Electrolytes, battery cells, batteries, and electrical devices

Abstract

This application provides an electrolyte, a battery cell, a battery, and an electrical device, wherein the electrolyte contains a solvent, the solvent contains a first solvent, the first solvent contains an organic siloxane compound, and the content of the first solvent is 20% or more of the total weight of the solvent.

Description

[Technical Field]

[0001] This application relates to electrolytes, battery cells, batteries, and electrical devices. [Background technology]

[0002] In recent years, batteries have been widely applied in various fields, including energy storage and power systems such as hydroelectric, thermal, wind, and solar power plants, as well as power tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, and aerospace. As batteries are applied and become more widespread, the energy density of conventional batteries with carbon-based materials as the negative electrode is insufficient to meet the demand, thus creating a need for battery systems with higher energy densities. Batteries with materials such as lithium metal as the negative electrode have high energy densities, but such batteries have short cycle lives. The above description does not necessarily constitute prior art and is merely intended to provide background art information related to this application. [Overview of the Initiative]

[0003] This application provides an electrolyte, battery cell, battery, and electrical device capable of improving the cycle performance of a battery.

[0004] A first aspect of this application provides an electrolyte comprising a solvent, wherein the solvent comprises a first solvent, the first solvent comprises an organosiloxane compound, and the content of the first solvent is 20% or more by weight of the total solvent.

[0005] During their research, the inventors discovered that using an organosiloxane compound as the main solvent in the electrolyte (containing 20% ​​or more of the total weight of the solvent) can enhance the oxidation resistance of the electrolyte and reduce oxidative decomposition of the electrolyte, thereby improving the cycle stability of the battery and extending its cycle life.

[0006] In any embodiment, the first solvent comprises one or more of the organosiloxane compounds shown in formula (I), [ka] R , , , , 3 , 4 , 1 , , , 22 , , 12 , 2 ,

[0007] , 1 , , 3 , , 4 ,

[0008] , 2 , 23 , 21 , 11 、R 2 、R 3 、R 4 are each independently a hydrogen atom, C1-C10 alkyl, C1-C10 alkoxy, C2-C10 alkoxyalkyl, one of the groups shown in formula (a), and R 1 、R 2 、R 3 、R<000000VIII> at least one of which contains C1-C10 alkoxy, one of the groups shown in formula (a),

Chemical formula

[0007] When the first solvent contains the organosiloxane compound shown in formula (I), the oxidation resistance of the electrolyte can be enhanced, the oxidative decomposition of the electrolyte can be reduced, and further, the negative electrode can be stabilized and the reductive decomposition of the electrolyte can also be reduced, thereby increasing the cycle stability and lengthening the cycle life of the battery in a higher voltage range.

[0008] In any embodiment, R 1 、R 2 、R 3 、R 4 It should be noted that there may be some inaccuracies in the translation due to the complexity and potential ambiguity of the original patent text, especially in chemical formula-related content. It is advisable to double-check with a professional in the relevant field for a more accurate understanding.Each of these groups independently contains one of the following groups: C1-C5 alkyl, C1-C5 alkoxy, C2-C5 alkoxyalkyl, or the group shown in formula (a). This reduces the steric hindrance of the first solvent, improves the solubility of the first solvent in the electrolyte salt, and improves the miscibility of the first solvent with other solvents, thereby increasing the cycle stability and extending the cycle life of the battery.

[0009] In any embodiment, R 1 , R 2 , R 3 , R 4 Two of them independently contain a C1-C10 alkoxy or one of the groups shown in formula (a).

[0010] In any embodiment, R 1 , R 2 , R 3 , R 4 Two of them independently contain a C1-C5 alkoxy, one of the groups shown in formula (a).

[0011] This reduces the steric hindrance of the first solvent, improves its solubility in the electrolyte salt, and improves the miscibility of the first solvent with other solvents, thereby increasing the battery's cycle stability and extending its cycle life.

[0012] In any embodiment, L 1 , L 2 Each of these independently represents one of the following: C1-C5 alkylene, C1-C5 alkylene oxy, or C2-C5 alkylene oxyalkylene. Two silicon atoms form a linking group L. 1 , L 2 When linked via L, the shielding effect of the silicon atom on the oxygen atom's lone electron pair can be reduced to a certain extent, and the linking group L 1 , L 2Furthermore, the formation of a solvation structure through chelation between the oxygen atoms at both ends and the cations in the electrolyte can be promoted, thereby increasing the solubility of the first solvent in the electrolyte salt and improving the miscibility of the first solvent with other solvents. As a result, the electrolyte can have appropriate ionic conductivity, and the cycle performance of the battery can be further improved.

[0013] In any embodiment, L 1 , L 2 Each of these independently represents a C2-C3 alkylene oxy. 1 , L 2 When the range is within the above range, it contributes to the formation of a solvation structure by chelation between the first solvent and cations in the electrolyte, thereby increasing the solubility of the first solvent in relation to the electrolyte salt and also increasing the miscibility of the first solvent with other solvents. As a result, the electrolyte can have appropriate ionic conductivity, and further improve the battery's cycle performance.

[0014] In any embodiment, R 11 , R 12 , R 21 , R 22 , R 23 Each of these independently contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl.

[0015] In any embodiment, R 11 , R 12 , R 21 , R 22 Each independently contains a C1-C5 alkyl group, R 23 It contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl.

[0016] In any embodiment, m and p can never be zero at the same time.

[0017] In any embodiment, n and q independently represent 0, 1, or 2, and n and q can never be 0 at the same time.

[0018] In any given embodiment, m, n, and p are all 0, and q is an integer between 1 and 5.

[0019] In any given example, m and n are both 0, p is 1, and q is an integer between 1 and 5.

[0020] In any given embodiment, m is 0, n is an integer between 1 and 5, p is 1, and q is an integer between 1 and 5.

[0021] In any given embodiment, m is 1, n is an integer between 1 and 5, p is 1, and q is an integer between 1 and 5.

[0022] In any embodiment, m, n, and p are all 0, q is 1 or 2, and R 21 , R 22 , R 23 Each of these independently contains one of the following: C1-C10 alkyl, C1-C10 alkoxy, or C2-C10 alkoxyalkyl.

[0023] In any embodiment, m, n, and p are all 0, q is 1 or 2, and R 21 , R 22 , R 23 Each of these independently contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl.

[0024] In any embodiment, m, n, and p are all 0, q is 1 or 2, and R 21 , R 22 Each independently contains a C1-C5 alkyl group, R 23 It contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl.

[0025] In any embodiment, m and n are both 0, p is 1, q is 1 or 2, and L 2 R represents one of the following: C1-C10 alkylene, C1-C10 alkylene oxy, or C2-C10 alkylene oxyalkylene.21 , R 22 , R 23 Each of these independently contains one of the following: C1-C10 alkyl, C1-C10 alkoxy, or C2-C10 alkoxyalkyl.

[0026] In any embodiment, m and n are both 0, p is 1, q is 1 or 2, and L 2 R represents one of the following: C1-C5 alkylene, C1-C5 alkylene oxy, or C2-C5 alkylene oxyalkylene. 21 , R 22 , R 23 Each of these independently contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl.

[0027] In any embodiment, m and n are both 0, p is 1, q is 1 or 2, and L 2 R represents one of the following: C1-C5 alkylene, C1-C5 alkylene oxy, or C2-C5 alkylene oxyalkylene. 21 , R 22 Each independently contains a C1-C5 alkyl group, R 23 It contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or 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 C2-C3 alkylene oxy, R 21 , R 22 Each independently contains a C1-C5 alkyl group, R 23 It contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl.

[0029] In any embodiment, m is 0, n is 1 or 2, p is 1, q is 1 or 2, L 2 R represents one of the following: C1-C10 alkylene, C1-C10 alkylene oxy, or C2-C10 alkylene oxyalkylene. 11 , R12 , R 21 , R 22 , R 23 are each independently selected from C1-C10 alkyl, C1-C10 alkoxy, and C2-C10 alkoxyalkyl.

[0030] In any embodiment, m is 0, n is 1 or 2, p is 1, q is 1 or 2, and L 2 represents one of C1-C5 alkylene, C1-C5 alkyleneoxy, and C2-C5 alkyleneoxyalkylene, and R 11 , R 12 , R 21 , R 22 , R 23 are each independently selected from C1-C5 alkyl, C1-C5 alkoxy, and C2-C5 alkoxyalkyl.

[0031] In any embodiment, m is 0, n is 1 or 2, p is 1, q is 1 or 2, and L 2 represents one of C1-C5 alkylene, C1-C5 alkyleneoxy, and C2-C5 alkyleneoxyalkylene, and R 11 , R 12 , R 21 , R 22 are each independently selected from C1-C5 alkyl, and R 23 represents one of C1-C5 alkyl, C1-C5 alkoxy, and C2-C5 alkoxyalkyl. ​​​​​​​​​​​​​​​​​​In any embodiment, m is 1, n is 1 or 2, p is 1, q is 1 or 2, and L 1 and L 2 each independently represents one of C1-C10 alkylene, C1-C10 alkyleneoxy, and C2-C10 alkyleneoxyalkylene, and R 11 and R 12 and R 21 and R 22 and R 23 each independently includes one of C1-C10 alkyl, C1-C10 alkoxy, and C2-C10 alkoxyalkyl.

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

[0035] In any embodiment, m is 1, n is 1 or 2, p is 1, q is 1 or 2, and L 1 and L 2 each independently represents one of C1-C5 alkylene, C1-C5 alkyleneoxy, and C2-C5 alkyleneoxyalkylene, and R 11 and R 12 and R 21 and R 22 each independently includes C1-C5 alkyl, and R 23 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, and L 1 and L 2Each of these independently represents a C2-C3 alkylene oxy, and R 11 , R 12 , R 21 , R 22 Each independently contains a C1-C5 alkyl group, R 23 It contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl.

[0037] In any embodiment, if x is the number of silicon atoms in the first solvent and y is the number of oxygen atoms in the first solvent, then 0.5 ≤ y / x ≤ 4, and selectively, 1 ≤ y / x ≤ 2. By further adjusting the ratio of oxygen atoms to silicon atoms in the molecular structure of the organosiloxane compound, the solubility of the first solvent in electrolyte salts can be increased, and the miscibility of the first solvent with other solvents can also be increased.

[0038] In any embodiment, if x is the number of silicon atoms in the first solvent, then 1 ≤ x ≤ 10, selectively 1 ≤ x ≤ 5, and more selectively 1 ≤ x ≤ 3. When the number of silicon atoms in the first solvent is within the above range, the ionic conductivity of the electrolyte can be increased.

[0039] In any embodiment, if y is the number of oxygen atoms in the first solvent, then 1 ≤ y ≤ 20, selectively 1 ≤ y ≤ 10, and more selectively 1 ≤ y ≤ 6. When the number of oxygen atoms in the first solvent is within the above range, the ionic conductivity of the electrolyte can be increased.

[0040] In any example, the solvent described in 1 is It contains one or more of the organosiloxane compounds shown in JPEG2026509902000004.jpg154168.

[0041] In any embodiment, the first solvent comprises one or more of the organosiloxane compounds shown in A-1, A-2, A-5, A-6, A-7, and A-11.

[0042] This improves the battery's cycle stability and extends its cycle life.

[0043] In any embodiment, the content of the first solvent is 40% to 80% of the total weight of the solvent, and selectively 50% to 70%. When the content of the first solvent is within the above range, the stabilizing effect of the first solvent on the positive and negative electrodes can be better exerted, contributing to the formation of an electrolyte with appropriate ionic conductivity, thereby contributing to higher battery cycle stability and a longer cycle life.

[0044] In any given embodiment, the content of the first solvent is 100% of the total weight of the solvent.

[0045] In any embodiment, the solvent further comprises a second solvent and / or a third solvent, and selectively, the solvent further comprises the second solvent and the third solvent simultaneously.

[0046] In any embodiment, the second solvent comprises one or more ester and halogenated ester compounds, ether compounds, and first fluoroether compounds, wherein the molecular structure of the first fluoroether compound does not have a fluorine atom directly bonded to the α-carbon atom directly bonded to the oxygen atom on the ether oxygen bond functional group, and selectively comprises one or more ether compounds and first fluoroether compounds. The second solvent can promote the dissolution of the electrolyte salt, promote ion transport, and increase the ionic conductivity of the electrolyte. As a result, the combination of the first and second solvents can further improve the cycle performance of the battery.

[0047] In any embodiment, the ester and halogenated ester compounds include one or more carbonate esters and halogenated carbonate ester compounds, carboxylic acid esters and halogenated carboxylic acid ester compounds, and selectively include one or more of dimethyl carbonate, diethyl carbonate, ethylmethyl carbonate, ethylene carbonate, vinylene carbonate, propylene carbonate, fluoroethylene carbonate, difluoroethylene carbonate, methyltrifluoroethyl carbonate, ethyltrifluoroethyl carbonate, bis(2,2,2-trifluoroethyl) carbonate, methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl 2,2,2-trifluoroacetate, and 2,2,2-trifluoroethyl acetate.

[0048] In any embodiment, the ether compound comprises 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 optionally comprises one or more of dimethoxypropane and diethoxyethane.

[0049] In any embodiment, the first fluoroether compound is It contains one or more of the compounds in JPEG2026509902000005.jpg252170, and selectively contains one or more of B-2 and B-5.

[0050] When the second solvent is within the above range, the dissolution of the electrolyte salt is promoted, ion transport is promoted, and the ionic conductivity of the electrolyte can be increased. At the same time, the stability to the negative and positive electrodes can also be increased, thereby improving the battery's cycle performance.

[0051] In any embodiment, the second solvent comprises one or more of dimethoxypropane, diethoxyethane, B-2, and B-5. When the second solvent is within the above range, it is possible to further promote the dissolution of the electrolyte salt, promote ion transport, increase the ionic conductivity of the electrolyte, and at the same time further increase the stability to the negative and positive electrodes, thereby further improving the cycle performance of the battery.

[0052] In any embodiment, the third solvent comprises one or more of alkanes and halogenated alkane compounds, aromatic hydrocarbons and halogenated aromatic hydrocarbon compounds, and second fluoroether compounds, wherein the molecular structure of the second fluoroether compound has at least one fluorine atom directly bonded to the α-carbon atom directly bonded to the oxygen atom on the ether oxygen bond functional group, and optionally comprises 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 stability of the electrolyte against a positive electrode of 4V or higher.

[0053] In any embodiment, the alkane and halogenated alkane compound comprises one or more of cyclohexane and decafluoropentane.

[0054] 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.

[0055] In any embodiment, the second fluoroether compound is 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, ethyltrifluoromethyl ether, difluoromethyl-2,2,3,3,3-pentafluoropropyl ether, heptafluoropropyl-1,2,2,2-tetrafluoroethyl ether The ether comprises one or more of the following: ether, difluoromethyl 2,2,3,3-tetrafluoropropyl ether, perfluoroisopropyl methyl ether, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, ethyl-1,1,2,2-tetrafluoroethyl ether, ethyl-2,2,2-tetrafluoroethyl ether, and bis(1,1,2,2-tetrafluoroethyl) ether, and optionally comprises one or more of the following: 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether and 1,2-bis(1,1,2,2-tetrafluoroethoxy)ethane.

[0056] When the third solvent is within the above range, its compatibility with the first and second solvents is increased, improving the oxidation resistance of the electrolyte and promoting the formation of an SEI film containing a large amount of inorganic fluorine components, thereby improving the Coulomb efficiency and cycle life of the battery.

[0057] In any embodiment, the third solvent comprises 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 containing a large amount of inorganic fluorine can be promoted, thereby further improving the Coulomb efficiency and cycle life of the battery.

[0058] In any embodiment, the content of the second solvent is 40% or less by weight of the total solvent, and selectively between 10% and 30%. This can further improve the battery's cycle performance.

[0059] In any embodiment, the content of the third solvent is 40% or less by weight of the total solvent, and selectively between 10% and 30%. 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 containing a large amount of inorganic fluorine components can be promoted.

[0060] In any embodiment, the electrolyte further comprises an additive, the additive comprising one or more of propanesultone, ethylene sulfate, ethylene sulfite, tris(trimethylsilyl) phosphate, tris(trimethylsilyl) phosphite, tris(trifluoroethyl) phosphate, tris(trifluoroethyl) phosphite, tris(trimethylsilyl) borate, dimethylmaleic anhydride, and 1,4-diisocyanatobutane. The additive can assist in film formation and improve the positive electrode interface stability and / or negative electrode interface stability.

[0061] In any embodiment, the content of the additive is 5% or less by weight of the electrolyte, and is selectively between 0.5% and 3%.

[0062] In any embodiment, the electrolyte comprises a first anion, the first anion comprising one or more of the following: bisfluorosulfonylimide anion, bistrifluoromethanesulfonylimide anion, bisoxalatoborate anion, difluorooxalatoborate anion, difluorobisoxalatophosphate anion, tetrafluorooxalatophosphate anion, difluorophosphate anion, hexafluorophosphate anion, tetrafluoroborate anion, hexafluoroarsenate anion, and trifluoromethanesulfonate anion.

[0063] In any embodiment, the first anion comprises one or more bisfluorosulfonyliimide anions and bistrifluoromethanesulfonyliimide anions. The first anion can decompose on the surface of the negative electrode to form an SEI film containing a large amount of inorganic fluorine components, promoting dense metal deposition, thereby contributing to a longer battery cycle life. The first anion also has high oxidation stability, which can improve the battery's cycle stability and extend its cycle life over higher voltage ranges.

[0064] In any embodiment, the molar concentration of the first anion in the electrolyte is 0.5 mol / L to 4 mol / L, selectively 0.8 mol / L to 2.4 mol / L, and more selectively 1.2 mol / L to 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, nor is the stability of the electrolyte to the positive and negative electrodes, thereby contributing to a longer battery cycle life.

[0065] In any embodiment, the electrolyte comprises a first cation, the first cation comprising one or more alkali metal ions and alkaline earth metal ions, selectively comprising one or more lithium ions, sodium ions, potassium ions, and magnesium ions, and more selectively comprising lithium ions.

[0066] A second aspect of this application provides a battery cell containing the electrolyte described in the first aspect of this application.

[0067] In any embodiment, the battery cell includes a metal battery cell, a metal-air battery cell, a metal-sulfur battery cell, and a negative electrode-free metal battery cell, and optionally includes a lithium metal battery cell, a negative electrode-free lithium metal battery cell, a lithium-air battery cell, and a lithium-sulfur battery cell.

[0068] A third aspect of this application provides a battery including the battery cell described in the second aspect of this application.

[0069] A fourth aspect of this application provides an electrical device including the battery described in the third aspect of this application.

[0070] The electrical device of this application includes a battery provided in this application and therefore has at least the same advantages as the aforementioned battery. [Brief explanation of the drawing]

[0071] To more clearly illustrate the technical solution of this application, the drawings used in this application are briefly described below. The drawings described below are merely for illustrating some embodiments of this application, and it will be apparent that those skilled in the art can conceive of other drawings based on these drawings without any creative effort. [Figure 1] This is a schematic diagram of one embodiment of the battery cell of the present application. [Figure 2] This is an exploded schematic diagram of one embodiment of the battery cell of the present application. [Figure 3] This is a schematic diagram of one embodiment of the battery module of this application. [Figure 4] This is a schematic diagram of one embodiment of the battery pack of this application. [Figure 5] Figure 4 is an exploded schematic diagram of an embodiment of the battery pack shown. [Figure 6] This is a schematic diagram of one embodiment of an electrical device that includes the battery of this application as a power source. [Modes for carrying out the invention]

[0072] The following describes in detail embodiments of the electrolyte, battery cell, battery, and electrical device of this application, with appropriate reference to the drawings. However, unnecessary details may be omitted. For example, detailed explanations of well-known matters and redundant explanations of identical structures may be omitted. This is to avoid unnecessarily verbose explanations, making it easier for those skilled in the art to understand. Furthermore, the drawings and the following explanation are provided to enable those skilled in the art to fully understand this application and are not intended to limit the intent of the claims.

[0073] The “range” disclosed in this application is limited to a lower and upper limit, and a given range is limited by selecting one lower limit and one upper limit, and the selected lower and upper limits define the boundary of a special range. Such limited ranges may or may not include endpoint values ​​and can be combined arbitrarily, that is, any lower limit and any upper limit can be combined to form a single range. For example, if the ranges 60-120 and 80-110 are listed for a particular parameter, the ranges 60-110 and 80-120 are also understood to be predictable. Similarly, if the minimum range values ​​are 1 and 2, and the maximum range values ​​are 3, 4 and 5, then the ranges 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5 are all predictable. In this application, unless otherwise specified, the numerical range “a-b” represents an abbreviated expression for any combination of real numbers between a and b, where both a and b are real numbers. For example, the numerical range "0 to 5" indicates that all real numbers between "0 to 5" are listed in this specification, and "0 to 5" is merely an abbreviated representation of combinations of these numbers. Furthermore, when a parameter is described as being an integer of 2 or more, it is equivalent to disclosing that the parameter is an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12.

[0074] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions, and such technical solutions should be considered to be included in the disclosures of this application.

[0075] Unless otherwise specified, all technical features and optional technical features of this application can be combined to form new technical solutions, and such technical solutions should be considered to be included in the disclosures of this application.

[0076] Unless otherwise specified, all steps of this application may be performed sequentially or randomly, preferably in order. For example, when the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed in order, or steps (b) and (a) performed in order. For example, when the method further includes step (c), it means that step (c) may be added to the method in any order, for example, the method may include steps (a), (b), and (c), or steps (a), (c), and (b), or steps (c), (a), and (b), or otherwise.

[0077] Unless otherwise specified, descriptions such as "includes" and "inclusive" in this application are open, but may also be closed. For example, such descriptions as "includes" and "inclusive" may further include or include other components not listed, or may include or include only the listed components.

[0078] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B." More specifically, any of the following conditions satisfy the "A or B" condition: 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).

[0079] Unless otherwise specified, terms such as "first," "second," and "third" in this application are used to distinguish different subjects and are not intended to describe a specific order or primary-secondary relationship.

[0080] Unless otherwise stated, terms used in this application have the meanings commonly understood by those skilled in the art.

[0081] Unless otherwise stated, the numerical values ​​of each parameter mentioned in this application can be measured by various measurement methods commonly used in the art, for example, according to the measurement methods shown in the embodiments of this application. Unless otherwise stated, the measurement temperature for all parameters is 25°C.

[0082] The term "alkyl" encompasses both linear and branched alkyl groups. Examples of alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, and isopentyl. In various examples, C1-C10 alkyl means that the alkyl group may contain 1 to 10 carbon atoms.

[0083] The alkyl portion in the term "alkoxy" includes both linear and branched alkyl groups. Examples of alkoxy include, but are not limited to, methoxy, ethoxy, and propoxy. In various examples, C1-C10 alkoxy means that the alkoxy may contain 1 to 10 carbon atoms.

[0084] The term "alkoxyalkyl" refers to a group in which one end of an alkyl group is a bonded position and the other end is bonded to an alkoxy group. In various examples, C2-C10 alkoxyalkyl means that the alkoxyalkyl group may contain 2 to 10 carbon atoms.

[0085] In this specification, "#" indicates a linking position where it is present.

[0086] Throughout this specification, substituents of compounds are disclosed in groups or ranges. It is clearly expected that such descriptions will include individual subcombinations of members within these groups and ranges. For example, the term "C1-C5 alkyl" is clearly expected to disclose C1, C2, C3, C4, C5, C1-C5, C1-C4, C1-C3, C1-C2, C2-C5, C2-C4, C2-C3, C3-C5, C3-C4, and C4-C5 alkyls individually. Another example is the integer range of 3 to 10, which is clearly expected to disclose 3, 4, 5, 6, 7, 8, 9, and 10 individually. Based on this, other groups or ranges can be clearly expected.

[0087] The batteries referred to in the embodiments of this application may include a single physical module comprising one or more battery cells to provide higher voltage and capacity. For example, the batteries referred to in this application may include battery cells, battery modules, or battery packs.

[0088] A battery cell is the smallest component of a battery and can perform charging and discharging functions on its own. Battery cells may be cylindrical, flattened, rectangular, or have other shapes, and are not limited to these in the embodiments of this application. Figure 1 shows a rectangular battery cell 5 as an example.

[0089] If there are multiple battery cells, the multiple battery cells are connected in series, parallel, or in a mixed configuration via current collectors. In some embodiments, the battery may be a battery module. If there are multiple battery cells, the multiple battery cells are arranged and fixed together to form a single battery module. In some embodiments, the battery may be a battery pack, which includes a box and battery cells, and the battery cells or battery modules are housed within the box. In some embodiments, the box may be part of the vehicle's chassis structure. For example, part of the box may be at least part of the vehicle's bottom plate, or part of the vehicle's cross members and side members.

[0090] In some embodiments, the battery may be an energy storage device. The energy storage device includes energy storage containers, energy storage cabinets, and the like.

[0091] The battery cells provided in the embodiments of this application include battery cells that use alkali metals, alkaline earth metals, and alloys thereof as negative electrode active materials. For example, the battery cells provided in the embodiments of this application include metal battery cells, metal-air battery cells, metal-sulfur battery cells, and negative electrode-free metal battery cells. As an example, 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.

[0092] A battery cell generally includes an electrode assembly. The electrode assembly typically includes a positive electrode sheet, a negative electrode sheet, and a separator located between the positive and negative electrode sheets. The electrode assembly may have a wound structure or a laminated structure, and is not limited to these in the embodiments of this application.

[0093] The battery cell may further include an outer casing, which can be used to enclose the electrode assembly and electrolyte. The outer casing may be a rigid case, such as a hard plastic case, an aluminum case, or a steel case. The outer casing may also be a soft pack, such as a pouch-type soft pack. The material of the soft pack may be a plastic, such as one or more of polypropylene (PP), polybutylene terephthalate (PBT), and polybutylene succinate (PBS).

[0094] In some embodiments, as shown in Figure 2, the exterior may include a case 51 and a cover plate 53. The case 51 may include a bottom plate and side plates connected to the bottom plate, and the bottom plate and side plates surround and form a housing cavity. The case 51 has an opening that communicates with the housing cavity, and the cover plate 53 covers the opening to seal the housing cavity. The electrode assemblies 52 are sealed within the housing cavity. The number of electrode assemblies 52 contained in the battery cell 5 may be one or more and can be adjusted as needed.

[0095] In some embodiments, the battery cells may be assembled as a battery module, and the number of battery cells included in the battery module may be one or more, and the specific number can be adjusted according to the application and capacity of the battery module. Figure 3 is a schematic diagram of an example battery module 4. As shown in Figure 3, in the battery module 4, the multiple battery cells 5 may be arranged sequentially along the length of the battery module 4. Of course, they may be arranged in any other manner. Furthermore, the multiple battery cells 5 may be fixed by fastening members.

[0096] Selectively, the battery module 4 may further include a housing having a housing space, in which a plurality of battery cells 5 are housed.

[0097] In some embodiments, the battery modules may be assembled as a battery pack, and the number of battery modules included in the battery pack can be adjusted according to the application and capacity of the battery pack.

[0098] Figures 4 and 5 are schematic diagrams of an example battery pack 1. As shown in Figures 4 and 5, the battery pack 1 may include a box and a plurality of battery modules 4 provided inside the box. The box includes an upper box 2 and a lower box 3, the upper box 2 covering the lower box 3 and forming a sealed space for housing the battery modules 4. The plurality of battery modules 4 may be arranged in the box in any manner.

[0099] High energy density is an irreversible trend in the future development of batteries, and batteries using alkali metals, alkaline earth metals, and their alloys as negative electrode active materials are attracting widespread attention due to their high energy density. However, large-scale applications of these batteries face various challenges. For example, currently, electrolytes typically use ether-based solvents as the main solvent, but ether-based solvents have poor oxidation resistance and can oxidize and decompose on the positive electrode side after several charge-discharge cycles, resulting in low battery cycle performance.

[0100] Currently, the main strategy for improving battery cycle performance is to improve the composition of the electrolyte.

[0101] In light of this, the inventor improved the electrolyte.

[0102] The electrolyte provided in the embodiments of this application comprises a solvent, the solvent comprises a first solvent, the first solvent comprises an organosiloxane compound, and the content of the first solvent is 20% or more of the total weight of the solvent.

[0103] Currently, when organosiloxane compounds are used in electrolytes, they are used as additives, and the amount used in the electrolyte is usually 15% or less, and even more specifically, usually 5% or less.

[0104] During their research, the inventors discovered that using an organosiloxane compound as the main solvent in the electrolyte (containing 20% ​​or more of the total weight of the solvent) can enhance the oxidation resistance of the electrolyte and reduce oxidative decomposition of the electrolyte, thereby improving the cycle stability of the battery and extending its cycle life.

[0105] The first solvent of the electrolyte provided in the embodiments of this application comprises an organosiloxane compound, the molecular structure of which contains at least one Si-O bond, and the oxidation resistance of the Si-O bond is stronger compared to that of a CO bond. For example, compared to common ether-based solvents containing a CO bond, such as 1,2-dimethoxyethane (DME), the first solvent can have a lower highest occupied orbital (HOMO) energy level. Therefore, the electrolyte provided in the embodiments of this application can have enhanced oxidation resistance, thereby reducing oxidative decomposition of the electrolyte and further increasing the cycle stability and cycle life of the battery employing the electrolyte.

[0106] In some embodiments, the first solvent may contain one or more of the organosiloxane compounds shown in formula (I). [ka] R 1 , R 2 , R 3 , R 4 Each independently contains one of the following: a hydrogen atom, a C1-C10 alkyl group, a C1-C10 alkoxy group, a C2-C10 alkoxyalkyl group, or a group shown in formula (a), and R 1 , R 2 , R 3 , R 4 At least one of them contains a C1-C10 alkoxy, one of the groups shown in formula (a), [ka] # indicates the connection position, L 1 , L 2 Each of these independently represents one of the following: C1-C10 alkylene, C1-C10 alkylene oxy, or C2-C10 alkylene oxyalkylene. 11 , R 12 , R 21 , R 22 , R 23Each of the following independently contains one of a hydrogen atom, a C1-C10 alkyl group, a C1-C10 alkoxy group, or a C2-C10 alkoxyalkyl group; m and p independently represent either 0 or 1; and n and q independently represent either 0 or an integer between 1 and 5, and n and q can never be 0 at the same time.

[0107] The first solvent contains an organic siloxane compound shown in formula (I), and exhibits a strong shielding effect of silicon atoms on the oxygen atom electron cloud, thereby lowering the solvation energy of the electrolyte. This promotes anion decomposition film formation in the electrolyte, for example, by forming an SEI film containing a large amount of inorganic fluorine components, thereby improving the battery's cycle performance. On the other hand, it can also raise the electrode potential of the negative electrode, reduce reductive decomposition of the electrolyte, increase the surface energy of the electrolyte, promote dense metal deposition, and further improve the battery's Coulomb efficiency and cycle stability.

[0108] The first solvent contains an organic siloxane compound shown in formula (I). By designing the molecular structure, the solubility of the first solvent in the electrolyte salt can be increased, and the miscibility between the first solvent and other solvents can also be increased. This contributes to enhancing the oxidation resistance of the electrolyte at high voltages (e.g., 4V or higher) and can induce dense metal deposition.

[0109] Therefore, when the first solvent contains an organic siloxane compound shown in formula (I), the oxidation resistance of the electrolyte can be enhanced, the oxidative decomposition of the electrolyte can be reduced, and the negative electrode can be stabilized, reducing the reductive decomposition of the electrolyte. As a result, the electrolyte provided in the embodiments of this application can improve the cycle stability of the battery and extend its cycle life over a higher voltage range.

[0110] n and q each independently represent integers from 0 to 5. When n represents an integer from 2 to 5, the bases in each set of parentheses may be the same or different. For example, when n is 2, L 1 -O-Si(R) 11 )(R 12 )- is the first unit, L 2 -O-Si(R)11 )(R 12 )- is the second unit. R in the first unit 11 and R in the second unit 11 R in the first unit may be the same or different. 12 and R in the second unit 12 The bases may be the same or different. When q represents an integer between 2 and 5, the bases in each set of parentheses may be the same or different. For example, if q is 2, L 2 -O-Si(R) 21 )(R 22 )- is the first unit, R 23 -O-Si(R) 21 )(R 22 )- is the second unit. R in the first unit 21 and R in the second unit 21 R in the first unit may be the same or different. 22 and R in the second unit 22 They may be the same or different.

[0111] In some embodiments, R 1 , R 2 , R 3 , R 4 Each of these independently contains one of the following groups: C1-C5 alkyl, C1-C5 alkoxy, C2-C5 alkoxyalkyl, or the group shown in formula (a). This reduces the steric hindrance of the first solvent, improves the solubility of the first solvent in the electrolyte salt, and improves the miscibility of the first solvent with other solvents, thereby increasing the cycle stability and extending the cycle life of the battery.

[0112] In some embodiments, R 1 , R 2 , R 3 , R 4 Two of them independently contain a C1-C10 alkoxy, one of the groups shown in formula (a). Selectively, R 1 , R 2 , R 3 , R 4Two of these compounds independently contain a C1-C5 alkoxy or one of the groups shown in formula (a). This reduces the steric hindrance of the first solvent, improves its solubility in the electrolyte salt, and improves the miscibility between the first solvent and other solvents, thereby increasing the battery's cycle stability and extending its cycle life.

[0113] In some embodiments, R 11 , R 12 , R 21 , R 22 , R 23 Each of these independently contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl.

[0114] In some embodiments, R 11 , R 12 , R 21 , R 22 Each independently contains one of the following: C1-C10 alkyl or C2-C10 alkenyl, R 23 It contains one of the following: C1-C10 alkyl, C1-C10 alkoxy, or C2-C10 alkoxyalkyl. Selectively, R 11 , R 12 , R 21 , R 22 Each independently contains a C1-C5 alkyl group, R 23 It contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl.

[0115] In some embodiments, m and p cannot be 0 at the same time. For example, m is 0 and p is 1, or m is 1 and p is 0, or both m and p are 1.

[0116] In some embodiments, L 1 , L 2 Each of these independently represents one of the following: C1-C5 alkylene, C1-C5 alkylene oxy, or C2-C5 alkylene oxyalkylene.

[0117] Two silicon atoms form a linking group L1 , L 2 When linked via L, the shielding effect of the silicon atom on the oxygen atom's lone electron pair can be reduced to a certain extent, and the linking group L 1 , L 2 Furthermore, it contributes to the formation of a solvation structure through chelation between the oxygen atoms at both ends and the cations in the electrolyte, thereby increasing the solubility of the first solvent in the electrolyte salt and improving the miscibility of the first solvent with other solvents. As a result, the electrolyte can have appropriate ionic conductivity, and the cycle performance of the battery can be further improved.

[0118] In some embodiments, L 1 , L 2 Each of these independently represents a C2-C3 alkylene oxy. 1 , L 2 When the range is within the above range, it contributes to the formation of a solvation structure by chelation between the first solvent and cations in the electrolyte, thereby increasing the solubility of the first solvent in relation to the electrolyte salt and also increasing the miscibility of the first solvent with other solvents. As a result, the electrolyte can have appropriate ionic conductivity, and further improve the battery's cycle performance.

[0119] In some embodiments, n and q independently represent 0, 1, or 2, and n and q can never be 0 at the same time.

[0120] In some embodiments, m, n, and p are all 0, and q is an integer between 1 and 5.

[0121] In some embodiments, m, n, and p are all 0, and q is 1 or 2, R 21 , R 22 , R 23 Each independently contains one of C1-C10 alkyl, C1-C10 alkoxy, or C2-C10 alkoxyalkyl. Selectively, m, n, and p are all 0, and q is 1 or 2, and R 21 , R 22 , R 23Each independently contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl. More selectively, m, n, and p are all 0, and q is 1 or 2, R 21 , R 22 Each independently contains a C1-C5 alkyl group, R 23 It contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl.

[0122] When the group shown in formula (a) is within the above range, the solubility of the first solvent in the electrolyte salt can be increased, and the miscibility of the first solvent with other solvents can also be increased. As a result, the electrolyte can have appropriate ionic conductivity, which further contributes to improving the battery's cycle performance.

[0123] In some examples, m and n are both 0, p is 1, and q is an integer between 1 and 5.

[0124] In some embodiments, m and n are both 0, p is 1, q is 1 or 2, and L 2 R represents one of the following: C1-C10 alkylene, C1-C10 alkylene oxy, or C2-C10 alkylene oxyalkylene. 21 , R 22 , R 23 Each independently contains one of C1-C10 alkyl, C1-C10 alkoxy, or C2-C10 alkoxyalkyl. Selectively, m and n are both 0, p is 1, and q is 1 or 2, L 2 R represents one of the following: C1-C5 alkylene, C1-C5 alkylene oxy, or C2-C5 alkylene oxyalkylene. 21 , R 22 , R 23 Each independently contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl. More selectively, m and n are both 0, p is 1, and q is 1 or 2, L 2R represents one of the following: C1-C5 alkylene, C1-C5 alkylene oxy, or C2-C5 alkylene oxyalkylene. 21 , R 22 Each independently contains a C1-C5 alkyl group, R 23 It contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl. More selectively, m and n are both 0, p is 1, and q is 1 or 2, L 2 represents C2-C3 alkylene oxy, R 21 , R 22 Each independently contains a C1-C5 alkyl group, R 23 It contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl.

[0125] When the group shown in formula (a) is within the above range, the solubility of the first solvent in the electrolyte salt can be increased, and the miscibility of the first solvent with other solvents can also be increased. As a result, the electrolyte can have appropriate ionic conductivity, which further contributes to improving the battery's cycle performance.

[0126] In some of the embodiments, m is 0, n is an integer from 1 to 5, p is 1, and q is an integer from 1 to 5.

[0127] In some embodiments, m is 0, n is 1 or 2, p is 1, q is 1 or 2, L 2 R represents one of the following: C1-C10 alkylene, C1-C10 alkylene oxy, or C2-C10 alkylene oxyalkylene. 11 , R 12 , R 21 , R 22 , R 23 Each independently contains one of C1-C10 alkyl, C1-C10 alkoxy, or C2-C10 alkoxyalkyl. Selectively, m is 0, n is 1 or 2, p is 1, q is 1 or 2, and L 2R represents one of the following: C1-C5 alkylene, C1-C5 alkylene oxy, or C2-C5 alkylene oxyalkylene. 11 , R 12 , R 21 , R 22 , R 23 Each independently contains one of C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl. More selectively, m is 0, n is 1 or 2, p is 1, q is 1 or 2, and L 2 R represents one of the following: C1-C5 alkylene, C1-C5 alkylene oxy, or C2-C5 alkylene oxyalkylene. 11 , R 12 , R 21 , R 22 Each independently contains a C1-C5 alkyl group, R 23 It contains one of C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl. More selectively, m is 0, n is 1 or 2, p is 1, q is 1 or 2, and L 2 represents C2-C3 alkylene oxy, R 11 , R 12 , R 21 , R 22 Each independently contains a C1-C5 alkyl group, R 23 It contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl.

[0128] In some embodiments, m is 1, n is an integer between 1 and 5, p is 1, and q is an integer between 1 and 5.

[0129] In some embodiments, m is 1, n is 1 or 2, p is 1, q is 1 or 2, L 1 , L 2 Each of these independently represents one of the following: C1-C10 alkylene, C1-C10 alkylene oxy, or C2-C10 alkylene oxyalkylene. 11 , R 12 , R 21 , R 22 , R 23Each independently contains one of C1-C10 alkyl, C1-C10 alkoxy, or C2-C10 alkoxyalkyl. Selectively, m is 1, n is 1 or 2, p is 1, q is 1 or 2, and L 1 , L 2 Each of these independently represents one of the following: C1-C5 alkylene, C1-C5 alkylene oxy, or C2-C5 alkylene oxyalkylene. 11 , R 12 , R 21 , R 22 , R 23 Each independently contains one of C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl. More selectively, m is 1, n is 1 or 2, p is 1, q is 1 or 2, and L 1 , L 2 Each of these independently represents one of the following: C1-C5 alkylene, C1-C5 alkylene oxy, or C2-C5 alkylene oxyalkylene. 11 , R 12 , R 21 , R 22 Each independently contains a C1-C5 alkyl group, R 23 It contains one of C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl. More selectively, m is 1, n is 1 or 2, p is 1, q is 1 or 2, and L 1 , L 2 Each of these independently represents a C2-C3 alkylene oxy, and R 11 , R 12 , R 21 , R 22 Each independently contains a C1-C5 alkyl group, R 23 It contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl.

[0130] When the group shown in formula (a) is within the above range, the solubility of the first solvent in the electrolyte salt can be increased, and the miscibility of the first solvent with other solvents can also be increased. As a result, the electrolyte can have appropriate ionic conductivity, which further contributes to improving the battery's cycle performance.

[0131] In some examples, if x is the number of silicon atoms in the first solvent and y is the number of oxygen atoms in the first solvent, then 0.5 ≤ y / x ≤ 4, and selectively, 1 ≤ y / x ≤ 2.

[0132] After extensive research, the inventors discovered that by adjusting the ratio of oxygen atoms to silicon atoms in the molecular structure of the organosiloxane compound, the solubility of the first solvent in the electrolyte salt and the miscibility of the first solvent with other solvents could be further improved. When the ratio of oxygen atoms to silicon atoms (y / x) is small, the silicon atoms reduce the polarity of the first solvent molecule and shield the electron cloud of the oxygen atoms, weakening the ability of the oxygen atoms to coordinate with ions, reducing the solubility of the first solvent in the electrolyte salt, decreasing the ionic conductivity of the prepared electrolyte, and affecting the battery's cycle performance. On the other hand, when the ratio of oxygen atoms to silicon atoms (y / x) is large, the steric hindrance of the first solvent increases, and the electron clouds of multiple oxygen atoms repel each other, reducing the solubility of the first solvent in the electrolyte salt and decreasing the miscibility of the first solvent with other solvents.

[0133] In some examples, if x is the number of silicon atoms in the first solvent, then 1 ≤ x ≤ 10, selectively 1 ≤ x ≤ 5, and more selectively 1 ≤ x ≤ 3.

[0134] After extensive research, the inventor discovered that the ionic conductivity of the electrolyte can be enhanced when the number of silicon atoms in the first solvent is within the above range.

[0135] In some examples, if y is the number of oxygen atoms in the first solvent, then 1 ≤ y ≤ 20, selectively 1 ≤ y ≤ 10, and more selectively 1 ≤ y ≤ 6.

[0136] After extensive research, the inventor discovered that the ionic conductivity of the electrolyte can be enhanced when the number of oxygen atoms in the first solvent is within the above range.

[0137] In some embodiments, the following conditions are met: 0.5 ≤ y / x ≤ 4, 1 ≤ x ≤ 10, and 1 ≤ y ≤ 20. More selectively, the following conditions are met: 1 ≤ y / x ≤ 2, 1 ≤ x ≤ 5, and 1 ≤ y ≤ 10. More selectively, the following conditions are met: 1 ≤ y / x ≤ 2, 1 ≤ x ≤ 3, and 1 ≤ y ≤ 6. This allows for greater solubility of the first solvent in the electrolyte salt, greater miscibility between the first solvent and other solvents, thereby contributing to the formation of an electrolyte with appropriate ionic conductivity and further improving the battery's cycle performance.

[0138] In some examples, the first solvent is It may contain one or more of the organic siloxane compounds shown in JPEG2026509902000008.jpg146170.

[0139] In some embodiments, the first solvent may contain one or more of the organosiloxane compounds shown in A-1, A-2, A-5, A-6, A-7, and A-11. This can further improve the cycle stability of the battery and extend its cycle life.

[0140] In some embodiments, the first solvent may contain one or more of the organosiloxane compounds shown in A-6 and A-7. This can further improve the battery's cycle stability and extend its cycle life.

[0141] In some examples, the content of the first solvent may be 100% of the total weight of the solvent.

[0142] In some embodiments, the content of the first solvent may be 20% to 90% of the total weight of the solvent, and selectively 30% to 85%, 40% to 80%, or 50% to 70%. When the content of the first solvent is within the above range, the stabilizing effect of the first solvent on the positive and negative electrodes can be better exerted, contributing to the formation of an electrolyte with appropriate ionic conductivity, thereby contributing to higher battery cycle stability and a longer cycle life.

[0143] In some embodiments, the solvent may further contain a second solvent.

[0144] In some embodiments, the second solvent may include one or more of ester and halogenated ester compounds, ether compounds, and first fluoroether compounds, and none of the first fluoroether compounds have a fluorine atom directly bonded to the α-carbon atom directly bonded to the oxygen atom on the ether oxygen bond functional group in the molecular structure of the first fluoroether compounds.

[0145] The silicon atoms in the molecular structure of the first solvent have a certain shielding effect on the lone pairs of electrons of the oxygen atoms, thus weakening the solubility of the first solvent in the electrolyte salt and lowering the ionic conductivity of the electrolyte. The second solvent can promote the dissolution of the electrolyte salt and facilitate ion transport, thereby increasing the ionic conductivity of the electrolyte. As a result, the combination of the first and second solvents can further improve the battery's cycle performance.

[0146] In some embodiments, the ester and halogenated ester compounds may include one or more of the following: carbonate esters and halogenated carbonate compounds, carboxylic acid esters and halogenated carboxylic acid compounds.

[0147] In some embodiments, the ester and halogenated ester compounds may include one or more of the following: dimethyl carbonate, diethyl carbonate, ethylmethyl carbonate, ethylene carbonate, vinylene carbonate, propylene carbonate, fluoroethylene carbonate, difluoroethylene carbonate, methyltrifluoroethyl carbonate, ethyltrifluoroethyl carbonate, bis(2,2,2-trifluoroethyl) carbonate, methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl 2,2,2-trifluoroacetate, and ethyl 2,2,2-trifluoroethyl acetate.

[0148] In some embodiments, the ether compound may include 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. Selectively, the ether compound may include one or more of dimethoxypropane and diethoxyethane.

[0149] In some examples, the first fluoroether compound is It may contain one or more of the compounds in JPEG2026509902000009.jpg244170. Selectively, the first fluoroether compound may contain one or more of B-2 and B-5.

[0150] When the second solvent is within the above range, the dissolution of the electrolyte salt is promoted, ion transport is promoted, and the ionic conductivity of the electrolyte can be increased. At the same time, the stability to the negative and positive electrodes can also be increased, thereby improving the battery's cycle performance.

[0151] In some embodiments, the second solvent may contain one or more ether compounds and first fluoroether compounds.

[0152] In some embodiments, the second solvent may include one or more of dimethoxypropane, diethoxyethane, B-2, and B-5.

[0153] When the second solvent is within the above range, the dissolution of the electrolyte salt is further promoted, ion transport is facilitated, and the ionic conductivity of the electrolyte can be increased. At the same time, the stability to the negative and positive electrodes can be further increased, thereby further improving the battery's cycle performance.

[0154] In some examples, the content of the second solvent may be 40% or less of the total weight of the solvent, and is selectively 10% to 30%. This can further improve the battery's cycle performance.

[0155] In some embodiments, the solvent may further contain a third solvent.

[0156] 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 second fluoroether compounds, wherein the molecular structure of the second fluoroether compound has at least one fluorine atom directly bonded to the α-carbon atom directly bonded to the oxygen atom on the ether oxygen bond functional group.

[0157] The third solvent can be miscible with the first and second solvents, thereby improving the oxidation resistance of the electrolyte and further enhancing its stability against positive electrodes of 4V or higher.

[0158] In some embodiments, the third solvent may contain one or more of the following: a halogenated alkane compound, a halogenated aromatic hydrocarbon compound, or a second fluoroether compound. When the third solvent contains fluorine atoms, it contributes to the decomposition and formation of an SEI film containing a large amount of inorganic fluorine components at the negative electrode, further promoting denser metal deposition and improving the Coulomb efficiency and cycle life of the battery. As a result, when the third solvent contains fluorine atoms, the reversibility of the positive and negative electrodes can be further improved, further enhancing the Coulomb efficiency and cycle life of the battery.

[0159] In some embodiments, the alkane and halogenated alkane compounds may include one or more of cyclohexane and decafluoropentane.

[0160] In some embodiments, the aromatic hydrocarbon and halogenated aromatic hydrocarbon compounds may include one or more of benzene, toluene, p-xylene, m-xylene, o-xylene, fluorobenzene, p-difluorobenzene, m-difluorobenzene, o-difluorobenzene, trifluorotoluene, and trifluoromethoxybenzene.

[0161] In some embodiments, the second fluoroether compound may include one or more of 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, and bis(1,1,2,2-tetrafluoroethyl) ether, and selectively 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.

[0162] When the third solvent is within the above range, its compatibility with the first and second solvents becomes higher, the oxidation resistance of the electrolyte can be improved, the formation of an SEI film containing a large amount of inorganic fluorine components can be promoted, and thereby the Coulomb efficiency and cycle life of the battery can be improved.

[0163] 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.

[0164] In some embodiments, the third solvent may include one or more of the second fluoroether compounds.

[0165] 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.

[0166] When the third solvent is within the above range, the oxidation resistance of the electrolyte can be further improved, the formation of an SEI film containing a large amount of inorganic fluorine components can be promoted, and thereby the Coulomb efficiency and cycle life of the battery can be further improved.

[0167] In some embodiments, in the total weight of the solvent, the content of the third solvent may be 40% or less, and optionally 10% - 30%. 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 containing a large amount of inorganic fluorine components can be promoted. Also, since the dissolving ability of the third solvent in the electrolyte is weak, when the content of the third solvent is within the above range, the adverse effects on electrolyte salt solubility and ion transport can also be reduced.

[0168] In some embodiments, the solvent may further contain a second and a third solvent simultaneously. This can promote the dissolution of the electrolyte salt, facilitate ion transport, increase the ionic conductivity of the electrolyte, further improve the oxidation resistance of the electrolyte, promote the formation of an SEI film containing a large amount of inorganic fluorine components, and further improve the battery's cycle performance.

[0169] In some embodiments, the electrolyte may further contain additives. In this application, the type of additive is not particularly limited as long as it does not impair the spirit of this application. For example, the additive may include one or more of the following: propanesultone (PS), ethylene sulfate (DTD), ethylene sulfite (ES), tris(trimethylsilyl) phosphate (TMSP), tris(trimethylsilyl) phosphite, tris(trifluoroethyl) phosphate, tris(trifluoroethyl) phosphite, tris(trimethylsilyl) borate, dimethylmaleic anhydride, and 1,4-diisocyanatobutane.

[0170] The additive can assist in film formation and improve the stability of the positive electrode interface and / or the negative electrode interface.

[0171] In some embodiments, the additive content may be 5% or less of the total weight of the electrolyte, and is selectively between 0.5% and 3%. When the additive content is within this range, it contributes to improving the battery's cycle performance.

[0172] In some embodiments, the electrolyte contains a first anion, the first anion being a bisfluorosulfonylimide anion (FSI - ), bistrifluoromethanesulfonyliimide anion (TFSI - ), bisoxalatobolate anion (BOB - ), difluorooxalatoborate anion (DFOB - ), difluorobisoxalatophosphate anion (DFOP - ), tetrafluorooxalatophosphate anion (TFOP -), difluorophosphate anion (PO2F2 - ), hexafluorophosphate anion (PF6 - ), tetrafluoroborate anion (BF4 - ), hexafluoroarsenate anion (AsF6 - ), trifluoromethanesulfonate anion (CF3SO3 - ) may include one or more of the following.

[0173] In some embodiments, the first anion is the bisfluorosulfonylimide anion (FSI - ), bistrifluoromethanesulfonyliimide anion (TFSI - ), difluorooxalatoborate anion (DFOB - ), tetrafluorooxalatophosphate anion (TFOP - ) may contain one or more of the following. Selectively, the first anion may be a bisfluorosulfonylimid anion (FSI - ), bistrifluoromethanesulfonyliimide anion (TFSI - The first anion may contain one or more of the following: The first anion can decompose on the surface of the negative electrode to form an SEI film containing a large amount of inorganic fluorine components, promoting dense metal deposition, thereby contributing to a longer battery cycle life. The first anion also has high oxidation stability, which can improve the battery's cycle stability and extend its cycle life in a higher voltage range.

[0174] In some embodiments, the molar concentration of the first anion in the electrolyte may be 0.5 mol / L to 4 mol / L, selectively 0.8 mol / L to 2.4 mol / L, and more selectively 1.2 mol / L to 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, nor is the stability of the electrolyte relative to the positive and negative electrodes, thereby contributing to a longer battery cycle life.

[0175] In some embodiments, the electrolyte contains a first cation, which may contain one or more alkali metal ions and alkaline earth metal ions, and selectively one or more lithium ions, sodium ions, potassium ions, and magnesium ions, and more selectively lithium ions.

[0176] In some embodiments, the electrolyte contains a solvent, the solvent contains a first solvent, the first solvent contains one or more of the organic siloxane compounds shown in formula (I), and the content of the first solvent is 20% or more of the total weight of the solvent. [ka]

[0177] R 1 , R 2 , R 3 , R 4 Each independently contains one of the following: a hydrogen atom, a C1-C10 alkyl group, a C1-C10 alkoxy group, a C2-C10 alkoxyalkyl group, or a group shown in formula (a), and R 1 , R 2 , R 3 , R 4 At least one of them contains a C1-C10 alkoxy or one of the groups shown in formula (a). [ka]

[0178] # indicates the connection position, L 1 , L 2 Each of these independently represents one of the following: C1-C10 alkylene, C1-C10 alkylene oxy, or C2-C10 alkylene oxyalkylene. 11 , R 12 , R 21 , R 22 , R 23Each independently contains one of a hydrogen atom, C1-C10 alkyl, C1-C10 alkoxy, and C2-C10 alkoxyalkyl, m and p each independently represent 0 or 1, n and q each independently represent 0 or an integer from 1 to 5, and n and q are not simultaneously 0. Further, in the organosiloxane compound represented by formula (I), if the number of silicon atoms in the first solvent is x and the number of oxygen atoms in the first solvent is y, then 0.5 ≦ y / x ≦ 4, 1 ≦ x ≦ 10, and 1 ≦ y ≦ 20, and optionally, 1 ≦ y / x ≦ 2, 1 ≦ x ≦ 5, and 1 ≦ y ≦ 10, and more optionally, 1 ≦ y / x ≦ 2, 1 ≦ x ≦ 3, and 1 ≦ y ≦ 6. Thereby, the cycle performance of the battery can be made higher.

[0179] In some embodiments, the electrolyte contains a solvent, and the solvent contains a first solvent, a second solvent, and a third solvent.

[0180] The first solvent contains one or more of the organosiloxane compounds represented by formula (I), and the content of the first solvent is 20% or more in the total weight of the solvent.

Chemical formula

[0181] R 1 、R 2 、R 3 、R 4 Each independently contains one of a hydrogen atom, C1-C10 alkyl, C1-C10 alkoxy, C2-C10 alkoxyalkyl, and the group represented by formula (a), and at least one of R 1 、R 2 、R 3 、R 4 contains one of C1-C10 alkoxy and the group represented by formula (a).

Chemical formula

[0182] [[ID=�3]] # represents the connection position, L 1 " 、L 2Each of these independently represents one of the following: C1-C10 alkylene, C1-C10 alkylene oxy, or C2-C10 alkylene oxyalkylene. 11 , R 12 , R 21 , R 22 , R 23 Each independently contains one of the following: a hydrogen atom, a C1-C10 alkyl, a C1-C10 alkoxy, or a C2-C10 alkoxyalkyl; m and p independently represent 0 or 1; n and q independently represent 0 or an integer from 1 to 5; and n and q are never simultaneously 0. Furthermore, in the organic siloxane compound shown in formula (I), if x is the number of silicon atoms in the first solvent and y is the number of oxygen atoms in the first solvent, then 0.5 ≤ y / x ≤ 4, 1 ≤ x ≤ 10, and 1 ≤ y ≤ 20, selectively 1 ≤ y / x ≤ 2, 1 ≤ x ≤ 5, and 1 ≤ y ≤ 10, and more selectively 1 ≤ y / x ≤ 2, 1 ≤ x ≤ 3, and 1 ≤ y ≤ 6.

[0183] The second solvent contains one or more of ester and halogenated ester compounds, ether compounds, and first fluoroether compounds, and none of the α-carbon atoms directly bonded to the oxygen atom on the ether oxygen bond functional group in the molecular structure of the first fluoroether compounds have a fluorine atom directly bonded to the α-carbon atom. Selectively, the second solvent contains one or more of the ether compounds and first fluoroether compounds. The content of the second solvent is 40% or less of the total weight of the solvent, and selectively between 10% and 30%.

[0184] The third solvent comprises one or more of the following: alkanes and halogenated alkane compounds, aromatic hydrocarbons and halogenated aromatic hydrocarbon compounds, and second fluoroether compounds, wherein the molecular structure of the second fluoroether compound has at least one fluorine atom directly bonded to the α-carbon atom directly bonded to the oxygen atom on the ether oxygen bond functional group. Selectively, the third solvent comprises one or more of the second fluoroether compounds. The content of the third solvent is 40% or less of the total weight of the solvent, and selectively between 10% and 30%.

[0185] This allows for improved battery cycle performance.

[0186] [Preparation method] Methods for preparing electrolytes are well known. For example, an electrolyte can be obtained by uniformly mixing an electrolyte salt (composed of the first anion and first cation mentioned above), a solvent, and any additives. In the preparation process, the order in which each material is added is not particularly limited; they may be added simultaneously or in batches.

[0187] The components in the electrolyte and their content may be measured according to methods common in this art. For example, they may be detected by methods such as gas chromatography-mass spectrometry (GC-MS), ion chromatography (IC), liquid chromatography (LC), and inductively coupled plasma emission spectrometry (ICP-OES).

[0188] The battery cell includes a positive electrode sheet and a negative electrode sheet.

[0189] The structure and / or composition of the positive electrode sheet and the negative electrode sheet may be selected according to the type of battery cell, and are not limited thereto in the embodiments of this application. The battery cells of the embodiments of this application may include metal battery cells, metal-air battery cells, metal-sulfur battery cells, and negative electrode-free metal battery cells, etc. For example, 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, etc. In some embodiments, the battery cells may include lithium metal battery cells, negative electrode-free lithium metal battery cells, lithium-air battery cells, and lithium-sulfur battery cells.

[0190] [Positive electrode sheet] In some embodiments, the positive electrode sheet includes a positive electrode current collector and a positive electrode film layer provided on at least one surface of the positive electrode current collector, the positive electrode film layer containing 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 provided on one or both of the two opposing surfaces of the positive electrode current collector.

[0191] The type of positive electrode active material may be selected according to the type of battery cell, and is not limited to this in the embodiments of this application.

[0192] For example, if 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 modified compounds thereof. 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 modified compounds thereof. Examples of lithium-containing phosphates may include, but are not limited to, one or more of lithium iron phosphate, lithium iron phosphate and carbon composites, lithium manganese phosphate, lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, lithium iron manganese phosphate and carbon composites, and modified compounds thereof. In some embodiments, to further increase the energy density of the battery, the positive electrode active material has the general formula Li a Ni b Co c M d O e A fIt may contain one or more of the lithium transition metal oxides and their modified compounds. 0.8 ≦ a ≦ 1.2, 0.5 ≦ b < 1, 0 < c < 1, 0 < d < 1, 1 ≦ e ≦ 2, 0 ≦ f ≦ 1, M contains one or more of Mn, Al, Zr, Zn, Cu, Cr, Mg, Fe, V, Ti and B, and A contains one or more of N, F, S and Cl.

[0193] As an example, the positive electrode active material may contain one or more of 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 O2, LiFePO4, LiMnPO4.

[0194] 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 contain one or more of sodium-containing transition metal oxides, polyanion materials (phosphates, fluorophosphates, pyrophosphates, sulfates, etc.), Prussian blue-based materials, but is not limited thereto. As an example, the positive electrode active material is NaFeO2, NaCoO2, NaCrO2, NaMnO2, NaNiO2, NaNi 1 / 2 Ti 1 / 2 O2, NaNi 1 / 2 Mn 1 / 2 O2, Na 2 / 3 Fe1 / 3 Mn 2 / 3 O2, NaNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2, NaFePO4, NaMnPO4, NaCoPO4, Prussian blue-based materials, general formula is X p M' q (PO4) r O x Y 3-x It may contain one or more of the materials that are General Formula X. p M' q (PO4) r O x Y 3-x So, 0 <p≦4、0<q≦2、1≦r≦3、0≦x≦2であり、XはH + Li + kaNa + , K + and NH4 + It contains one or more of the following, M' contains a transition metal and selectively contains one or more of V, Ti, Mn, Fe, Co, Ni, Cu, and Zn, and Y contains a halogen atom and selectively contains one or more of F, Cl, and Br.

[0195] The modified compounds for each of the above positive electrode active materials may be obtained by doping and / or surface coating the positive electrode active material.

[0196] 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 the following: elemental sulfur, sulfur-carbon composite material, sulfur-conductive polymer composite material, and sulfur-metal oxide composite material.

[0197] In some embodiments, the positive electrode film layer further selectively comprises a positive electrode conductive agent. The type of positive electrode conductive agent is not particularly limited in this application, and examples include one or more of the following: superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0198] In some embodiments, the positive electrode film layer further selectively comprises a positive electrode binder. The type of positive electrode binder is not particularly limited in this application, and as an example, the positive electrode binder may include one or more of the following: polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorine-containing acrylate resins.

[0199] In some embodiments, a metal foil or a composite current collector can be used as the positive electrode current collector. An example of a metal foil is aluminum foil. The composite current collector may include a polymer material substrate layer and a metal material layer formed on at least one surface of the polymer material substrate layer. For example, the metal material may include one or more of aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. For example, the polymer material substrate layer may include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0200] For example, the positive electrode film layer may be obtained by coating a positive electrode slurry onto a positive electrode current collector, drying, and cold pressing. The positive electrode slurry is usually formed by dispersing a positive electrode material, a selective conductive agent, a selective binder, and any other components in a solvent and stirring them uniformly. The solvent may, but is not limited to, N-methylpyrrolidone (NMP).

[0201] [Negative electrode sheet] In some embodiments, the negative electrode sheet may include a negative electrode current collector and a first metal layer provided on at least one surface of the negative electrode current collector, and the metal elements in the first metal layer may include one or more alkali metal elements and alkaline earth metal elements.

[0202] In some embodiments, the metallic material in the first metallic layer may include one or more of the following: elemental lithium, lithium alloy, elemental sodium, sodium alloy, elemental potassium, potassium alloy, elemental magnesium, and magnesium alloy.

[0203] Lithium alloys may be alloys formed from metallic lithium and other metallic or nonmetallic elements. For example, the other metallic elements in a lithium alloy may include one or more of tin, zinc, aluminum, magnesium, silver, gold, gallium, indium, and platinum, and the nonmetallic elements in a lithium alloy may include one or more of boron, carbon, and silicon.

[0204] A sodium alloy may be an alloy formed from metallic sodium and other metallic or nonmetallic 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 nonmetallic elements in the sodium alloy may include one or more of boron, carbon, and silicon.

[0205] Potassium alloys may be alloys formed from metallic magnesium and other metallic or nonmetallic elements. For example, the other metallic elements in a magnesium alloy may include one or more of tin, zinc, aluminum, sodium, lithium, silver, gold, gallium, indium, and platinum, and the nonmetallic elements in a potassium alloy may include one or more of boron, carbon, and silicon.

[0206] A magnesium alloy may be an alloy formed from metallic magnesium and other metallic or nonmetallic elements. For example, the other metallic elements in a magnesium alloy may include one or more of tin, zinc, aluminum, sodium, lithium, silver, gold, gallium, indium, and platinum, and the nonmetallic elements in a magnesium alloy may include one or more of boron, carbon, and silicon.

[0207] In some embodiments, the negative electrode sheet may be assembled and formed by including a negative electrode current collector but not including a first metal layer, thereby forming a negative electrode-free metal battery cell.

[0208] In some embodiments, the negative electrode current collector may include a metal foil, a three-dimensional porous current collector, or a composite current collector. Examples of metal foils include copper foil, copper alloy foil, nickel foil, and nickel alloy foil. Examples of three-dimensional porous current collectors include copper mesh, nickel mesh, foamed copper, and foamed nickel. The composite current collector may include a polymer material substrate layer and a metal material layer formed on at least one surface of the polymer material substrate layer. For example, the metal material may include one or more of copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. For example, the polymer material substrate layer may include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0209] In some embodiments, the surface of the negative electrode current collector may further have a conductive coating to promote uniform metal deposition. The conductive coating may contain conductive carbon, which may contain one or more of carbon fibers, carbon nanotubes, graphene, and fullerene.

[0210] [Separator] The battery cell may further include a separator. The separator may be placed between the positive electrode sheet and the negative electrode sheet and primarily serves to prevent internal short circuits. In this application, the type of separator is not particularly limited, and any known porous structure membrane having good chemical and mechanical stability can be selected.

[0211] In some embodiments, the separator material may include one or more of the following: glass fiber, nonwoven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and polyimide. The separator may be a single-layer film or a multilayer composite film. If the separator is a multilayer composite film, the materials of each layer may be the same or different.

[0212] Methods for manufacturing battery cells are well known. In some embodiments, a battery cell may be formed by assembling a positive electrode sheet, a separator, a negative electrode sheet, and an electrolyte. For example, a battery cell may be obtained by forming an electrode assembly from a positive electrode sheet, a separator, and a negative electrode sheet through a winding process and / or a lamination process, placing the electrode assembly in an outer casing, injecting an electrolyte after oven drying, and then going through processes such as vacuum packaging, settling, chemical conversion, and molding. Multiple battery cells may be further assembled into a battery module by series connection, parallel connection, or mixed connection. Multiple battery modules may be further formed into a battery pack by series connection, parallel connection, or mixed connection. In some embodiments, multiple battery cells may be directly assembled into a battery pack.

[0213] Electrical equipment Embodiments of this application further provide an electrical device comprising one or more of the battery cells, battery modules, or battery packs provided in the embodiments of this application. The battery cells, battery modules, or battery packs may be used as a power source for the electrical device or as an energy storage unit for the electrical device. The electrical device may be, but is not limited to, mobile devices (e.g., mobile phones, tablet computers, laptop computers, etc.), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), trains, ships and satellites, energy storage systems, etc.

[0214] The electrical device may be configured with battery cells, battery modules, or battery packs as needed for its use.

[0215] Figure 6 is a schematic diagram of an example of an electrical device. This electrical device may be a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. To meet the requirements for high power output and high energy density, this electrical device may use a battery pack or battery module.

[0216] Other examples of electrical devices may include mobile phones, tablet computers, and laptop computers. These electrical devices are typically required to be lightweight and thin, and may use battery cells as a power source.

[0217] Examples The following examples illustrate the disclosures of this application in more detail. These examples are for illustrative purposes only, as it will be obvious to those skilled in the art that various modifications and changes can be made within the scope of the disclosures of this application. Unless otherwise noted, all parts, percentages and ratios reported in the following examples are by weight, and all reagents used in the examples are either commercially available or obtained by conventional methods and can be used as is without further processing, and all equipment used in the examples is commercially available.

[0218] Example 1 (1) Preparation of the electrolyte 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 bisfluorosulfonyliimide salt was added to 5 ml of the solvent and stirred thoroughly to form a colorless, transparent electrolyte with a concentration of 1.5 mol / L.

[0219] (2) Manufacturing of positive electrode sheets 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 reaction system was homogeneous to obtain a positive electrode slurry with a solid content of 70%. The positive electrode slurry was uniformly applied to two surfaces of the aluminum foil of the positive electrode current collector, dried, then transferred to an oven for further drying, and then cut into 40mm x 50mm rectangles for use as positive electrode sheets. The application amount was 25mg / cm². 2 That was the case.

[0220] (3) Manufacturing of negative electrode sheets A 50μm thick lithium foil was laminated with a 12μm thick copper foil using a roll press method, and then cut into a 41mm x 51mm rectangle to prepare for use as a negative electrode sheet.

[0221] (4) Manufacturing of separators A porous polyethylene membrane was cut into 45mm x 55mm rectangles and prepared for use as a separator.

[0222] (5) Battery manufacturing One pre-cut positive electrode sheet was laminated with two pre-cut negative electrode sheets, and the positive and negative electrode sheets were separated with a separator to obtain an electrode assembly. The electrode assembly was placed in an aluminum plastic film pouch, 0.30 g of the prepared electrolyte was injected, and then, after processes such as vacuum hot press packaging and standing (at least 6 hours), a battery was obtained. The rated capacity of the battery was 140 mAh.

[0223] Cycle life measurement At 25°C, the manufactured battery was charged with a constant current of 0.2C (28mA) to 4.5V, and then charged with a constant voltage until the current became 0.1C (14mA). At this point, the battery was fully charged, and the charge capacity at this time, i.e., the first charge capacity, was recorded. After letting the battery stand for 5 minutes, it was discharged with a constant current of 1C (140mA) to 2.8V. This constituted one charge-discharge cycle, and the discharge capacity at this time, i.e., the first discharge capacity, was recorded. The battery's cycle charge-discharge measurement was performed according to the above method, and the discharge capacity for each cycle was recorded. The process was stopped until the battery's discharge capacity had decreased to 80% of the first discharge capacity, and the number of cycles at this point indicated the battery's cycle life.

[0224] Examples 2-45 The battery manufacturing method and measurement method are similar to those in Example 1, except for the difference in the electrolyte composition; please refer to Table 1 for details.

[0225] C-1 is This represents JPEG2026509902000014.jpg28170, and C-2 is This represents JPEG2026509902000015.jpg27170.

[0226] The content of the first, second, and third solvents is based on the total weight of the solvents.

[0227] PS stands for propanesultone, DTD stands for ethylene sulfate, and TMSP stands for tris(trimethylsilyl)phosphate.

[0228] The additive content is based on the total weight of the electrolyte.

[0229] Comparative Example 1 The battery manufacturing method and measurement method are similar to those in Example 1, except that the electrolyte composition is different.

[0230] The first solvent B-5 and the second solvent C-1 were thoroughly mixed in a 50:50 weight ratio to form a solvent. 1.4025 g of lithium bisfluorosulfonyliimide salt was added to 5 ml of the solvent and stirred thoroughly to form a colorless, transparent electrolyte with a concentration of 1.5 mol / L.

[0231] Comparative Example 2 The battery manufacturing method and measurement method are similar to those in Example 1, except that the electrolyte composition is different.

[0232] 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 bisfluorosulfonyliimide salt was added to 5 ml of the solvent and stirred thoroughly to form a colorless, transparent electrolyte with a concentration of 1.5 mol / L.

[0233] Comparative Example 3 1.4025 g of lithium bisfluorosulfonyliimide salt was added to 5 ml of 1,2-dimethoxyethane and stirred thoroughly to form a colorless, transparent electrolyte with a concentration of 1.5 mol / L.

[0234] Comparative Example 4 Ethylene carbonate and ethylmethyl 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 with a concentration of 1.0 mol / L. [Table 1] JPEG2026509902000017.jpg206170

[0235] The measurement results from Examples 1-45 and Comparative Examples 1-4 show that using the first solvent as the main solvent can improve the battery's cycle performance.

[0236] Summarizing the measurement results from Examples 1-4, it can be seen that by adjusting the weight content of the first, second, and third solvents, the effects of each component can be better utilized, and the battery's cycle performance can be further improved.

[0237] Summarizing the measurement results from Examples 1, 5-7, it can be seen that the battery's cycle performance can be further improved when the solvent contains the first, second, and third solvents simultaneously.

[0238] Summarizing the measurement results from Examples 1, 8-13, it can be seen that the battery's cycle performance can be further improved by adjusting the electrolyte concentration.

[0239] Summarizing the measurement results from Examples 1, 14-24, it can be seen that the battery's cycle performance can be further improved when the first solvent contains A-1, A-2, A-5, A-6, A-7, and A-11.

[0240] Summarizing the measurement results from Examples 1, 25-31, it can be seen that the battery's cycle performance can be further improved when the second solvent contains dimethylpropane, diethylethane, B-2, and B-5.

[0241] Summarizing the measurement results from Examples 1 and 32-34, it can be seen that the battery's cycle performance can be further improved when the third solvent contains C-1 and C-2.

[0242] Summarizing the measurement results from Examples 1, 35-36, it can be seen that the battery's cycle performance can be further improved when the electrolyte salt contains lithium bisfluorosulfonylimide (LiFSI).

[0243] Summarizing the measurement results from Examples 1, 37-45, it can be seen that the battery's cycle performance can be further improved when the electrolyte contains a small amount of film-forming additive.

[0244] It should be noted that this application is not limited to the embodiments described above. The embodiments described above are merely illustrative, and all embodiments having substantially the same technical idea and achieving the same function and effect within the scope of the technical solution of this application are included in the technical scope of this application. Furthermore, other forms that are constructed by adding various modifications to the embodiments that a person skilled in the art could conceive of, and by combining some of the components of the embodiments, are also included in the scope of this application, without departing from the gist of this application. [Explanation of Symbols]

[0245] In drawings, the figures are not necessarily drawn according to actual proportions. The explanation of the reference numbers is as follows: 1 Battery pack 2. Top box 3. Lower box 4 Battery Modules 5 battery cells 51 cases 52 Electrode assembly 53 Lid plate.

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 20% or more of the total weight of the solvent.

2. The first solvent comprises one or more of the organosiloxane compounds shown in formula (I), 【Chemistry 1】 R １ , R ２ , R ３ , R ４ Each independently contains one of the following: a hydrogen atom, a C1-C10 alkyl group, a C1-C10 alkoxy group, a C2-C10 alkoxyalkyl group, and a group shown in formula (a), and R １ , R ２ , R ３ , R ４ At least one of them contains a C1-C10 alkoxy, one of the groups shown in formula (a), 【Chemistry 2】 # represents the connection position, L １ , L ２ each independently represents one of C1-C10 alkylene, C1-C10 alkyleneoxy, C2-C10 alkyleneoxyalkylene, R １１ , R １２ , R ２１ , R ２２ , R ２３ each independently contains one of a hydrogen atom, C1-C10 alkyl, C1-C10 alkoxy, C2-C10 alkoxyalkyl, m and p each independently represent 0 or 1, n and q each independently represent 0 or an integer of 1 to 5, and n and q are not simultaneously 0. The electrolytic solution according to claim 1.

3. The first solvent is, (1) R １ , R ２ , R ３ , R ４ However, each independently contains one of the groups shown in formula (a): C1-C5 alkyl, C1-C5 alkoxy, C2-C5 alkoxyalkyl, (2) R １ , R ２ , R ３ , R ４ Two of them independently contain a C1-C10 alkoxy, one of the groups shown in formula (a), (3) Caution １ , R ２ , R ３ , R ４ Two of them independently contain one of the C1-C5 alkoxy groups shown in formula (a). (4) L １ , L ２ However, each independently represents one of the following: C1-C5 alkylene, C1-C5 alkylene oxy, or C2-C5 alkylene oxyalkylene. (5) L １ , L ２ However, each independently represents a C2-C3 alkylene oxy, (6) R １１ , R １２ , R ２１ , R ２２ , R ２３ However, each independently contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl. (7) R １１ , R １２ , R ２１ , R ２２ However, each independently contains a C1-C5 alkyl group, R ２３ It contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl. (8) m and p are not both zero at the same time. (9) n and q each independently represent 0, 1, or 2, and n and q are never 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 from 1 to 5, p is 1, and q is an integer from 1 to 5. The electrolyte according to claim 2, satisfying at least one of the following conditions.

4. The base shown in formula (a) is (1) m, n, and p are all 0, and q is 1 or 2, R ２１ , R ２２ , R ２３ However, each independently contains one of the following: C1-C10 alkyl, C1-C10 alkoxy, or C2-C10 alkoxyalkyl. (2) m, n, and p are all 0, and q is 1 or 2, R ２１ , R ２２ , R ２３ However, each independently contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl. (3) m, n, and p are all 0, and q is 1 or 2, R ２１ , R ２２ However, each independently contains a C1-C5 alkyl group, R ２３ It contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl. (4) m and n are both 0, p is 1, q is 1 or 2, L ２ However, R represents one of the following: C1-C10 alkylene, C1-C10 alkylene oxy, or C2-C10 alkylene oxyalkylene. ２１ , R ２２ , R ２３ However, each independently contains one of the following: C1-C10 alkyl, C1-C10 alkoxy, or C2-C10 alkoxyalkyl. (5) m and n are both 0, p is 1, q is 1 or 2, L ２ However, R represents one of the following: C1-C5 alkylene, C1-C5 alkylene oxy, or C2-C5 alkylene oxyalkylene. ２１ , R ２２ , R ２３ However, each independently contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl. (6) m and n are both 0, p is 1, q is 1 or 2, L ２ However, R represents one of the following: C1-C5 alkylene, C1-C5 alkylene oxy, or C2-C5 alkylene oxyalkylene. ２１ , R ２２ However, each independently contains a C1-C5 alkyl group, R ２３ It contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl. (7) m and n are both 0, p is 1, q is 1 or 2, L ２ This represents C2-C3 alkylene oxy, R ２１ , R ２２ However, each independently contains a C1-C5 alkyl group, R ２３ It contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl. (8) m is 0, n is 1 or 2, p is 1, q is 1 or 2, L ２ However, R represents one of the following: C1-C10 alkylene, C1-C10 alkylene oxy, or C2-C10 alkylene oxyalkylene. １１ , R １２ , R ２１ , R ２２ , R ２３ However, each independently contains one of the following: C1-C10 alkyl, C1-C10 alkoxy, or C2-C10 alkoxyalkyl. (9) m is 0, n is 1 or 2, p is 1, q is 1 or 2, L ２ However, R represents one of the following: C1-C5 alkylene, C1-C5 alkylene oxy, or C2-C5 alkylene oxyalkylene. １１ , R １２ , R ２１ , R ２２ , R ２３ However, each independently contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl. (10) m is 0, n is 1 or 2, p is 1, q is 1 or 2, L ２ However, R represents one of the following: C1-C5 alkylene, C1-C5 alkylene oxy, or C2-C5 alkylene oxyalkylene. １１ , R １２ , R ２１ , R ２２ However, each independently contains a C1-C5 alkyl group, R ２３ However, it contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl. where m is 0, n is 1 or 2, p is 1, q is 1 or 2, and L ２ represents C2-C3 alkyleneoxy, and R １１ , R １２ , R ２１ , R ２２ each independently contains C1-C5 alkyl, and R ２３ contains one of C1-C5 alkyl, C1-C5 alkoxy, and C2-C5 alkoxyalkyl where 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, and R １１ , R １２ , R ２１ , R ２２ , R ２３ each independently contains 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 However, each independently represents one of the following: C1-C5 alkylene, C1-C5 alkylene oxy, and C2-C5 alkylene oxyalkylene. １１ , R １２ , R ２１ , R ２２ , R ２３ However, each independently contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl. (14) m is 1, n is 1 or 2, p is 1, q is 1 or 2, L １ , L ２ However, each independently represents one of the following: C1-C5 alkylene, C1-C5 alkylene oxy, and C2-C5 alkylene oxyalkylene. １１ , R １２ , R ２１ , R ２２ However, each independently contains a C1-C5 alkyl group, R ２３ It contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl. (15) m is 1, n is 1 or 2, p is 1, q is 1 or 2, L １ , L ２ However, each independently represents a C2-C3 alkylene oxy, R １１ , R １２ , R ２１ , R ２２ However, each independently contains a C1-C5 alkyl group, R ２３ It contains one of the following: C1-C5 alkyl, C1-C5 alkoxy, or C2-C5 alkoxyalkyl. The electrolyte according to claim 2 or 3, satisfying at least one of the following conditions.

5. Let x be the number of silicon atoms in the first solvent, and let y be the number of oxygen atoms in the first solvent. Then the first solvent is: (1) 0.5 ≤ y / x ≤ 4, selectively, 1 ≤ y / x ≤ 2. (2) 1 ≤ x ≤ 10, selectively 1 ≤ x ≤ 5, more selectively 1 ≤ x ≤ 3, (3) 1 ≤ y ≤ 20, selectively 1 ≤ y ≤ 10, more selectively 1 ≤ y ≤ 6, The electrolyte according to any one of claims 1 to 4, satisfying at least one of the following conditions.

6. The first solvent is, It contains one or more of the organosiloxane compounds shown, The electrolyte according to any one of claims 1 to 5, wherein the first solvent selectively comprises 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% to 80% of the total weight of the solvent, and selectively 50% to 70%.

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

9. The solvent further comprises a second solvent and / or a third solvent, and selectively, the solvent further comprises the second solvent and the third solvent simultaneously. The second solvent comprises one or more ester compounds and halogenated ester compounds, ether compounds, and first fluoroether compounds, wherein the molecular structure of the first fluoroether compound does not have a fluorine atom directly bonded to the α-carbon atom directly bonded to the oxygen atom on the ether oxygen bond functional group, and selectively comprises one or more ether compounds and first fluoroether compounds. The electrolyte according to any one of claims 1 to 7, wherein the third solvent comprises one or more of alkanes and halogenated alkane compounds, aromatic hydrocarbons and halogenated aromatic hydrocarbon compounds, and second fluoroether compounds, wherein the molecular structure of the second fluoroether compound has at least one fluorine atom directly bonded to the α-carbon atom directly bonded to the oxygen atom on the ether oxygen bond functional group, and optionally comprises one or more of the second fluoroether compounds.

10. The ester and halogenated ester compounds include one or more of carbonate esters and halogenated carbonate ester compounds, carboxylic acid esters and halogenated carboxylic acid ester compounds, and selectively include one or more of dimethyl carbonate, diethyl carbonate, ethylmethyl carbonate, ethylene carbonate, vinylene carbonate, propylene carbonate, fluoroethylene carbonate, difluoroethylene carbonate, methyltrifluoroethyl carbonate, ethyltrifluoroethyl carbonate, bis(2,2,2-trifluoroethyl) carbonate, methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl 2,2,2-trifluoroacetate, ethyl 2,2,2-trifluoroethyl acetate, and / or The ether compounds include 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 optionally one or more of dimethoxypropane and diethoxyethane, and / or The first fluoroether compound is It comprises one or more of the compounds, selectively comprising one or more of B-2 and B-5, and / or The alkane and halogenated alkane compounds include one or more of cyclohexane and decafluoropentane, and / or The aforementioned aromatic hydrocarbons and halogenated aromatic hydrocarbon compounds include one or more of benzene, toluene, p-xylene, m-xylene, o-xylene, fluorobenzene, p-difluorobenzene, m-difluorobenzene, o-difluorobenzene, trifluorotoluene, and / or, The second fluoroether compound is 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, ethyltrifluoromethyl ether, difluoromethyl-2,2,3,3,3-pentafluoropropyl ether, heptafluoropropyl-1,2,2,2-tetrafluoroethyl ether, difluoro The electrolyte according to claim 9, comprising one or more of methyl 2,2,3,3-tetrafluoropropyl ether, perfluoroisopropyl methyl ether, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, ethyl-1,1,2,2-tetrafluoroethyl ether, ethyl-2,2,2-tetrafluoroethyl ether, and bis(1,1,2,2-tetrafluoroethyl) ether, and selectively comprising 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.

11. The second solvent comprises one or more of dimethoxypropane, diethoxyethane, B-2, and B-5, and / or The electrolyte according to claim 10, wherein the third solvent comprises 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. In the total weight of the aforementioned solvent, the content of the second solvent is 40% or less, selectively 10% to 30%, and / or The electrolyte according to any one of claims 9 to 11, wherein the content of the third solvent is 40% or less in the total weight of the solvent, and is selectively 10% to 30%.

13. The electrolyte further contains an additive, the additive comprising one or more of propanesultone, ethylene sulfate, ethylene sulfite, tris(trimethylsilyl) phosphate, tris(trimethylsilyl) phosphite, tris(trifluoroethyl) phosphate, tris(trifluoroethyl) phosphite, tris(trimethylsilyl) borate, dimethylmaleic anhydride, and 1,4-diisocyanatobutane. The electrolyte according to any one of claims 1 to 12, wherein the content of the additive is selectively 5% or less in the total weight of the electrolyte, and selectively 0.5% to 3%.

14. The electrolyte contains a first anion, and the first anion contains one or more of the following: bisfluorosulfonylimide anion, bistrifluoromethanesulfonylimide anion, bisoxalatoborate anion, difluorooxalatoborate anion, difluorobisoxalatophosphate anion, tetrafluorooxalatophosphate anion, difluorophosphate anion, hexafluorophosphate anion, tetrafluoroborate anion, hexafluoroarsenate anion, and trifluoromethanesulfonate anion. Selectively, the first anion comprises one or more of bisfluorosulfonyliimide anions and / or bistrifluoromethanesulfonyliimide anions. The electrolyte according to any one of claims 1 to 13, wherein selectively, the molar concentration of the first anion in the electrolyte is 0.5 mol / L to 4 mol / L, selectively 0.8 mol / L to 2.4 mol / L, and more selectively 1.2 mol / L to 1.8 mol / L.

15. The electrolyte according to any one of claims 1 to 14, wherein the electrolyte comprises a first cation, the first cation comprises one or more alkali metal ions and alkaline earth metal ions, and selectively comprises one or more lithium ions, sodium ions, potassium ions, and magnesium ions, and more selectively comprises lithium ions.

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 cell includes a metal battery cell, a metal-air battery cell, a metal-sulfur battery cell, and a negative electrode-free metal battery cell, and optionally includes a lithium metal battery cell, a negative electrode-free lithium metal battery cell, a lithium-air battery cell, and a lithium-sulfur battery cell.

18. A battery comprising the battery cell described in claim 16 or 17.

19. An electrical device comprising the battery described in claim 18.

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