Anti-overcharge additive, non-aqueous electrolyte containing same and non-aqueous electrolyte battery

Abstract

The invention provides an anti-overcharge additive, a non-aqueous electrolyte containing the anti-overcharge additive and a non-aqueous electrolyte battery, and belongs to the technical field of lithium ion batteries, the anti-overcharge additive has a structure shown in a formula I, and the impurity content is controlled within the range. According to the present invention, a non-aqueous electrolyte battery can be obtained in which not only overcharge can be prevented in a battery system having a charge voltage of 4.2 V or more, but also an increase in impedance can be suppressed, and both cycle life and storage life can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of lithium ion batteries and relates to an anti-overcharge additive, a non-aqueous electrolyte containing the additive and a non-aqueous electrolyte battery. Background Art

[0002] Lithium-ion batteries have significant advantages such as high energy density, low self-discharge rate, wide operating temperature range, long cycle life, and no memory effect. They are widely used in 3C digital, new energy vehicles, energy storage power stations, and aerospace. With the rapid expansion of the electric vehicle market, the safety of lithium-ion batteries has received more and more attention. Due to the use of flammable organic solvents, non-aqueous electrolyte batteries have safety risks under misoperation conditions. In particular, when the battery is overcharged, excessive lithium precipitation occurs on the surface of the negative electrode, and at the same time the positive electrode structure is destroyed, releasing oxygen, which quickly causes an exothermic decomposition reaction between the electrode and the electrolyte interface, leading to thermal runaway, causing battery rupture, fire, and explosion.

[0003] In order to solve these problems, the traditional method is to install an overcharge protection circuit for the battery, but it cannot completely eliminate the danger of overcharging. The more commonly used method is to add a benzene ring-containing anti-overcharge additive to the electrolyte. The benzene ring structure undergoes a polymerization reaction under a certain voltage. The resulting polymer can cause diaphragm occlusion and adhere to the electrode surface, causing a physical separation between the electrode and the electrolyte, increasing the internal resistance of the battery and blocking the further increase of the voltage. In addition, the polymerization reaction also produces a large amount of gas, which can cause the safety mechanisms inside the battery, such as the safety valve and the safety explosion-proof valve (CID), to be activated to prevent the battery from exploding.

[0004] For example, patent documents CN112310477A, ​​CN106887641A, CN102780041A, CN112186245A and Japanese Patent Application No. 2020-047588 disclose technologies for adding benzene derivatives with various substituents to non-aqueous electrolytes. In particular, biphenyl (BP) and cyclohexylbenzene (CHB) are commonly used in lithium-ion batteries for 3C applications, which can effectively inhibit battery overcharging. However, on the one hand, the addition of existing additives will damage the cycle performance of the battery and increase the battery impedance; on the other hand, the oxidation resistance of existing anti-overcharge additives is poor, and they can only be used in lithium-ion batteries with a charging voltage of less than 4.2V. As the battery capacity increases, the design voltage becomes higher and higher, and these additives themselves will undergo oxidative decomposition, affecting battery performance. Diphenyl carbonate is disclosed in CN114171791A, but the additive has many impurities, which has a great impact on battery performance and anti-overcharge performance. If it is not purified, it cannot be used directly in the electrolyte. Summary of the invention

[0005] In view of the deficiencies of the prior art, an object of the present invention is to provide an overcharge prevention additive, a non-aqueous electrolyte solution containing the same, and a non-aqueous electrolyte battery.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] In one aspect, the present invention provides an anti-overcharge additive having a structure shown in Formula I:

[0008]

[0009] wherein a is an integer of 0-5 (e.g., 0, 1, 2, 3, 4 or 5), R is one of H, C1-C8 alkyl, C1-C8 alkoxy, C1-C8 haloalkyl, C2-C8 alkenyl, C2-C8 alkenyloxy, C2-C8 haloalkenyl, C2-C8 alkynyl, C2-C8 alkynyloxy, C2-C8 haloalkynyl, phenyl, phenoxy, halophenyl or halogen; each R is the same or different; when X is C, P, B or Si, m is an integer of 2-4.

[0010] In the present invention, when X is C, P, B or Si, m is 2, 3 or 4, respectively.

[0011] Preferably, the anti-overcharge additive is any one of diphenyl carbonate, triphenyl phosphate, triphenyl borate or tetraphenyl silicate.

[0012] In the present invention, the overcharge prevention additive needs to be refined, and the overcharge prevention additive contains at least one of the following impurities:

[0013] Alcohols: 0.1-1500ppm (e.g. 0.1ppm, 1ppm, 3ppm, 5ppm, 10ppm, 100ppm, 300ppm, 500ppm, 800ppm, 1000ppm, 1300ppm or 1500ppm); Phenol: 0.1-2000ppm (e.g. 0.1ppm, 1ppm, 3ppm, 5ppm, 10ppm, 100ppm, 300ppm, 500ppm, 800ppm, 1000ppm, 1300ppm or 1500ppm); ppm, 1500ppm, 1800ppm or 2000ppm); dimethyl carbonate: 0.1-5000ppm (0.1ppm, 1ppm, 5ppm, 10ppm, 100ppm, 300ppm, 500ppm, 800ppm, 1000ppm, 2000ppm, 3000ppm, 4000ppm or 5000ppm); anisole: 0.1-150ppm (e.g. 0.1ppm, 1ppm, 5ppm, 10ppm, 30ppm, 500ppm, 800ppm, 1000ppm, 2000ppm, 3000ppm, 4000ppm or 5000ppm); 0ppm, 80ppm, 100ppm, 130ppm or 150ppm); methyl phenyl carbonate: 0.1-200ppm (e.g. 0.1ppm, 1ppm, 5ppm, 10ppm, 30ppm, 50ppm, 80ppm, 100ppm, 130ppm, 150ppm, 180ppm or 200ppm); moisture: 0.1-100ppm (e.g. 0.1ppm, 1ppm, 3ppm, 5ppm, 10ppm, 30ppm, 50ppm); m, 80ppm or 100ppm); acidity (converted to HF): 0.1-1000ppm (e.g., 0.1ppm, 1ppm, 3ppm, 5ppm, 10ppm, 100ppm, 300ppm, 500ppm, 800ppm or 1000ppm); chloride ion: 0.1-150ppm (e.g., 0.1ppm, 1ppm, 5ppm, 10ppm, 30ppm, 50ppm, 80ppm, 100ppm, 130ppm or 150ppm).

[0014] In the present invention, by controlling the impurity content in the anti-overcharge additive, a non-aqueous electrolyte battery can be obtained that can not only prevent overcharge in a battery system with a charging voltage above 4.2V, but also suppress impedance increase, thereby improving both cycle life and storage life.

[0015] On the other hand, the present invention provides a non-aqueous electrolyte, which includes an electrolyte, a non-aqueous organic solvent and an additive, wherein the additive includes the overcharge prevention additive as described above.

[0016] Preferably, the content of the anti-overcharge additive in the non-aqueous electrolyte is 0.2-15wt%, for example, 0.2wt%, 0.5wt%, 0.8wt%, 1wt%, 1.5wt%, 2wt%, 4wt%, 5wt%, 8wt%, 10wt%, 12wt%, 14wt% or 15wt%.

[0017] Preferably, the electrolyte in the non-aqueous electrolyte is a lithium salt.

[0018] Preferably, the lithium salt is selected from one or a combination of at least two of lithium hexafluorophosphate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethylsulfonyl)imide, lithium tetrafluoroborate or lithium trifluoromethanesulfonate.

[0019] Preferably, the content of electrolyte in the non-aqueous electrolyte is 8-30wt%, for example 8wt%, 10wt%, 12wt%, 15wt%, 18wt%, 20wt%, 22wt%, 25wt%, 28wt% or 30wt%.

[0020] Preferably, the non-aqueous organic solvent in the non-aqueous electrolyte is selected from one or a combination of at least two of dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene carbonate, propylene carbonate, ethyl acetate, propyl acetate or 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether.

[0021] Preferably, the content of non-aqueous organic solvent in the non-aqueous electrolyte is 5-80wt%, for example 5wt%, 8wt%, 10wt%, 15wt%, 20wt%, 30wt%, 40wt%, 50wt%, 60wt%, 70wt% or 80wt%.

[0022] Preferably, the additives further include other additives.

[0023] Preferably, the other additives are selected from vinylene carbonate, vinyl sulfite, vinyl ethylene carbonate, tris(trimethylsilyl)borate, tris(trimethylsilyl)phosphate, pentafluorocyclotriphosphazene, ethylene glycol bis(propionitrile) ether, succinonitrile, vinyl sulfate, propylene sulfate, fluoroethylene carbonate, chloroethylene carbonate, 4-methyl vinyl sulfite, 4-methyl vinyl sulfate, butylene sulfite, methylene methanedisulfonate, lithium difluorooxalatoborate, lithium difluorobisoxalatophosphate, lithium difluorophosphate, lithium bistrifluoromethylsulfonyl imide, lithium bisoxalatoborate, lithium bisfluorosulfonyl imide, lithium tetrafluorooxalatophosphate or lithium tetrafluoroborate, or a combination of at least two thereof.

[0024] Preferably, the content of the other additives in the non-aqueous electrolyte is 0.1-5.5wt%, for example 0.1wt%, 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt% or 5.5wt%.

[0025] In another aspect, the present invention provides a nonaqueous electrolyte battery comprising a positive electrode and a negative electrode and the nonaqueous electrolyte solution as described above.

[0026] In the present invention, the positive electrode and the negative electrode are capable of occluding and releasing metal ions.

[0027] Preferably, the positive electrode comprises at least one of the following metal oxides:

[0028] LiCoO2, LiMnO2, LiMn2O4, LiNi 0.5 Mn 1.5 O4, LiFePO4, LiNi x1 Co y1 M (1-x1-y1) O2 or Li x2 Ni y2 M (1-y2) O2;

[0029] In LiNi x1 Co y1 M (1-x1-y1) In O2, 0.1<x1≤0.95, 0.1<y1≤0.95, 0≤(1-x1-y1), M is at least one element selected from Al, Mn, Co, Fe, Cu, Mg, Ti, Zr, Ce and W,

[0030] In Li x2 Ni y2 M (1-y2) In O2, 0<x2≤1.2, 0.85≤y2≤0.99, and M is at least one element selected from Al, Mn, Co, Fe, Cu, Mg, Ti, Zr, Ce and W.

[0031] Preferably, the negative electrode includes a negative electrode active material, and the negative electrode active material contains at least one of graphite, hard carbon, and metal particles capable of forming an alloy with Li.

[0032] Preferably, the metal particles capable of forming an alloy with Li are at least one selected from silicon, tin, aluminum, zinc, and oxides thereof.

[0033] Preferably, the negative electrode active material containing graphite and metal particles capable of forming an alloy with Li is a composite and / or a mixture of metal particles and graphite particles.

[0034] Preferably, relative to the sum of the negative electrode active material containing graphite and metal particles capable of forming an alloy with Li, the content of the metal particles capable of forming an alloy with Li is 0.1-50wt%, for example, 0.1wt%, 3wt%, 5wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt% or 50wt%.

[0035] It should be noted that in this specification, when "-" is used and a numerical value or physical property value is sandwiched before and after it to express, it is used as a range including the values ​​before and after it. For example, the marking of the numerical range of "1-50" includes both its lower limit "1" and upper limit "50". In addition, the marking of other numerical ranges is the same.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The anti-overcharge additive of the present invention has a structure as shown in Formula I and, by controlling the impurity content within the range, can obtain a non-aqueous electrolyte battery that can not only prevent overcharge in a battery system with a charging voltage of more than 4.2V, but also inhibit impedance increase, thereby improving both cycle life and storage life. DETAILED DESCRIPTION

[0038] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0039] Comparative Example 1:

[0040] Production of positive plate

[0041] LiNi 0.85 Co 0.12 Al 0.03 The lithium nickel composite oxide represented by O2 is mixed in such a way that it reaches 100 kg, acetylene black as a conductive agent reaches 1 kg, and polyvinylidene fluoride as a binder reaches 0.9 kg. The mixture is put into N-methyl-2-pyrrolidone as a dispersion medium, and kneaded to produce a positive electrode mixture slurry. The positive electrode active material slurry is applied to both sides of the positive electrode collector formed by aluminum foil, and dried to form a positive electrode mixture layer. The positive electrode mixture layer is compressed in a manner to reach a specified thickness, and the compressed electrode plate is cut into a specified size. Finally, the positive electrode connector is joined to the exposed portion of the positive electrode collector where the positive electrode mixture layer is not formed, thereby producing a positive electrode plate.

[0042] Negative plate production

[0043] Graphite as a negative electrode active material is mixed in an amount of 96 kg, styrene butadiene rubber as a binder is mixed in an amount of 2 kg, and carboxymethyl cellulose as a thickener is mixed in an amount of 2 kg. The mixture is put into water as a dispersion medium and kneaded to produce a negative electrode mixture slurry. The negative electrode mixture slurry is applied to both sides of a negative electrode collector formed of copper foil, and dried to form a negative electrode mixture layer. The negative electrode mixture layer is compressed in a manner to reach a specified thickness, and the compressed electrode plate is cut into a specified size. Finally, a negative electrode connector is joined to the exposed portion of the negative electrode collector where the negative electrode mixture layer is not formed, thereby producing a negative electrode plate.

[0044] Electrode body fabrication

[0045] The positive electrode plate and the negative electrode plate were wound with a separator formed of a polyethylene microporous film interposed therebetween to produce an electrode body. The end of the separator at the end of the winding of the electrode body was fixed with an adhesive tape.

[0046] Preparation of non-aqueous electrolyte

[0047] Ethylene carbonate (EC), ethyl methyl carbonate (EMC) and dimethyl carbonate (DMC) were mixed in a volume ratio of 4:3:3 (1 atmosphere, 25°C) to prepare a non-aqueous solvent. Lithium hexafluorophosphate (LiPF6) as an electrolyte salt was dissolved in the non-aqueous solvent at a concentration of 13 wt%, and 2 wt% of vinylene carbonate (VC) and 0.7 wt% of lithium difluorophosphate (LiPO2F2) were added as cycle performance improving additives to prepare a non-aqueous electrolyte (basic electrolyte, see Table 1 for details).

[0048] Sealing body production

[0049] The terminal cover, valve core, annular insulating plate and terminal plate are stacked to make a sealing body. The valve core and the terminal plate are formed of aluminum plates, and the valve core can deform as the internal pressure of the battery increases. In order to enable the valve core to receive the internal pressure of the battery, a plurality of vents are provided on the terminal plate. If the internal pressure of the battery reaches a specified value, the joint between the valve core and the terminal plate breaks, and the current path inside the sealing body is disconnected. As shown in this experimental example, the current blocking mechanism is composed of the valve core, the insulating plate and the terminal plate.

[0050] Fabrication of non-aqueous electrolyte secondary batteries

[0051] An upper insulating plate and a lower insulating plate are arranged at the upper and lower parts of the electrode body, respectively, and the electrode body is inserted into the outer can. The negative electrode terminal is connected to the bottom of the outer can, and the positive electrode terminal is connected to the sealing body. After the non-aqueous electrolyte is injected into the interior of the outer can, the sealing body is embedded and fixed to the opening of the outer can with the help of a gasket, thereby making a cylindrical non-aqueous electrolyte secondary battery. Five batteries are made under the same conditions, and the results are averaged.

[0052] Comparative Example 2

[0053] In addition to adding the anti-overcharge additive biphenyl (BP) to the non-aqueous electrolyte, and the amount of the additive added is set to the value recorded in Table 1, the same operation as in Comparative Example 1 is performed to prepare a cylindrical non-aqueous electrolyte secondary battery. Under the same conditions, 5 batteries were made and the results were averaged. It should be noted that the amount of additives added recorded in Table 1 is expressed as a percentage relative to the mass of the basic electrolyte, and biphenyl (BP) is removed by vacuum distillation to remove impurities. Gas chromatography, moisture meter, acid-base titrator, and turbidity method are used to set the purity of the additives, as well as the content of impurities, moisture, acidity, and chloride ions of each component (see Table 2).

[0054] Examples 1 to 9

[0055] In addition to switching the anti-overcharge additive biphenyl (BP, battery grade) in the non-aqueous electrolyte to diphenyl carbonate (DPC) containing different impurities, the same operation as in Comparative Example 2 was performed to produce a cylindrical non-aqueous electrolyte secondary battery. Under the same conditions, 5 batteries were made and the results were averaged. It should be noted that the amount of diphenyl carbonate (DPC) added recorded in Table 1 is expressed as a percentage relative to the mass of the basic electrolyte. Diphenyl carbonate (DPC) is removed from impurities by the following vacuum distillation, and specific compounds are used to adjust the impurity content. Gas chromatography, moisture meter, acid-base titrator, and turbidity method are used to set the purity of the additive, as well as the content of impurities, moisture, acidity, and chloride ions of each component.

[0056] Vacuum distillation method of diphenyl carbonate (DPC): 1) Instruments and equipment: glass distillation column; packing ring; sand bath pot; zeolite; flask; condensation reflux ratio distributor. 2) Experimental steps: Add diphenyl carbonate (DPC) solid and zeolite into the flask, use glass distillation column for negative pressure distillation; after adding the raw materials, evacuate the distillation system and start heating; extract in sections according to the change of top temperature, and keep samples of the distilled products; perform content analysis. 3) Use chromatographic grade acetonitrile as solvent and HP-5 chromatographic column for detection.

[0057] Embodiments 10 to 13

[0058] In addition to switching the anti-overcharge additive biphenyl (BP, battery grade) in the non-aqueous electrolyte to triphenyl phosphate (TPP) containing different impurities, the same operation as in Comparative Example 2 was performed to produce a cylindrical non-aqueous electrolyte secondary battery. Under the same conditions, 5 batteries were made and the results were averaged. It should be noted that the amount of triphenyl phosphate (TPP) added recorded in Table 1 is expressed as a percentage relative to the mass of the basic electrolyte. Triphenyl phosphate (TPP) is removed from impurities by vacuum distillation, and specific compounds are used to adjust the impurity content. Gas chromatography, moisture meter, acid-base titrator, and turbidity method are used to set the purity of the additive, as well as the content of impurities, moisture, acidity, and chloride ions of each component.

[0059] Vacuum distillation method of triphenyl phosphate (TPP): 1) Instruments and equipment: glass distillation column; packing ring; sand bath pot; zeolite; flask; condensation reflux ratio distributor. 2) Experimental steps: add triphenyl phosphate (TPP) and zeolite to the flask, use the glass distillation column for negative pressure distillation; after adding the raw materials, evacuate the distillation system and start heating; extract in sections according to the change of top temperature, and keep samples of the distilled products; perform content analysis. 3) Use chromatographic grade acetonitrile as solvent and HP-5 chromatographic column for detection.

[0060] Evaluation of battery performance of comparative examples and embodiments:

[0061] (1) Overcharge test

[0062] Each battery of Comparative Examples 1 to 2 and Examples 1 to 13 was charged at a constant current of 3C, with the upper limit of the charging voltage set at 20V. The battery voltage and resistance before and after the test were measured at 25°C, and the highest temperature reached on the battery surface during the test was recorded. Table 3 shows the measurement results, which are the average values ​​of 5 batteries.

[0063] (2) Cycle test

[0064] Each battery of Comparative Examples 1 to 2 and Examples 1 to 13 was charged at a constant current of 1C, with the upper and lower limits of the charging voltage set to 4.35V and 3V, respectively, at a temperature of 25°C, and the battery capacity change was measured. Five batteries were made under the same conditions. Table 3 shows the measurement results, which are the average values ​​of the five batteries.

[0065] (3) Rate experiment

[0066] Each battery of Comparative Examples 1 to 2 and Examples 1 to 13 was charged at a constant current of 5C, with the upper and lower limits of the charging voltage set to 4.35V and 3V, respectively, at a temperature of 25°C, and the battery capacity change was measured. Five batteries were made under the same conditions. Table 3 shows the measurement results, which are the average values ​​of the five batteries.

[0067] Table 1

[0068]

[0069]

[0070] Table 2

[0071]

[0072]

[0073] Table 3

[0074]

[0075]

[0076] Comparative Example 1: Using a basic electrolyte without an anti-overcharge additive, the battery cycle performance is good, but the anti-overcharge performance is unqualified, and the battery catches fire and explodes.

[0077] Comparative Example 2: When the traditional anti-overcharge additive biphenyl (BP) is added to the basic electrolyte, the battery cycle performance and anti-overcharge performance are deteriorated, and the battery will catch fire and explode.

[0078] Examples 1 to 5: 0.5% to 15% high-purity diphenyl carbonate (DPC) is added to the basic electrolyte respectively. Under the premise of maintaining the cycle performance and rate characteristics of the battery, the overcharge protection performance is guaranteed and the battery will not catch fire or explode.

[0079] Examples 6 to 13: When the impurity content in diphenyl carbonate (DPC) exceeds a certain limit, the overcharge protection performance can be basically maintained, and the battery will not catch fire or explode, but the cycle performance and rate characteristics of the battery are greatly deteriorated.

[0080] Examples 14 to 18: 0.5% to 13% high-purity triphenyl phosphate (TPP) is added to the basic electrolyte respectively. Under the premise of maintaining the cycle performance and rate characteristics of the battery, the overcharge protection performance is guaranteed and the battery will not catch fire or explode.

[0081] Examples 19 to 21: When the impurity content in triphenyl phosphate (TPP) exceeds a certain limit, the overcharge protection performance can be basically maintained, and the battery will not catch fire or explode, but the cycle performance and rate characteristics of the battery are greatly deteriorated.

[0082] In Examples 22 to 24, 0.8% to 9% of high-purity triphenyl borate is respectively added to the basic electrolyte. Under the premise of maintaining the cycle performance and rate characteristics of the battery, the anti-overcharge performance is guaranteed and the battery will not catch fire or explode.

[0083] The chloride ion content in Example 25 is relatively high, resulting in a significant deterioration in the cycle performance and rate characteristics of the battery.

[0084] In Examples 26 to 28, 0.5% to 11% of high-purity tetraphenyl silicate is respectively added to the basic electrolyte. Under the premise of maintaining the cycle performance and rate characteristics of the battery, the anti-overcharge performance is guaranteed and the battery will not catch fire or explode.

[0085] The moisture content in Example 29 is relatively high, resulting in a significant deterioration in the cycle performance and rate characteristics of the battery.

[0086] As described above, according to the present invention, by adding an anti-overcharge additive to the original electrolyte, the battery can be prevented from catching fire and exploding when overcharged while maintaining the battery performance. The present invention can provide a non-aqueous electrolyte secondary battery that takes into account both the battery characteristics at high temperature and high voltage requirements and the safety during overcharge, and therefore has great applicability in electric vehicles and energy storage applications.

[0087] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the anti-overcharge additive, the non-aqueous electrolyte and the non-aqueous electrolyte battery containing the same, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An anti-overcharge additive, characterized in that: The anti-overcharge additive has a structure shown in Formula I: wherein a is an integer of 0-5 (e.g., 0, 1, 2, 3, 4 or 5), R is one of H, C1-C8 alkyl, C1-C8 alkoxy, C1-C8 haloalkyl, C2-C8 alkenyl, C2-C8 alkenyloxy, C2-C8 haloalkenyl, C2-C8 alkynyl, C2-C8 alkynyloxy, C2-C8 haloalkynyl, phenyl, phenoxy, halophenyl or halogen; each R is the same or different; when X is C, P, B or Si, m is an integer of 2-4.

2. The overcharge prevention additive according to claim 1, characterized in that: The anti-overcharge additive is any one of diphenyl carbonate, triphenyl phosphate, triphenyl borate or tetraphenyl silicate.

3. The overcharge prevention additive according to claim 1 or 2, characterized in that: The overcharge prevention additive contains at least one of the following impurities: Alcohols: 0.1-1500ppm; Phenol: 0.1-2000ppm; Dimethyl carbonate: 0.1-5000ppm; Anisole: 0.1-150ppm; Methyl phenyl carbonate: 0.1-200ppm; Moisture: 0.1-100ppm; Acidity converted to HF: 0.1-1000ppm; Chloride ion: 0.1-150ppm.

4. A non-aqueous electrolyte, characterized in that: The non-aqueous electrolyte comprises an electrolyte, a non-aqueous organic solvent and an additive, wherein the additive comprises the overcharge prevention additive according to any one of claims 1 to 3.

5. The non-aqueous electrolyte according to claim 4, characterized in that The content of the overcharge prevention additive in the non-aqueous electrolyte is 0.2-15 wt %.

6. The non-aqueous electrolyte according to claim 4 or 5, characterized in that: The electrolyte in the non-aqueous electrolyte is a lithium salt; The lithium salt is selected from one or a combination of at least two of lithium hexafluorophosphate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethylsulfonyl)imide, lithium tetrafluoroborate or lithium trifluoromethanesulfonate; The content of electrolyte in the non-aqueous electrolyte is 8-30 wt %.

7. The non-aqueous electrolyte according to any one of claims 4 to 6, characterized in that: The non-aqueous organic solvent in the non-aqueous electrolyte is selected from one or a combination of at least two of dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene carbonate, propylene carbonate, ethyl acetate, propyl acetate or 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether; The content of the non-aqueous organic solvent in the non-aqueous electrolyte is 5-80 wt %.

8. The non-aqueous electrolyte according to any one of claims 4 to 7, characterized in that: The additives also include other additives; The other additives are selected from vinylene carbonate, vinyl sulfite, vinyl ethylene carbonate, tris(trimethylsilyl)borate, tris(trimethylsilyl)phosphate, pentafluorocyclotriphosphazene, ethylene glycol bis(propionitrile) ether, succinonitrile, vinyl sulfate, propylene sulfate, fluoroethylene carbonate, chloroethylene carbonate, 4-methyl vinyl sulfite, 4-methyl vinyl sulfate, butylene sulfite, methylene methanedisulfonate, lithium difluorooxalatoborate, lithium difluorobisoxalatophosphate, lithium difluorophosphate, lithium bistrifluoromethylsulfonyl imide, lithium bisoxalatoborate, lithium bisfluorosulfonyl imide, lithium tetrafluorooxalatophosphate or lithium tetrafluoroborate, or a combination of at least two thereof; The content of the other additives in the non-aqueous electrolyte is 0.1-5.5 wt %.

9. A non-aqueous electrolyte battery, characterized in that: The nonaqueous electrolyte battery comprises a positive electrode and a negative electrode and the nonaqueous electrolyte solution according to any one of claims 4 to 8.

10. The nonaqueous electrolyte battery according to claim 9, characterized in that The positive electrode comprises at least one of the following metal oxides: LiCoO2, LiMnO2, LiMn2O4, LiNi 0.5 Mn 1.5 O4, LiFePO4, LiNi x1 Co y1 M (1-x1-y1) O2 or Li x2 Ni y2 M (1-y2) O2; In LiNi x1 Co y1 M (1-x1-y1) In O2, 0.1<x1≤0.95, 0.1<y1≤0.95, 0≤(1-x1-y1), M is at least one element selected from Al, Mn, Co, Fe, Cu, Mg, Ti, Zr, Ce and W, In Li x2 Ni y2 M (1-y2) In O2, 0<x2≤1.2, 0.85≤y2≤0.99, and M is at least one element selected from Al, Mn, Co, Fe, Cu, Mg, Ti, Zr, Ce and W; The negative electrode comprises a negative electrode active material, wherein the negative electrode active material comprises at least one of graphite, hard carbon and metal particles capable of forming an alloy with Li; The metal particles capable of forming an alloy with Li are selected from at least one of silicon, tin, aluminum, zinc, and oxides thereof; The negative electrode active material containing graphite and metal particles capable of forming an alloy with Li is a composite and / or a mixture of metal particles and graphite particles; The content of the metal particles capable of forming an alloy with Li is 0.1-50 wt % relative to the total amount of the negative electrode active material containing graphite and the metal particles capable of forming an alloy with Li.

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