Battery and electric device

Abstract

A battery and an electric device. The battery comprises an electrolyte solution, wherein the electrolyte solution comprises a first diluent, the first diluent comprising at least one of the compounds represented by formulas (I) to (IV), where R11, R12, R13, R14, R21, R22, R23, R24, R31, R32, R33, R34, R35, R41, R42, R43 and R44 each independently comprise any one of H, F, Cl, Br, I, an alkyl having 1-3 carbon atoms, and a haloalkyl having 1-3 carbon atoms, and at least one of R11, R12, R13 and R14 comprises any one of an haloalkyl having 1-3 carbon atoms, F, Cl, Br and I. The battery comprising the electrolyte solution has good cycle life.

Description

Batteries and electrical devices

[0001] Priority information

[0002] This application claims priority and benefits of patent application 202311180181.6 filed with the State Intellectual Property Office of China on September 13, 2023, and the entire text of which is incorporated herein by reference. Technical Field

[0003] The present application belongs to the technical field of secondary batteries, and specifically relates to a battery and an electrical device. Background Art

[0004] Secondary batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as in military equipment, aerospace and other fields.

[0005] Diluents are commonly used in the electrolyte of secondary batteries. However, existing secondary batteries containing diluents have a short cycle life.

[0006] Summary of the Invention

[0007] In view of the technical problems existing in the background technology, the present application provides a battery, aiming to solve the problem of short cycle life of the battery containing the battery.

[0008] To achieve the above objectives, the first aspect of the present application provides a battery, comprising an electrolyte, wherein the electrolyte comprises a first diluent, and the first diluent comprises at least one of the compounds represented by Formula I to Formula IV:

[0009] In Formula I, R 11 、R 12 、R 13 、R 14 Each independently includes any one of H, F, Cl, Br, I, an alkyl group of 1-3 carbon atoms, and a haloalkyl group of 1-3 carbon atoms, and R 11 , R 12 , R 13 and R 14 At least one of a haloalkyl group containing 1 to 3 carbon atoms, F, Cl, Br, and I;

[0010] In formula II, R 21 、R 22 、R 23 、R 24 Each independently includes any one of H, F, Cl, Br, I, an alkyl group of 1 to 3 carbon atoms, and a haloalkyl group of 1 to 3 carbon atoms;

[0011] In formula III, R 31 、R 32 、R 33 、R 34 、R 35 Each independently includes any one of H, F, Cl, Br, I, an alkyl group of 1 to 3 carbon atoms, and a haloalkyl group of 1 to 3 carbon atoms;

[0012] In formula IV, R 41 、R 42 、R 43 and R 44 Each independently includes any one of H, F, Cl, Br, I, an alkyl group of 1 to 3 carbon atoms, and a haloalkyl group of 1 to 3 carbon atoms.

[0013] The present application includes at least the following beneficial effects: In the present application, the electrolyte includes a first diluent, and the lithium salt has a low solubility in the first diluent, so that the first diluent has little effect on the concentration of the lithium salt in the electrolyte. It can reduce the viscosity of the electrolyte and improve the wettability without changing the solvation structure of the electrolyte, thereby improving the cycle performance of the battery containing it.

[0014] In some embodiments of the present application, in Formula II, R 21 , R 22 , R 23 and R 24 At least one of the alkyl halide groups includes 1 to 3 carbon atoms, F, Cl, Br, and I. Thus, the cycle life of the secondary battery can be improved.

[0015] In some embodiments of the present application, in Formula III, R 31 , R 32 , R 33 , R 34 and R 35 At least one of the alkyl halide groups includes 1 to 3 carbon atoms, F, Cl, Br, and I. Thus, the cycle life of the secondary battery can be improved.

[0016] In some embodiments of the present application, in Formula IV, R 41 , R 42 , R 43 and R 44 At least one of the alkyl halide groups includes 1 to 3 carbon atoms, F, Cl, Br, and I. Thus, the cycle life of the secondary battery can be improved.

[0017] In some embodiments of the present application, the compound represented by Formula I includes at least one of compounds I5 to I12:

[0018] Therefore, the first diluent uses at least one of the above substances, which can improve the cycle life of the secondary battery.

[0019] In some embodiments of the present application, the compound represented by formula II includes at least one of compounds II1 to II12:

[0020] Therefore, the first diluent uses at least one of the above substances, which can improve the cycle life of the secondary battery.

[0021] In some embodiments of the present application, the compound represented by formula III includes at least one of compounds III1 to III12:

[0022] Therefore, the first diluent uses at least one of the above substances, which can improve the cycle life of the secondary battery.

[0023] In some embodiments of the present application, the compound represented by formula IV includes at least one of compounds IV1 to IV12:

[0024] Therefore, the first diluent uses at least one of the above substances, which can improve the cycle life of the secondary battery.

[0025] In some embodiments of the present application, the electrolyte further includes a lithium salt, and the lithium salt includes at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethylsulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorophosphate, lithium difluorodioxalatophosphate, or lithium tetrafluorooxalatophosphate. Thus, the cycle life of the secondary battery can be improved.

[0026] In some embodiments of the present application, the electrolyte further includes a solvent, and the solvent includes at least one of methyl n-butyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol dimethyl ether, 1,2-dimethoxypropane, or 1,3-dimethoxypropane. As such, these substances have excellent solubility for lithium salts and strong antioxidant properties, thereby improving the cycle life of the secondary battery.

[0027] In some embodiments of the present application, the electrolyte further comprises a solvent, and the molar ratio of the solvent to the first diluent is 0.2-2. Thus, within the above-mentioned molar ratio of the lithium salt to the solvent, a locally high-concentration electrolyte can be formed. This electrolyte has the advantages of both high lithium salt concentration and low viscosity, thereby improving the cycle life of the secondary battery.

[0028] In some embodiments of the present application, the electrolyte further comprises a lithium salt and a solvent, wherein the molar ratio of the lithium salt to the solvent is 1:(0.8-3). Thus, within the above-mentioned molar ratio of the lithium salt to the solvent, a locally high-concentration electrolyte can be formed. This electrolyte combines the advantages of high lithium salt concentration and low viscosity, thereby improving the cycle life of the secondary battery.

[0029] In some embodiments of the present application, the electrolyte further includes a second diluent, which includes at least one of 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, 1-(1,1,2,2-tetrafluoroethoxy) propane, 1,1,2,2-tetrafluoroethyl ethyl ether, bis(2,2,2-trifluoroethyl) ether, benzene or anisole. Thus, the second diluent and the first diluent are used in combination so that the electrolyte has a low melting point and a high boiling point, which broadens the application scenarios of the electrolyte and improves the cycle life of the secondary battery. In addition, the price of the second diluent is low, which reduces the cost of the electrolyte.

[0030] In some embodiments of the present application, in the electrolyte, the ratio of the amount of the second diluent to the amount of the first diluent is b, 0 < b ≤ 2. Therefore, when the ratio of the amount of the second diluent to the amount of the first diluent is within the above range, the secondary battery has a long cycle life.

[0031] In some embodiments of the present application, in the electrolyte, the amount of the solvent is m, the amount of the first diluent is p, and the amount of the second diluent is q, and 0.2 ≤ m / (p + q) ≤ 2. Within the above range of the amount ratio of the solvent to the diluent (the first diluent and the second diluent), the cycle life of the secondary battery can be improved.

[0032] In some embodiments of the present application, the battery includes a lithium metal negative electrode plate, which includes a negative electrode current collector and an active material layer disposed on at least a portion of the surface of the negative electrode current collector. The active material layer includes at least one of elemental lithium metal or a lithium metal alloy. The low operating voltage and high specific capacity of lithium are utilized to significantly increase the energy density of the battery.

[0033] In some embodiments of the present application, the lithium metal alloy has a chemical formula of LiR, wherein R comprises at least one of tin, zinc, aluminum, magnesium, silver, gold, gallium, indium, platinum, boron, carbon, or silicon. Thus, the battery has an excellent cycle life.

[0034] A second aspect of the present application provides an electrical device comprising the battery described in the first aspect.

[0035] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0037] FIG1 is a schematic structural diagram of a battery cell according to an embodiment of the present application;

[0038] FIG2 is a schematic structural diagram of a battery module according to an embodiment of the present application;

[0039] FIG3 is a schematic structural diagram of a battery pack according to an embodiment of the present application;

[0040] FIG4 is an exploded view of FIG3 ;

[0041] FIG5 is a schematic diagram of an embodiment of an electric device using a battery as a power source;

[0042] FIG6 is a scanning electron microscope image of the negative electrode sheet of the secondary battery of Example 2 of the present application after 30 cycles;

[0043] FIG7 is a scanning electron microscope image of the negative electrode sheet of the secondary battery of Example 3 of the present application after 30 cycles;

[0044] FIG8 is a scanning electron microscope image of the negative electrode sheet of the secondary battery of Example 15 of the present application after 30 cycles.

[0045] Explanation of reference numerals: 1: battery pack; 2: upper case; 3: lower case; 4: battery module; 5: battery cell. DETAILED DESCRIPTION

[0046] The following embodiments of the technical solution of the present application are described in detail. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only used as examples and are not intended to limit the scope of protection of the present application.

[0047] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0048] For the sake of clarity, only some numerical ranges are specifically disclosed herein. However, any lower limit may be combined with any upper limit to form an unspecified range; and any lower limit may be combined with other lower limits to form an unspecified range, and similarly, any upper limit may be combined with any other upper limit to form an unspecified range. In addition, each individually disclosed point or single value may itself serve as a lower limit or upper limit and be combined with any other point or single value, or with other lower limits or upper limits, to form an unspecified range.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0050] With the technological advancements and increasing demand for electric vehicles and rechargeable mobile devices, secondary batteries, as a representative of the new energy sector, have seen rapid growth in research. Secondary batteries offer a wide range of applications due to their compact size and weight, making them easy to carry and use. Their high specific energy content allows for greater energy storage capacity, and lithium-ion batteries exhibit no memory effect, requiring no full discharge and recharge.

[0051] In secondary batteries, taking lithium batteries as an example, Li + The solvation structure of Li plays an important role in determining the characteristics of the solid electrolyte interface (SEI). In low lithium salt concentration electrolytes, due to the presence of a large amount of solvent, Li + It is easy to form a solvent-based solvation sheath, and then a SEI film produced by solvent decomposition is usually obtained; with the increase of lithium salt concentration, due to the lack of free solvent, a higher concentration is conducive to more anions participating in Li + The surrounding solvation sheath can generate an anion-derived SEI film dominated by inorganic components, thus realizing Li + However, electrolytes with high lithium salt concentrations often have problems such as high viscosity, low wettability, and low ionic conductivity.

[0052] In the present application, the electrolyte includes a first diluent, and the first diluent adopts a five-membered ring. The two conjugated double bonds on the five-membered ring of Formula I to Formula IV can delocalize the lone pair of electrons of the heteroatom, significantly weakening the solubility of the first diluent for lithium salts and improving their antioxidant properties. The solubility of lithium salts in the first diluent is low, and the viscosity of the electrolyte can be reduced and the wettability can be improved without changing the solvation structure of the electrolyte, thereby improving the cycle performance of the battery containing it.

[0053] The battery disclosed in the embodiments of the present application can be used in electrical devices that use the battery as a power source or various energy storage systems that use the battery as an energy storage element. Electrical devices may include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, battery cars, electric cars, ships, spacecraft, and the like. Among them, electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like, and spacecraft may include airplanes, rockets, space shuttles, and spacecraft, and the like.

[0054] In a first aspect, the present application provides a battery comprising an electrolyte, wherein the electrolyte comprises a first diluent, and the first diluent comprises at least one of the compounds represented by Formula I to Formula IV:

[0055] In Formula I, R 11 、R 12 、R 13 、R 14 Each independently includes any one of H, F, Cl, Br, I, an alkyl group of 1-3 carbon atoms, and a haloalkyl group of 1-3 carbon atoms, and R 11 , R 12 , R 13 and R 14 At least one of a haloalkyl group containing 1 to 3 carbon atoms, F, Cl, Br, and I;

[0056] In formula II, R 21 、R 22 、R 23 、R 24 Each independently includes any one of H, F, Cl, Br, I, an alkyl group of 1 to 3 carbon atoms, and a haloalkyl group of 1 to 3 carbon atoms;

[0057] In formula III, R 31 、R 32 、R 33 、R 34 、R 35 Each independently includes any one of H, F, Cl, Br, I, an alkyl group of 1 to 3 carbon atoms, and a haloalkyl group of 1 to 3 carbon atoms;

[0058] In formula IV, R 41 、R 42 、R 43 、R 44 Each independently includes any one of H, F, Cl, Br, I, an alkyl group of 1 to 3 carbon atoms, and a haloalkyl group of 1 to 3 carbon atoms.

[0059] It can be understood that, in the haloalkyl group of 1-3 carbon atoms, the haloalkyl group refers to an alkyl group in which at least one H atom is replaced by a halogen atom. As an example, the halogen atom may include F, Cl, Br, and I.

[0060] The present application includes at least the following beneficial effects: in the electrolyte of the present application, the first diluent includes at least one of the compounds shown in Formula I to Formula IV, O in Formula I, S in Formula II, N in Formula III, and S=O in Formula IV have weak electron-donating capabilities and good compatibility with the electrolyte, while Formula I to Formula IV use five-membered ring small molecules, the two conjugated double bonds on the five-membered ring can delocalize the lone pair of electrons of heteroatoms (atoms other than carbon atoms, for example, O atoms in Formula I), significantly weaken the first diluent's ability to dissolve lithium salts, and improve the first diluent's antioxidant properties. The first diluent, as an inert component in the electrolyte, does not participate in the reaction, and can reduce the viscosity of the electrolyte and improve the wettability without changing the electrolyte solvation structure, which is conducive to the production of an anion-derived SEI film mainly composed of inorganic components, realizing Li + The uniform and rapid transport of ions improves the cycle performance of batteries containing them.

[0061] In some embodiments of the present application, in Formula I, R 11 , R 12 , R 13 and R 14 At least one of the halogenated alkyl groups including 1 to 3 carbon atoms, F, Cl, Br, and I. Specifically, halogens such as F, Cl, Br, and I are electron-withdrawing groups. The substitution of electron-withdrawing groups on the five-membered ring reduces the electron-donating ability of the heteroatom, thereby reducing the solubility of the lithium salt in the first diluent, while improving the antioxidant performance of the first diluent, thereby improving the cycle life of the secondary battery.

[0062] In addition, the above-mentioned halogen substitution can improve the redox stability of the electrolyte and reduce the flammability of the electrolyte. The first diluent containing halogen has better SEI stability and high conductivity, which can further improve the cycle life of the secondary battery.

[0063] In addition, when the first diluent contains a halogenated alkyl group with 1-3 carbon atoms, the boiling point of the first diluent can be increased, and an electrolyte with a wide melting and boiling point can be formed, which broadens the application scenarios of the electrolyte and improves the cycle life of the secondary battery. The price of the second diluent is low, which reduces the cost of the electrolyte.

[0064] In some embodiments of the present application, in Formula II, R 21 , R 22 , R 23 and R 24At least one of the halogenated alkyl groups including 1 to 3 carbon atoms, F, Cl, Br, and I. Specifically, halogens such as F, Cl, Br, and I are electron-withdrawing groups. The substitution of electron-withdrawing groups on the five-membered ring can reduce the solubility of the lithium salt in the first diluent, improve the antioxidant performance of the first diluent, and thus increase the cycle life of the secondary battery.

[0065] In some embodiments of the present application, in Formula III, R 31 , R 32 , R 33 , R 34 and R 35 At least one of the halogenated alkyl groups including 1 to 3 carbon atoms, F, Cl, Br, and I. Specifically, halogens such as F, Cl, Br, and I are electron-withdrawing groups. The substitution of electron-withdrawing groups on the five-membered ring can reduce the solubility of the lithium salt in the first diluent, improve the antioxidant performance of the first diluent, and thus increase the cycle life of the secondary battery.

[0066] In some embodiments of the present application, in Formula IV, R 41 , R 42 , R 43 、R 44 At least one of the halogenated alkyl groups including 1 to 3 carbon atoms, F, Cl, Br, and I. Specifically, halogens such as F, Cl, Br, and I are electron-withdrawing groups. The substitution of electron-withdrawing groups on the five-membered ring can reduce the solubility of the lithium salt in the first diluent, improve the antioxidant performance of the first diluent, and thus increase the cycle life of the secondary battery.

[0067] In some embodiments of the present application, the compound represented by Formula I includes at least one of compounds I5 to I12:

[0068] Specifically, the above substances are low in cost and easily available. The first diluent uses at least one of the above substances, which can improve the cycle life of the secondary battery.

[0069] In some embodiments of the present application, the compound represented by formula II includes at least one of compounds II1 to II12:

[0070] Specifically, the above substances are low in cost and easily available. The first diluent uses at least one of the above substances, which can improve the cycle life of the secondary battery.

[0071] In some embodiments of the present application, the compound represented by formula III includes at least one of compounds III1 to III12:

[0072] Specifically, the above substances are low in cost and easily available. The first diluent uses at least one of the above substances, which can improve the cycle life of the secondary battery.

[0073] In some embodiments of the present application, the compound represented by formula IV includes at least one of compounds IV1 to IV12:

[0074] Specifically, the above substances are low in cost and easily available. The first diluent uses at least one of the above substances, which can improve the cycle life of the secondary battery.

[0075] It is understood that the compounds represented by the above formulas I to IV in the examples of the present application can be purchased or prepared by commonly used preparation methods in the art.

[0076] In some embodiments of the present application, the electrolyte further includes a lithium salt, and the lithium salt includes at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonyl imide, lithium bistrifluoromethylsulfonyl imide, lithium trifluoromethanesulfonate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorophosphate, lithium difluorodioxalatophosphate or lithium tetrafluorooxalatophosphate. Specifically, the above-mentioned lithium salt has low solubility in the first diluent, and the lithium salt-solvent cluster is dispersed in the first diluent. The introduction of the first diluent reduces the total salt concentration in the electrolyte while retaining the local coordination environment of the high concentration salt-solvent cluster in the electrolyte, which can improve the cycle life of the secondary battery. In some other embodiments of the present application, the lithium salt includes at least one of lithium bisfluorosulfonyl imide or lithium difluorooxalatoborate.

[0077] In some embodiments of the present application, the electrolyte further includes a solvent, and the solvent includes at least one of methyl n-butyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol dimethyl ether, 1,2-dimethoxypropane, or 1,3-dimethoxypropane. Therefore, the above-mentioned substances are ether solvents, have good solubility for lithium salts, and have strong antioxidant properties, which can improve the cycle life of the secondary battery.

[0078] In addition, the first diluent of the present application has good compatibility with the solvent in the electrolyte, so that the electrolyte forms a clear and uniform solution, reduces the probability of phase separation, and makes the electrolyte have sufficient stability; the first diluent has a low viscosity, which reduces the overall viscosity of the electrolyte.

[0079] In some embodiments of the present application, the electrolyte further comprises a solvent, and the ratio of the amount of the solvent to the first diluent is 0.2-2. Specifically, the ratio of the amount of the solvent to the first diluent can be 0.2-1.9, 0.3-1.8, 0.4-1.7, 0.5-1.6, 0.6-1.5, 0.7-1.4, 0.8-1.3, 0.9-1.2, 1-1.1, etc. Thus, within the range of the above-mentioned ratio of the amount of the lithium salt to the solvent, a locally high-concentration electrolyte can be formed. This electrolyte has the advantages of both high lithium salt concentration and low viscosity, and can improve the cycle life of the secondary battery. In addition, on the one hand, the solubility of the first diluent for the lithium salt can be reduced, thereby improving the oxidation resistance of the electrolyte. On the other hand, the boiling point of the electrolyte caused by excessive content can be reduced, thereby reducing the probability of battery gas production and thermal runaway, thereby further improving the cycle performance of the battery.

[0080] In some embodiments of the present application, the electrolyte further includes a lithium salt and a solvent, and the molar ratio of the lithium salt to the solvent is 1:(0.8-3). Specifically, the molar ratio of the lithium salt to the solvent can be 1:(0.8-2.9), 1:(1-2.5), 1:(1.5-2), 1:(1.8-2), etc. Within the above-mentioned molar ratio range of the lithium salt to the solvent, a local high-concentration electrolyte can be formed, the concentration of the lithium salt in the solvent is high (greater than 3 mol / L), the solubility of the lithium salt in the first diluent is low, and the lithium salt-solvent clusters are dispersed in the first diluent. The introduction of the first diluent reduces the total salt concentration in the electrolyte while retaining the local coordination environment of the high-concentration salt-solvent clusters in the electrolyte, which can improve the cycle life of the secondary battery. In other embodiments of the present application, the molar ratio of the lithium salt to the solvent is 1:(1-2).

[0081] In some embodiments of the present application, the electrolyte further includes a second diluent, which includes at least one of 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, 1-(1,1,2,2-tetrafluoroethoxy) propane, 1,1,2,2-tetrafluoroethyl ethyl ether, bis(2,2,2-trifluoroethyl) ether, benzene or anisole. Specifically, the second diluent and the first diluent are both used as inert components and are used in combination. On the one hand, while not changing the solvation structure of the electrolyte, the viscosity of the electrolyte can be reduced and the wettability can be improved, which is conducive to the production of an anion-derived SEI film based on inorganic components, and the realization of Li +On the other hand, the first diluent has a high melting point and the second diluent has a low melting point. The two are used together to make the electrolyte have a low melting point and a high boiling point, which broadens the application scenarios of the electrolyte. In addition, the price of the second diluent is low, which reduces the cost of the electrolyte.

[0082] In some embodiments of the present application, the amount of concentration of the lithium salt in the diluent (the first diluent and / or the second diluent) is lower than 0.25M. For example, the amount of concentration of the lithium salt in the diluent (the first diluent and / or the second diluent) is 0.02M-0.25M, 0.05M-0.2M, 0.15M-0.2M, etc., which can reduce the viscosity of the electrolyte and improve the wettability without changing the solvation structure of the electrolyte, thereby facilitating the formation of an anion-derived SEI film mainly composed of inorganic components, and realizing Li + The uniform and rapid transport of ions improves the cycle performance of batteries containing them.

[0083] In some embodiments of the present application, in the electrolyte, the ratio b of the amount of the second diluent to the amount of the first diluent is 0<b≤2. Specifically, b can satisfy 0<b≤1.9, 0.1≤b≤1.8, 0.3≤b≤1.6, 0.5≤b≤1.5, 0.7≤b≤1.3, 0.8≤b≤1, etc. The ratio of the amount of the second diluent to the amount of the first diluent is within the above range, so that the electrolyte has a low melting point and a high boiling point, which broadens the application scenarios of the electrolyte, and can also form a locally high-concentration electrolyte, thereby improving the cycle life of the secondary battery. In addition, the price of the second diluent is low, which reduces the cost of the electrolyte.

[0084] In some embodiments of the present application, in the electrolyte, the amount of the solvent is m, the amount of the first diluent is p, and the amount of the second diluent is q, and 0.2≤m / (p+q)≤2. For example, the value of m / (p+q) can be 0.2-1.9, 0.3-1.7, 0.5-1.5, 0.7-1.4, 0.9-1.3, 1-1.2, etc., and m / (p+q) represents the ratio of the amount of the solvent and the diluent (the first diluent and the second diluent) in the electrolyte. Within the range of the above-mentioned ratio of the amount of the solvent and the diluent, a locally high-concentration electrolyte can be formed, the lithium salt has low solubility in the diluent, and the lithium salt-solvent clusters are dispersed in the diluent. The diluent can reduce the total salt concentration in the electrolyte while retaining the local coordination environment of the high-concentration salt-solvent clusters in the electrolyte, which can improve the cycle life of the secondary battery. In some other embodiments of the present application, m / (p+q)=0.2-1.

[0085] In some embodiments of the present application, the electrolyte further includes additives. For example, the additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives capable of improving certain battery properties, such as additives that improve battery overcharge performance, additives that improve battery high-temperature performance, and additives that improve battery low-temperature performance.

[0086] The electrolyte proposed in this application can be prepared by the following method:

[0087] At room temperature, in a stirring mixing tank, the solvent and the diluent are evenly mixed, and then the lithium salt is added thereto and stirred and dissolved to obtain an electrolyte.

[0088] A battery is a battery that can be recharged to activate the active materials after discharge and continue to be used.

[0089] It can be understood that the battery proposed in this application is a lithium-ion battery.

[0090] Typically, a battery cell consists of a positive electrode sheet, a negative electrode sheet, a separator, and an electrolyte. During the battery's charge and discharge process, active metal ions (lithium ions) are inserted and removed between the positive and negative electrode sheets. The separator is placed between the positive and negative electrode sheets to isolate them. The electrolyte conducts the active metal ions between the positive and negative electrode sheets.

[0091] [Positive electrode]

[0092] In some embodiments of the present application, the positive electrode plate includes a positive electrode current collector, which can be a metal foil, a metal foam or a composite current collector. For example, as the metal foil, aluminum or stainless steel with a silver surface treatment, stainless steel, copper, aluminum, nickel, carbon electrode, carbon or titanium, etc. can be used. The composite current collector may include a polymer material base layer and a metal layer. The foam metal may be nickel foam, copper foam, aluminum foam, alloy foam, etc. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0093] In some embodiments of the present application, the positive electrode plate may further include a positive electrode active material layer, and the positive electrode active material layer includes a positive electrode active material. The specific type of the positive electrode active material is not limited, and active materials known in the art that can be used for battery positive electrodes can be used. Those skilled in the art can select according to actual needs.

[0094] The positive electrode active material may include, but is not limited to, at least one of a lithium transition metal oxide, an olivine-structured lithium-containing phosphate, and their respective modified compounds. Examples of lithium transition metal oxides may include, but are not limited to, at least one of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and their modified compounds. Examples of olivine-structured lithium-containing phosphates may include, but are not limited to, at least one of lithium iron phosphate, a composite material of lithium iron phosphate and carbon, lithium manganese phosphate, a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, a composite material of lithium iron manganese phosphate and carbon, and their modified compounds. These materials can all be obtained through commercial channels.

[0095] The battery's charge and discharge processes are accompanied by the intercalation and deintercalation of Li, and the Li content varies when the battery is discharged to different states. In the examples of this application, the Li content in the positive electrode materials listed is the initial state of the material, that is, the state before the material is added. When the positive electrode material is used in a battery system, the Li content will change after charge and discharge cycles.

[0096] In the examples of the present application regarding the positive electrode materials, the molar content of O is only a theoretical value. Lattice oxygen release will cause the molar content of oxygen to change, and the actual molar content of O will fluctuate.

[0097] The modified compounds of the above materials may be doping-modified and / or surface-coated modified materials.

[0098] The positive electrode active material layer may also optionally include a binder, a conductive agent, and other optional auxiliary agents.

[0099] As an example, the conductive agent may include at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, Super P (SP), graphene, and carbon nanofibers.

[0100] As an example, the adhesive may include at least one of styrene-butadiene rubber (SBR), water-based acrylic resin, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), ethylene-vinyl acetate copolymer (EVA), polyacrylic acid (PAA), carboxymethyl cellulose (CMC), polyvinyl alcohol (PVA), and polyvinyl butyral (PVB).

[0101] [Negative electrode]

[0102] The negative electrode sheet includes a negative electrode current collector and an active material layer disposed on at least one surface of the negative electrode current collector, wherein the active material layer includes a negative electrode active material.

[0103] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the active material layer is provided on either or both of the two facing surfaces of the negative electrode current collector.

[0104] In some embodiments of the present application, the negative electrode current collector may be a metal foil or a composite current collector. For example, copper foil may be used as the metal foil. The composite current collector may include a polymer base layer and a metal layer formed on at least one surface of the polymer base material. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer base material (such as a base material of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0105] In some embodiments of the present application, the active material layer includes a negative electrode active material, and the negative electrode active material can be a negative electrode active material for a battery that is well known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate. The silicon-based material can be selected from at least one of elemental silicon, silicon oxides, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material can be selected from at least one of elemental tin, tin oxides, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries can also be used. These negative electrode active materials can be used alone or in combination of two or more.

[0106] In some embodiments of the present application, the battery includes a lithium metal negative electrode plate, and the lithium metal negative electrode plate includes a negative electrode current collector and an active material layer provided on at least a portion of the surface of the negative electrode current collector, and the active material layer includes at least one of a single lithium metal or a lithium metal alloy. By utilizing the low operating voltage and high specific capacity of lithium, the energy density of the battery is greatly improved. In addition, using the electrolyte of the present application, the solubility of the lithium metal negative electrode plate in the diluent (the first diluent and / or the second diluent) is poor, and the use of the diluent of the present application is conducive to the generation of a solid electrolyte interface layer (SEI) with good mechanical strength and chemical stability, optimizing the performance of the SEI, reducing the probability of lithium dendrites in the lithium metal negative electrode plate, and reducing the battery life attenuation caused by lithium consumption.

[0107] In some embodiments of the present application, the lithium metal alloy has the chemical formula LiR, where R comprises at least one of tin, zinc, aluminum, magnesium, silver, gold, gallium, indium, platinum, boron, carbon, or silicon. The active material layer employs the aforementioned lithium metal alloy. The lithium alloy has a higher potential than lithium, exhibits excellent electrolyte stability, and exhibits low side reactions. This improves the stability of the lithium metal negative electrode, reduces the likelihood of lithium dendrites forming in the negative electrode sheet, and thus increases the cycle life of the secondary battery.

[0108] By using the lithium metal negative electrode plate of the present application, lithium is not easily dissolved in the first diluent and / or the second diluent, nor is it easily reacted with the first diluent and / or the second diluent, which significantly reduces the lithium corrosion phenomenon that occurs during the long cycle of the battery. The electrolyte and the negative electrode have good compatibility, and at the same time optimize the performance of the SEI film, inhibit the growth of lithium dendrites, and improve the cycle life of the secondary battery.

[0109] In addition, the lithium metal negative electrode plate of the present application is used in combination with an ether solvent (at least one of methyl n-butyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol dimethyl ether, 1,2-dimethoxypropane or 1,3-dimethoxypropane) in the electrolyte to reduce the viscosity of the electrolyte and achieve better cycle effect of the lithium metal battery.

[0110] In some embodiments of the present application, when a lithium metal negative electrode sheet is used, the preparation method is as follows: lithium foil or lithium metal alloy is coated on a current collector by single-sided rolling, and then cut into negative electrode sheets.

[0111] In some embodiments of the present application, when the negative electrode active material is at least one of artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, the active material layer may further optionally include a binder. The binder may be selected from at least one of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS).

[0112] In some embodiments of the present application, when the negative electrode active material is at least one of artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, the active material layer may further optionally include a conductive agent. The conductive agent may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0113] In some embodiments of the present application, the active material layer may optionally further include other auxiliary agents, such as a thickener (eg, sodium carboxymethyl cellulose (CMC-Na)).

[0114] In some embodiments of the present application, when the negative electrode active material adopts at least one of artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based material, tin-based material and lithium titanate, the negative electrode plate can be prepared by the following method: the above-mentioned components for preparing the negative electrode plate, such as the negative electrode active material, the conductive agent, the binder and any other components are dispersed in a solvent (such as deionized water) to form a negative electrode slurry; the negative electrode slurry is coated on the negative electrode collector, and after drying, cold pressing and other processes, the negative electrode plate can be obtained.

[0115] [Isolation film]

[0116] As the above-mentioned isolation membrane, the present application has no special restrictions and any known porous structure isolation membrane with electrochemical stability and mechanical stability can be selected according to actual needs. For example, it can include a single-layer or multi-layer film containing at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.

[0117] In some embodiments of the present application, the charge and discharge rate of the battery cell should be controlled between 0.01C and 8C. For example, the discharge rate can be 0.01C-7.9C, 0.1C-7.5C, 0.5C-7C, 1C-6.5C, 1.5C-6C, 2C-5C, 3C-4C, etc.

[0118] In some embodiments of the present application, the ambient temperature of the battery cell cycle should be controlled between 0°C and 80°C. For example, the ambient temperature of the cycle can be 1°C-80°C, 5°C-75°C, 10°C-70°C, 20°C-60°C, 30°C-50°C, etc.

[0119] The embodiment of the present application has no particular limitation on the shape of the battery cell, which can be cylindrical, square or any other shape. FIG1 shows a battery cell 5 with a square structure as an example.

[0120] In some embodiments of the present application, the battery cell 5 may include an outer packaging for packaging the positive electrode sheet, the negative electrode sheet, and the electrolyte.

[0121] In some embodiments of the present application, the outer packaging may include a housing and a cover. The housing may include a bottom plate and side plates connected to the bottom plate, with the bottom plate and side plates enclosing a receiving cavity. The housing may have an opening communicating with the receiving cavity, and the cover may be positioned over the opening to seal the receiving cavity.

[0122] The positive electrode sheet, negative electrode sheet, and separator can be wound or laminated to form an electrode assembly. The electrode assembly is encapsulated in the housing. The number of electrode assemblies contained in a battery cell can include one or more, which can be adjusted according to demand.

[0123] In some embodiments of the present application, the outer packaging of the battery cell may include a hard shell, such as a hard plastic shell, an aluminum shell, or a steel shell.

[0124] The outer packaging of the battery cell 5 may also include a soft bag, such as a bag-type soft bag. The material of the soft bag may be plastic, such as at least one of polypropylene (PP), polybutylene terephthalate (PBT), and polybutylene succinate (PBS).

[0125] In some embodiments of the present application, battery cells may be assembled into a battery module. The battery module may contain multiple batteries, and the specific number may be adjusted according to the application and capacity of the battery module.

[0126] Figure 2 shows an example battery module 4. Referring to Figure 2 , within the battery module 4, multiple battery cells 5 may be arranged sequentially along the length of the battery module 4. Of course, they may also be arranged in any other manner. Furthermore, the multiple battery cells 5 may be secured together using fasteners.

[0127] The battery module 4 may further include a housing having a housing space, wherein a plurality of battery cells 5 are housed in the housing space. In some embodiments of the present application, the battery modules may be assembled into a battery pack, and the number of battery modules contained in the battery pack may be adjusted according to the application and capacity of the battery pack.

[0128] Figures 3 and 4 illustrate an example battery pack 1. Referring to Figures 3 and 4 , the battery pack 1 may include a battery box and multiple battery modules 4 disposed within the battery box. The battery box comprises an upper case 2 and a lower case 3. The upper case 2 can be positioned over the lower case 3 to form an enclosed space for accommodating the battery modules 4. The multiple battery modules 4 can be arranged in any manner within the battery box.

[0129] In a third aspect, the present application provides an electrical device comprising the battery described in the second aspect. Specifically, the battery can serve as a power source for the electrical device, or as an energy storage unit for the electrical device. The electrical device may include, but is not limited to, mobile devices (e.g., mobile phones, laptops), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks), electric trains, ships, satellites, and energy storage systems.

[0130] FIG5 shows an example of an electric device, which includes a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle.

[0131] As another example, electric devices may include mobile phones, tablet computers, and laptop computers. These electric devices are generally required to be lightweight and thin, and may use batteries as power sources.

[0132] In order to make the technical problems, technical solutions and beneficial effects solved by the embodiments of the present application clearer, the following will be further described in detail with reference to the embodiments and drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present application and its applications. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0133] Example 1

[0134]

Positive electrode preparation

[0135] The positive electrode active material lithium iron phosphate (LFP), the conductive agent acetylene black, and the binder polyvinylidene fluoride were mixed in a mass ratio of 98:1:1, and the solvent N-methylpyrrolidone was added and stirred until the system became uniform to obtain a positive electrode slurry. The positive electrode slurry was evenly coated on both sides of the positive electrode current collector aluminum foil, dried at room temperature, and then transferred to an oven for further drying. The positive electrode sheet was then cut into 40mm×50mm rectangles. The positive electrode surface capacity was 3.5mAh / cm 2 .

[0136]

Negative electrode sheet preparation

[0137] A lithium foil with a thickness of 50 μm was coated on a copper foil with a thickness of 12 μm by single-sided rolling, and then cut into a rectangle of 41 mm×51 mm as a negative electrode sheet.

[0138]

Isolation film

[0139] Polyethylene porous membrane is selected as the isolation membrane.

[0140]

Electrolyte preparation

[0141] The solvent and the first diluent are mixed evenly to obtain a transparent solution, which is the mixed solvent. Lithium bis(fluorosulfonyl)imide is added to the mixed solvent and stirred thoroughly to form a transparent electrolyte solution of a certain concentration. The parameters are shown in Table 1.

[0142] A pre-cut positive electrode sheet was paired with two pre-cut negative electrode sheets, separated by the aforementioned separator film. The cells were then wrapped in an aluminum-plastic film bag to form a laminated dry cell. The pre-cut electrolyte was injected at a rate of 2.1 g / Ah, based on the battery's rated capacity. The aluminum-plastic film bag was then vacuum-pressed and sealed. After standing at room temperature for at least 6 hours, cycling testing could begin. The laminated battery prepared in this manner had a rated capacity of 140 mAh.

[0143] The secondary batteries containing electrolytes of Examples 2-43 and Comparative Examples 1-3 are the same as those in Example 1 except for different parameters (see Table 1). In Example 20, the molar ratio of I5 and III5 is 1:1, in Example 21, the molar ratio of I5, II11 and III5 is 1:1:1, in Example 22, the molar ratio of I5, II11, III5 and IV5 is 1:1:1:1, and in Example 43, the molar ratio of lithium bis(fluorosulfonyl)imide and lithium difluorooxalatoborate is 1:1.

[0144] The parameters of the electrolytes of Examples 1-43 and Comparative Examples 1-3 of the present application are shown in Table 1.

[0145] Table 1

[0146] In Table 1, “ / ” indicates that no addition was made.

[0147] The structural formula of the first diluent used in Table 1 is shown in Table 2.

[0148] Table 2

[0149] Performance testing:

[0150] 1. Scanning electron microscope image

[0151] The secondary batteries of Examples 1-2 and 14 were cycled at an ambient temperature of 25°C and subjected to charge-discharge cycles at a rate of 0.5C (i.e., 70 mA). The charge and discharge cutoff voltages were set at 4.3V and 2.8V, respectively. After 30 cycles, the secondary batteries were disassembled, and scanning electron micrographs of the negative electrodes were taken, resulting in Figures 6-8.

[0152] As can be seen from Figures 6-8, after the secondary batteries of Examples 1-2 and Example 14 of the present application were cycled 30 times, no obvious dendritic metallic lithium was seen in the scanning electron microscope of the negative electrode sheet. It can be seen that the use of the lithium metal negative electrode and electrolyte of the present application can reduce the probability of lithium dendrites in the lithium metal negative electrode sheet and reduce the battery life degradation caused by lithium consumption.

[0153] 2.Battery cycle life test:

[0154] Taking Example 1 as an example, the secondary battery was cycled at an ambient temperature of 25°C and at a charge / discharge rate of 0.5C (i.e., 70 mA). The charge and discharge cutoff voltages were set at 4.3V and 2.8V, respectively. The battery life was considered complete when the discharge capacity decayed to 80% of the initial discharge capacity, and the number of cycles at this point was recorded. The cycle life test results for Examples 1-43 and Comparative Examples 1-3 are shown in Table 3.

[0155] Table 3

[0156] As can be seen from Table 3, in Examples 2-43 of the present application, the first diluent is used in the electrolyte, and the battery cycle performance is excellent. In Comparative Example 1, the first diluent in the electrolyte is fluorobenzene, no diluent is added to the electrolyte in Comparative Example 2, and only the second diluent is used in the electrolyte in Comparative Example 3, and the battery cycle performance is significantly lower than that of Example 2-43. This is because, in Example 2-43, the addition of the first diluent allows the two conjugated double bonds on the five-membered ring to delocalize the lone pair electrons of the heteroatom, significantly weakening the first diluent's ability to dissolve lithium salts, improving the antioxidant properties of the first diluent, reducing the viscosity of the electrolyte, and improving the wettability, thereby improving the cycle performance of the battery containing it.

[0157] The cycle performance of the battery of Example 2-43 is better than that of Example 1. This is because the halogen or alkyl halide contained in Example 2-5 can improve the redox stability of the electrolyte and reduce the flammability of the electrolyte, and the first diluent containing halogen has a better SEI stability and high conductivity, which can further improve the cycle life of the secondary battery. The corresponding substances of Examples 6-21 are used as diluents, and the effect of the five-membered ring and conjugated double bond is stronger, and the antioxidant performance is better, which can further improve the cycle life of the secondary battery. The corresponding ratios or material selections of Examples 22-43 are more obvious in matching with the diluent, making the electrolyte more stable and further improving the cycle life of the secondary battery.

[0158] In addition, compared with Examples 2-5, Example 1 has no substituent on the five-membered ring, and the five-membered ring of Examples 2-5 has an electron-withdrawing group or a halogenated alkyl group with 1-3 carbon atoms, and the cycle performance of the secondary battery of Examples 2-5 is further improved; similarly, compared with Examples 7-10, Example 6 has no substituent on the five-membered ring, and the five-membered ring of Examples 7-10 has an electron-withdrawing group or a halogenated alkyl group with 1-3 carbon atoms, and the cycle performance of the secondary battery of Examples 7-10 is further improved; Example 11, Example 14 and Example 12, Example 13, Example 15 Compared with the above, there is no electron-withdrawing group or halogenated alkyl group with 1-3 carbon atoms on the five-membered ring, and the cycle performance of the secondary batteries of Examples 12, 13 and 15 is further improved; Compared with Examples 17-19, Example 16 has no substituent on the five-membered ring, and the five-membered rings of Examples 17-19 have electron-withdrawing groups or halogenated alkyl group with 1-3 carbon atoms, and the cycle performance of the secondary batteries of Examples 17-19 is further improved. It can be seen that substituents such as halogenated alkyl groups with 1-3 carbon atoms, F, Cl, Br, I, etc. on the five-membered ring can improve the cycle life of the secondary battery.

[0159] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery, wherein: The electrolyte includes a first diluent, and the first diluent includes at least one of the compounds shown in Formula I to Formula IV: In Formula I, R 11 , R 12 , R 13 , R 14 Each independently includes any one of H, F, Cl, Br, I, an alkyl group of 1 to 3 carbon atoms, and a halogenated alkyl group of 1 to 3 carbon atoms, and R 11 , R 12 , R 13 and R 14 At least one of the following: a halogenated alkyl group having 1 to 3 carbon atoms, F, Cl, Br, or I; In formula II, R 21 , R 22 , R 23 , R 24 Each independently includes any one of H, F, Cl, Br, I, an alkyl group of 1 to 3 carbon atoms, and a haloalkyl group of 1 to 3 carbon atoms; In Formula III, R 31 , R 32 , R 33 , R 34 , R 35 Each independently includes any one of H, F, Cl, Br, I, an alkyl group of 1 to 3 carbon atoms, and a haloalkyl group of 1 to 3 carbon atoms; In Formula IV, R 41 , R 42 , R 43 , R 44 Each independently includes any one of H, F, Cl, Br, I, an alkyl group having 1 to 3 carbon atoms, and a halogenated alkyl group having 1 to 3 carbon atoms.

2. The battery according to claim 1, wherein In formula II, R 21 , R 22 , R 23 and R 24 At least one of a halogenated alkyl group containing 1 to 3 carbon atoms, F, Cl, Br, I; and / or In Formula III, R 31 , R 32 , R 33 , R 34 and R 35 At least one of a halogenated alkyl group containing 1 to 3 carbon atoms, F, Cl, Br, I; and / or In Formula IV, R 41 , R 42 , R 43 and R 44 At least one of the following is any one of a halogenated alkyl group containing 1 to 3 carbon atoms, F, Cl, Br, and I.

3. The battery according to claim 1, wherein The compound represented by formula I includes at least one of compounds I5 to I12:

4. The battery according to claim 1, wherein The compound represented by formula II includes at least one of compounds II1 to II12:

5. The battery according to claim 1, wherein The compound represented by formula III includes at least one of compounds III1 to III12:

6. The battery according to claim 1, wherein The compound represented by formula IV includes at least one of compounds IV1 to IV12:

7. The battery according to any one of claims 1 to 6, wherein The electrolyte also includes a lithium salt, and the lithium salt includes at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethylsulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorophosphate, lithium difluorobis(oxalatophosphate) or lithium tetrafluorooxalatophosphate.

8. The battery according to any one of claims 1 to 7, wherein The electrolyte further includes a solvent, and the solvent includes at least one of methyl n-butyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol dimethyl ether, 1,2-dimethoxypropane or 1,3-dimethoxypropane.

9. The battery according to any one of claims 1 to 8, wherein The electrolyte further includes a solvent, and the ratio of the amount of the solvent to the first diluent is 0.2-2.

10. The battery according to any one of claims 1 to 9, wherein The electrolyte further includes a lithium salt and a solvent, and the molar ratio of the lithium salt to the solvent is 1:(0.8-3).

11. The battery according to claim 10, wherein The electrolyte also includes a second diluent, which includes at least one of 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, 1-(1,1,2,2-tetrafluoroethoxy)propane, 1,1,2,2-tetrafluoroethyl ethyl ether, bis(2,2,2-trifluoroethyl) ether, benzene or anisole.

12. The battery according to claim 11, wherein In the electrolyte, the ratio of the amount of the second diluent to the amount of the first diluent is b, 0<b≤2.

13. The battery according to claim 11, wherein In the electrolyte, the amount of the solvent is m, the amount of the first diluent is p, and the amount of the second diluent is q, and 0.2≤m / (p+q)≤2.

14. The battery according to any one of claims 1 to 13, wherein The battery comprises a lithium metal negative electrode plate, which comprises a negative electrode current collector and an active material layer disposed on at least a portion of the surface of the negative electrode current collector, wherein the active material layer comprises at least one of single lithium metal or a lithium metal alloy.

15. The battery according to claim 14, wherein The chemical formula of the lithium metal alloy is LiR, and the R includes at least one of tin, zinc, aluminum, magnesium, silver, gold, gallium, indium, platinum, boron, carbon or silicon.

16. An electrical device, wherein: A battery comprising the battery according to any one of claims 1 to 15.

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