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 solvent, the solvent comprises a first solvent, the first solvent comprises an organosiloxane compound, and the content of the first solvent is greater than or equal to 20% based on the total weight of the solvent.

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 solution comprising a solvent, wherein the solvent comprises a first solvent, the first solvent comprises an organic siloxane compound, and the content of the first solvent is greater than or equal to 20%, based on the total weight of the solvent.

[0006] The inventors discovered in their research that when an organosiloxane compound is used as the main solvent of the electrolyte (the content is greater than or equal to 20%, based on the total weight of the solvent), the oxidation resistance of the electrolyte can be improved and the oxidative decomposition of the electrolyte can be reduced, thereby improving the cycle stability of the battery and extending the cycle life of the battery.

[0007] In any embodiment, the first solvent comprises one or more of the organosiloxane compounds represented by formula (I),

[0008] R 1 、R 2 、R 3 、R 4 Each independently includes a hydrogen atom, a C1-C10 alkyl group, a C1-C10 alkoxy group, a C2-C10 alkoxyalkyl group, or a group represented by formula (a), and R 1 、R 2 、R 3 、R 4 At least one of the groups includes a C1-C10 alkoxy group and a group represented by formula (a),

[0009] # indicates the connection position, L 1 、L 2 Each independently represents one of C1-C10 alkylene, C1-C10 alkyleneoxy, and C2-C10 alkyleneoxyalkylene, R 11 、R 12 、R 21 、R 22 、R 23 Each independently includes one of a hydrogen atom, a C1-C10 alkyl group, a C1-C10 alkoxy group, and a C2-C10 alkoxyalkyl group, m and p each independently represent 0 or 1, n and q each independently represent 0 or an integer of 1-5, and n and q are not 0 at the same time.

[0010] When the first solvent includes an organosiloxane compound represented by formula (I), the oxidation resistance of the electrolyte can be improved, the oxidative decomposition of the electrolyte can be reduced, and the negative electrode can be further stabilized, and the reductive decomposition of the electrolyte can be reduced, thereby enabling the battery to have high cycle stability and long cycle life at a higher voltage range.

[0011] In any embodiment, R 1 、R 2 、R 3 、R 4 Each independently includes one of a C1-C5 alkyl group, a C1-C5 alkoxy group, a C2-C5 alkoxyalkyl group, and a group represented by formula (a). This can reduce the steric hindrance of the first solvent, improve the solubility of the first solvent in the electrolyte salt, and improve the miscibility of the first solvent with other solvents, thereby enabling the battery to have high cycle stability and long cycle life.

[0012] In any embodiment, R 1 、R 2 、R 3 、R 4 The two of them independently include one of a C1-C10 alkoxy group and a group represented by formula (a).

[0013] In any embodiment, R 1 、R 2 、R 3 、R 4 The two of them independently include one of a C1-C5 alkoxy group and a group represented by formula (a).

[0014] This can reduce the steric hindrance of the first solvent, improve the solubility of the first solvent in the electrolyte salt, and improve the miscibility of the first solvent with other solvents, thereby enabling the battery to have high cycle stability and long cycle life.

[0015] In any embodiment, L 1 、L 2Each independently represents one of C1-C5 alkylene, C1-C5 alkyleneoxy, and C2-C5 alkyleneoxyalkylene. The two silicon atoms are connected by a linking group L 1 、L 2 When connected, it can alleviate the shielding effect of silicon atoms on the lone pair electrons of oxygen atoms to a certain extent, and also help the connecting group L 1 、L 2 The oxygen atoms at both ends chelate with cations in the electrolyte to form a solvation structure, thereby making the first solvent more soluble in the electrolyte salt and more miscible with other solvents. As a result, the electrolyte can have suitable ionic conductivity, thereby improving the cycle performance of the battery.

[0016] In any embodiment, L 1 、L 2 Each independently represents a C2-C3 alkyleneoxy group. 1 、L 2 Within this range, the first solvent facilitates chelation with cations in the electrolyte to form a solvation structure, thereby improving the solubility of the first solvent for the electrolyte salt and further improving the miscibility of the first solvent with other solvents. As a result, the electrolyte can have suitable ionic conductivity, further improving the cycle performance of the battery.

[0017] In any embodiment, R 11 、R 12 、R 21 、R 22 、R 23 Each independently includes one of C1-C5 alkyl, C1-C5 alkoxy, and C2-C5 alkoxyalkyl.

[0018] In any embodiment, R 11 、R 12 、R 21 、R 22 Each independently includes a C1-C5 alkyl group, and R 23 It includes one of C1-C5 alkyl, C1-C5 alkoxy and C2-C5 alkoxyalkyl.

[0019] In any embodiment, m and p are not 0 at the same time.

[0020] In any embodiment, n and q each independently represent 0, 1 or 2, and n and q are not 0 at the same time.

[0021] In any embodiment, m, n, and p are all 0, and q is an integer from 1 to 5.

[0022] In any embodiment, m and n are both 0, p is 1, and q is an integer from 1 to 5.

[0023] In any embodiment, m is 0, n is an integer from 1 to 5, p is 1, and q is an integer from 1 to 5.

[0024] In any embodiment, m is 1, n is an integer from 1 to 5, p is 1, and q is an integer from 1 to 5.

[0025] In any embodiment, m, n, and p are all 0, q is 1 or 2, and R 21 、R 22 、R 23 Each independently includes one of a C1-C10 alkyl group, a C1-C10 alkoxy group, and a C2-C10 alkoxyalkyl group.

[0026] In any embodiment, m, n, and p are all 0, q is 1 or 2, and R 21 、R 22 、R 23 Each independently includes one of C1-C5 alkyl, C1-C5 alkoxy, and C2-C5 alkoxyalkyl.

[0027] In any embodiment, m, n, and p are all 0, q is 1 or 2, and R 21 、R 22 Each independently includes C1-C5 alkyl, R 23 It includes one of C1-C5 alkyl, C1-C5 alkoxy and C2-C5 alkoxyalkyl.

[0028] In any embodiment, m and n are both 0, p is 1, q is 1 or 2, and L 2 represents one of C1-C10 alkylene, C1-C10 alkyleneoxy, and C2-C10 alkyleneoxyalkylene, R 21 、R 22 、R 23 Each independently includes one of a C1-C10 alkyl group, a C1-C10 alkoxy group, and a C2-C10 alkoxyalkyl group.

[0029] In any embodiment, m and n are both 0, p is 1, q is 1 or 2, and L 2 represents one of C1-C5 alkylene, C1-C5 alkyleneoxy, and C2-C5 alkyleneoxyalkylene, R 21 、R 22 、R 23 Each independently includes one of C1-C5 alkyl, C1-C5 alkoxy, and C2-C5 alkoxyalkyl.

[0030] In any embodiment, m and n are both 0, p is 1, q is 1 or 2, and L 2represents one of C1-C5 alkylene, C1-C5 alkyleneoxy, and C2-C5 alkyleneoxyalkylene, R 21 、R 22 Each independently includes C1-C5 alkyl, R 23 It includes one of C1-C5 alkyl, C1-C5 alkoxy and C2-C5 alkoxyalkyl.

[0031] In any embodiment, m and n are both 0, p is 1, q is 1 or 2, and L 2 represents C2-C3 alkyleneoxy, R 21 、R 22 Each independently includes C1-C5 alkyl, R 23 It includes one of C1-C5 alkyl, C1-C5 alkoxy and C2-C5 alkoxyalkyl.

[0032] In any embodiment, m is 0, n is 1 or 2, p is 1, q is 1 or 2, L 2 represents one of C1-C10 alkylene, C1-C10 alkyleneoxy, and C2-C10 alkyleneoxyalkylene, R 11 、R 12 、R 21 、R 22 、R 23 Each independently includes one of a C1-C10 alkyl group, a C1-C10 alkoxy group, and a C2-C10 alkoxyalkyl group.

[0033] In any embodiment, m is 0, n is 1 or 2, p is 1, q is 1 or 2, L 2 represents one of C1-C5 alkylene, C1-C5 alkyleneoxy, and C2-C5 alkyleneoxyalkylene, R 11 、R 12 、R 21 、R 22 、R 23 Each independently includes one of C1-C5 alkyl, C1-C5 alkoxy, and C2-C5 alkoxyalkyl.

[0034] In any embodiment, m is 0, n is 1 or 2, p is 1, q is 1 or 2, L 2 represents one of C1-C5 alkylene, C1-C5 alkyleneoxy, and C2-C5 alkyleneoxyalkylene, R 11 、R 12 、R 21 、R 22 Each independently includes C1-C5 alkyl, R 23 It includes one of C1-C5 alkyl, C1-C5 alkoxy and C2-C5 alkoxyalkyl.

[0035] In any embodiment, m is 0, n is 1 or 2, p is 1, q is 1 or 2, L 2 represents C2-C3 alkyleneoxy, R 11 、R 12 、R 21 、R 22 Each independently includes C1-C5 alkyl, R 23 It includes one of C1-C5 alkyl, C1-C5 alkoxy and C2-C5 alkoxyalkyl.

[0036] In any embodiment, m is 1, n is 1 or 2, p is 1, q is 1 or 2, L 1 、L 2 Each independently represents one of C1-C10 alkylene, C1-C10 alkyleneoxy, and C2-C10 alkyleneoxyalkylene, R 11 、R 12 、R 21 、R 22 、R 23 Each independently includes one of a C1-C10 alkyl group, a C1-C10 alkoxy group, and a C2-C10 alkoxyalkyl group.

[0037] In any embodiment, m is 1, n is 1 or 2, p is 1, q is 1 or 2, L 1 、L 2 Each independently represents one of C1-C5 alkylene, C1-C5 alkyleneoxy, and C2-C5 alkyleneoxyalkylene, and R 11 、R 12 、R 21 、R 22 、R 23 Each independently includes one of C1-C5 alkyl, C1-C5 alkoxy, and C2-C5 alkoxyalkyl.

[0038] In any embodiment, m is 1, n is 1 or 2, p is 1, q is 1 or 2, L 1 、L 2 Each independently represents one of C1-C5 alkylene, C1-C5 alkyleneoxy, and C2-C5 alkyleneoxyalkylene, and R 11 、R 12 、R 21 、R 22 Each independently includes C1-C5 alkyl, R 23 It includes one of C1-C5 alkyl, C1-C5 alkoxy and C2-C5 alkoxyalkyl.

[0039] In any embodiment, m is 1, n is 1 or 2, p is 1, q is 1 or 2, L 1 、L 2Each independently represents a C2-C3 alkyleneoxy group, R 11 、R 12 、R 21 、R 22 Each independently includes C1-C5 alkyl, R 23 It includes one of C1-C5 alkyl, C1-C5 alkoxy and C2-C5 alkoxyalkyl.

[0040] In any embodiment, the number of silicon atoms in the first solvent is denoted as x, and the number of oxygen atoms in the first solvent is denoted as y, then 0.5≤y / x≤4, optionally, 1≤y / x≤2. Further adjusting the ratio of the number of oxygen atoms to the number of silicon atoms in the molecular structure of the organosiloxane compound can improve the solubility of the first solvent for the electrolyte salt and also improve the miscibility of the first solvent with other solvents.

[0041] In any embodiment, the number of silicon atoms in the first solvent is denoted as x, then 1≤x≤10, optionally, 1≤x≤5, and more optionally, 1≤x≤3. When the number of silicon atoms in the first solvent is within the above range, the electrolyte can have good ion conductivity.

[0042] In any embodiment, the number of oxygen atoms in the first solvent is denoted as y, then 1≤y≤20, optionally, 1≤y≤10, and more optionally, 1≤y≤6. When the number of oxygen atoms in the first solvent is within the above range, the electrolyte can have good ion conductivity.

[0043] In any embodiment, the first solvent comprises one or more of the following organosiloxane compounds:

[0044] In any embodiment, the first solvent includes one or more of the organosiloxane compounds shown in A-1, A-2, A-5, A-6, A-7, and A-11.

[0045] This can make the battery have higher cycle stability and longer cycle life.

[0046] In any embodiment, the content of the first solvent is 40%-80%, optionally 50%-70%, based on the total weight of the solvent. When the content of the first solvent is within the above range, the first solvent can better play its role in stabilizing the positive electrode and the negative electrode, and also helps to form an electrolyte with suitable ionic conductivity, thereby helping the battery have higher cycle stability and longer cycle life.

[0047] In any embodiment, the content of the first solvent is 100%, based on the total weight of the solvent.

[0048] In any embodiment, the solvent further includes a second solvent and / or a third solvent. Optionally, the solvent further includes both a second solvent and a third solvent.

[0049] In any embodiment, the second solvent includes one or more of an ester and a halogenated ester compound, an ether compound, and a first fluoroether compound. In the molecular structure of the first fluoroether compound, the α-carbon atom directly connected to the oxygen atom on the ether oxygen bond functional group does not have a fluorine atom directly connected to the α-carbon atom, and can be selected from one or more of an ether compound and a first fluoroether compound. The second solvent can promote the dissolution of the electrolyte salt, promote ion transport, and also make the electrolyte have good ionic conductivity. Therefore, by combining the first solvent with the second solvent, the cycle performance of the battery can be further improved.

[0050] In any embodiment, the ester and halogenated ester compounds include one or more of carbonates and halogenated carbonate compounds, carboxylates and halogenated carboxylate compounds, and can be optionally substituted with dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, ethylene carbonate, vinylene 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, 2,2,2-trifluoroacetic acid methyl ester, and 2,2,2-trifluoroethyl acetate. One or more.

[0051] In any embodiment, the ether compound includes one or more of 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, diethoxyethane, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, tetrahydrofuran, tetrahydropyran, 1,3-dioxolane, 1,3-dioxane, and 1,4-dioxane, and can optionally include one or more of dimethoxypropane and diethoxyethane.

[0052] In any embodiment, the first fluoroether compound includes one or more of the following compounds:

[0053] It can be selected to include one or more of B-2 and B-5.

[0054] When the second solvent is within the above range, on the one hand, it can promote the dissolution of the electrolyte salt and promote ion transport, so that the electrolyte has good ionic conductivity. On the other hand, it can also have good stability for the negative electrode and the positive electrode, thereby improving the cycle performance of the battery.

[0055] In any embodiment, the second solvent includes one or more of dimethoxypropane, diethoxyethane, B-2, and B-5. When the second solvent is within the above range, it can further promote the dissolution of the electrolyte salt and ion transport, thereby improving the ionic conductivity of the electrolyte solution. It can also further enhance the stability of the negative electrode and the positive electrode, thereby further improving the cycle performance of the battery.

[0056] In any embodiment, the third solvent includes one or more of an alkane and a halogenated alkane compound, an aromatic hydrocarbon and a halogenated aromatic hydrocarbon compound, and a second fluoroether compound. The second fluoroether compound has at least one fluorine atom directly attached to the α-carbon atom directly attached to the oxygen atom of the ether oxygen bond functional group in its molecular structure, and may optionally include one or more of the second fluoroether compounds. The third solvent is miscible with the first and second solvents, thereby improving the oxidation resistance of the electrolyte and further improving the electrolyte's stability to positive electrodes above 4V.

[0057] In any embodiment, the alkane and halogenated alkane compound include one or more of cyclohexane and decafluoropentane.

[0058] In any embodiment, the aromatic hydrocarbon and halogenated aromatic hydrocarbon compound include one or more of benzene, toluene, p-xylene, m-xylene, o-xylene, fluorobenzene, p-difluorobenzene, m-difluorobenzene, o-difluorobenzene, trifluorotoluene, and trifluoromethoxybenzene.

[0059] In any embodiment, the second fluoroether compound includes 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-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether, ethyl trifluoromethyl ether, difluoromethyl-2,2,3,3,3-pentafluoropropyl ether, heptafluoropropyl-1,2,2,2- One or more of 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, bis(1,1,2,2-tetrafluoroethyl) ether, and optionally one or more of 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether and 1,2-bis(1,1,2,2-tetrafluoroethoxy)ethane.

[0060] When the third solvent is within the above range, it has better compatibility with the first solvent and the second solvent, and can improve the oxidation resistance of the electrolyte and promote the formation of an SEI film rich in inorganic fluorine components, thereby improving the coulombic efficiency and cycle life of the battery.

[0061] In any embodiment, the third solvent includes one or more of 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether and 1,2-bis(1,1,2,2-tetrafluoroethoxy)ethane. When the third solvent is within the above range, the oxidation resistance of the electrolyte can be further improved, and the formation of an SEI film rich in inorganic fluorine components can be promoted, thereby further improving the coulombic efficiency and cycle life of the battery.

[0062] In any embodiment, the content of the second solvent is less than or equal to 40%, and optionally 10%-30%, based on the total weight of the solvent, thereby further improving the cycle performance of the battery.

[0063] In any embodiment, the content of the third solvent is less than or equal to 40%, and optionally 10%-30%, based on the total weight of the solvent. When the content of the third solvent is within the above range, the oxidation resistance of the electrolyte can be improved and the formation of an SEI film rich in inorganic fluorine components can be promoted.

[0064] In any embodiment, the electrolyte further includes an additive, and the additive includes one or more of propane sultone, vinyl sulfate, vinyl sulfite, tris(trimethylsilyl) phosphate, tris(trimethylsilyl) phosphite, tris(trifluoroethyl) phosphate, tris(trifluoroethyl) phosphite, tris(trimethylsilyl) borate, dimethyl maleic anhydride, and 1,4-diisocyanate. The additive can assist film formation and improve the positive electrode interface stability and / or negative electrode interface stability.

[0065] In any embodiment, the content of the additive is less than or equal to 5%, and can be optionally 0.5%-3%, based on the total weight of the electrolyte.

[0066] In any embodiment, the electrolyte includes a first anion, and the first anion includes 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.

[0067] In any embodiment, the first anion includes one or more of a bis(fluorosulfonyl)imide anion and a bis(trifluoromethanesulfonyl)imide anion. The first anion can 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. Furthermore, the first anion has good oxidative stability, enabling the battery to have high cycle stability and a long cycle life at a higher voltage range.

[0068] In any embodiment, the molar concentration of the first anion in the electrolyte is 0.5 mol / L-4 mol / L, optionally 0.8 mol / L-2.4 mol / L, and more optionally 1.2 mol / L-1.8 mol / L. By adjusting the concentration of the first anion within the above range, the ion transport performance of the electrolyte is not affected, and the stability of the electrolyte to the positive and negative electrodes is not affected, thereby helping the battery to have a longer cycle life.

[0069] In any embodiment, the electrolyte includes a first cation, which includes one or more of alkali metal ions and alkaline earth metal 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.

[0070] A second aspect of the present application provides a battery cell, comprising the electrolyte of the first aspect of the present application.

[0071] In any embodiment, 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.

[0072] A third aspect of the present application provides a battery, comprising the battery cell of the second aspect of the present application.

[0073] A fourth aspect of the present application provides an electrical device comprising the battery of the third aspect of the present application.

[0074] 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

[0075] 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.

[0076] FIG1 is a schematic diagram of a battery cell according to an embodiment of the present application.

[0077] FIG2 is an exploded schematic diagram of an embodiment of a battery cell of the present application.

[0078] FIG3 is a schematic diagram of an embodiment of a battery module of the present application.

[0079] FIG4 is a schematic diagram of an embodiment of a battery pack of the present application.

[0080] FIG. 5 is an exploded schematic diagram of the embodiment of the battery pack shown in FIG. 4 .

[0081] FIG6 is a schematic diagram of an embodiment of an electric device including the battery of the present application as a power source.

[0082] 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

[0083] 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.

[0084] " 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, the numerical range "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, it 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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).

[0090] Unless otherwise specified, in this application, the terms "first", "second", "third", etc. are used to distinguish different objects rather than to describe a specific order or a primary-secondary relationship.

[0091] Unless otherwise specified, the terms used in this application have the common meanings that are commonly understood by those skilled in the art.

[0092] 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.

[0093] The term "alkyl" encompasses both straight and branched chain alkyl groups. Examples of 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 alkyl group, i.e., an alkyl group, may contain 1-10 carbon atoms.

[0094] The alkyl portion of the term "alkoxy" encompasses both straight-chain and branched alkyl groups. Examples of alkoxy groups include, but are not limited to, methoxy, ethoxy, propoxy, and the like. In various embodiments, a C1-C10 alkoxy group, i.e., an alkoxy group, may contain 1-10 carbon atoms.

[0095] The term "alkoxyalkyl" refers to a group having an alkyl group at one end as a connecting position and an alkoxy group at the other end. In various embodiments, the C2-C10 alkoxyalkyl group, i.e., the alkoxyalkyl group, may contain 2-10 carbon atoms.

[0096] Throughout this manual, “#” indicates a link location.

[0097] Throughout this specification, substituents of compounds are disclosed in groups or ranges. It is expressly intended that such descriptions include every individual subcombination of members of these groups and ranges. For example, it is expressly intended that the term "C1-C5 alkyl" individually disclose C1, C2, C3, C4, C5, C1-C5, C1-C4, C1-C3, C1-C2, C2-C5, C2-C4, C2-C3, C3-C5, C3-C4, C4-C5 alkyl. As another example, integers ranging from 3 to 10 are expressly intended to individually disclose 3, 4, 5, 6, 7, 8, 9, and 10. Accordingly, other groups or ranges may be expressly intended.

[0098] The battery mentioned in the embodiments of the present application may include one or more battery cells to provide a single physical module with 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.

[0099] 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.

[0100] 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.

[0101] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0102] The battery cells provided by the embodiments of the present application include battery cells using alkali metals, alkaline earth metals, and alloys thereof as negative electrode active materials. For example, the battery cells provided by 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 include 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.

[0103] 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.

[0104] 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).

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] High energy density is an irreversible trend in future battery development. Batteries using alkali metals, alkaline earth metals, 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, ether solvents are currently commonly used as the main solvent in electrolytes. However, ether solvents have weak oxidation resistance and may oxidize and decompose on the positive electrode after repeated charge and discharge cycles, resulting in poor battery cycle performance.

[0111] In order to improve the cycle performance of batteries, the current strategy is mainly to improve the composition of the electrolyte.

[0112] In view of this, the inventors improved the electrolyte.

[0113] The electrolyte provided in the embodiment of the present application includes a solvent, the solvent includes a first solvent, the solvent includes a first solvent, the first solvent includes an organic siloxane compound, and the content of the first solvent is greater than or equal to 20%, based on the total weight of the solvent.

[0114] Currently, when organic siloxane compounds are used in electrolytes, they are used as additives to the electrolytes, and their usage in the electrolytes is usually less than 15%, and further, usually less than 5%.

[0115] The inventors discovered in their research that when an organosiloxane compound is used as the main solvent of the electrolyte (the content is greater than or equal to 20%, based on the total weight of the solvent), the oxidation resistance of the electrolyte can be improved and the oxidative decomposition of the electrolyte can be reduced, thereby improving the cycle stability of the battery and extending the cycle life of the battery.

[0116] The first solvent of the electrolyte provided in the embodiment of the present application includes an organosiloxane compound, which includes at least one Si-O bond in its molecular structure. Compared with the CO bond, the Si-O bond has better oxidation resistance. For example, compared with conventional ether solvents containing CO bonds, such as 1,2-dimethoxyethane (DME), the first solvent can have a lower highest occupied molecular orbital (HOMO) energy level. Therefore, the electrolyte provided in the embodiment of the present application can have improved oxidation resistance, so that the oxidative decomposition of the electrolyte is less, which can enable the battery using the electrolyte to have high cycle stability and long cycle life.

[0117] In some embodiments, the first solvent may include one or more of the organosiloxane compounds represented by formula (I),

[0118] R 1 、R 2 、R 3 、R 4 Each independently includes a hydrogen atom, a C1-C10 alkyl group, a C1-C10 alkoxy group, a C2-C10 alkoxyalkyl group, or a group represented by formula (a), and R 1 、R 2 、R 3 、R 4 At least one of the groups includes a C1-C10 alkoxy group and a group represented by formula (a),

[0119] # indicates the connection position, L 1 、L 2 Each independently represents one of C1-C10 alkylene, C1-C10 alkyleneoxy, and C2-C10 alkyleneoxyalkylene, R 11 、R 12 、R 21 、R 22 、R 23 Each independently includes one of a hydrogen atom, a C1-C10 alkyl group, a C1-C10 alkoxy group, and a C2-C10 alkoxyalkyl group, m and p each independently represent 0 or 1, n and q each independently represent 0 or an integer of 1-5, and n and q are not 0 at the same time.

[0120] The first solvent comprises an organosiloxane compound represented by formula (I). The shielding effect between the silicon atoms and the oxygen atoms' electron clouds is relatively strong, thereby enabling the electrolyte to have a low solvation energy. This can promote the decomposition of anions in the electrolyte into a film, such as the formation of an inorganic fluorine-rich SEI film, improving the battery's cycling performance. Furthermore, it can increase the electrode potential of the negative electrode, reduce the reductive decomposition of the electrolyte, and increase the surface energy of the electrolyte, promoting dense metal deposition, thereby improving the battery's coulombic efficiency and cycling stability.

[0121] The first solvent includes an organosiloxane compound represented by formula (I). After molecular structure design, the first solvent can have good solubility for electrolyte salts and can also have good miscibility with other solvents, thereby helping to improve the oxidation resistance of the electrolyte under high voltage (for example, above 4V) and can also induce dense metal deposition.

[0122] Therefore, when the first solvent includes the organosiloxane compound shown in formula (I), the oxidation resistance of the electrolyte can be improved, the oxidative decomposition of the electrolyte can be reduced, and the negative electrode can be further stabilized, reducing the reductive decomposition of the electrolyte. Thus, the electrolyte provided in the embodiment of the present application can enable the battery to have high cycle stability and long cycle life at a higher voltage range.

[0123] n and q each independently represent an integer of 0 or 1-5. When n represents an integer of 2-5, the groups in the brackets may be the same or different. For example, when n is 2, the group near L 1 -O-Si(R 11 )(R 12 )- is recorded as the first group, close to L 2 -O-Si(R 11 )(R 12 )- is recorded as the second group. R in the first group 11 With R in the second group 11 Can be the same or different; R in the first group 12 With R in the second group 12 When q represents an integer of 2-5, the groups in the brackets can be the same or different. For example, when q is 2, the groups near L 2 -O-Si(R 21 )(R 22 )- is recorded as the first group, close to R 23 -O-Si(R 21 )(R 22 )- is recorded as the second group. R in the first group 21 With R in the second group 21 Can be the same or different; R in the first group 22 With R in the second group 22 It can be the same or different.

[0124] In some embodiments, R 1 、R 2 、R 3 、R 4Each independently includes one of a C1-C5 alkyl group, a C1-C5 alkoxy group, a C2-C5 alkoxyalkyl group, and a group represented by formula (a). This can reduce the steric hindrance of the first solvent, improve the solubility of the first solvent in the electrolyte salt, and improve the miscibility of the first solvent with other solvents, thereby enabling the battery to have high cycle stability and long cycle life.

[0125] In some embodiments, R 1 、R 2 、R 3 、R 4 The two of them independently include one of C1-C10 alkoxy and the group represented by formula (a). 1 、R 2 、R 3 、R 4 The two independently include one of a C1-C5 alkoxy group and a group represented by formula (a). This can reduce the steric hindrance of the first solvent, improve the solubility of the first solvent in the electrolyte salt, and improve the miscibility of the first solvent with other solvents, thereby enabling the battery to have high cycle stability and long cycle life.

[0126] In some embodiments, R 11 、R 12 、R 21 、R 22 、R 23 Each independently includes one of C1-C5 alkyl, C1-C5 alkoxy, and C2-C5 alkoxyalkyl.

[0127] In some embodiments, R 11 、R 12 、R 21 、R 22 Each independently includes one of C1-C10 alkyl and C2-C10 alkenyl, and R 23 Including one of C1-C10 alkyl, C1-C10 alkoxy, C2-C10 alkoxyalkyl. 11 、R 12 、R 21 、R 22 Each independently includes a C1-C5 alkyl group, and R 23 It includes one of C1-C5 alkyl, C1-C5 alkoxy and C2-C5 alkoxyalkyl.

[0128] In some embodiments, m and p are not both 0. For example, m is 0 and p is 1, or m is 1 and p is 0, or both m and p are 1.

[0129] In some embodiments, L 1 、L 2Each independently represents one of a C1-C5 alkylene group, a C1-C5 alkyleneoxy group, and a C2-C5 alkyleneoxyalkylene group.

[0130] The two silicon atoms are connected by a linker group L 1 、L 2 When connected, it can alleviate the shielding effect of silicon atoms on the lone pair electrons of oxygen atoms to a certain extent, and also help the connecting group L 1 、L 2 The oxygen atoms at both ends chelate with cations in the electrolyte to form a solvation structure, thereby making the first solvent more soluble in the electrolyte salt and more miscible with other solvents. As a result, the electrolyte can have suitable ionic conductivity, thereby improving the cycle performance of the battery.

[0131] In some embodiments, L 1 、L 2 Each independently represents a C2-C3 alkyleneoxy group. 1 、L 2 Within this range, the first solvent facilitates chelation with cations in the electrolyte to form a solvation structure, thereby improving the solubility of the first solvent for the electrolyte salt and further improving the miscibility of the first solvent with other solvents. As a result, the electrolyte can have suitable ionic conductivity, further improving the cycle performance of the battery.

[0132] In some embodiments, n and q each independently represent 0, 1 or 2, and n and q are not 0 at the same time.

[0133] In some embodiments, m, n, and p are all 0, and q is an integer from 1 to 5.

[0134] In some embodiments, m, n, and p are all 0, q is 1 or 2, and R 21 、R 22 、R 23 Each independently includes one of C1-C10 alkyl, C1-C10 alkoxy, and C2-C10 alkoxyalkyl. Optionally, m, n, and p are all 0, q is 1 or 2, and R 21 、R 22 、R 23 Each independently includes one of C1-C5 alkyl, C1-C5 alkoxy, and C2-C5 alkoxyalkyl. More preferably, m, n, and p are all 0, q is 1 or 2, and R 21 、R 22 Each independently includes C1-C5 alkyl, R 23 It includes one of C1-C5 alkyl, C1-C5 alkoxy and C2-C5 alkoxyalkyl.

[0135] When the group represented by formula (a) is within the above range, the first solvent can have better solubility for the electrolyte salt and better miscibility with other solvents. As a result, the electrolyte can have suitable ionic conductivity, which helps improve the cycle performance of the battery.

[0136] In some embodiments, m and n are both 0, p is 1, and q is an integer from 1 to 5.

[0137] In some embodiments, m and n are both 0, p is 1, q is 1 or 2, and L 2 represents one of C1-C10 alkylene, C1-C10 alkyleneoxy, and C2-C10 alkyleneoxyalkylene, R 21 、R 22 、R 23 Each independently includes one of C1-C10 alkyl, C1-C10 alkoxy, and C2-C10 alkoxyalkyl. Optionally, m and n are both 0, p is 1, q is 1 or 2, and L 2 represents one of C1-C5 alkylene, C1-C5 alkyleneoxy, and C2-C5 alkyleneoxyalkylene, R 21 、R 22 、R 23 Each independently includes one of C1-C5 alkyl, C1-C5 alkoxy, and C2-C5 alkoxyalkyl. More preferably, m and n are both 0, p is 1, q is 1 or 2, and L 2 represents one of C1-C5 alkylene, C1-C5 alkyleneoxy, and C2-C5 alkyleneoxyalkylene, R 21 、R 22 Each independently includes C1-C5 alkyl, R 23 Including one of C1-C5 alkyl, C1-C5 alkoxy, C2-C5 alkoxyalkyl. Further optionally, m, n are both 0, p is 1, q is 1 or 2, L 2 represents C2-C3 alkyleneoxy, R 21 、R 22 Each independently includes C1-C5 alkyl, R 23 It includes one of C1-C5 alkyl, C1-C5 alkoxy and C2-C5 alkoxyalkyl.

[0138] When the group represented by formula (a) is within the above range, the first solvent can have better solubility for the electrolyte salt and better miscibility with other solvents. As a result, the electrolyte can have suitable ionic conductivity, which helps improve the cycle performance of the battery.

[0139] In some embodiments, m is 0, n is an integer from 1 to 5, p is 1, and q is an integer from 1 to 5.

[0140] In some embodiments, m is 0, n is 1 or 2, p is 1, q is 1 or 2, and L 2 represents one of C1-C10 alkylene, C1-C10 alkyleneoxy, and C2-C10 alkyleneoxyalkylene, R 11 、R 12 、R 21 、R 22 、R 23 Each independently includes one of C1-C10 alkyl, C1-C10 alkoxy, and C2-C10 alkoxyalkyl. Optionally, m is 0, n is 1 or 2, p is 1, q is 1 or 2, L 2 represents one of C1-C5 alkylene, C1-C5 alkyleneoxy, and C2-C5 alkyleneoxyalkylene, R 11 、R 12 、R 21 、R 22 、R 23 Each independently includes one of C1-C5 alkyl, C1-C5 alkoxy, and C2-C5 alkoxyalkyl. More preferably, m is 0, n is 1 or 2, p is 1, q is 1 or 2, L 2 represents one of C1-C5 alkylene, C1-C5 alkyleneoxy, and C2-C5 alkyleneoxyalkylene, R 11 、R 12 、R 21 、R 22 Each independently includes C1-C5 alkyl, R 23 Including one of C1-C5 alkyl, C1-C5 alkoxy, C2-C5 alkoxyalkyl. Further optionally, m is 0, n is 1 or 2, p is 1, q is 1 or 2, L 2 represents C2-C3 alkyleneoxy, R 11 、R 12 、R 21 、R 22 Each independently includes C1-C5 alkyl, R 23 It includes one of C1-C5 alkyl, C1-C5 alkoxy and C2-C5 alkoxyalkyl.

[0141] In some embodiments, m is 1, n is an integer from 1 to 5, p is 1, and q is an integer from 1 to 5.

[0142] In some embodiments, m is 1, n is 1 or 2, p is 1, q is 1 or 2, and L 1 、L 2 Each independently represents one of C1-C10 alkylene, C1-C10 alkyleneoxy, and C2-C10 alkyleneoxyalkylene, R 11 、R 12 、R21 、R 22 、R 23 Each independently includes one of C1-C10 alkyl, C1-C10 alkoxy, and C2-C10 alkoxyalkyl. Optionally, m is 1, n is 1 or 2, p is 1, q is 1 or 2, L 1 、L 2 Each independently represents one of C1-C5 alkylene, C1-C5 alkyleneoxy, and C2-C5 alkyleneoxyalkylene, and R 11 、R 12 、R 21 、R 22 、R 23 Each independently includes one of C1-C5 alkyl, C1-C5 alkoxy, and C2-C5 alkoxyalkyl. More preferably, m is 1, n is 1 or 2, p is 1, q is 1 or 2, and L 1 、L 2 Each independently represents one of C1-C5 alkylene, C1-C5 alkyleneoxy, and C2-C5 alkyleneoxyalkylene, and R 11 、R 12 、R 21 、R 22 Each independently includes C1-C5 alkyl, R 23 Including one of C1-C5 alkyl, C1-C5 alkoxy, C2-C5 alkoxyalkyl. Further optionally, m is 1, n is 1 or 2, p is 1, q is 1 or 2, L 1 、L 2 Each independently represents a C2-C3 alkyleneoxy group, R 11 、R 12 、R 21 、R 22 Each independently includes C1-C5 alkyl, R 23 It includes one of C1-C5 alkyl, C1-C5 alkoxy and C2-C5 alkoxyalkyl.

[0143] When the group represented by formula (a) is within the above range, the first solvent can have better solubility for the electrolyte salt and better miscibility with other solvents. As a result, the electrolyte can have suitable ionic conductivity, which helps improve the cycle performance of the battery.

[0144] In some embodiments, the number of silicon atoms in the first solvent is denoted as x, and the number of oxygen atoms in the first solvent is denoted as y, then 0.5≤y / x≤4, optionally, 1≤y / x≤2.

[0145] After in-depth research, the inventors discovered that further adjusting the ratio of the number of oxygen atoms to the number of silicon atoms in the molecular structure of the organosiloxane compound can improve the solubility of the first solvent for the electrolyte salt and also improve the miscibility of the first solvent with other solvents. When the ratio y / x of the number of oxygen atoms to the number of silicon atoms is small, the silicon atoms reduce the polarity of the first solvent molecules and shield the electron clouds of the oxygen atoms, thereby weakening the ability of the oxygen atoms to coordinate with ions, reducing the solubility of the first solvent for the electrolyte salt, reducing the ionic conductivity of the prepared electrolyte, and affecting the cycle performance of the battery. When the ratio y / x of the number of oxygen atoms to the number of silicon atoms is large, the steric hindrance of the first solvent is increased, and the electron clouds of multiple oxygen atoms will repel each other, thereby reducing the solubility of the first solvent for the electrolyte salt and the miscibility of the first solvent with other solvents.

[0146] In some embodiments, the number of silicon atoms in the first solvent is denoted as x, then 1≤x≤10, optionally, 1≤x≤5, more optionally, 1≤x≤3.

[0147] After in-depth research, the inventors found that when the number of silicon atoms in the first solvent is within the above range, the electrolyte can have better ion conductivity.

[0148] In some embodiments, the number of oxygen atoms in the first solvent is denoted as y, then 1≤y≤20, optionally, 1≤y≤10, more optionally, 1≤y≤6.

[0149] After in-depth research, the inventors found that when the number of oxygen atoms in the first solvent is within the above range, the electrolyte can have better ion conductivity.

[0150] In some embodiments, 0.5≤y / x≤4, 1≤x≤10, and 1≤y≤20. Alternatively, 1≤y / x≤2, 1≤x≤5, and 1≤y≤10. More preferably, 1≤y / x≤2, 1≤x≤3, and 1≤y≤6. Thus, the first solvent can have better solubility for the electrolyte salt and better miscibility with other solvents, thereby facilitating the formation of an electrolyte solution with suitable ionic conductivity, thereby improving the cycle performance of the battery.

[0151] In some embodiments, the first solvent may include one or more of the organosiloxane compounds shown below:

[0152] In some embodiments, the first solvent may include one or more of the organosiloxane compounds shown in A-1, A-2, A-5, A-6, A-7, and A-11, thereby enabling the battery to have higher cycle stability and longer cycle life.

[0153] In some embodiments, the first solvent may include one or more of the organosiloxane compounds shown in A-6 and A-7, thereby enabling the battery to have higher cycle stability and longer cycle life.

[0154] In some embodiments, the content of the first solvent may be 100%, based on the total weight of the solvent.

[0155] In some embodiments, the content of the first solvent may be 20%-90%, optionally 30%-85%, 40%-80%, or 50%-70%, based on the total weight of the solvent. When the content of the first solvent is within the above range, the first solvent can better play its role in stabilizing the positive electrode and the negative electrode, and also helps form an electrolyte with suitable ionic conductivity, thereby helping the battery have higher cycle stability and longer cycle life.

[0156] In some embodiments, the solvent may further include a second solvent.

[0157] In some embodiments, the second solvent may include one or more of esters and halogenated ester compounds, ether compounds, and first fluoroether compounds, and the first fluoroether compound has no fluorine atom directly connected to the α-carbon atom directly connected to the oxygen atom on the ether oxygen bond functional group in the molecular structure.

[0158] The silicon atoms in the molecular structure of the first solvent have a certain shielding effect on the lone pairs of electrons of oxygen atoms, thereby weakening the first solvent's solubility in the electrolyte salt, resulting in insufficient ionic conductivity of the electrolyte. The second solvent can promote the dissolution of the electrolyte salt, promote ion transport, and also provide the electrolyte with good ionic conductivity. Therefore, the combination of the first and second solvents can further improve the cycle performance of the battery.

[0159] In some embodiments, the ester and halogenated ester compounds may include one or more of carbonate and halogenated carbonate compounds, carboxylate and halogenated carboxylate compounds.

[0160] In some embodiments, esters and halogenated ester compounds may include one or more of dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene carbonate, vinylene 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, and ethyl 2,2,2-trifluoroacetate.

[0161] In some embodiments, the ether compound may include 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, diethoxyethane, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, tetrahydrofuran, tetrahydropyran, 1,3-dioxolane, 1,3-dioxane, 1,4-dioxane. Alternatively, the ether compound may include one or more of dimethoxypropane and diethoxyethane.

[0162] In some embodiments, the first fluoroether compound may include one or more of the following compounds:

[0163] Optionally, the first fluoroether compound may include one or more of B-2 and B-5.

[0164] When the second solvent is within the above range, on the one hand, it can promote the dissolution of the electrolyte salt and promote ion transport, so that the electrolyte has good ionic conductivity. On the other hand, it can also have good stability for the negative electrode and the positive electrode, thereby improving the cycle performance of the battery.

[0165] In some embodiments, the second solvent may include one or more of an ether compound and a first fluoroether compound.

[0166] In some embodiments, the second solvent may include one or more of dimethoxypropane, diethoxyethane, B-2, and B-5.

[0167] When the second solvent is within the above range, on the one hand, it can further promote the dissolution of the electrolyte salt and promote ion transport, so that the electrolyte has good ionic conductivity. On the other hand, it can further improve the stability of the negative electrode and the positive electrode, thereby further improving the cycle performance of the battery.

[0168] In some embodiments, the content of the second solvent may be less than or equal to 40%, and optionally 10%-30%, based on the total weight of the solvent, thereby further improving the cycle performance of the battery.

[0169] In some embodiments, the solvent may further include a third solvent.

[0170] In some embodiments, the third solvent may include one or more of alkanes and halogenated alkane compounds, aromatic hydrocarbons and halogenated aromatic hydrocarbon compounds, and a second fluoroether compound, wherein the second fluoroether compound has at least one fluorine atom directly connected to the α-carbon atom directly connected to the oxygen atom on the ether oxygen bond functional group in its molecular structure.

[0171] The third solvent is miscible with the first solvent and the second solvent, thereby improving the oxidation resistance of the electrolyte and further improving the stability of the electrolyte to positive electrodes above 4V.

[0172] In some embodiments, the third solvent may include one or more of a halogenated alkane compound, a halogenated aromatic hydrocarbon compound, and a second fluorinated ether compound. When the third solvent contains fluorine atoms, it helps to decompose and form an SEI film rich in inorganic fluorine components at the negative electrode, further promoting dense metal deposition and further improving the coulombic efficiency and cycle life of the battery. Therefore, when the third solvent contains fluorine atoms, the reversibility of the positive and negative electrodes can be further improved, thereby improving the coulombic efficiency and cycle life of the battery.

[0173] In some embodiments, the alkane and halogenated alkane compound may include one or more of cyclohexane and decafluoropentane.

[0174] In some embodiments, the aromatic hydrocarbon and halogenated aromatic hydrocarbon compound may include one or more of benzene, toluene, p-xylene, m-xylene, o-xylene, fluorobenzene, p-difluorobenzene, m-difluorobenzene, o-difluorobenzene, trifluorotoluene, and trifluoromethoxybenzene.

[0175] In some embodiments, the second fluoroether compound may include 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-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether, ethyl trifluoromethyl ether, difluoromethyl-2,2,3,3,3-pentafluoropropyl ether, heptafluoropropyl-1,2,2,2- One or more of 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, bis(1,1,2,2-tetrafluoroethyl) ether, and optionally one or more of 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether and 1,2-bis(1,1,2,2-tetrafluoroethoxy)ethane.

[0176] When the third solvent is within the above range, it has better compatibility with the first solvent and the second solvent, and can improve the oxidation resistance of the electrolyte and promote the formation of an SEI film rich in inorganic fluorine components, thereby improving the coulombic efficiency and cycle life of the battery.

[0177] In some embodiments, the third solvent may include one or more of a halogenated alkane compound, a halogenated aromatic hydrocarbon compound, and a second fluoroether compound.

[0178] In some embodiments, the third solvent can include one or more of the second fluoroether compounds.

[0179] In some embodiments, the third solvent may include one or more of 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether and 1,2-bis(1,1,2,2-tetrafluoroethoxy)ethane.

[0180] When the third solvent is within the above range, the oxidation resistance of the electrolyte can be further improved, and the formation of a SEI film rich in inorganic fluorine components can be promoted, thereby further improving the coulombic efficiency and cycle life of the battery.

[0181] In some embodiments, the content of the third solvent may be less than or equal to 40%, and may be 10%-30%, based on the total weight of the solvent. When the content of the third solvent is within the above range, the oxidation resistance of the electrolyte can be improved and the formation of an SEI film rich in inorganic fluorine components can be promoted. In addition, since the third solvent has a poor solubility for the electrolyte, when the content of the third solvent is within the above range, its negative impact on the solubility of the electrolyte salt and ion transport can also be reduced.

[0182] In some embodiments, the solvent may also include a second solvent and a third solvent. This can promote the dissolution of the electrolyte salt, promote ion transport, and provide the electrolyte with good ionic conductivity. It can also further enhance the oxidation resistance of the electrolyte and promote the formation of an SEI film rich in inorganic fluorine components, thereby improving the battery's cycle performance.

[0183] 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.

[0184] Additives can assist film formation and improve the positive electrode interface stability and / or negative electrode interface stability.

[0185] In some embodiments, the content of the additive may be less than or equal to 5%, and may be 0.5%-3%, based on the total weight of the electrolyte. When the content of the additive is within the above range, it helps to improve the cycle performance of the battery.

[0186] In some embodiments, the electrolyte includes a first anion, which 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 - )

[0187] In some embodiments, the first anion may include a bis(fluorosulfonyl)imide anion (FSI - ), bis(trifluoromethanesulfonyl)imide anion (TFSI - ), difluorooxalatoborate anion (DFOB - ), tetrafluorooxalophosphate anion (TFOP - ) in one or more. Alternatively, the first anion may include a bis(fluorosulfonyl)imide anion (FSI - ), bis(trifluoromethanesulfonyl)imide anion (TFSI - ). The first anion can decompose on the surface of the negative electrode to form an SEI film rich in inorganic fluorine components, promoting dense metal deposition, thereby helping the battery to have a longer cycle life. At the same time, the first anion also has good oxidative stability, which can enable the battery to have high cycle stability and long cycle life at a higher voltage range.

[0188] In some embodiments, the molar concentration of the first anion in the electrolyte can be 0.5 mol / L-4 mol / L, optionally 0.8 mol / L-2.4 mol / L, and more optionally 1.2 mol / L-1.8 mol / L. By adjusting the concentration of the first anion within the above range, it will not affect the ion transport performance of the electrolyte, nor will it affect the stability of the electrolyte to the positive and negative electrodes, thereby helping the battery have a longer cycle life.

[0189] In some embodiments, the electrolyte includes a first cation, which may include one or more of alkali metal ions and alkaline earth metal 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.

[0190] In some embodiments, the electrolyte includes a solvent, the solvent includes a first solvent, the first solvent includes one or more of the organosiloxane compounds represented by formula (I), and the content of the first solvent is greater than or equal to 20%, based on the total weight of the solvent.

[0191] R 1 、R 2 、R 3 、R 4 Each independently includes a hydrogen atom, a C1-C10 alkyl group, a C1-C10 alkoxy group, a C2-C10 alkoxyalkyl group, or a group represented by formula (a), and R 1 、R 2 、R 3 、R 4 At least one of them includes a C1-C10 alkoxy group and a group represented by formula (a).

[0192] # indicates the connection position, L 1 、L 2 Each independently represents one of C1-C10 alkylene, C1-C10 alkyleneoxy, and C2-C10 alkyleneoxyalkylene, R 11 、R 12 、R 21 、R 22 、R 23Each independently includes one of a hydrogen atom, a C1-C10 alkyl group, a C1-C10 alkoxy group, and a C2-C10 alkoxyalkyl group, m and p each independently represent 0 or 1, n and q each independently represent an integer of 0 or 1-5, and n and q are not 0 at the same time. In the organosiloxane compound represented by formula (I), the number of silicon atoms in the first solvent is recorded as x, the number of oxygen atoms in the first solvent is recorded as y, 0.5≤y / x≤4, 1≤x≤10, and 1≤y≤20, optionally, 1≤y / x≤2, 1≤x≤5, and 1≤y≤10, more optionally, 1≤y / x≤2, 1≤x≤3, and 1≤y≤6. This can make the battery have better cycle performance.

[0193] In some embodiments, the electrolyte includes a solvent, and the solvent includes a first solvent, a second solvent, and a third solvent.

[0194] The first solvent includes one or more of the organosiloxane compounds represented by formula (I), and the content of the first solvent is greater than or equal to 20%, based on the total weight of the solvent.

[0195] R 1 、R 2 、R 3 、R 4 Each independently includes a hydrogen atom, a C1-C10 alkyl group, a C1-C10 alkoxy group, a C2-C10 alkoxyalkyl group, or a group represented by formula (a), and R 1 、R 2 、R 3 、R 4 At least one of them includes a C1-C10 alkoxy group and a group represented by formula (a).

[0196] # indicates the connection position, L 1 、L 2 Each independently represents one of C1-C10 alkylene, C1-C10 alkyleneoxy, and C2-C10 alkyleneoxyalkylene, R 11 、R 12 、R 21 、R 22 、R 23Each independently includes one of a hydrogen atom, a C1-C10 alkyl group, a C1-C10 alkoxy group, and a C2-C10 alkoxyalkyl group, m and p each independently represent 0 or 1, n and q each independently represent 0 or an integer of 1-5, and n and q are not 0 at the same time; and in the organosiloxane compound represented by formula (I), the number of silicon atoms in the first solvent is recorded as x, the number of oxygen atoms in the first solvent is recorded as y, 0.5≤y / x≤4, 1≤x≤10, and 1≤y≤20, optionally, 1≤y / x≤2, 1≤x≤5, and 1≤y≤10, more optionally, 1≤y / x≤2, 1≤x≤3, and 1≤y≤6.

[0197] The second solvent includes one or more of an ester, a halogenated ester compound, an ether compound, and the first fluoroether compound, wherein the first fluoroether compound has no fluorine atoms directly attached to the α-carbon atom directly attached to the oxygen atom of the ether oxygen bond functional group in the molecular structure. Alternatively, the second solvent includes one or more of an ether compound and the first fluoroether compound. The content of the second solvent is less than or equal to 40%, and optionally 10% to 30%, based on the total weight of the solvent.

[0198] The third solvent includes one or more of an alkane and a halogenated alkane compound, an aromatic hydrocarbon and a halogenated aromatic hydrocarbon compound, and a second fluoroether compound, wherein the second fluoroether compound has at least one fluorine atom directly bonded to the α-carbon atom directly bonded to the oxygen atom of the ether oxygen bond functional group in its molecular structure. Optionally, the third solvent includes one or more of the second fluoroether compounds. The content of the third solvent is less than or equal to 40%, and optionally 10% to 30%, based on the total weight of the solvent.

[0199] This can make the battery have better cycle performance.

[0200] [Preparation method]

[0201] Methods for preparing the electrolyte are well known. For example, the electrolyte salt (composed of the first anion and the first cation described above), a solvent, and any optional additives can be uniformly mixed to obtain the 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.

[0202] 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.

[0203] A battery cell includes a positive electrode sheet and a negative electrode sheet.

[0204] 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.

[0205] [Positive electrode]

[0206] 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.

[0207] 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.

[0208] 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 fOne 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.

[0209] 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 0.2 O2 (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.

[0210] 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 / 3O2, 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.

[0211] 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.

[0212] 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.

[0213] 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.

[0214] 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.

[0215] 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).

[0216] 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).

[0217] [Negative electrode]

[0218] In some embodiments, the negative electrode sheet 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 and alkaline earth metal elements.

[0219] 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, and magnesium alloy.

[0220] 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.

[0221] 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.

[0222] 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.

[0223] 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.

[0224] 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.

[0225] 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).

[0226] 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.

[0227] [Isolation film]

[0228] The battery cell may also include a separator. This separator can be placed 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 may be used.

[0229] 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.

[0230] 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 electrolyte, and then vacuum packaged, allowed to stand, formed, and shaped to obtain a battery cell. Multiple battery cells can also be further connected in series, in parallel, or mixed to form a battery module. Multiple battery modules can also be connected in series, in parallel, or mixed to form a battery pack. In some embodiments, multiple battery cells can also directly form a battery pack.

[0231] Electrical devices

[0232] 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.

[0233] The electrical device can select battery cells, battery modules or battery packs according to its usage requirements.

[0234] 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.

[0235] 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.

[0236] Example

[0237] 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.

[0238] Example 1

[0239] (1) Preparation of electrolyte

[0240] The first solvent A-6, the second solvent B-5, and the third solvent C-1 were thoroughly mixed in a weight ratio of 60:20:20 to form a solvent. 1.4025 g of lithium bis(fluorosulfonyl)imide was added to 5 ml of the solvent and stirred thoroughly to form a colorless, transparent electrolyte solution with a concentration of 1.5 mol / L.

[0241] (2) Preparation of positive electrode sheet

[0242] 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. It was then cut into 40mm×50mm rectangles as positive electrode sheets for later use. The coating amount was 25mg / cm 2 .

[0243] (3) Preparation of negative electrode sheet

[0244] 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.

[0245] (4) Preparation of isolation membrane

[0246] The polyethylene porous film was cut into a rectangle of 45 mm × 55 mm and used as a separator for later use.

[0247] (5) Preparation of batteries

[0248] 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.

[0249] Cycle life test

[0250] At 25°C, the prepared battery was charged at a constant current of 0.2C (28mA) to 4.5V. 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 was allowed to rest for 5 minutes, it was discharged at a constant current of 1C (140mA) to 2.8V. This constituted a cycle of charge and discharge. 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.

[0251] Example 2-45

[0252] The preparation and testing methods of the battery are similar to those of Example 1, except that the composition of the electrolyte is different, as shown in Table 1 for details.

[0253] C-1 indicates C-2 indicates

[0254] The content of the first solvent, the second solvent and the third solvent is based on the total weight of the solvents.

[0255] PS stands for propane sultone, DTD stands for vinyl sulfate, and TMSP stands for tris(trimethylsilyl)phosphate.

[0256] The content of the additive is based on the total weight of the electrolyte.

[0257] Comparative Example 1

[0258] The preparation and testing methods of the battery are similar to those of Example 1, except that the composition of the electrolyte is different.

[0259] The first solvent B-5 and the second solvent C-1 were mixed thoroughly at a weight ratio of 50:50 to form a solvent. 1.4025 g of lithium bis(fluorosulfonyl)imide was added to 5 ml of the solvent and stirred thoroughly to form a colorless, transparent electrolyte solution with a concentration of 1.5 mol / L.

[0260] Comparative Example 2

[0261] The preparation and testing methods of the battery are similar to those of Example 1, except that the composition of the electrolyte is different.

[0262] The first solvent A-6, the second solvent B-5, and the third solvent C-1 were thoroughly mixed in a weight ratio of 2:49:49 to form a solvent. 1.4025 g of lithium bis(fluorosulfonyl)imide was added to 5 ml of the solvent and stirred thoroughly to form a colorless, transparent electrolyte solution with a concentration of 1.5 mol / L.

[0263] Comparative Example 3

[0264] Take 1.4025g of lithium bis(fluorosulfonyl)imide salt, add it to 5ml of 1,2-dimethoxyethane, and stir thoroughly to form a colorless and transparent electrolyte with a concentration of 1.5mol / L.

[0265] Comparative Example 4

[0266] Ethylene carbonate and ethyl methyl carbonate were thoroughly mixed in a weight ratio of 30:70 to form a solvent. 0.76 g of lithium hexafluorophosphate was added to 5 ml of the solvent and stirred thoroughly to form a colorless, transparent electrolyte solution with a concentration of 1.0 mol / L.

[0267] Table 1

[0268] Based on the test results of Examples 1-45 and Comparative Examples 1-4, it can be seen that using the first solvent as the main solvent can improve the cycle performance of the battery.

[0269] Based on the test results of Examples 1-4, it can be seen that by adjusting the weight content of the first solvent, the second solvent, and the third solvent, the effect of each component can be better exerted and the cycle performance of the battery can be further improved.

[0270] Based on the test results of Examples 1, 5-7, it can be seen that when the solvent includes the first solvent, the second solvent, and the third solvent at the same time, the cycle performance of the battery can be further improved.

[0271] Based on the test results of Examples 1 and 8-13, it can be seen that the cycle performance of the battery can be further improved by adjusting the concentration of the electrolyte.

[0272] Based on the test results of Examples 1 and 14-24, it can be seen that when the first solvent includes A-1, A-2, A-5, A-6, A-7, and A-11, the cycle performance of the battery can be further improved.

[0273] Based on the test results of Examples 1 and 25-31, it can be seen that when the second solvent includes dimethylpropane, diethylethane, B-2, and B-5, the cycle performance of the battery can be further improved.

[0274] Based on the test results of Examples 1 and 32-34, it can be seen that when the third solvent includes C-1 and C-2, the cycle performance of the battery can be further improved.

[0275] Based on the test results of Examples 1, 35-36, it can be seen that when the electrolyte salt includes lithium bis(fluorosulfonyl)imide (LiFSI), the cycle performance of the battery can be further improved.

[0276] Based on the test results of Examples 1 and 37-45, it can be seen that further including a small amount of film-forming additives in the electrolyte helps to improve the cycle performance of the battery.

[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 solvent, wherein the solvent comprises a first solvent, the first solvent comprises an organic siloxane compound, and the content of the first solvent is greater than or equal to 20%, based on the total weight of the solvent.

2. The electrolyte according to claim 1, wherein The first solvent comprises one or more of the organosiloxane compounds represented by formula (I), R 1 , R 2 , R 3 , R 4 Each independently includes a hydrogen atom, a C1-C10 alkyl group, a C1-C10 alkoxy group, a C2-C10 alkoxyalkyl group, or a group represented by formula (a), and R 1 , R 2 , R 3 , R 4 At least one of the groups includes C1-C10 alkoxy, one of the groups represented by formula (a), # indicates the connection position, L 1 , L 2 Each independently represents one of C1-C10 alkylene, C1-C10 alkyleneoxy, and C2-C10 alkyleneoxyalkylene, R 11 , R 12 , R 21 , R 22 , R 23 Each independently includes a hydrogen atom, a C1-C10 alkyl group, a C1-C10 alkoxy group, and a C2-C10 alkoxyalkyl group; m and p each independently represent 0 or 1; n and q each independently represent 0 or an integer of 1-5, and n and q are not 0 at the same time.

3. The electrolyte according to claim 2, wherein The first solvent satisfies at least one of the following conditions (1) to (13): (1)R 1 , R 2 , R 3 , R 4 Each independently includes one of a C1-C5 alkyl group, a C1-C5 alkoxy group, a C2-C5 alkoxyalkyl group, and a group represented by formula (a); (2)R 1 , R 2 , R 3 , R 4 The two of them independently include one of a C1-C10 alkoxy group and a group represented by formula (a); (3)R 1 , R 2 , R 3 , R 4 The two of them independently include one of a C1-C5 alkoxy group and a group represented by formula (a); (4)L 1 , L 2 Each independently represents one of C1-C5 alkylene, C1-C5 alkyleneoxy, and C2-C5 alkyleneoxyalkylene; (5)L 1 , L 2 Each independently represents a C2-C3 alkyleneoxy group; (6)R 11 , R 12 , R 21 , R 22 , R 23 Each independently includes one of C1-C5 alkyl, C1-C5 alkoxy, and C2-C5 alkoxyalkyl; (7)R 11 , R 12 , R 21 , R 22 Each independently includes a C1-C5 alkyl group, and R 23 Including one of C1-C5 alkyl, C1-C5 alkoxy, C2-C5 alkoxyalkyl; (8) m and p are not 0 at the same time; (9) n and q each independently represent 0, 1 or 2, and n and q are not 0 at the same time; (10) m, n, and p are all 0, and q is an integer from 1 to 5; (11) m and n are both 0, p is 1, and q is an integer from 1 to 5; (12) m is 0, n is an integer from 1 to 5, p is 1, and q is an integer from 1 to 5; (13) m is 1, n is an integer of 1-5, p is 1, and q is an integer of 1-5.

4. The electrolyte according to claim 2 or 3, wherein The group represented by formula (a) satisfies at least one of the following conditions (1) to (15): (1) m, n, and p are all 0, q is 1 or 2, R 21 , R 22 , R 23 Each independently includes one of C1-C10 alkyl, C1-C10 alkoxy, and C2-C10 alkoxyalkyl; (2) m, n, and p are all 0, q is 1 or 2, R 21 , R 22 , R 23 Each independently includes one of C1-C5 alkyl, C1-C5 alkoxy, and C2-C5 alkoxyalkyl; (3) m, n, and p are all 0, q is 1 or 2, R 21 , R 22 Each independently includes C1-C5 alkyl, R 23 Including one of C1-C5 alkyl, C1-C5 alkoxy, C2-C5 alkoxyalkyl; (4) m and n are both 0, p is 1, q is 1 or 2, L 2 represents one of C1-C10 alkylene, C1-C10 alkyleneoxy, and C2-C10 alkyleneoxyalkylene, R 21 , R 22 , R 23 Each independently includes one of C1-C10 alkyl, C1-C10 alkoxy, and C2-C10 alkoxyalkyl; (5) m and n are both 0, p is 1, q is 1 or 2, L 2 represents one of C1-C5 alkylene, C1-C5 alkyleneoxy, and C2-C5 alkyleneoxyalkylene, R 21 , R 22 , R 23 Each independently includes one of C1-C5 alkyl, C1-C5 alkoxy, and C2-C5 alkoxyalkyl; (6) m and n are both 0, p is 1, q is 1 or 2, L 2 represents one of C1-C5 alkylene, C1-C5 alkyleneoxy, and C2-C5 alkyleneoxyalkylene, R 21 , R 22 Each independently includes C1-C5 alkyl, R 23 Including one of C1-C5 alkyl, C1-C5 alkoxy, C2-C5 alkoxyalkyl; (7) m and n are both 0, p is 1, q is 1 or 2, L 2 represents C2-C3 alkyleneoxy, R 21 , R 22 Each independently includes C1-C5 alkyl, R 23 Including one of C1-C5 alkyl, C1-C5 alkoxy, C2-C5 alkoxyalkyl; (8) m is 0, n is 1 or 2, p is 1, q is 1 or 2, L 2 represents one of C1-C10 alkylene, C1-C10 alkyleneoxy, and C2-C10 alkyleneoxyalkylene, R 11 , R 12 , R 21 , R 22 , R 23 Each independently includes one of C1-C10 alkyl, C1-C10 alkoxy, and C2-C10 alkoxyalkyl; (9) m is 0, n is 1 or 2, p is 1, q is 1 or 2, L 2 represents one of C1-C5 alkylene, C1-C5 alkyleneoxy, and C2-C5 alkyleneoxyalkylene, R 11 , R 12 , R 21 , R 22 , R 23 Each independently includes one of C1-C5 alkyl, C1-C5 alkoxy, and C2-C5 alkoxyalkyl; (10) m is 0, n is 1 or 2, p is 1, q is 1 or 2, L 2 represents one of C1-C5 alkylene, C1-C5 alkyleneoxy, and C2-C5 alkyleneoxyalkylene, R 11 , R 12 , R 21 , R 22 Each independently includes C1-C5 alkyl, R 23 Including one of C1-C5 alkyl, C1-C5 alkoxy, C2-C5 alkoxyalkyl; (11) m is 0, n is 1 or 2, p is 1, q is 1 or 2, L 2 represents C2-C3 alkyleneoxy, R 11 , R 12 , R 21 , R 22 Each independently includes C1-C5 alkyl, R 23 Including one of C1-C5 alkyl, C1-C5 alkoxy, C2-C5 alkoxyalkyl; (12) m is 1, n is 1 or 2, p is 1, q is 1 or 2, L 1 , L 2 Each independently represents one of C1-C10 alkylene, C1-C10 alkyleneoxy, and C2-C10 alkyleneoxyalkylene, R 11 , R 12 , R 21 , R 22 , R 23 Each independently includes one of C1-C10 alkyl, C1-C10 alkoxy, and C2-C10 alkoxyalkyl; (13) m is 1, n is 1 or 2, p is 1, q is 1 or 2, L 1 , L 2 Each independently represents one of C1-C5 alkylene, C1-C5 alkyleneoxy, and C2-C5 alkyleneoxyalkylene, and R 11 , R 12 , R 21 , R 22 , R 23 Each independently includes one of C1-C5 alkyl, C1-C5 alkoxy, and C2-C5 alkoxyalkyl; (14) m is 1, n is 1 or 2, p is 1, q is 1 or 2, L 1 , L 2 Each independently represents one of C1-C5 alkylene, C1-C5 alkyleneoxy, and C2-C5 alkyleneoxyalkylene, and R 11 , R 12 , R 21 , R 22 Each independently includes C1-C5 alkyl, R 23 Including one of C1-C5 alkyl, C1-C5 alkoxy, C2-C5 alkoxyalkyl; (15) m is 1, n is 1 or 2, p is 1, q is 1 or 2, L 1 , L 2 Each independently represents a C2-C3 alkyleneoxy group, R 11 , R 12 , R 21 , R 22 Each independently includes C1-C5 alkyl, R 23 It includes one of C1-C5 alkyl, C1-C5 alkoxy and C2-C5 alkoxyalkyl.

5. The electrolyte according to any one of claims 1 to 4, wherein The number of silicon atoms in the first solvent is denoted as x, and the number of oxygen atoms in the first solvent is denoted as y. Then the first solvent satisfies at least one of the following conditions (1) to (3): (1) 0.5≤y / x≤4, optionally, 1≤y / x≤2; (2) 1≤x≤10, optionally, 1≤x≤5, more optionally, 1≤x≤3; (3) 1≤y≤20, optionally, 1≤y≤10, more optionally, 1≤y≤6.

6. The electrolyte according to any one of claims 1 to 5, wherein The first solvent includes one or more of the following organosiloxane compounds: Optionally, the first solvent includes one or more of the organosiloxane compounds shown in A-1, A-2, A-5, A-6, A-7, and A-11.

7. The electrolyte according to any one of claims 1 to 6, wherein: The content of the first solvent is 40%-80%, optionally 50%-70%, based on the total weight of the solvent.

8. The electrolyte according to any one of claims 1 to 6, wherein: The content of the first solvent is 100%, based on the total weight of the solvent.

9. The electrolyte according to any one of claims 1 to 7, wherein: The solvent further includes a second solvent and / or a third solvent. Optionally, the solvent further includes both the second solvent and the third solvent. The second solvent includes one or more of esters and halogenated ester compounds, ether compounds, and the first fluoroether compound. In the molecular structure of the first fluoroether compound, the α-carbon atom directly connected to the oxygen atom on the ether oxygen bond functional group does not have a fluorine atom directly connected to the α-carbon atom, and can be selected from one or more of the ether compound and the first fluoroether compound. The third solvent includes one or more of alkanes and halogenated alkane compounds, aromatic hydrocarbons and halogenated aromatic hydrocarbon compounds, and a second fluoroether compound. The second fluoroether compound has at least one fluorine atom directly connected to the α-carbon atom directly connected to the oxygen atom on the ether oxygen bond functional group in its molecular structure, and may optionally include one or more of the second fluoroether compounds.

10. The electrolyte according to claim 9, wherein The ester and halogenated ester compounds include one or more of carbonate and halogenated carbonate compounds, carboxylate and halogenated carboxylate compounds, and can be selected from dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene carbonate, vinylene 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, and one or more of ethyl 2,2,2-trifluoroacetate; and / or, The ether compound includes one or more of 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, diethoxyethane, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, tetrahydrofuran, tetrahydropyran, 1,3-dioxolane, 1,3-dioxane, and 1,4-dioxane, and may be selected from one or more of dimethoxypropane and diethoxyethane; and / or, The first fluoroether compound includes one or more of the following compounds: Optionally, it may include one or more of B-2 and B-5; and / or, The alkane and halogenated alkane compound include one or more of cyclohexane and decafluoropentane; and / or, The aromatic hydrocarbon and halogenated aromatic hydrocarbon compound include one or more of benzene, toluene, p-xylene, m-xylene, o-xylene, fluorobenzene, p-difluorobenzene, m-difluorobenzene, o-difluorobenzene, trifluorotoluene, and trifluoromethoxybenzene; and / or, The second fluoroether compound includes 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-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, bis(1,1,2,2-tetrafluoroethyl) ether, one or more of which may be selected from 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, 1,2-bis(1,1,2,2-tetrafluoroethyl) ether One or more of (4-(2-fluoroethoxy)ethane.

11. The electrolyte according to claim 10, wherein The second solvent includes one or more of dimethoxypropane, diethoxyethane, B-2, and B-5; and / or, The third solvent includes one or more of 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether and 1,2-bis(1,1,2,2-tetrafluoroethoxy)ethane.

12. The electrolyte according to any one of claims 9 to 11, wherein: The content of the second solvent is less than or equal to 40%, and can be 10%-30%, based on the total weight of the solvent; and / or, The content of the third solvent is less than or equal to 40%, and can be optionally 10%-30%, based on the total weight of the solvent.

13. The electrolyte according to any one of claims 1 to 12, wherein: 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 content of the additive is less than or equal to 5%, and can be 0.5%-3%, based on the total weight of the electrolyte.

14. The electrolyte according to any one of claims 1 to 13, wherein: The electrolyte includes a first anion, and the first anion includes 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 first anion includes one or more of a bis(fluorosulfonyl)imide anion and a bis(trifluoromethanesulfonyl)imide anion; and / or, Optionally, the molar concentration of the first anion in the electrolyte is 0.5 mol / L-4 mol / L, optionally 0.8 mol / L-2.4 mol / L, and more optionally 1.2 mol / L-1.8 mol / L.

15. The electrolyte according to any one of claims 1 to 14, wherein: The electrolyte includes a first cation, which includes one or more of an alkali metal ion and an alkaline earth metal 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.

16. A battery cell comprising the electrolyte according to any one of claims 1 to 15.

17. The battery cell according to claim 16, wherein: 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.

18. A battery comprising the battery cell according to claim 16 or 17.

19. An electrical device comprising the battery according to claim 18.

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