Electrolyte solution and battery

Abstract

Electrolyte solution, wherein the electrolyte solution comprises a first additive, wherein the first additive has a structure as shown in Formula 1: wherein in Formula 1 R1 is selected from the group consisting of H, halogen, phenyl, alkylene-phenyl, substituted or unsubstituted saturated C1 to C10 hydrocarbon group, substituted or unsubstituted C2 to C10 alkenyl and substituted or unsubstituted C2 to C10 alkynyl and the substituent is selected from the group consisting of hydroxyl, halogen and a combination thereof; R2, R3, R4, R5, R6 and R7 are each independently selected from the group consisting of H, halogen, saturated C1 to C10 hydrocarbon group, C2 to C10 alkenyl, C2 to C10 alkynyl, halogen-substituted saturated C1 to C10 hydrocarbon group, halogen-substituted C2 to C10 alkenyl and halogen-substituted C2 to C10 alkynyl.

Description

[0001] The present application claims priority from Chinese patent application No. 2023106913559 entitled “ELECTROLYTIC SOLUTION AND BATTERY”, filed with the Chinese Patent Office on June 12, 2023, and claims priority from Chinese patent application No. 2023106913544 entitled “ELECTROLYTIC SOLUTION AND BATTERY”, filed with the Chinese Patent Office on June 12, 2023, which are incorporated in full by reference into this document. TECHNICAL AREA

[0002] The present application relates to an electrolyte solution and a battery and concerns the technical field of batteries. BACKGROUND

[0003] Batteries are widely used as energy supply devices. As one of the key components of a battery, an electrolyte solution includes a non-aqueous solvent, an electrolyte, and an additive. A suitable additive can effectively improve battery performance.

[0004] Phosphate compounds have been widely recognized by those skilled in the art as electrolyte solution additives. For example, Chinese patent publication no. CN114899490A provides a cyclic phosphate additive comprising an unsaturated five-membered cyclic phosphate and its derivatives, which helps to improve the room-temperature cycle performance, high-temperature cycle performance, and high-temperature storage performance of a lithium-ion battery; Chinese patent publication no. CN114824484A provides a cyclic phosphate electrolyte solution additive which helps to improve the room-temperature cycle performance and initial Coulombic efficiency of a lithium-ion battery; Chinese patent publication no.CN115377495A provides a phosphate additive that helps improve the room-temperature cycle stability of a lithium-ion battery with a high-nickel / silicon-carbon ternary system; Chinese patent publication CN115832436A provides an electrolyte solution capable of balancing high-temperature and low-temperature performance, improving the low-temperature discharge performance as well as the room-temperature and high-temperature lifetime of the battery through the combined action of a triphenyl phosphoranylide compound and a compound with a carbonyl group. How to improve the high-temperature and low-temperature performance of a battery using a single-component phosphate compound is one of the research areas for those skilled in the art.

[0005] SUMMARY OF THE INVENTION The present application provides an electrolyte solution that helps to improve the high-temperature and low-temperature performance of a battery.

[0006] The present application also provides a battery containing the aforementioned electrolyte solution.

[0007] A first aspect of the present application provides an electrolyte solution comprising a first additive, and the first additive has the structure shown in Formula 1: wherein in Formula 1 R1 is selected from the group consisting of H, halogen, phenyl, alkylene-phenyl, substituted or unsubstituted saturated C1 to C10 hydrocarbon group, substituted or unsubstituted C2 to C10 alkenyl and substituted or unsubstituted C2 to C10 alkynyl and the substituent is selected from the group consisting of hydroxyl, halogen and a combination thereof; R2, R3, R4, R5, R6 and R7 are independently selected from the group consisting of H, halogen, saturated C1 to C10 hydrocarbon group, C2 to C10 alkenyl, C2 to C10 alkynyl, halogen-substituted saturated C1 to C10 hydrocarbon group, halogen-substituted C2 to C10 alkenyl and halogen-substituted C2 to C10 alkynyl.

[0008] In the electrolyte solution described above, R1 is selected from the group consisting of alkylene-phenyl, substituted or unsubstituted saturated C1 to C10 hydrocarbon group, substituted or unsubstituted C2 to C10 alkenyl and substituted or unsubstituted C2 to C10 alkynyl, and the substituent is selected from the group consisting of hydroxyl, halogen and a combination thereof.

[0009] In the electrolyte solution described above, R1 is selected from the group consisting of substituted or unsubstituted saturated C2 to C4 hydrocarbon groups, C2 to C4 alkenyl and C2 to C4 alkynyl, and the substituent is selected from the group consisting of hydroxyl, halogen and a combination thereof.

[0010] In the electrolyte solution described above, R2, R3, R4, R5, R6 and R7 are independently selected from the group consisting of H, saturated C1 to C10 hydrocarbon group and halogen-substituted C1 to C10 hydrocarbon group.

[0011] In the electrolyte solution described above, the first additive is selected from the group consisting of compounds shown in Formula 1-1 to Formula 1-13, and a combination thereof:

[0012] In the electrolyte solution described above, the mass fraction of the first additive is in the range of 0.1% to 10% of the total mass of the electrolyte solution.

[0013] The electrolyte solution described above further includes a second additive, and the second additive is selected from the group consisting of vinylene carbonate, ethylene sulfate, vinylethylene carbonate, 1,3-propanesultone, fluoroethylene carbonate and a combination thereof.

[0014] In the electrolyte solution described above, the mass ratio of the first additive to the second additive is in the range of 1:0.1 to 1:3.0.

[0015] The electrolyte solution described above also includes a non-aqueous organic solvent and a lithium salt.

[0016] In the electrolyte solution described above, the lithium salt is selected from the group consisting of an inorganic lithium salt, a lithium carboxylate, a lithium sulfonate, a lithium imide, a methylated lithium salt, a lithium borate, a lithium oxalate, a fluorine-containing organic lithium salt and a combination thereof.

[0017] The electrolyte solution described above contains a concentration of the lithium salt in the range of 0.5 M to 2 M.

[0018] In the electrolyte solution described above, the non-aqueous organic solvent is selected from the group consisting of a carbonate compound, a carboxylate compound, an ether compound, a sulfone compound and a combination thereof.

[0019] The electrolyte solution described above further includes a third additive and is the third additive selected from the group consisting of a film-forming additive, a conductive additive, a flame-retardant additive, an overcharge protection additive, an additive to improve high-temperature and low-temperature performance, and a combination thereof.

[0020] A second aspect of the present application provides a battery that incorporates any of the electrolyte solutions described above.

[0021] The phosphate additive for the electrolyte solution provided by the present application has a three-dimensional skeletal structure, as shown in Formula 1. It can not only participate in the formation of the SEI film, but also create cavity channels during the film-forming process and increase the porosity of the SEI film, which is advantageous for improving ion transport efficiency, reducing the influence of temperature on ion transport efficiency, and thereby improving the high-temperature and low-temperature performance of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following section briefly presents the drawings needed to describe the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. The person skilled in the art will also be able to draw other drawings based on these without any creative effort. Fig. 1 is an H-NMR spectrum of the electrolyte solution additive shown in Formula 1-1 and provided by Example 1 of the present application; Fig. 2 is a P-NMR spectrum of the electrolyte solution additive shown in Formula 1-1 and provided by Example 1 of the present application. DETAILED DESCRIPTION

[0023] To clarify the tasks, technical solutions, and advantages of the present application, the embodiments of the present application are combined below to describe the technical solutions in these embodiments unambiguously and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of them. Based on the embodiments in the present application, all other embodiments that the person skilled in the art can implement without creative effort fall within the scope of protection of the present application.

[0024] A first aspect of the present application provides an electrolyte solution comprising an additive, and the additive has a structure shown in Formula 1: wherein in Formula 1 R1 is selected from the group consisting of H, halogen, phenyl, alkylene-phenyl, substituted or unsubstituted saturated C1 to C10 hydrocarbon group, substituted or unsubstituted C2 to C10 alkenyl and substituted or unsubstituted C2 to C10 alkynyl and the substituent is selected from the group consisting of hydroxyl, halogen and a combination thereof; R2, R3, R4, R5, R6 and R7 are each independently selected from the group consisting of H, halogen, saturated C1 to C10 hydrocarbon group, C2 to C10 alkenyl, C2 to C10 alkynyl, halogen-substituted saturated C1 to C10 hydrocarbon group, halogen-substituted C2 to C10 alkenyl and halogen-substituted C2 to C10 alkynyl.

[0025] In the present application, the saturated hydrocarbon group refers to an alkyl group with the corresponding number of carbon atoms with the general structural formula -C n H 2n+1 When an alkyl group is defined with a specific number of carbon atoms, it includes all geometric isomers with that number of carbon atoms. For example, the saturated hydrocarbon group is selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclobutyl, n-pentyl, isopentyl, neopentyl, cyclopentyl, methylcyclopentyl, ethylcyclopentyl, n-hexyl, isohexyl, cyclohexyl, n-heptyl, octyl, and the like. Furthermore, each hydrogen atom in the saturated hydrocarbon group can be substituted.

[0026] In the present application, the alkenyl refers to an unsaturated hydrocarbon group with the corresponding number of carbon atoms, containing one or more carbon-carbon double bonds. For example, the alkenyl is selected from the group consisting of vinyl, n-propenyl, isopropenyl, n-but-2-enyl, but-3-enyl, n-hex-3-enyl, an aromatic hydrocarbon group, and the like. Furthermore, each hydrogen atom in the alkenyl can be substituted.

[0027] In the present application, the alkynyl refers to an unsaturated hydrocarbon group with the corresponding number of carbon atoms, containing one or more carbon-carbon triple bonds. For example, the alkynyl is selected from the group consisting of ethynyl, n-propynyl, isopropynyl, n-but-2-ynyl, but-3-ynyl, n-hex-3-ynyl, and the like. Furthermore, each hydrogen atom in the alkenyl can be substituted.

[0028] In the present application, alkylene refers to a saturated linear or branched divalent group with the corresponding number of carbon atoms, derived from the corresponding alkane by removing two carbon atoms. Alkylene-phenyl refers to an alkylene bonded to an aryl group.

[0029] The phosphate additive for the electrolyte solution provided by the present application has a three-dimensional skeletal structure, as shown in Formula 1. It can not only participate in the formation of the SEI film, but also create cavity channels during the film-forming process and increase the porosity of the SEI film, which is advantageous for improving ion transport efficiency, reducing the influence of temperature on ion transport efficiency, and thereby improving the high-temperature and low-temperature performance of the battery.

[0030] In a specific embodiment, R1 is selected from the group consisting of alkylene-phenyl, substituted or unsubstituted saturated C1 to C10 hydrocarbon group, substituted or unsubstituted C2 to C10 alkenyl and substituted or unsubstituted C2 to C10 alkynyl, and the substituent is selected from the group consisting of hydroxyl, halogen and a combination thereof.

[0031] In a specific embodiment, R1 is selected from the group consisting of substituted or unsubstituted saturated C2 to C4 hydrocarbon groups, C2 to C4 alkenyl and C2 to C4 alkynyl, and the substituent is selected from the group consisting of hydroxyl, halogen and a combination thereof.

[0032] In a specific embodiment, R2, R3, R4, R5, R6 and R7 are each independently selected from the group consisting of H, saturated C1 to C10 hydrocarbon group and halogen-substituted C1 to C10 hydrocarbon group.

[0033] Furthermore, the additive is selected from the group consisting of compounds shown in Formula 1-1 to Formula 1-13, and a combination thereof:

[0034] The compounds represented by formulas 1-1 to 1-13 provided in the present application have suitable substituents which help to further improve the porosity and stability of the SEI film.

[0035] In one specific embodiment, the concentration of the first additive, taking into account its effectiveness, is not less than 0.1%. However, an excessive amount of the first additive increases the viscosity and ionic conductivity of the electrolyte solution, which affects the battery's capacity and impedance. Therefore, the mass fraction of the first additive in the electrolyte solution ranges from 0.1% to 10% of the total mass of the electrolyte solution; specifically, it can be 0.1%, 0.2%, 0.5%, 0.8%, 1.0%, 2.0%, 3.0%, 4.0%, 5.0%, 6.0%, 7.0%, 8.0%, 9.0%, or 10.0%, or any range between these two values.

[0036] Furthermore, the mass fraction of the first additive is in the range of 0.5% to 5% of the total mass of the electrolyte solution.

[0037] In a specific embodiment, the electrolyte solution further comprises a second additive. The second additive is a film-forming additive, in particular selected from the group consisting of vinylene carbonate, ethylene sulfate, vinylethylene carbonate, 1,3-propanesultone, fluoroethylene carbonate, and a combination thereof. Based on the first additive, shown in Formula 1, the combined use with the second additive helps to further improve the high-temperature and low-temperature performance of the battery.

[0038] Furthermore, the second additive tends to generate significant gassing under high-temperature conditions, which affects the battery's high-temperature storage and cycle performance. Therefore, the concentration of the second additive should not be too high. Specifically, the mass ratio of the first additive to the second additive ranges from 1:0.1 to 1:3.0; more precisely, it can be 1:0.1, 1:0.2, 1:0.5, 1:1.0, 1:1.2, 1:1.5, 1:1.8, 1:2.5, 1:2.2, 1:2.5, 1:2.8, or 1:3.0, or any range between these two values.

[0039] Furthermore, the mass ratio of the first additive to the second additive is in the range of 1:0.1 to 1:1.0.

[0040] The electrolyte solution provided by the present application further comprises a non-aqueous organic solvent and a lithium salt. The types of non-aqueous organic solvent and lithium salt can be conventional materials used in the industry. Specifically, the non-aqueous organic solvent is selected from the group consisting of a carbonate compound, a carboxylate compound, an ether compound, a sulfone compound, and a combination thereof.

[0041] Specifically, the carbonate compound is selected from the group consisting of a cyclic carbonate, an acyclic carbonate, and a combination thereof. The cyclic carbonate is selected from the group consisting of ethylene carbonate (EC), propylene carbonate (PC), and a combination thereof; the acyclic carbonate is selected from the group consisting of dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), methyl propyl carbonate (MPC), and a combination thereof.

[0042] The carboxylate compound contains a cyclic carboxylate and an acyclic carboxylate. The cyclic carboxylate is selected from the group consisting of γ-butyrolactone, γ-valerolactone, γ-hexanolactone, ε-caprolactone, and a combination thereof; The acyclic carboxylate is selected from the group consisting of methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, tert-butyl acetate, methyl propionate (PP), ethyl propionate, n-propyl propionate, isopropyl propionate, n-butyl propionate, isobutyl propionate, tert-butyl propionate, methyl butyrate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, methyl isobutyrate, ethyl isobutyrate, n-propyl isobutyrate, isopropyl isobutyrate and a combination thereof.

[0043] The ether compound can be an acyclic ether with 3 to 10 carbon atoms or a cyclic ether with 3 to 6 carbon atoms. For example, the acyclic ether with 3 to 10 carbon atoms is selected from the group consisting of diethyl ether, bis(2-fluoroethyl) ether, bis(2,2-difluoroethyl) ether, bis(2,2,2-trifluoroethyl) ether, ethyl(2-fluoroethyl) ether, ethyl(2,2,2-trifluoroethyl) ether, ethyl(1,1,2,2-tetrafluoroethyl) ether, (2-fluoroethyl)(2,2,2-trifluoroethyl) ether, (2-fluoroethyl)(1,1,2,2-tetrafluoroethyl) ether, (2,2,2-trifluoroethyl)(1,1,2,2-tetrafluoroethyl) ether, ethyl-n-propyl ether, ethyl(3-fluoropropyl) ether, ethyl(3,3,3-trifluoropropyl) ether, ethyl(2,2,3,3-tetrafluoropropyl) ether, ethyl(2,2,3,3,3-pentafluoropropyl) ether, 2-Fluoroethyl-n-propyl ether, (2-fluoroethyl)(3-fluoropropyl) ether, (2-fluoroethyl)(3,3,3-trifluoropropyl) ether, (2-fluoroethyl)(2,2,3,3-tetrafluoropropyl) ether, (2-fluoroethyl)(2,2,3,3,3-pentafluoropropyl) ether, 2,2,2-trifluoroethyl n-propyl ether, (2,2,2-Trifluorethyl)(3-fluorpropyl)ether, (2,2,2-Trifluorethyl)(3,3,3-trifluorpropyl)ether, (2,2,2-Trifluorethyl)(2,2,3,3-tetrafluorpropyl)ether, (2,2,2-Trifluorethyl)(2,2,3,3,3-pentafluorpropyl)ether, 1,1,2,2-Tetrafluorethyl-n-propylether, (1,1,2,2-Tetrafluorethyl)(3-fluorpropyl)ether, (1,1,2,2-Tetrafluorethyl)(3,3,3-trifluorpropyl)ether, (1,1,2,2-Tetrafluorethyl)(2,2,3,3-tetrafluorpropyl)ether, (1,1,2,2-Tetrafluorethyl)(2,2,3,3,3-pentafluorpropyl)ether, Di-n-propylether, (N-Propyl)(3-fluorpropyl)ether, (N-Propyl)(3,3,3-trifluorpropyl)ether, (N-Propyl)(2,2,3,3-tetrafluorpropyl)ether, (N-Propyl)(2,2,3,3,3-pentafluorpropyl)ether, Bis(3-fluorpropyl)ether, (3-Fluorpropyl)(3,3,3-trifluorpropyl)ether, (3-Fluorpropyl)(2,2,3,3-tetrafluorpropyl)ether, (3-Fluorpropyl)(2,2,3,3,3-pentafluorpropyl)ether, Bis(3,3,3-trifluorpropyl)ether, (3,3,3-Trifluorpropyl)(2,2,3,3-tetrafluorpropyl)ether, (3,3,3-Trifluorpropyl)(2,2,3,3,3-pentafluorpropyl)ether, Bis(2,2,3,3-tetrafluorpropyl)ether, (2,2,3,3-Tetrafluorpropyl)(2,2,3,3,3-pentafluorpropyl)ether, Bis(2,2,3,3,3-pentafluorpropyl)ether, Di-n-butylether, Dimethoxymethan, Methoxyethoxymethan, Methoxy(2-fluorethoxy)methan, Methoxy(2,2,2-trifluorethoxy)methan, Methoxy(1,1,2,2-tetrafluorethoxy)methan, Diethoxymethan, Ethoxy(2-fluorethoxy)methan, Ethoxy(2,2,2-trifluorethoxy)methan, Ethoxy(1,1,2,2-tetrafluorethoxy)methan, Bis(2-fluorethoxy)methan, (2-Fluorethoxy)(2,2,2-trifluorethoxy)methan, (2-Fluorethoxy)(1,1,2,2-tetrafluorethoxy)methan, Bis(2,2,2-trifluorethoxy)methan, (2,2,2-Trifluorethoxy)(1,1,2,2-tetrafluorethoxy)methan, Bis(1,1,2,2-tetrafluorethoxy)methan, Dimethoxyethan, Methoxyethoxyethan, Methoxy(2-fluorethoxy)ethan, Methoxy(2,2,2-trifluorethoxy)ethan, Methoxy(1,1,2,2-tetrafluorethoxy)ethan, Diethoxyethan, Ethoxy(2-fluorethoxy)ethan, Ethoxy(2,2,2-trifluorethoxy)ethan, Ethoxy(1,1,2,2-tetrafluorethoxy)ethan, Bis(2-fluorethoxy)ethan, (2-Fluorethoxy)(2,2,2-trifluorethoxy)ethan, (2-Fluorethoxy)(1,1,2,2-tetrafluorethoxy)ethan,Bis(2,2,2-trifluoroethoxy)ethane, (2,2,2-trifluoroethoxy)(1,1,2,2-tetrafluoroethoxy)ethane, bis(1,1,2,2-tetrafluoroethoxy)ethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether and a combination thereof; is the cyclic ether with 3 to 6 carbon atoms selected from the group consisting of tetrahydrofuran, 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, 1,3-dioxolane, 2-methyl-1,3-dioxolane, 4-methyl-1,3-dioxolane, 1,4-dioxane and a combination thereof.

[0044] Furthermore, some hydrogen atoms in the molecular structure of the ether compound may be substituted by fluorine.

[0045] If the ether compound is present as an additional solvent, it is easy to avoid the problem of capacity decrease due to co-intercalation of the ether compound with lithium ions in the case where the active material for negative electrodes is a carbon-containing material.

[0046] The sulfone compound is selected from the group consisting of dimethyl sulfone, ethyl methyl sulfone, diethyl sulfone, n-propyl methyl sulfone, isopropyl methyl sulfone, n-butyl methyl sulfone, tert-butyl methyl sulfone, monofluoromethyl methyl sulfone, difluoromethyl methyl sulfone, trifluoromethyl methyl sulfone, monofluoroethyl methyl sulfone, difluoroethyl methyl sulfone, trifluoroethyl methyl sulfone, pentafluoroethyl methyl sulfone, ethyl monofluoromethyl sulfone, ethyl difluoromethyl sulfone, ethyl trifluoromethyl sulfone, ethyl pentafluoroethyl sulfone, trifluoromethyl n-propyl sulfone, trifluoromethyl isopropyl sulfone, trifluoroethyl n-butyl sulfone, trifluoroethyl tert-butyl sulfone, trifluoromethyl n-butyl sulfone, trifluoromethyl tert-butyl sulfone, and combinations thereof; when the sulfone compound is present as an additive solvent, it can improve the cycle performance and cycle retention of the battery, reduce solution viscosity, and improve electrochemical performance.

[0047] In a preferred embodiment, the solvent used in the present application comprises both a cyclic organic solvent and an acyclic organic solvent. The following are optional solvent combinations: The non-aqueous organic solvent contains ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC) and methyl propionate (PP), and a mass ratio of EC, PC, DEC and PP is in the range of 1 to 10:1 to 10:1 to 10:1 to 10; furthermore, the mass ratio of EC, PC, DEC and PP is in the range of 10:1:1 to 10:1 to 10.

[0048] The non-aqueous organic solvent contains ethylene carbonate (EC), diethyl carbonate (DEC) and ethyl methyl carbonate (EMC) and a mass ratio of EC, DEC and EMC is in the range of 1:0.1 to 10:0.1 to 10; furthermore, the mass ratio of EC, DEC and EMC is in the range of 1:0.2 to 5:0.2 to 5; and furthermore, the mass ratio of EC, DEC and EMC is in the range of 1:0.5 to 2:0.5 to 2.

[0049] The non-aqueous organic solvent contains ethylene carbonate (EC), propylene carbonate (PC) and ethyl methyl carbonate (EMC) and a mass ratio of EC, PC and EMC is in the range of 1:0.1 to 10:0.1 to 10; furthermore, the mass ratio of EC, PC and EMC is in the range of 1:0.2 to 5:0.2 to 5; and furthermore, the mass ratio of EC, PC and EMC is in the range of 1:0.5 to 2:0.5 to 2.

[0050] The non-aqueous organic solvent contains ethylene carbonate (EC), dimethyl carbonate (DMC) and ethyl methyl carbonate (EMC) and a mass ratio of EC, DMC and EMC is in the range of 1:0.1 to 10:0.1 to 10; furthermore, the mass ratio of EC, DMC and EMC is in the range of 1:0.2 to 5:0.2 to 5; and furthermore, the mass ratio of EC, DMC and EMC is in the range of 1:0.5 to 2:0.5 to 2.

[0051] In the present application, the lithium salt may be selected from the group consisting of an inorganic lithium salt, a lithium carboxylate, a lithium sulfonate, a lithium imide, a methylated lithium, a lithium borate, a lithium oxalate, a fluorine-containing organic lithium salt, and a combination thereof. Specifically, the inorganic lithium salt is selected from the group consisting of LiPF6, LiBF4, LiClO4, LiAlF4, LiSbF6, LiTaF6, LiWF7, and a combination thereof; the lithium carboxylate is selected from the group consisting of HCO2Li, CH3CO2Li, CH2FCO2Li, CHF2CO2Li, CF3CO2Li, CF3CH2CO2Li, CF3CF2CO2Li, CF3CF2CF2CO2Li, CF3CF2CF2CO2Li, and a combination thereof. The lithium sulfonate is selected from the group consisting of FSO3Li, CH3SO3Li, CH2FSO3Li, CHF2SO3Li, CF3SO3Li, CF3CF2SO3Li, CF3CF2CF2SO3Li, CF3CF2CF2CF2SO3Li and a combination thereof;The lithium imide is selected from the group consisting of LiN(FCO)2, LiN(FCO)(FSO2), lithium bis(fluorosulfonyl)imide LiN(FSO2)2, LiN(FSO2)(CF3SO2), lithium bis(trifluoromethanesulfonyl)imide LiN(CF3SO2)2, LiN(C2F5SO2)2, lithium 1,1,2,2-tetrafluoroethane-1,2-disulfonimide, lithium 1,1,2,2,3,3-hexafluoropropane-1,3-disulfonimide, LiN(CF3SO2)(C4F9SO2) and a combination thereof; the methylated lithium salt is selected from the group consisting of LiC(FSO2)3, LiC(CF3SO2)3, LiC(C2F5SO2)3 and a combination thereof; the lithium borate is selected from the group consisting of lithium difluoro(oxalato)borate, lithium bis(oxalato)borate and a combination thereof; The lithium oxalate is selected from the group consisting of lithium tetrafluoro(oxalato)phosphate, lithium difluorobis(oxalato)phosphate, lithium tris(oxalato)phosphate and a combination thereof;The fluorine-containing organic lithium salt is selected from the group consisting of LiPF4(CF3)2, LiPF4(C2F5)2, LiPF4(CF3SO2)2, LiPF4(C2FsSO2)2, LiBF3CF3, LiBF3CzF5, LiBF3C3F7, LiBF2(CF3)2, LiBF2(C2F5)2, LiBF2(CF3SO2)2, LiBF2(C2F5SO2)2 and a combination thereof.

[0052] Furthermore, the lithium salt is selected from the group consisting of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis(oxalato)borate, lithium difluoro(oxalate)borate, lithium difluoro(oxalato)phosphate, lithium tetrafluoro(oxalato)phosphate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide and a combination thereof.

[0053] Furthermore, the concentration of the lithium salt is in the range of 0.5 M to 2 M; even further, the concentration of the lithium salt is in the range of 0.5 M to 1.5 M; beyond that, the concentration of the lithium salt is in the range of 0.7 M to 1.5 M.

[0054] In addition, the electrolyte solution provided by the present application further comprises other additives. These other additives are selected from the group consisting of a film-forming additive, a conductive additive, a flame-retardant additive, an overcharge protection additive, an additive for improving high-temperature and low-temperature performance, and a combination thereof. The specific types and amounts can be determined as required.

[0055] In a specific embodiment, the additive for improving high-temperature and low-temperature performance is selected from the group consisting of vinylene carbonate, ethylene sulfate, vinylethylene carbonate, 1,3-propanesultone, fluoroethylene carbonate, and a combination thereof. Using the formula shown in Formula 1 in combination with the aforementioned additives helps to further optimize the high-temperature and low-temperature performance of the battery.

[0056] A second aspect of the present application provides a battery that incorporates any of the electrolyte solutions described above.

[0057] Based on the electrolyte solution provided by the first aspect of the present application, the battery provided by the present application exhibits good high-temperature and low-temperature performance.

[0058] In one specific embodiment, the battery is a lithium-ion battery. In addition to the electrolyte solution provided by the first aspect of the present application, it also includes a positive electrode plate, a negative electrode plate, and a separator. Specifically, this means: The positive electrode plate comprises a current collector with a positive electrode and a layer of active material for positive electrodes arranged on the surface of the current collector with positive electrodes. The active material layer for positive electrodes comprises an active electrode material, a conductive agent, and a binder. The current collector with positive electrodes is generally an aluminum foil. The active electrode material for positive electrodes is selected from lithium transition metal oxides, for example, from the group consisting of LiCoO₂, LiMn₂O₄, LiMnO₂, Li₂MnO₄, LiFePO₄, Li 1+a Mn 1-x M x O2, LiCo 1-x M x O2, LiFe 1-x M x PO4, and Li2Mn 1-x O4, and M is selected from the group consisting of Ni, Co, Mn, Al, Cr, Mg, Zr, Mo, V, Ti, B, F and a combination thereof, 0 ≤ a < 0.2, 0 ≤ x < 1.

[0059] The negative electrode plate comprises a current collector with a negative electrode and a layer of active material for negative electrodes, which is arranged on the surface of the current collector with negative electrodes. The active material layer for negative electrodes comprises an active material for negative electrodes, a conductive agent, and a binder. The current collector with negative electrodes is generally a copper foil. The active material for negative electrodes is selected from the group consisting of a carbon-containing material, a silicon-carbon material, an alloy material, a lithium-containing metal composite oxide, and a combination thereof.

[0060] The selection of the conductive material and the binder in the active material layer for positive electrodes and the active material layer for negative electrodes may involve conventional materials used in engineering.

[0061] The separator is selected from the group consisting of polyolefin, aromatic polyamide, polytetrafluoroethylene, polyethersulfone and a combination thereof, which can be specifically defined according to requirements.

[0062] The following detailed description of the solutions provided by the present application is combined with specific embodiments: Example 1

[0063] The electrolyte solution provided in this embodiment comprises a non-aqueous organic solvent, a lithium salt, and an additive. The non-aqueous organic solvent comprises ethylene carbonate (EC), propylene carbonate (PC), methyl propionate (PP), and diethyl carbonate (DEC), with a mass ratio of EC:PC:PP:DEC of 3:2:5:5. The lithium salt is LiPF6, with a concentration of 1 mol / L. The additive has the structure shown in Formula 1-1, and its mass fraction is 1.0% of the total mass of the electrolyte solution.

[0064] The preparation procedure for the compound shown in Formula 1-1 was as follows: 5 g of 2-ethyl-2-(hydroxymethyl)-1,3-propanediol were added to a three-necked flask, then 25 ml of 1,4-dioxane were added, and the mixture was heated to 95 °C under a nitrogen atmosphere and reacted with an excess of phosphorus oxychloride for 4 hours. Upon completion, the solvent was removed by evaporation, and the crude product obtained was recrystallized with distilled water. The resulting product was then dried under vacuum at 70 °C to obtain a white solid. The white solid was subjected to NMR analysis. The obtained 1H NMR and 3P NMR spectra are shown in Fig. 1 or Fig. Figures 2 are shown, confirming that the compound shown in formula 1-1 was indeed synthesized. The reaction involved is as follows:

[0065] The electrolyte solution formulations provided in Examples 2 to 16 and Comparative Examples 1 to 6 are essentially the same as in Example 1, with the following differences: the type of the first additive used in Examples 2 to 9 is different; the volume ratio of the non-aqueous organic solvent in Example 10 is different; the composition of the non-aqueous organic solvent in Example 11 is different; the type of lithium salt in Example 12 is different; the amount of the first additive used in Examples 13 to 16 is different; the additive with the structure shown in Formula 1 is not added in Comparative Examples 1 and 2; the additives used in Comparative Examples 3 to 6 are compounds used in Formulas 2 to 4. The specific differences are listed in Table 1.

[0066] Examples 17 to 20 further include a second additive; the electrolyte solution formulations provided in Examples 21 to 45 and in Comparative Examples 7 to 9 are essentially the same as those in Example 17, with the following differences: the amounts of the first and second additives in Examples 21 to 33 are different; the volume ratio of the non-aqueous organic solvent in Example 34 is different; the type of the first additive in Examples 35 to 45 is different; only the second additive is included in Comparative Examples 7 to 9, and the first additive is not included. The specific differences are listed in Table 2. Table 1: Composition of the electrolyte solutions provided by Examples 1 to 16 and Comparative Examples 1 to 6 Basic electrolyte solution First additive Content of the first additive Example 1 EC:PC:PP:DEC=3:2:5:5, 1 mol / l LiPF6 Formula 1-1 1,0 % Example 2 EC:PC:PP:DEC=3:2:5:5, 1 mol / l LiPF6 Formula 1-2 1,0 % Example 3 EC:PC:PP:DEC=3:2:5:5, 1 mol / l LiPF6 Formula 1-3 1,0 % Example 4 EC:PC:PP:DEC=3:2:5:5, 1 mol / l LiPF6 Formula 1-4 1,0 % Example 5 EC:PC:PP:DEC=3:2:5:5, 1 mol / l LiPF6 Formula 1-5 1,0 % Example 6 EC:PC:PP:DEC=3:2:5:5, 1 mol / l LiPF6 Formula 1-6 1,0 % Example 7 EC:PC:PP:DEC=3:2:5:5, 1 mol / l LiPF6 Formula 1-7 1,0 % Example 8 EC:PC:PP:DEC=3:2:5:5, 1 mol / l LiPF6 Formula 1-8 1,0 % Example 9 EC:PC:PP:DEC=3:2:5:5, 1 mol / l LiPF6 Formula 1-9 1,0 % Example 10 EC:PC:PP:DEC=18:7:20:20, 1 mol / 1 LiPF6 Formula 1-1 1,0 % Example 11 EC:DEC:EMC=3:2:5, 1 mol / l LiPF6 Formula 1-1 1,0 % Example 12 EC:PC:PP:DEC=3:2:5:5, 1 mol / l LiN(FSO2)2 Formula 1-1 1,0 % Example 13 EC:PC:PP:DEC=3:2:5:5, 1 mol / l LiPF6 Formula 1-1 0,5 % Example 14 EC:PC:PP:DEC=3:2:5:5, 1 mol / l LiPF6 Formula 1-1 2,0 % Example 15 EC:PC:PP:DEC=3:2:5:5, 1 mol / l LiPF6 Formula 1-1 5,0 % Example 16 EC:PC:PP:DEC=3:2:5:5, 1 mol / l LiPF6 Formula 1-1 10,0 % Comparison example 1 EC:PC:PP:DEC=3:2:5:5, 1 mol / l LiPF6 / Comparison example 2 EC:PC:PP:DEC=18:7:20:20, 1 mol / l LiPF6 / Comparison example 3 EC:PC:PP:DEC=3:2:5:5, 1 mol / l LiPF6 Formula 2 1,0 % Comparison example 4 EC:PC:PP:DEC=3:2:5:5, 1 mol / l LiPF6 Formula 3 1,0 % Comparison example 5 EC:PC:PP:DEC=3:2:5:5, 1 mol / l LiPF6 Formula 4 1,0 % Comparison example 6 EC:PC:PP:DEC=3:2:5:5, 1 mol / l LiPF6 Formula 5 1,0 % Table 2: Composition of the electrolyte solutions provided by Examples 17 to 45 and Comparative Examples 7 to 9 Basic electrolyte solution First additive Content of the first additive Second additive Content of the second additive The relationship of the first addendum to the second addendum Example 17 EC:PC:PP:DEC=3:2:5:5 Formula 1-1 1,0 % Ethylene sulfate 1,0 % 1,1 Example 18 EC:PC:PP:DEC=3:2:5:5 Formula 1-1 1,0 % Fluoroethylene carbonate 1,0 % 1,1 Example 19 EC:PC:PP:DEC=3:2:5:5 Formula 1-1 1,0 % 1,3-Propane sultone 1,0 % 1,1 Example 20 EC:PC:PP:DEC=3:2:5:5 Formula 1-1 1,0 % Vinyl carbonate 1,0 % 1,1 Example 21 EC:PC:PP:DEC=3:2:5:5 Formula 1-1 0,50 % Vinyl carbonate 0,50 % 1:1 Example 22 EC:PC:PP:DEC=3:2:5:5 Formula 1-1 0,50 % Vinyl carbonate 1,00 % 1:2 Example 23 EC:PC:PP:DEC=3:2:5:5 Formula 1-1 0,50 % Vinyl carbonate 1,50 % 1:3 Example 24 EC:PC:PP:DEC=3:2:5:5 Formula 1-1 1,00 % Vinyl carbonate 0,50 % 1:0,5 Example 25 EC:PC:PP:DEC=3:2:5:5 Formula 1-1 1,00 % Vinyl carbonate 2,00 % 1:2 Example 26 EC:PC:PP:DEC=3:2:5:5 Formula 1-1 2,00 % Vinyl carbonate 1,00 % 1:0,5 Example 27 EC:PC:PP:DEC=3:2:5:5 Formula 1-1 2,00 % Vinyl carbonate 2,00 % 1:1 Example 28 EC:PC:PP:DEC=3:2:5:5 Formula 1-1 2,00 % Vinyl carbonate 4,00 % 1:2 Example 29 EC:PC:PP:DEC=3:2:5:5 Formula 1-1 0,05 % Vinyl carbonate 0,05 % 1:1 Example 30 EC:PC:PP:DEC=3:2:5:5 Formula 1-1 4,00 % Vinyl carbonate 2,00 % 1:0,5 Example 31 EC:PC:PP:DEC=3:2:5:5 Formula 1-1 5,00 % Vinyl carbonate 2,50 % 1:0,5 Example 32 EC:PC:PP:DEC=3:2:5:5 Formula 1-1 1,00 % Vinyl carbonate 3,00 % 1:3 Example 33 EC:PC:PP:DEC=3:2:5:5 Formula 1-1 1,00 % Vinyl carbonate 4,00 % 1:4 Example 34 EC:DEC:EMC=3:2:5 Formula 1-1 1,00 % Vinyl carbonate 1,00 % 1:1 Example 35 EC:PC:PP:DEC=3:2:5:5 Formula 1-9 1,00 % Vinyl carbonate 0,50 % 1:0,5 Example 36 EC:PC:PP:DEC=3:2:5:5 Formula 1-9 1,00 % Vinyl carbonate 1,00 % 1:1 Example 37 EC:PC:PP:DEC=3:2:5:5 Formula 1-9 1,00 % Vinyl carbonate 2,00 % 1:2 Example 38 EC:PC:PP:DEC=3:2:5:5 Formula 1-4 1,00 % Vinyl carbonate 1,00 % 1:1 Example 39 EC:PC:PP:DEC=3:2:5:5 Formula 1-10 1,00 % Vinyl carbonate 1,00 % 1:1 Example 40 EC:PC:PP:DEC=3:2:5:5 Formula 1-11 1,00 % Vinyl carbonate 1,00 % 1:1 Example 41 EC:PC:PP:DEC=3:2:5:5 Formula 1-5 1,00 % Vinyl carbonate 1,00 % 1:1 Example 42 EC:PC:PP:DEC=3:2:5:5 Formula 1-7 1,00 % Vinyl carbonate 1,00 % 1:1 Example 43 EC:PC:PP:DEC=3:2:5:5 Formula 1-8 1,00 % Vinyl carbonate 1,00 % 1:1 Example 44 EC:PC:PP:DEC=3:2:5:5 Formula 1-12 1,00 % Vinyl carbonate 1,00 % 1:1 Example 45 EC:PC:PP:DEC=3:2:5:5 Formula 1-13 1,00 % Vinyl carbonate 1,00 % 1:1 Comparison example 7 EC:PC:PP:DEC=3:2:5:5 / Vinyl carbonate 0,50 % / Comparison example 8 EC:PC:PP:DEC=3:2:5:5 / Vinyl carbonate 1,00 % / Comparison example 9 EC:PC:PP:DEC=3:2:5:5 / Vinyl carbonate 2,00 % /

[0067] The lithium-ion batteries were assembled using the electrolyte solutions provided in Examples 1-45 and Comparative Examples 1-9, with positive electrode plates, separators, and negative electrode plates. The manufacturing procedure was as follows: The active material slurry for the positive electrodes was prepared by uniformly mixing the positive electrode material (NCM523), the conductive agent SuperP (conductive carbon black), CNT (carbon nanotubes), and the binder PVDF (polyvinylidene fluoride) in a mass ratio of 96.3:2:0.5:1.2. This slurry was applied to the surface of an aluminum foil, dried at 85 °C, and then cold-pressed. Edge finishing, milling, and trimming were then performed. After trimming, the electrode was dried under vacuum at 95 °C for 12 hours, and tabs were welded to form the positive electrode plate with an areal density of 33 mg / cm². 2 to obtain.

[0068] The active material slurry for the negative electrodes was prepared by uniformly mixing graphite, conductive agent SuperP, thickener CMC, and binder SBR (styrene-butadiene rubber emulsion) in a mass ratio of 95:1.5:1.0:2.5. This slurry was applied to the surface of a copper foil, dried at 85 °C, and then cold-pressed. Edge finishing, milling, and trimming were then performed. After trimming, the electrode was vacuum-dried at 85 °C for 12 hours, and tabs were welded to form the negative electrode plate, which has an areal density of 20.3 mg / cm². 2 to obtain.

[0069] The aforementioned positive electrode plate, separator, and negative electrode plate were assembled into a lithium-ion battery measuring 4.7 mm thick, 55 mm wide, and 60 mm long using a stacking process. The theoretical capacity was 1600 mAh. The battery was baked under vacuum at 75 °C for 10 hours, and the aforementioned electrolyte solution was injected. After standing for 24 hours, a pressure of 3 kg / cm² was applied. 2The battery was charged at a constant current of 0.1C for 6 hours, followed by aging at 45°C for 2 days. It was then charged at 0.1C to 4.4V and at a constant voltage until the current dropped to 0.05C (80mA). Subsequently, it was discharged at 0.1C to 3.0V to establish initial coulombic efficiency. Charge and discharge cycles were performed at 0.5C and 1C, each lasting one week. Finally, the battery was charged at 1C to 3.8V for storage, thus completing the battery manufacturing process.

[0070] The manufactured lithium-ion batteries underwent high-temperature and low-temperature performance tests. The test procedures are as follows, and the results are shown in Table 3: Cycle test at 25 °C: At 25 °C, the battery was charged to 4.4 V at a constant current of 1.0 C, then charged at a constant voltage of 4.4 V until the cutoff current reached 0.05 C. The battery was then discharged at a constant current of 1.0 C. The discharge capacity was recorded as C0. The charge-discharge steps were repeated for 500 cycles, and the discharge capacity at the 500th cycle was recorded as C500. The capacity retention rate was calculated as C500 / C0*100.

[0071] Cycle test at 45 °C: At 45 °C, the battery was charged to 4.4 V at a constant current of 1.0 C, then charged at a constant voltage until the cutoff current reached 0.05 C. The battery was then discharged at a constant current of 1.0 C. The discharge capacity was recorded as C0. The charge-discharge steps were repeated for 300 cycles, and the discharge capacity at the 300th cycle was recorded as C300. The capacity retention rate was calculated as C300 / C0 * 100%.

[0072] Capacity retention test after storage at 60 °C for 14 days: At 25 °C, the battery was charged to 4.4 V at a constant current of 1.0 C, then charged at a constant voltage of 4.4 V until the cutoff current reached 0.05 C. The battery was then discharged at a constant current of 1.0 C, and the discharge capacity was recorded as C0. At 25 °C, the battery was charged to 4.4 V at a constant current of 1.0 C, then charged at a constant voltage of 4.4 V until the cutoff current reached 0.05 C. The battery was then brought to 60 °C and stored for 14 days. After storage, the battery was discharged at a constant current of 1.0 C, and the discharge capacity was recorded as C1. The capacity retention after 14 days of storage at 60 °C was calculated as C1 / C0*100%.

[0073] Low-temperature discharge test at -20 °C: At 25 °C, the battery was charged to 4.4 V at a constant current of 1.0 C, then charged at a constant voltage of 4.4 V until the cutoff current reached 0.05 C. The battery was then discharged at a constant current of 0.5 C, and the discharge capacity was recorded as C0. At 25 °C, the battery was charged to 4.4 V at a constant current of 1.0 C, then charged at a constant voltage of 4.4 V until the cutoff current reached 0.05 C. The battery was then cooled to -20 °C and left for 240 minutes. The battery was then discharged at a constant current of 0.5 C, and the discharge capacity was recorded as C1. The discharge rate at -20 °C was calculated as C1 / C0 * 100%. Table 3: Performance test results of the batteries provided in Examples 1-45 and Comparison Examples 1-9 Cycle test at 25 °C Cycle test at 45 °C Capacitive retention rate test after storage at 60 °C for 14 days Low-temperature discharge test at -20 °C Example 1 89 % 75 % 52 % 73 % Example 2 88 % 74 % 51% 72 % Example 3 89 % 74 % 52 % 72 % Example 4 91 % 77 % 55 % 75 % Example 5 86 % 73 % 50 % 70 % Example 6 83 % 71 % 46 % 68 % Example 7 92 % 79 % 58 % 66 % Example 8 91 % 78 % 56 % 63 % Example 9 87 % 74 % 51% 73 % Example 10 88 % 74 % 51% 71 % Example 11 88 % 72 % 54 % 74 % Example 12 82 % 70 % 51% 65 % Example 13 82 % 69 % 50 % 65 % Example 14 85 % 68 % 53 % 69 % Example 15 69 % 60 % 48 % 50 % Example 16 66 % 58 % 43 % 46 % Example 17 91 % 82 % 85 % 82 % Example 18 95 % 85 % 82 % 80 % Example 19 94 % 81 % 89 % 82 % Example 20 95 % 86 % 89 % 84 % Example 21 89 % 79 % 80 % 76 % Example 22 91 % 81 % 84 % 79 % Example 23 91 % 80 % 85 % 78 % Example 24 93 % 83 % 84 % 81 % Example 25 92 % 85 % 83 % 82 % Example 26 90 % 82 % 86 % 80 % Example 27 92 % 83 % 85 % 82 % Example 28 89 % 80 % 81 % 79 % Example 29 82 % 72 % 70 % 70 % Example 30 86 % 76 % 73 % 72 % Example 31 70 % 60 % 50 % 51 % Example 32 93 % 82 % 80 % 77 % Example 33 91 % 81 % 78 % 73 % Example 34 91 % 80 % 82 % 80 % Example 35 94 % 85 % 86 % 78 % Example 36 96 % 87 % 90 % 80 % Example 37 93 % 86 % 84 % 77 % Example 38 92 % 81 % 81 % 79 % Example 39 94 % 82 % 80 % 83 % Example 40 90 % 80 % 81 % 77 % Example 41 91 % 81 % 82 % 80 % Example 42 93 % 82 % 84 % 79 % Example 43 95 % 81 % 83 % 78 % Example 44 92 % 84 % 83 % 81 % Example 45 91 % 80 % 85 % 76 % Comparison example 1 69 % 55 % 35 % 38 % Comparison example 2 68 % 53 % 32 % 36 % Comparison example 3 79 % 65 % 42 % 49 % Comparison example 4 77 % 63 % 46 % 51 % Comparison example 5 76 % 65 % 44 % 55 % Comparison example 6 88 % 74 % 51 % 52 % Comparison example 7 75 % 59 % 52 % 55 % Comparison example 8 80 % 65 % 60 % 62 % Comparison example 9 78 % 62 % 56 % 57 %

[0074] According to Table 3, the high-temperature and low-temperature performance of the lithium-ion batteries provided in Examples 1-9 and Comparative Examples 3-6 are better than those of Comparative Examples 1-2, suggesting that the additive helps improve the battery's high-temperature and low-temperature performance, particularly the low-temperature discharge performance. Based on Examples 1-9, it can be seen that additives with different structures influence the performance of the lithium-ion battery. For example, when the electrolyte solution contains a compound with the structure shown in Formula 1-4, the high-temperature performance of the lithium-ion battery is significantly improved, which is attributed to the high electronegativity of the F-cell and the high stability of the interface film formed.When the electrolyte solution contains compounds with the structures shown in Formulas 1-7 and 1-8, the cycle and storage performance of the lithium-ion battery are significantly improved. This is due to the electrophoretic polymerization of double or triple bonds, which form a dense interface film. The number of carbon atoms also influences the performance of the lithium-ion battery. For example, compounds with the structures shown in Formulas 1-1 to 1-3 result in better battery performance compared to compounds with the structures shown in Formulas 4-5. This is due to the porosity of the interface film being either too high or too low, resulting from the R1 carbon chain being too short or too long.For example, in a hydroxymethyl group, the chain is too short, creating larger cavities that allow more electrolyte solution to come into contact with the surface, leading to oxidative degradation and electrode polarization. Additionally, HF, formed from the degradation of the electrolyte solution, more readily corrodes the electrode, causing structural damage and resulting in reduced room temperature and high-temperature cycle performance and high-temperature storage performance. In a pentyl group, the chain is too long, creating lower porosity, making it difficult for Li+ to be transported across the interface, resulting in reduced low-temperature performance.

[0075] According to Examples 10-12 and Example 34, the high-temperature and low-temperature performance of the battery show similar effects when the composition of the non-aqueous organic solvent and the type of lithium salt in the basic electrolyte solution are different, which suggests that the compound represented by Formula 1 provided in the present application has good compatibility and is suitable for use in various electrolyte solutions.

[0076] According to Examples 13-16, the high-temperature and low-temperature performance of the battery improves when the additive content in the electrolyte solution gradually increases, as shown in Formula 1-1. However, when the additive content increases to 5%, the battery performance decreases. For this reason, the preferred range of the additive, as represented by Formula 1, is from 0.5% to 2%, and preferably 1%.

[0077] According to Examples 17-20 and Comparative Examples 7-9, the additive shown in Formula 1-1 exhibits good compatibility with the second additive, which helps to further improve the high-temperature and low-temperature performance of the battery, and the second additive is preferably vinylene carbonate VC.

[0078] According to Examples 21-33, if the ratio of the first additive to the second additive is approximately 1:1, this helps to further improve the high-temperature and low-temperature performance of the lithium-ion battery.

[0079] According to Examples 35-37, the room temperature / high temperature performance of the lithium-ion battery is improved in the presence of the second additive compared to the first additive shown in Equation 1-1, while the low temperature performance is affected.

[0080] According to Examples 38-45, other first additives exhibit effects similar to those of the compound shown in Formula 1-1.

[0081] Finally, it should be noted that the foregoing embodiments are used only to illustrate the technical solutions of the application, and not to limit them. Although the present application has been described in detail with reference to the foregoing embodiments, a person skilled in the art will understand that they may still modify the technical solutions described in the foregoing embodiments or replace some or all of the technical features accordingly. Such modifications or replacements do not alter the core of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] CH 2023106913559

[0001] CH 2023106913544

[0001] CN 114899490A

[0004] CN 114824484A

[0004] CN 115377495A

[0004] CN 115832436A

[0004]

Claims

[1] Electrolyte solution, wherein the electrolyte solution comprises a first additive, the first additive having a structure as shown in Formula 1: wherein in Formula 1 R1 is selected from the group consisting of H, halogen, phenyl, alkylene-phenyl, substituted or unsubstituted saturated C1 to C10 hydrocarbon group, substituted or unsubstituted C2 to C10 alkenyl and substituted or unsubstituted C2 to C10 alkynyl and the substituent is selected from the group consisting of hydroxyl, halogen and a combination thereof; R2, R3, R4, R5, R6 and R7 are each independently selected from the group consisting of H, halogen, saturated C1 to C10 hydrocarbon group, C2 to C10 alkenyl, C2 to C10 alkynyl, halogen-substituted saturated C1 to C10 hydrocarbon group, halogen-substituted C2 to C10 alkenyl and halogen-substituted C2 to C10 alkynyl. [2] Electrolyte solution according to claim 1, wherein R1 is selected from the group consisting of alkylene phenyl, substituted or unsubstituted saturated C1 to C10 hydrocarbon group, substituted or unsubstituted C2 to C10 alkenyl and substituted or unsubstituted C2 to C10 alkynyl and the substituent is selected from the group consisting of hydroxyl, halogen and a combination thereof. [3] Electrolyte solution according to claim 1 or 2, wherein R1 is selected from the group consisting of substituted or unsubstituted saturated C2 to C4 hydrocarbon group, C2 to C4 alkenyl and C2 to C4 alkynyl and the substituent is selected from the group consisting of hydroxyl, halogen and a combination thereof. [4] Electrolyte solution according to any one of claims 1 to 3, wherein R2, R3, R4, R5, R6 and R7 are each independently selected from the group consisting of H, saturated C1 to C10 hydrocarbon group and halogen-substituted C1 to C10 hydrocarbon group. [5] Electrolyte solution according to any one of claims 1 to 4, wherein the first additive is selected from the group consisting of compounds shown in Formula 1-1 to Formula 1-13 and a combination thereof: [6] Electrolyte solution according to any one of claims 1 to 5, wherein a mass fraction of the first additive is in the range of 0.1% to 10% of a total mass of the electrolyte solution. [7] Electrolyte solution according to any one of claims 1 to 6, wherein the electrolyte solution further comprises a second additive and the second additive is selected from the group consisting of vinylene carbonate, ethylene sulfate, vinylethylene carbonate, 1,3-propanesultone, fluoroethylene carbonate and a combination thereof. [8] Electrolyte solution according to claim 7, wherein the mass ratio of the first additive to the second additive is in the range of 1:0.1 to 1:3.

0. [9] Electrolyte solution according to any one of claims 1 to 8, wherein the electrolyte solution further comprises a non-aqueous organic solvent and a lithium salt. [10] Electrolyte solution according to claim 9, wherein the lithium salt is selected from the group consisting of an inorganic lithium salt, a lithium carboxylate, a lithium sulfonate, a lithium imide, a methylated lithium salt, a lithium borate, a lithium oxalate, a fluorine-containing organic lithium salt and a combination thereof. [11] Electrolyte solution according to claim 9 or 10, wherein the concentration of the lithium salt is in the range of 0.5 M to 2 M. [12] Electrolyte solution according to claim 9, wherein the non-aqueous organic solvent is selected from the group consisting of a carbonate compound, a carboxylate compound, an ether compound, a sulfone compound and a combination thereof. [13] Electrolyte solution according to any one of claims 1 to 12, wherein the electrolyte solution further comprises a third additive and the third additive is selected from the group consisting of a film-forming additive, a conductive additive, a flame-retardant additive, an overcharge protection additive, an additive to improve high-temperature and low-temperature performance and a combination thereof. [14] Battery comprising the electrolyte solution according to any one of claims 1 to 13.

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