Compound and use thereof, non-aqueous electrolyte solution, and battery

Abstract

In order to solve the problem that existing lithium-ion batteries have a high-temperature behavior and a relatively large impedance, the present invention provides a compound selected from compounds represented by structural formula (1), wherein x is an integer of 0 to 3, y is an integer of 0 to 3, and 1 ≤ x + y; a is an integer of 0 to 4, b is an integer of 0 to 4, c is an integer of 0 to 4, and 1 ≤ a + b + c; R1, R2, and R3 are each independently selected from alkylene groups having 1-4 carbon atoms; R4 and R5 are each independently selected from hydrogen or alkyl groups having 1-6 carbon atoms; and R6, R7, R8, R9, R10, R11, R12, R13, and R14 are each independently selected from alkyl groups having 1-6 carbon atoms. In addition, also disclosed in the present invention are a use of the compound, a non-aqueous electrolyte solution, and a battery. The compound provided by the present invention can form a passivation film structure having high integrity, a uniform film thickness and good electrolyte ion permeability on a surface of an electrode and is conducive to improving the high-temperature behavior and prolonging the service life of the battery.

Description

Compound and application thereof, non-aqueous electrolyte and battery Technical Field

[0001] The present invention belongs to the technical field of battery materials, and in particular relates to a compound and application thereof, a non-aqueous electrolyte and a battery. Background Art

[0002] Secondary batteries have been widely used in 3C digital products such as mobile phones and laptops, as well as new energy vehicles, due to their advantages such as high operating voltage, wide operating temperature range, high energy density and power density, no memory effect and long cycle life.

[0003] Secondary battery electrolytes are generally composed of lithium salts, solvents, and additives. During the charging process of a lithium-ion battery, lithium ions in the battery's positive electrode material are deintercalated and embedded in the carbon negative electrode through the electrolyte. In the initial stage, the electrolyte components preferentially accept electrons, reacting on the surface of the carbon negative electrode to produce compounds such as Li2CO3, Li2O, and LiOH, thereby forming a passivation film on the negative electrode surface. This passivation film is called the solid electrolyte interface (SEI) film. The SEI film formed during the initial charging process prevents further decomposition of the electrolyte on the carbon negative electrode surface and acts as a lithium ion conductor, allowing only lithium ions to pass through. However, during subsequent charge and discharge cycles of the lithium-ion battery, changes in the electrode may cause the SEI film to rupture. This may cause the negative electrode to be exposed to the electrolyte again and continue to react with the electrolyte, consuming the electrolyte and generating gas. This increases the internal pressure of the lithium-ion battery and reduces the battery's cycle life. When batteries are stored or cycled at high temperatures, the volume of the electrodes changes significantly, making the SEI film more susceptible to rupture. This leads to a more pronounced degradation of the electrochemical performance of lithium-ion batteries at high temperatures. Therefore, the quality of the SEI film significantly affects the high-temperature performance of lithium-ion batteries.

[0004] To enhance the performance of lithium-ion batteries, many researchers have added various negative electrode film-forming agents, such as vinylene carbonate (VC), fluoroethylene carbonate (FEC), and diethylene sulfate (DTD), to the electrolyte to improve the quality of the SEI film, thereby improving various battery performance characteristics. Although existing film-forming additives can improve the high-temperature performance of batteries to a certain extent, they still cannot meet market needs. At the same time, film-forming additives will increase the impedance of the battery to a certain extent. Developing an additive that can balance the high-temperature performance and impedance issues of the battery is an urgent problem that needs to be solved.

[0005] Summary of the Invention

[0006] In view of the problems of high-temperature performance and high impedance in existing lithium-ion batteries, the present invention provides a compound and its application, a non-aqueous electrolyte and a battery.

[0007] The technical solutions adopted by the present invention to solve the above technical problems are as follows:

[0008] In one aspect, the present invention provides a compound selected from the group consisting of compounds represented by structural formula 1:

[0009] wherein x is an integer of 0-3, y is an integer of 0-3, 1≤x+y, a is an integer of 0-4, b is an integer of 0-4, c is an integer of 0-4, 1≤a+b+c, R1, R2 and R3 are each independently selected from an alkylene group having 1-4 carbon atoms, R4 and R5 are each independently selected from hydrogen or an alkyl group having 1-6 carbon atoms; R6, R7, R8, R9, R 10 、R 11 、R 12 、R 13 and R 14 Each is independently selected from an alkyl group having 1 to 6 carbon atoms.

[0010] Optional, x+y≤3, a+b+c≤8.

[0011] Optionally, the compound represented by structural formula 1 is selected from one or more of the following compounds:

[0012] In another aspect, the present invention provides use of the compound as described above as an additive for non-aqueous electrolytes.

[0013] In another aspect, the present invention provides a non-aqueous electrolyte solution comprising a non-aqueous organic solvent, an electrolyte salt, and a first additive, wherein the first additive comprises the compound described above.

[0014] Optionally, based on the total mass of the non-aqueous electrolyte being 100%, the content of the compound represented by structural formula 1 is 0.05-10%.

[0015] Optionally, the electrolyte salt is selected from at least one of lithium salt, sodium salt, potassium salt, magnesium salt, zinc salt and aluminum salt.

[0016] Optionally, the non-aqueous electrolyte further includes a second additive, and the second additive includes at least one of a cyclic sulfate compound, a sultone compound, a cyclic carbonate compound, a phosphate compound, a borate compound, and a nitrile compound.

[0017] Optionally, the cyclic sulfate compound is selected from vinyl sulfate, 4-methylvinyl sulfate, propylene sulfate, At least one of;

[0018] The sultone compound is selected from 1,3-propane sultone, 1,4-butane sultone, propenyl-1,3-sultone, At least one of;

[0019] The cyclic carbonate compound is selected from at least one of vinylene carbonate, vinyl ethylene carbonate, methylene carbonate, fluoroethylene carbonate, trifluoromethylethylene carbonate, bisfluoroethylene carbonate or the compound shown in structural formula 2:

[0020] In the structural formula 2, R 21 、R 22 、R 23 、R 24 、R 25 、R 26 Each is independently selected from a hydrogen atom, a halogen atom, and a C1-C5 group;

[0021] The phosphate compound is selected from at least one of tris(trimethylsilyl)phosphate, tris(triethylsilyl)phosphate, or the compound shown in structural formula 3:

[0022] In the structural formula 3, R 31 、R 32 、R 33 Each independently selected from a C1-C5 saturated hydrocarbon group, a C1-C5 unsaturated hydrocarbon group, a C1-C5 halogenated hydrocarbon group, -Si(C m H 2m+1 )3, m is a natural number from 1 to 3, and R 31 、R 32 、R 33 At least one of them is an unsaturated hydrocarbon group;

[0023] The borate compound is selected from at least one of tris(trimethylsilyl)borate and tris(triethylsilyl)borate;

[0024] The nitrile compound is selected from at least one of succinonitrile, glutaronitrile, ethylene glycol bis(propionitrile) ether, hexanetrionitrile, adiponitrile, pimelonitrile, suberonitrile, azelaic acid dinitrile and sebacononitrile.

[0025] Optionally, the non-aqueous organic solvent includes at least one of an ether solvent, a nitrile solvent, a carbonate solvent, a carboxylate solvent, and a sulfone solvent.

[0026] In another aspect, the present invention provides a battery comprising a positive electrode, a negative electrode, and the non-aqueous electrolyte as described above.

[0027] The compound provided by the present invention is a novel compound that can be used as an additive in non-aqueous electrolytes of batteries. It contains cyclic sulfate groups and siloxane groups. During the battery formation process, an electrochemical reaction can occur on the electrode surface to generate lithium sulfate salt. At the same time, the siloxane groups can cross-link with the generated lithium sulfate salt on the electrode surface to form a passivation film structure with strong integrity, uniform film thickness and good electrolyte ion permeability. The passivation film has high stability and can adapt to the volume change of the electrode without cracking during high-temperature cycling, thereby avoiding the continuous growth of the passivation film thickness, which is beneficial to improving the high-temperature performance and service life of the battery. DETAILED DESCRIPTION

[0028] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0029] An embodiment of the present invention provides a compound selected from the compound represented by structural formula 1:

[0030] wherein x is an integer of 0-3, y is an integer of 0-3, 1≤x+y, a is an integer of 0-4, b is an integer of 0-4, c is an integer of 0-4, 1≤a+b+c, R1, R2 and R3 are each independently selected from an alkylene group having 1-4 carbon atoms, R4 and R5 are each independently selected from hydrogen or an alkyl group having 1-6 carbon atoms; R6, R7, R8, R9, R 10 、R 11 、R 12 、R 13 and R 14 Each is independently selected from an alkyl group having 1 to 6 carbon atoms.

[0031] The above provides a new type of compound that can be used as an additive in a non-aqueous electrolyte of a battery. The compound contains a cyclic sulfate group and a siloxane group. During the battery formation process, an electrochemical reaction can occur on the electrode surface to generate lithium sulfate salt. At the same time, the siloxane group can cross-link with the generated lithium sulfate salt on the electrode surface to form a passivation film structure with strong integrity, uniform film thickness and good electrolyte ion permeability. The passivation film has high stability and can adapt to the volume change of the electrode without cracking during high-temperature cycling, thereby avoiding the continuous growth of the passivation film thickness, which is beneficial to improving the high-temperature performance and service life of the battery.

[0032] In some embodiments, x+y≤3, a+b+c≤8.

[0033] In some embodiments, the compound represented by Structural Formula 1 is selected from one or more of the following compounds:

[0034] It should be noted that the above are only examples of some compounds provided by the present invention and do not represent limitations of the present invention.

[0035] Those skilled in the art, knowing the structural formula of the compound shown in Structural Formula 1, can know the preparation method of the above compound based on common knowledge in the field of chemical synthesis.

[0036] One embodiment of the present invention provides a method for preparing the compound represented by structural formula 1, comprising the following steps:

[0037] The polyol and thionyl chloride undergo a substitution reaction to generate a monocyclic sulfite and / or a polycyclic sulfite with unreacted hydroxyl groups;

[0038] The purified monocyclic sulfite and / or polycyclic sulfite with unreacted hydroxyl groups is subjected to a substitution reaction with trialkylchlorosilane under alkaline conditions to generate a compound shown in structural formula 4;

[0039] wherein x is an integer of 0-3, y is an integer of 0-3, 1≤x+y, a is an integer of 0-4, b is an integer of 0-4, c is an integer of 0-4, 1≤a+b+c, R1, R2 and R3 are each independently selected from an alkylene group having 1-4 carbon atoms, R4 and R5 are each independently selected from hydrogen or an alkyl group having 1-6 carbon atoms; R6, R7, R8, R9, R 10 、R 11 、R 12 、R 13 and R 14 Each is independently selected from an alkyl group having 1 to 6 carbon atoms;

[0040] Then, an oxidizing agent is used to oxidize the sulfite ring in the compound represented by structural formula 4 to obtain the compound represented by structural formula 1.

[0041] In some embodiments, the oxidizing agent is selected from sodium periodate or sodium hypochlorite.

[0042] As an example of the present invention:

[0043] Compound 1 can be prepared by the following method:

[0044] Glycerol is reacted with an equivalent amount of thionyl chloride to synthesize glycerol cyclic sulfite, which is then purified by vacuum distillation. The purified glycerol cyclic sulfite is then reacted with trimethylsilyl chloride under alkaline conditions to generate glycerol cyclic sulfite trimethylsilyl ether, which is then oxidized with sodium periodate to obtain compound 1.

[0045] Compound 3 can be prepared by the following method:

[0046] Butanethrol is reacted with an equivalent amount of thionyl chloride to synthesize butanethrol cyclic sulfite, which is purified by recrystallization. The purified butanethrol cyclic sulfite is then reacted with trimethylsilyl chloride under alkaline conditions to generate butanethrol cyclic sulfite trimethylsilyl ether, which is then oxidized with sodium periodate to obtain compound 3.

[0047] Compound 13 can be prepared by the following method:

[0048] Glycerol was reacted with an equivalent amount of thionyl chloride to synthesize propylene glycol cyclic sulfite, which was purified by vacuum distillation. The purified propylene glycol cyclic sulfite was then reacted with triethylchlorosilane under alkaline conditions to generate propylene glycol cyclic sulfite triethylsilyl ether, which was then oxidized with sodium hypochlorite to obtain compound 13.

[0049] Compound 14 can be prepared by the following method:

[0050] Xylitol was reacted with 2 equivalents of thionyl chloride to synthesize xylitol bicyclic sulfite, which was purified by recrystallization. The purified xylitol bicyclic sulfite was then reacted with triethylchlorosilane under alkaline conditions to generate xylitol bicyclic sulfite triethylsilyl ether, which was then oxidized with sodium hypochlorite to obtain compound 14.

[0051] Another embodiment of the present invention provides use of the compound as described above as an additive for a non-aqueous electrolyte.

[0052] Another embodiment of the present invention provides a non-aqueous electrolyte solution including a non-aqueous organic solvent, an electrolyte salt, and a first additive, wherein the first additive includes the compound described above.

[0053] Since the compound as described above is used as the first additive of the non-aqueous electrolyte, the film formation stability on the electrode surface during the non-aqueous electrolyte formation stage can be effectively improved, the film formation impedance can be reduced, and thus the high temperature performance of the battery can be effectively improved.

[0054] In some embodiments, based on the total mass of the non-aqueous electrolyte being 100%, the content of the compound represented by Structural Formula 1 is 0.05-10%.

[0055] In a specific embodiment, based on the total mass of the non-aqueous electrolyte as 100%, the content of the compound represented by structural formula 1 may be 0.05%, 0.08%, 0.1%, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 3.8%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 7.8%, 8%, 8.5%, 9%, 9.5% or 10%.

[0056] In a preferred embodiment, based on 100% of the total mass of the non-aqueous electrolyte, the content of the compound represented by structural formula 1 is 0.5% to 5%.

[0057] When the content of the compound represented by structural formula 1 in the non-aqueous electrolyte is within the above range, the stability of the film formed on the electrode surface can be effectively maintained and the battery performance can be improved. If the content of the compound represented by structural formula 1 is too little, it is difficult to have a significant effect on improving the performance of the battery; if the content of the compound represented by structural formula 1 is too much, it may affect the functions of other substances in the electrolyte due to its excessive decomposition products.

[0058] In some embodiments, the electrolyte salt is selected from at least one of lithium salts, sodium salts, potassium salts, magnesium salts, zinc salts, and aluminum salts.

[0059] In a preferred embodiment, the electrolyte salt is selected from lithium salt or sodium salt.

[0060] The alkali metal ions formed by the dissociation of the electrolyte salt in the non-aqueous electrolyte are intercalated and deintercalated between the positive and negative electrodes to complete the charge and discharge cycle. The concentration of the electrolyte salt directly affects the transfer speed of the alkali metal ions, and the transfer speed of the alkali metal ions affects the potential change of the negative electrode. During the rapid charging process of the battery, it is necessary to increase the movement speed of the alkali metal ions as much as possible to prevent the negative electrode potential from dropping too quickly, resulting in the formation of lithium dendrites, which poses a safety hazard to the battery. At the same time, it can also prevent the battery's cycle capacity from decaying too quickly. When the content of the electrolyte salt is too low, the efficiency of the insertion and extraction of the alkali metal ions between the positive and negative electrodes will be reduced, and the demand for fast charging of the battery cannot be met. When the content of the electrolyte salt is too high, the viscosity of the non-aqueous electrolyte will increase, which is also not conducive to improving the efficiency of the insertion and extraction of the alkali metal ions, and increases the internal resistance of the battery.

[0061] In a specific embodiment, the concentration of the lithium salt is 0.1 mol / L-8 mol / L. In a preferred embodiment, the concentration of the lithium salt is 0.5 mol / L-2.5 mol / L. Specifically, the concentration of the electrolyte salt can be 0.5 mol / L, 1 mol / L, 1.5 mol / L, 2 mol / L, or 2.5 mol / L.

[0062] In a preferred embodiment, the lithium salt is selected from LiPF6, LiBOB, LiDFOB, LiPO2F2, LiBF4, LiSbF6, LiAsF6, LiN(SO2CF3)2, LiN(SO2C2F5)2, LiC(SO2CF3)3, LiN(SO2F)2, LiClO4, LiAlCl4, LiCF3SO3, Li2B 10 Cl 10 , at least one of lower aliphatic carboxylic acid lithium salts.

[0063] In a specific embodiment, the concentration of the sodium salt is 0.1 mol / L-2 mol / L. In a preferred embodiment, the concentration of the sodium salt is 0.4 mol / L-1.5 mol / L. Specifically, the concentration of the sodium salt can be 0.1 mol / L, 0.4 mol / L, 0.5 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L, 1 mol / L, 1.2 mol / L, 1.5 mol / L, or 2 mol / L.

[0064] In a specific embodiment, the sodium salt is selected from at least one of sodium perchlorate (NaClO4), sodium hexafluorophosphate (NaPF6), sodium tetrafluoroborate (NaBF4), sodium bis(fluorosulfonyl)imide (NaFSI), sodium trifluoromethanesulfonate (NaOTf), and sodium bis(trifluoromethylsulfonyl)imide (NaTFSI).

[0065] In some embodiments, the non-aqueous electrolyte further includes a second additive, and the second additive includes at least one of a cyclic sulfate compound, a sultone compound, a cyclic carbonate compound, a phosphate compound, a borate compound, and a nitrile compound.

[0066] Preferably, based on the total mass of the non-aqueous electrolyte being 100%, the content of the second additive is 0.01% to 10%.

[0067] In some embodiments, the cyclic sulfate compound is selected from vinyl sulfate, 4-methylvinyl sulfate, propylene sulfate, At least one of;

[0068] The sultone compound is selected from 1,3-propane sultone, 1,4-butane sultone, propenyl-1,3-sultone, At least one of;

[0069] The cyclic carbonate compound is selected from at least one of vinylene carbonate, vinyl ethylene carbonate, methylene carbonate, fluoroethylene carbonate, trifluoromethylethylene carbonate, bisfluoroethylene carbonate or the compound shown in structural formula 2:

[0070] In the structural formula 2, R 21 、R 22 、R 23 、R 24 、R 25 、R 26 Each is independently selected from a hydrogen atom, a halogen atom, and a C1-C5 group;

[0071] More preferably, the compound represented by structural formula 2 includes at least one of the following compounds 2-1 to 2-6:

[0072] The phosphate compound is selected from at least one of tris(trimethylsilyl)phosphate, tris(triethylsilyl)phosphate, or the compound shown in structural formula 3:

[0073] In the structural formula 3, R 31 、R 32 、R 33 Each independently selected from a C1-C5 saturated hydrocarbon group, a C1-C5 unsaturated hydrocarbon group, a C1-C5 halogenated hydrocarbon group, -Si(C m H 2m+1 )3, m is a natural number from 1 to 3, and R 31 、R 32 、R 33 At least one of them is an unsaturated hydrocarbon group;

[0074] In a preferred embodiment, the phosphate compound represented by the structural formula 3 may be at least one of tripropargyl phosphate, dipropargyl methyl phosphate, dipropargyl ethyl phosphate, dipropargyl propyl phosphate, dipropargyl trifluoromethyl phosphate, dipropargyl-2,2,2-trifluoroethyl phosphate, dipropargyl-3,3,3-trifluoropropyl phosphate, dipropargyl hexafluoroisopropyl phosphate, triallyl phosphate, diallyl methyl phosphate, diallyl ethyl phosphate, diallyl propyl phosphate, diallyl trifluoromethyl phosphate, diallyl-2,2,2-trifluoroethyl phosphate, diallyl-3,3,3-trifluoropropyl phosphate, and diallyl hexafluoroisopropyl phosphate;

[0075] The borate compound is selected from at least one of tris(trimethylsilyl)borate and tris(triethylsilyl)borate;

[0076] The nitrile compound is selected from at least one of succinonitrile, glutaronitrile, ethylene glycol bis(propionitrile) ether, hexanetrionitrile, adiponitrile, pimelonitrile, suberonitrile, azelaic acid dinitrile and sebacononitrile.

[0077] In other embodiments, the second additive may further include other additives that can improve battery performance: for example, additives that enhance battery safety, such as flame retardant additives such as fluorophosphates and cyclophosphazenes, or overcharge prevention additives such as tert-amylbenzene and tert-butylbenzene.

[0078] It should be noted that, unless otherwise specified, under normal circumstances, the content of any one of the optional substances in the second additive in the non-aqueous electrolyte is less than 10%, preferably, the content is 0.01-5%, and more preferably, the content is 0.1% to 2%. Specifically, the content of any one of the optional substances in the second additive can be 0.01%, 0.05%, 0.08%, 0.1%, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 3.8%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 7.8%, 8%, 8.5%, 9%, 9.5%, or 10%.

[0079] In some embodiments, the second additive includes fluoroethylene carbonate, and based on the total mass of the non-aqueous electrolyte being 100%, the amount of the fluoroethylene carbonate added is 0.01% to 30%.

[0080] In some embodiments, based on the total mass of the non-aqueous electrolyte being 100%, the mass content of the non-aqueous organic solvent is 65% to 90%.

[0081] Specifically, based on the total mass of the non-aqueous electrolyte as 100%, the mass content of the non-aqueous organic solvent can be 65%, 68%, 71%, 74%, 76%, 78%, 79%, 80%, 81.5%, 82%, 84%, 85%, 86%, 87%, 89%, or 90%.

[0082] In some embodiments, the non-aqueous organic solvent includes at least one of an ether solvent, a nitrile solvent, a carbonate solvent, and a carboxylate solvent.

[0083] In some embodiments, the ether solvent includes a cyclic ether or a chain ether, preferably a chain ether with 3 to 10 carbon atoms and a cyclic ether with 3 to 6 carbon atoms. The cyclic ether may be, but is not limited to, at least one of 1,3-dioxolane (DOL), 1,4-dioxolane (DX), a crown ether, tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-CH3-THF), and 2-trifluoromethyltetrahydrofuran (2-CF3-THF). The chain ether may be, but is not limited to, dimethoxymethane, diethoxymethane, ethoxymethoxymethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, and diethylene glycol dimethyl ether. Because chain ethers have high solvation ability with lithium ions and can improve ion dissociation, dimethoxymethane, diethoxymethane, and ethoxymethoxymethane are particularly preferred because they have low viscosity and can impart high ionic conductivity. The ether compound may be used alone or in any combination and ratio. The amount of the ether compound added is not particularly limited and is any amount that does not significantly impair the effects of the high-density lithium-ion battery of the present invention. The amount is typically 1% or more by volume, preferably 2% or more by volume, and more preferably 3% or more by volume, based on 100% by volume of the non-aqueous solvent. Furthermore, the amount is typically 30% or less by volume, preferably 25% or less by volume, and more preferably 20% or less by volume.

[0084] In some embodiments, the nitrile solvent may be, but is not limited to, at least one of acetonitrile, glutaronitrile, and malononitrile.

[0085] In some embodiments, the carbonate solvent includes a cyclic carbonate or a chain carbonate. The cyclic carbonate can be, but is not limited to, at least one of ethylene carbonate (EC), propylene carbonate (PC), γ-butyrolactone (GBL), and butylene carbonate (BC); the chain carbonate can be, but is not limited to, at least one of dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), and dipropyl carbonate (DPC). The content of the cyclic carbonate is not particularly limited and is arbitrary within the range that does not significantly damage the effect of the lithium-ion battery of the present invention. However, when using one alone, the lower limit of its content is generally 3% or more by volume, preferably 5% or more by volume, relative to the total amount of solvent in the non-aqueous electrolyte. By setting this range, the decrease in conductivity due to the decrease in the dielectric constant of the non-aqueous electrolyte can be avoided, and it is easy to achieve a good range of high current discharge characteristics, stability relative to the negative electrode, and cycle characteristics of the non-aqueous electrolyte battery. In addition, the upper limit is generally 90% or less by volume, preferably 85% or less by volume, and more preferably 80% or less by volume. By setting this scope, the oxidation / reduction tolerance of nonaqueous electrolyte can be improved, thereby contributing to the stability during high temperature storage. The content of linear carbonate is not particularly limited, and relative to the total amount of solvent of nonaqueous electrolyte, is usually more than 15% by volume, preferably more than 20% by volume, and more preferably more than 25% by volume. In addition, usually the volume ratio is less than 90%, preferably less than 85% by volume, and more preferably less than 80% by volume. By making the content of linear carbonate in the above-mentioned scope, it is easy to make the viscosity of nonaqueous electrolyte reach appropriate range, suppress the reduction of ionic conductivity, and then contribute to the output characteristics of nonaqueous electrolyte battery reach good scope. When using two or more linear carbonates in combination, make the total amount of linear carbonate meet the above-mentioned scope.

[0086] In certain embodiments, also can preferably use the linear carbonates with fluorine atoms (hereinafter referred to as " fluorinated linear carbonate ").The number of the fluorine atoms possessed by fluorinated linear carbonate is as long as being more than 1 then has no particular restrictions, but is generally below 6, preferably below 4.When fluorinated linear carbonate has a plurality of fluorine atoms, these fluorine atoms can be bonded on the same carbon, also can be bonded on different carbons.As fluorinated linear carbonate, can enumerate, fluorinated dimethyl carbonate derivatives, fluorinated ethyl methyl carbonate derivatives, fluorinated diethyl carbonate derivatives etc.

[0087] Carboxylate solvents include cyclic carboxylates and / or chain carbonates. Examples of cyclic carboxylates include at least one of γ-butyrolactone, γ-valerolactone, and δ-valerolactone. Examples of chain carbonates include at least one of methyl acetate (MA), ethyl acetate (EA), propyl acetate (EP), butyl acetate, propyl propionate (PP), and butyl propionate.

[0088] In some embodiments, the sulfone solvent includes a cyclic sulfone and a chain sulfone. Preferably, in the case of a cyclic sulfone, the compound generally has 3 to 6 carbon atoms, preferably 3 to 5 carbon atoms; in the case of a chain sulfone, the compound generally has 2 to 6 carbon atoms, preferably 2 to 5 carbon atoms. There is no particular limitation on the amount of sulfone solvent added, and it can be any amount that does not significantly impair the effect of the lithium-ion battery of the present invention. The volume ratio relative to the total amount of solvent in the non-aqueous electrolyte is generally 0.3% or more, preferably 0.5% or more, and more preferably 1% or more. Furthermore, the volume ratio is generally 40% or less, preferably 35% or less, and more preferably 30% or less. When two or more sulfone solvents are used in combination, the total amount of the sulfone solvents can be adjusted to meet the above range. When the amount of sulfone solvent added is within the above range, a non-aqueous electrolyte with excellent high-temperature storage stability tends to be obtained.

[0089] In a preferred embodiment, the non-aqueous organic solvent is a mixture of cyclic carbonate and chain carbonate.

[0090] Another embodiment of the present invention provides a battery including a positive electrode, a negative electrode, and the non-aqueous electrolyte as described above.

[0091] In a specific embodiment, the secondary battery is a lithium metal battery, a lithium ion battery, a lithium sulfur battery, a sodium ion battery, a magnesium ion battery, etc.

[0092] In some embodiments, the positive electrode includes a positive electrode material layer, and the positive electrode material layer includes a positive electrode active material. The type and content of the positive electrode active material are not particularly limited and can be selected according to actual needs, as long as it is a positive electrode active material or a conversion-type positive electrode material that can reversibly embed / de-embed metal ions (lithium ions, sodium ions, potassium ions, magnesium ions, zinc ions, aluminum ions, etc.).

[0093] In a preferred embodiment, the secondary battery is a lithium-ion battery, and its positive electrode active material can be selected from LiFe 1-x’ M' x’ PO4、LiMn 2-y’ M y’ O4 and LiNi x Co y Mn z M 1-x-y-zAt least one of O2, wherein M' is selected from at least one of Mn, Mg, Co, Ni, Cu, Zn, Al, Sn, B, Ga, Cr, Sr, V or Ti, M is selected from at least one of Fe, Co, Ni, Mn, Mg, Cu, Zn, Al, Sn, B, Ga, Cr, Sr, V or Ti, and 0≤x'<1, 0≤y'≤1, 0≤y≤1, 0≤x≤1, 0≤z≤1, x+y+z≤1, the positive electrode active material can also be selected from at least one of sulfide, selenide, and halide. More preferably, the positive electrode active material can be selected from LiCoO2, LiFePO4, LiFe 0.8 Mn 0.2 PO4, LiMn2O4, LiNi 0.5 Co 0.2 Mn 0.3 O2、LiNi 0.6 Co 0.2 Mn 0.2 O2、LiNi 0.8 Co 0.1 Mn 0.1 O2、LiNi 0.5 Co 0.2 Mn 0.2 Al 0.1 O2、LiNi 0.5 Co 0.2 Al 0.3 At least one of O2.

[0094] In a preferred embodiment, the secondary battery is a sodium ion battery, and its positive electrode active material includes but is not limited to at least one of transition metal oxides, Prussian materials, phosphates, sulfates, and titanates. The chemical formula of the transition metal oxide can be Na z M x O y , M can be selected from at least one of Cr, Fe, Co, Ni, Cu, Mn, Sn, Mo, Sb, and V. More preferably, the transition metal oxide is NaNi m Fe n Mn p O2(m+n+p=1,0≤m≤1,0≤n≤1,0≤p≤1) or NaNi m Co n Mn p O2 (m+n+p=1, 0≤m≤1, 0≤n≤1, 0≤p≤1); the molecular formula of the Prussian material is Na x M[M′(CN)6] y·zH2O, where M is a transition metal, M' is a transition metal, 0 < x ≤ 2, 0.8 ≤ y < 1, 0 < z ≤ 20. More preferably, the Prussian material is Na x Mn[Fe(CN)6] y ·nH2O (0 < x ≤ 2, 0 < y ≤ 1, 0 < z ≤ 10) or Na x Fe[Fe(CN)6] y ·nH2O (0 < x ≤ 2, 0 < y ≤ 1, 0 < z ≤ 10); The chemical formula of the phosphate is Na3(MO 1-x PO4)2F 1+2x , 0 ≤ x ≤ 1, M is selected from at least one of Al, V, Ge, Fe, Ga. More preferably, the phosphate is Na3(VPO4)2F3 or Na3(VOPO4)2F; The chemical formula of the phosphate is Na2MPO4F, M is selected from at least one of Fe, Mn. More preferably, the phosphate is Na2FePO4F or Na2MnPO4F; The titanate material can be selected from at least one of Na2Ti3O7, Na2Ti6O 13 , Na4Ti5O 12 , Li4Ti5O 12 , NaTi2(PO4)3; The chemical formula of the sulfate is Na2M(SO4)2·2H2O, M can be selected from at least one of Cr, Fe, Co, Ni, Cu, Mn, Sn, Mo, Sb, V

[0095] In some embodiments, the positive electrode further includes a positive electrode current collector, and the positive electrode material layer is disposed on the surface of the positive electrode current collector.

[0096] The positive electrode current collector is selected from metal materials that can conduct electrons. Preferably, the positive electrode current collector includes at least one of Al, Ni, tin, copper, and stainless steel. In a more preferred embodiment, the positive electrode current collector is selected from aluminum foil.

[0097] In some embodiments, the positive electrode active material layer further includes a positive electrode binder and a positive electrode conductive agent, and the positive electrode active material, the positive electrode binder, and the positive electrode conductive agent are blended to obtain the positive electrode material layer. <The positive electrode binder includes polyvinylidene fluoride, a copolymer of vinylidene fluoride, polytetrafluoroethylene, a copolymer of vinylidene fluoride-hexafluoropropylene, a copolymer of tetrafluoroethylene-hexafluoropropylene, a copolymer of tetrafluoroethylene-perfluoroalkyl vinyl ether, a copolymer of ethylene-tetrafluoroethylene, a copolymer of vinylidene fluoride-tetrafluoroethylene, a copolymer of vinylidene fluoride-trifluoroethylene, a copolymer of vinylidene fluoride-trichloroethylene, a copolymer of vinylidene fluoride-fluoroethylene, a copolymer of vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene, thermoplastic polyimide, a thermoplastic resin such as polyethylene and polypropylene; an acrylic resin; and at least one of styrene butadiene rubber.

[0099] The positive electrode conductive agent includes at least one of conductive carbon black, conductive carbon balls, conductive graphite, conductive carbon fibers, carbon nanotubes, graphene, or reduced graphene oxide.

[0100] In some embodiments, the negative electrode includes a negative electrode material layer, and the negative electrode material layer includes a negative electrode active material. The type and content of the negative electrode active material are not particularly limited and can be selected according to actual needs.

[0101] In a preferred embodiment, the secondary battery is a lithium-ion battery, and its negative electrode active material includes at least one of a carbon-based negative electrode, a silicon-based negative electrode, a tin-based negative electrode, and a lithium negative electrode. Carbon-based negative electrodes may include graphite, hard carbon, soft carbon, graphene, mesocarbon microbeads, and the like; silicon-based negative electrodes may include silicon materials, silicon oxides, silicon-carbon composites, and silicon alloys; tin-based negative electrodes may include tin, tin-carbon, tin-oxygen, and tin metal compounds; and lithium negative electrodes may include metallic lithium or a lithium alloy. Specifically, the lithium alloy may include at least one of a lithium-silicon alloy, a lithium-sodium alloy, a lithium-potassium alloy, a lithium-aluminum alloy, a lithium-tin alloy, and a lithium-indium alloy.

[0102] In a preferred embodiment, the secondary battery is a sodium-ion battery, and its negative electrode active material includes at least one of metallic sodium, graphite, soft carbon, hard carbon, carbon fiber, mesocarbon microbeads, silicon-based materials, tin-based materials, lithium titanate, or other metals capable of forming alloys with sodium. The alloy material may also be selected from an alloy material composed of at least one of Si, Ge, Sn, Pb, and Sb and C; the graphite may be selected from at least one of artificial graphite, natural graphite, and modified graphite; the silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, and silicon alloys; and the tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys.

[0103] In some embodiments, the negative electrode further comprises a negative electrode current collector, and the negative electrode material layer is disposed on the surface of the negative electrode current collector. The material of the negative electrode current collector can be the same as that of the positive electrode current collector, which will not be described in detail here.

[0104] In some embodiments, the negative electrode material layer further includes a negative electrode binder and a negative electrode conductive agent. The negative electrode active material, the negative electrode binder, and the negative electrode conductive agent are blended together to form the negative electrode material layer. The negative electrode binder and the negative electrode conductive agent may be the same as the positive electrode binder and the positive electrode conductive agent, respectively, and are not further described here.

[0105] In some embodiments, the secondary battery further includes a separator, and the separator is located between the positive electrode and the negative electrode.

[0106] The diaphragm can be an existing conventional diaphragm, which can be a ceramic diaphragm, a polymer diaphragm, a non-woven fabric, an inorganic-organic composite diaphragm, etc., including but not limited to single-layer PP (polypropylene), single-layer PE (polyethylene), double-layer PP / PE, double-layer PP / PP and three-layer PP / PE / PP diaphragms.

[0107] The present invention is further described below with reference to the following examples.

[0108] Table 1

[0109] Note: The compounds used in the following examples and comparative examples are selected from Table 1.

[0110] Examples 1 to 16

[0111] Examples 1 to 16 are used to illustrate the non-aqueous electrolyte, lithium-ion battery, and preparation method thereof disclosed in the present invention, and include the following steps:

[0112] 1) Preparation of non-aqueous electrolyte:

[0113] Ethylene carbonate (EC), diethyl carbonate (DEC) and ethyl methyl carbonate (EMC) were mixed in a mass ratio of EC:DEC:EMC=1:1:1, and then lithium hexafluorophosphate (LiPF6) was added to a molar concentration of 1.2 mol / L. Additives were added based on the total weight of the non-aqueous electrolyte as 100%. The types and contents of the additives are shown in Tables 2 and 3.

[0114] 2) Preparation of positive electrode sheet:

[0115] The positive electrode active material lithium nickel cobalt manganese oxide LiNi was mixed in a mass ratio of 93:4:3 0.5 Co 0.2 Mn 0.3 O2, conductive carbon black Super-P, and a binder called polyvinylidene fluoride (PVDF) are then dispersed in N-methyl-2-pyrrolidone (NMP) to create a positive electrode slurry. The slurry is evenly coated on both sides of aluminum foil, dried, rolled, and vacuum-dried, and then ultrasonically welded with aluminum lead wires to create a positive electrode sheet with a thickness of between 120 and 150 μm.

[0116] 3) Preparation of negative electrode sheet:

[0117] The negative electrode active material, artificial graphite, conductive carbon black Super-P, and binders styrene-butadiene rubber (SBR) and carboxymethyl cellulose (CMC), are mixed in a mass ratio of 94:1:2.5:2.5 and dispersed in deionized water to create a negative electrode slurry. The slurry is then coated on both sides of a copper foil, dried, rolled, and vacuum-dried. Nickel lead wires are then ultrasonically welded to create the negative electrode plate, which is between 120 and 150 μm thick.

[0118] 4) Preparation of battery cells:

[0119] A three-layer separator with a thickness of 20 μm was placed between the positive plate and the negative plate, and then the sandwich structure consisting of the positive electrode sheet, negative electrode sheet and separator was wound. The wound body was flattened and placed in an aluminum foil packaging bag, and vacuum-baked at 75°C for 48 hours to obtain a battery cell ready for liquid injection.

[0120] 5) Injection and formation of battery cells:

[0121] In a glove box with a dew point controlled below -40°C, the prepared electrolyte was injected into the battery cell, vacuum-sealed, and left to stand for 24 hours.

[0122] Then, the conventional formation of the first charge was carried out according to the following steps: 0.05C constant current charging for 180min, 0.2C constant current charging to 3.95V, secondary vacuum sealing, and then further 0.2C constant current charging to 4.2V, after being placed at room temperature for 24h, and then 0.2C constant current discharge to 3.0V, a LiNi 0.5 Co 0.2 Mn 0.3 O2 / artificial graphite lithium-ion battery.

[0123] Comparative Examples 1 to 4

[0124] Comparative Examples 1 to 4 are used to compare and illustrate the non-aqueous electrolyte, lithium-ion battery, and preparation method thereof disclosed in the present invention, and include most of the operating steps in Example 1, except that:

[0125] The types and contents of additives in the non-aqueous electrolyte are shown in Tables 2 and 3.

[0126] Performance Testing

[0127] The lithium-ion battery prepared above was subjected to the following performance tests:

[0128] High temperature storage performance test

[0129] The formed lithium-ion battery was charged to 4.2V at room temperature at a constant current of 1C, then charged at constant current and constant voltage until the current dropped to 0.05C, and then discharged to 3.0V at a constant current of 1C. The initial discharge capacity D1, initial battery volume V1, and initial impedance F1 of the battery were measured. After being fully charged and stored in an environment of 60°C for 30 days, the battery was discharged to 3V at 1C, and the battery's retention capacity D2, recovery capacity D3, impedance F2 after storage, and battery volume V2 after storage were measured. The calculation formula is as follows:

[0130] Battery capacity retention rate (%) = retention capacity D2 / initial capacity D1×100%;

[0131] Battery capacity recovery rate (%) = recovery capacity D3 / initial capacity D1×100%;

[0132] Volume expansion rate (%) = (battery volume after storage V2 - initial battery volume V1) / initial battery volume V1 × 100%;

[0133] Internal resistance growth rate (%) = (post-storage impedance F2 - initial impedance F1) / initial impedance F1 × 100%.

[0134] 1. Fill in Table 2 with the test results obtained from Examples 1 to 11 and Comparative Examples 1 to 4.

[0135] Table 2

[0136] The test results of Examples 1-8 and Comparative Example 1 show that, compared to non-aqueous electrolytes without the compound of Structural Formula 1, adding the compound of Structural Formula 1 as an additive to the non-aqueous electrolyte can effectively improve the high-temperature performance of the lithium-ion battery. The test results of Examples 1-8 show that as the content of the compound of Structural Formula 1 increases, the high-temperature storage performance of the lithium-ion battery first improves and then decreases. In particular, when the content of the compound is 0.5%-5.0%, the lithium-ion battery has the best overall performance. This indicates that during the charge and discharge cycle of the lithium-ion battery, when the content of the compound of Structural Formula 1 in the electrolyte is 0.5%-5.0%, it can ensure that the formed SEI film is regular, of moderate thickness, and has better stability.

[0137] From the comparison of the test results of Example 4 and Comparative Examples 2-4, it can be seen that compared with traditional vinylene carbonate (VC), vinyl sulfate (DTD) and 1,3-propane sultone (PS), the use of the compound represented by structural formula 1 provided in the present application as an additive can more significantly improve the storage performance of lithium-ion batteries at high temperatures, indicating that the passivation film formed by the compound represented by structural formula 1 has better high-temperature stability and is not easily destroyed under high temperature conditions.

[0138] It can be seen from the test results of Examples 4 and 9 to 11 that the use of vinylene carbonate (VC), vinyl sulfate (DTD) or 1,3-propane sultone (PS) in combination with the compound represented by Structural Formula 1 can more significantly improve the high-temperature storage performance of lithium-ion batteries. It is speculated that this is because VC, DTD, PS and the compound represented by Structural Formula 1 jointly participate in the formation of the passivation film on the surface of the positive and negative electrodes, which is beneficial to improving the quality of the passivation film.

[0139] 2. Fill in Table 3 with the test results obtained in Examples 4, 12 to 16 and Comparative Examples 1 to 4.

[0140] Table 3

[0141] By comparing the test results of Examples 4, 12 to 16 and Comparative Examples 1 to 4, it can be seen that compared with lithium ion batteries without additives or with existing additives, the lithium ion batteries obtained by using the compound of structural formula I provided by the present invention as an additive have better high-temperature storage performance.

[0142] Examples 17 to 32

[0143] Examples 17 to 32 are used to illustrate the preparation method of the non-aqueous electrolyte and sodium ion battery disclosed in the present invention, including the following steps:

[0144] 1) Preparation of non-aqueous electrolyte:

[0145] Ethylene carbonate (EC), diethyl carbonate (DEC) and ethyl methyl carbonate (EMC) were mixed in a mass ratio of EC:DEC:EMC = 1:1:1, and then sodium hexafluorophosphate (NaPF6) was added to a molar concentration of 1.2 mol / L. Additives were added based on the total weight of the non-aqueous electrolyte as 100%. The types and contents of the additives are shown in Tables 4 and 5.

[0146] 2) Preparation of positive electrode sheet:

[0147] The cathode active material Na₃V₂(PO₄)₃, conductive carbon black Super-P, and binder polyvinylidene fluoride (PVDF) are mixed in a mass ratio of 94:3:3 and then dispersed in N-methyl-2-pyrrolidone (NMP) to create a cathode slurry. The slurry is evenly coated on both sides of aluminum foil, dried, rolled, and vacuum-dried, and then ultrasonically welded with aluminum or nickel lead wires to form a cathode sheet with a thickness between 80 and 200 μm.

[0148] 3) Preparation of negative electrode sheet:

[0149] The negative electrode active material, spherical hard carbon, conductive carbon black Super-P, and binders styrene-butadiene rubber (SBR) and carboxymethyl cellulose (CMC), are mixed in a mass ratio of 97:1:1:1 and dispersed in deionized water to create a negative electrode slurry. The slurry is then coated on both sides of aluminum foil, dried, rolled, and vacuum-dried. Aluminum or nickel lead wires are then ultrasonically welded to create a negative electrode sheet with a thickness ranging from 80 to 300 μm.

[0150] 4) The positive electrode sheet, separator, and negative electrode sheet are stacked in order, and the preparation of the sodium ion battery is completed by aluminum-plastic film packaging, re-baking, liquid injection, static standing, formation, fixture shaping, secondary sealing, and capacity testing.

[0151] Comparative Examples 5 to 8

[0152] Comparative Examples 5 to 8 are used to compare and illustrate the preparation methods of the non-aqueous electrolyte and sodium ion battery disclosed in the present invention, and include most of the operating steps in Example 17, except that:

[0153] The types and contents of additives in the non-aqueous electrolyte are shown in Tables 4 and 5.

[0154] Performance Testing

[0155] The sodium ion batteries prepared in the examples and comparative examples were subjected to the following performance tests:

[0156] High temperature storage performance test

[0157] The formed sodium ion battery was charged to 4.0V at a constant current of 0.5C at room temperature, then charged at a constant voltage until the current dropped to 0.03C, and then discharged to 1.5V at a constant current of 1C. The battery's initial discharge capacity D1, initial battery volume V1, and initial impedance F1 were measured. After being fully charged and stored in a 60°C environment for 30 days, the battery was discharged to 3V at 1C, and the battery's retention capacity D2, recovery capacity D3, impedance F2 after storage, and battery volume V2 after storage were measured. The calculation formula is as follows:

[0158] Battery capacity retention rate (%) = retention capacity D2 / initial capacity D1×100%;

[0159] Battery capacity recovery rate (%) = recovery capacity D3 / initial capacity D1×100%;

[0160] Volume expansion rate (%) = (battery volume after storage V2 - initial battery volume V1) / initial battery volume V1 × 100%;

[0161] Internal resistance growth rate (%) = (post-storage impedance F2 - initial impedance F1) / initial impedance F1 × 100%.

[0162] 3. Fill in Table 4 with the test results obtained from Examples 17 to 27 and Comparative Examples 5 to 8.

[0163] Table 4

[0164] Comparing the test results of Examples 17-27 and Comparative Examples 5-8, it can be seen that, similar to the role played by the compound represented by Structural Formula 1 in lithium-ion batteries, the addition of the compound represented by Structural Formula 1 to the non-aqueous electrolyte of the sodium-ion battery can also improve the high-temperature storage performance of the sodium-ion battery, indicating that the passivation film formed by the decomposition of the compound represented by Structural Formula 1 on the surface of the positive and negative electrodes has high high-temperature stability, improves the performance stability of the positive and negative electrode materials in long-term cycles, and improves the cycle performance and storage performance of the sodium-ion battery at high temperatures. From the test results of Examples 17-27, it can be seen that as the content of the compound represented by Structural Formula 1 increases, the high-temperature storage performance and high-temperature cycle performance of the sodium-ion battery first increase and then decrease. In particular, when the content of the compound is 0.5% to 5%, the sodium-ion battery has the best comprehensive performance, indicating that during the charge and discharge cycle of the sodium-ion battery, when the content of the compound represented by Structural Formula 1 in the electrolyte is 0.5% to 5%, it can ensure that the SEI film formed is regular and of moderate thickness, and has better stability.

[0165] It can be seen from the test results of Example 20 and Comparative Examples 5-8 that compared with conventional film-forming additives, such as vinylene carbonate (VC), vinyl sulfate (DTD) or fluoroethylene carbonate (FEC), the use of the compound represented by structural formula 1 provided in the present application as an additive can more significantly improve the storage performance of sodium ion batteries at high temperatures, and the passivation film formed by the compound represented by structural formula 1 has better high-temperature stability.

[0166] It can be seen from the test results of Examples 20 and 25 to 27 that the use of vinylene carbonate (VC), vinyl sulfate (DTD) or fluoroethylene carbonate (FEC) in combination with the compound represented by Structural Formula 1 can more significantly improve the high-temperature cycle performance of the sodium ion battery. It is speculated that this is because VC, DTD or FEC and the compound represented by Structural Formula 1 jointly participate in the formation of the passivation film on the surface of the positive and negative electrodes, which is beneficial to improving the quality of the passivation film.

[0167] 4. Fill in Table 5 with the test results obtained in Examples 20, 28 to 32 and Comparative Examples 5 to 8.

[0168] Table 5

[0169] From the test results of Comparative Examples 20, 28 to 32 and Comparative Examples 5 to 8, it can be seen that compared with sodium ion batteries without additives or with existing additives, the sodium ion batteries obtained by using the compound of structural formula I provided by the present invention as an additive have better high-temperature cycle performance.

[0170] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A compound, characterized in that Selected from the compounds shown in structural formula 1: wherein x is an integer of 0-3, y is an integer of 0-3, 1≤x+y, a is an integer of 0-4, b is an integer of 0-4, c is an integer of 0-4, 1≤a+b+c, R1, R2 and R3 are each independently selected from an alkylene group having 1-4 carbon atoms, R4 and R5 are each independently selected from hydrogen or an alkyl group having 1-6 carbon atoms; R6, R7, R8, R9, R 10 , R 11 , R 12 , R 13 and R 14 Each is independently selected from an alkyl group having 1 to 6 carbon atoms.

2. The compound according to claim 1, characterized in that x+y≤3, a+b+c≤8.

3. The compound according to claim 1, characterized in that The compound represented by the structural formula 1 is selected from one or more of the following compounds:

4. Use of the compound according to any one of claims 1 to 3 as an additive for non-aqueous electrolyte.

5. A non-aqueous electrolyte, characterized in that: The invention comprises a non-aqueous organic solvent, an electrolyte salt and a first additive, wherein the first additive comprises the compound according to any one of claims 1 to 3.

6. The non-aqueous electrolyte according to claim 5, characterized in that Based on the total mass of the non-aqueous electrolyte being 100%, the content of the compound represented by the structural formula 1 is 0.05-10%.

7. The non-aqueous electrolyte according to claim 6, characterized in that Based on the total mass of the non-aqueous electrolyte being 100%, the content of the compound represented by the structural formula 1 is 0.5% to 5%.

8. The non-aqueous electrolyte according to claim 5, characterized in that The electrolyte salt is selected from at least one of lithium salts, sodium salts, potassium salts, magnesium salts, zinc salts and aluminum salts.

9. The non-aqueous electrolyte according to claim 5, characterized in that The non-aqueous electrolyte further includes a second additive, and the second additive includes at least one of a cyclic sulfate compound, a sultone compound, a cyclic carbonate compound, a phosphate compound, a borate compound, and a nitrile compound.

10. The non-aqueous electrolyte according to claim 9, characterized in that The cyclic sulfate ester compound is selected from vinyl sulfate, 4-methylvinyl sulfate, propylene sulfate, At least one of .

11. The non-aqueous electrolyte according to claim 9, characterized in that The sultone compound is selected from 1,3-propane sultone, 1,4-butane sultone, propenyl-1,3-sultone, At least one of .

12. The non-aqueous electrolyte according to claim 9, characterized in that The cyclic carbonate compound is selected from at least one of vinylene carbonate, ethylene carbonate, methylene carbonate, fluoroethylene carbonate, trifluoromethylethylene carbonate, bisfluoroethylene carbonate or the compound shown in structural formula 2: In the structural formula 2, R 21 , R 22 , R 23 , R 24 , R 25 , R 26 Each is independently selected from a hydrogen atom, a halogen atom, and a C1-C5 group.

13. The non-aqueous electrolyte according to claim 9, characterized in that The phosphate compound is selected from at least one of tris(trimethylsilyl)phosphate, tris(triethylsilyl)phosphate or the compound shown in structural formula 3: In the structural formula 3, R 31 , R 32 , R 33 Each independently selected from a C1-C5 saturated hydrocarbon group, a C1-C5 unsaturated hydrocarbon group, a C1-C5 halogenated hydrocarbon group, -Si(C m H 2m+1 )3, m is a natural number from 1 to 3, and R 31 , R 32 , R 33 At least one of them is an unsaturated hydrocarbon group.

14. The non-aqueous electrolyte according to claim 9, characterized in that The borate compound is selected from at least one of tris(trimethylsilyl)borate and tris(triethylsilyl)borate.

15. The non-aqueous electrolyte according to claim 9, characterized in that The nitrile compound is selected from at least one of succinonitrile, glutaronitrile, ethylene glycol bis(propionitrile) ether, hexanetrinitrile, adiponitrile, pimelonitrile, suberonitrile, azelaic acid dinitrile and sebacononitrile.

16. A battery, characterized in that: The invention comprises a positive electrode, a negative electrode and the non-aqueous electrolyte as claimed in any one of claims 5 to 15.

Images