41, B-60, and B-61.

5. The electrolyte according to any one of claims 1 to 4, in, X includes one or more elements of N, B, and P, and may optionally include one or more elements of N and B.

6. The electrolyte according to any one of claims 1 to 5, in, X includes N; a is 1, b is 1; R 1 including halosulfonyl or haloalkylsulfonyl, and optionally including fluorosulfonyl or fluoroalkylsulfonyl; R 2 It includes one or more of C1-C10 chain alkyl, C1-C10 oxo-chain alkyl, C3-C10 cyclic alkyl, C1-C10 oxo-cyclic alkyl, C1-C10 halogenated chain alkyl, C1-C10 oxo-halogenated chain alkyl, C3-C10 halogenated cyclic alkyl, and C1-C10 oxo-halogenated cyclic alkyl; it may optionally include one or more of C1-C10 oxo-chain alkyl, C1-C10 oxo-cyclic alkyl, C1-C10 oxo-halogenated chain alkyl, and C1-C10 oxo-halogenated cyclic alkyl; it may more optionally include one or more of C1-C10 oxo-chain alkyl and C1-C10 oxo-cyclic alkyl.

7. The electrolyte according to any one of claims 1 to 5, in, X includes B; a represents an integer greater than or equal to 1, b represents an integer greater than or equal to 1, and a+b is 4, optionally, a is 2, and b is 2; R 1 Each independently includes one or more of a halogen atom, an ester group -O-(C=O)-, and optionally two adjacent R 1 It can also form a ring with X, optionally, R 1 Each independently includes one or more of a fluorine atom and an ester group, and optionally two adjacent R 1 It can also form a ring with X; R 2 Each independently includes one or more of C1-C10 chain alkyl, C1-C10 oxo chain alkyl, C3-C10 cyclic alkyl, C1-C10 oxo cyclic alkyl, C1-C10 halogenated chain alkyl, C1-C10 oxo halogenated chain alkyl, C3-C10 halogenated cyclic alkyl, C1-C10 oxo halogenated cyclic alkyl, and optionally two adjacent R 2 It can also form a ring with X. Optionally, R 2 Each independently includes one or more of C1-C10 oxo-chain alkyl, C1-C10 oxo-cyclic alkyl, C1-C10 oxo-halogenated chain alkyl, and C1-C10 oxo-halogenated cyclic alkyl, and R 2 The oxygen atom in is directly connected to X, and more preferably, R 2 Each independently includes one or more of C1-C10 oxo-chain alkyl and C1-C10 oxo-cyclic alkyl, and R 2 The oxygen atom in is directly connected to X.

8. The electrolyte according to any one of claims 1 to 5, in, X includes P; a represents an integer greater than or equal to 1, b represents an integer greater than or equal to 1, and a+b is 6, optionally, a is 4 or 5, and b is 1 or 2; R 1 Each independently includes one or more of a halogen atom, an ester group -O-(C=O)-, and optionally two adjacent R 1 It can also form a ring with X, optionally, R 1 Each independently includes one or more of a fluorine atom, an ester group -O-(C=O)-, and optionally two adjacent R 1 It can also form a ring with X; R 2 Each independently includes one or more of C1-C10 chain alkyl, C1-C10 oxo chain alkyl, C3-C10 cyclic alkyl, C1-C10 oxo cyclic alkyl, C1-C10 halogenated chain alkyl, C1-C10 oxo halogenated chain alkyl, C3-C10 halogenated cyclic alkyl, C1-C10 oxo halogenated cyclic alkyl, and optionally two adjacent R 2 It can also form a ring with X, optionally, R 2 Each independently includes one or more of C1-C10 oxo-chain alkyl, C1-C10 oxo-cyclic alkyl, C1-C10 oxo-halogenated chain alkyl, and C1-C10 oxo-halogenated cyclic alkyl, and R 2 The oxygen atom in is directly connected to X, and more preferably, R 2 Each independently includes one or more of C1-C10 oxo-chain alkyl and C1-C10 oxo-cyclic alkyl, and R 2 The oxygen atom in is directly connected to X.

9. The electrolyte according to any one of claims 1 to 8, in, The first anion includes one or more of the following, Optionally, the first anion includes one or more of I-3, I-4, I-8, and I-9.

10. The electrolyte according to any one of claims 1 to 9, in, The molar concentration of the first anion in the electrolyte is 0.5-4 mol / L, optionally 1-3.5 mol / L, and more optionally 1.5-3 mol / L.

11. The electrolyte according to any one of claims 1 to 10, in, The electrolyte further includes a second anion, wherein the second anion includes one or more of a bisfluorosulfonyl imide anion, a bistrifluoromethanesulfonyl imide anion, a dioxalate borate anion, a difluorooxalate borate anion, a difluorodioxalate phosphate anion, a tetrafluorooxalate phosphate anion, a difluorophosphate anion, a hexafluorophosphate anion, a tetrafluoroborate anion, a hexafluoroarsenate anion, and a trifluoromethanesulfonate anion; Optionally, the second anion includes one or more of a bis(fluorosulfonyl)imide anion, a bis(trifluoromethanesulfonyl)imide anion, a difluorooxalatoborate anion, and a tetrafluorooxalatophosphate anion; and / or, Optionally, the molar concentration of the second anion in the electrolyte is less than or equal to 4 mol / L, optionally less than or equal to 2 mol / L, and more optionally less than or equal to 1 mol / L.

12. The electrolyte according to any one of claims 1 to 11, in, The electrolyte includes a first cation, which includes one or more of an alkali metal ion, an alkaline earth metal ion, a zinc ion, and an aluminum ion, and may optionally include one or more of a lithium ion, a sodium ion, a potassium ion, and a magnesium ion, and may further optionally include a lithium ion.

13. The electrolyte according to any one of claims 1 to 12, in, The electrolyte includes a solvent, the solvent includes a first solvent, and the first solvent includes one or more of ester and halogenated ester solvents, sulfone solvents, nitrile solvents, ether solvents, and ionic liquids; Optionally, the first solvent includes dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene carbonate, propylene carbonate, fluoroethylene carbonate, difluoroethylene carbonate, methyl trifluoroethyl carbonate, ethyl trifluoroethyl carbonate, di(2,2,2-trifluoroethyl) carbonate, methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl 2,2,2-trifluoroacetate, ethyl 2,2,2-trifluoroacetate, methyl ether, ethyl ether, propyl ether, butyl ether, methyl ethyl ether, methyl propyl ether, methyl butyl ether, ethyl propyl ether, ethyl butyl ether, propyl butyl One or more of ether, dimethoxymethane, diethoxymethane, dipropoxymethane, 1,2-dimethoxyethane, dimethoxypropane, 1,2-diethoxyethane, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, tetrahydrofuran, 1,3-dioxolane, tetrahydropyran, 1,3-dioxane, 1,4-dioxane, dimethyl sulfone, dimethyl sulfoxide, cyclopentane, ethyl methyl sulfone, tetramethylene sulfoxide, ethyl methyl sulfoxide, diethyl sulfone, diethyl sulfoxide, methyl phenyl sulfone, methyl phenyl sulfoxide, ethyl phenyl sulfoxide, ethyl phenyl sulfoxide, vinyl phenyl sulfone, vinyl phenyl sulfoxide, acetonitrile, propionitrile, butyronitrile, succinonitrile, and 2-butenenitrile; More optionally, the first solvent includes one or more of dimethoxymethane, diethoxymethane, dipropoxymethane, 1,2-dimethoxyethane, dimethoxypropane, 1,2-diethoxyethane, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether.

14. The electrolyte according to claim 13, in, The solvent further includes a second solvent, wherein the second solvent includes one or more of hydrocarbons, halogenated hydrocarbon solvents, and fluoroether solvents; Optionally, the second solvent includes cyclohexane, benzene, toluene, p-xylene, m-xylene, o-xylene, fluorobenzene, p-difluorobenzene, m-difluorobenzene, o-difluorobenzene, trifluorotoluene, trifluoromethoxybenzene, decafluoropentane, perfluoropentanone, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, 1,2-bis(1,1,2,2-tetrafluoroethoxy)ethane, bis(2,2,2-trifluoroethyl)ether, 1,1,2,3,3,3-hexafluoropropyl ethyl ether, 1H,1H,5H-octafluoro One or more of amyl-1,1,2,2-tetrafluoroethyl ether, ethyl trifluoromethyl ether, difluoromethyl-2,2,3,3,3-pentafluoropropyl ether, heptafluoropropyl-1,2,2,2-tetrafluoroethyl ether, difluoromethyl 2,2,3,3-tetrafluoropropyl ether, perfluoroisopropyl methyl ether, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, ethyl-1,1,2,2-tetrafluoroethyl ether, ethyl-2,2,2-tetrafluoroethyl ether, and bis(1,1,2,2-tetrafluoroethyl) ether; More optionally, the second solvent includes one or more of trifluoromethoxybenzene, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, and 1,2-bis(1,1,2,2-tetrafluoroethoxy)ethane.

15. The electrolyte according to claim 14, in, The weight ratio of the first solvent to the second solvent is (0.1-10):1, optionally (0.3-3):1, and more optionally (0.5-1.5):

1.

16. The electrolyte according to any one of claims 1 to 15, in, The electrolyte further includes an additive, wherein the additive includes one or more of propane sultone, vinyl sulfate, vinyl sulfite, tris(trimethylsilane) phosphate, tris(trimethylsilane) phosphite, tris(trifluoroethyl) phosphate, tris(trifluoroethyl) phosphite, tris(trimethylsilane) borate, dimethyl maleic anhydride, and 1,4-diisocyanate; Optionally, the weight proportion of the additive in the electrolyte is less than or equal to 5wt%, optionally less than or equal to 3wt%, and more optionally less than or equal to 1wt%.

17. A battery cell comprising the electrolyte according to any one of claims 1 to 16.

18. The battery cell according to claim 17, in, The battery cells include metal battery cells, metal-air battery cells, metal-sulfur battery cells and negative electrode-free metal battery cells, and may optionally include lithium metal battery cells, negative electrode-free lithium metal battery cells, lithium-air battery cells and lithium-sulfur battery cells.

19. A battery comprising the battery cell according to claim 17 or 18.

20. An electrical device comprising the battery according to claim 19.

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