Lithium carbon fluoride battery electrolyte and lithium carbon fluoride battery

Abstract

The invention discloses a lithium carbon fluoride battery electrolyte and a lithium carbon fluoride battery. In order to improve the long-time shelving safety performance and power discharge performance of a lithium carbon fluoride battery in a high-temperature environment and further improve the application prospect of the lithium carbon fluoride battery, the technical scheme adopted by the invention is as follows: the lithium carbon fluoride battery electrolyte is provided and comprises an organic solvent, electrolyte salt and an additive, wherein the electrolyte is a mixture of any one of lithium tetrafluoroborate, lithium bis (trifluoromethylsulfonyl) imide, lithium bis (fluorosulfonyl) imide and lithium trifluoromethanesulfonate and lithium difluorophosphate, and the additive comprises a silane additive, an anhydride additive and a phosphazene additive in a mass ratio of (1-5): (0.5-1): (3-10). According to the electrolyte system disclosed by the invention, the high-low temperature discharge capacity and the large-current pulse discharge capacity of the lithium carbon fluoride battery are obviously improved, and meanwhile, the high-temperature shelving safety performance is also obviously improved.

Description

Technical Field

[0001] The invention belongs to the technical field of lithium carbon fluoride batteries, and in particular relates to a lithium carbon fluoride battery electrolyte and a lithium carbon fluoride battery. Background Art

[0002] The battery of the tire pressure monitoring system has extremely high requirements for the working temperature. The theoretical working temperature range of the conventional CR series heat-resistant wide-temperature button-type lithium manganese battery is -20℃~+60℃. If the temperature is lower or higher than this range, the performance of the battery will be greatly reduced. In some northern cities in my country, the outdoor operating temperature of the equipment will be lower than -20℃, while the ambient temperature of some vehicle-mounted equipment is likely to be higher than 85℃.

[0003] Lithium carbon fluoride battery is a lithium / solid cathode system with the highest specific energy at present. The actual specific energy can reach 650Wh / kg (0.01C discharge). Its operating voltage is about 2.5V, and its operating temperature range is wide. It can work in the range of -40 to +130℃. It has low self-discharge and a storage life of more than 10 years. Lithium carbon fluoride battery uses carbon fluoride as the cathode and a mixed organic solvent containing lithium tetrafluoroborate or other lithium salts as the electrolyte. Its structure is similar to that of lithium manganese dioxide battery. Conductive carbon is generated during the discharge process of the battery, which increases the conductivity of the battery, thereby improving the discharge platform and efficiency of the battery. In addition to the characteristics of high temperature and low temperature resistance, lithium carbon fluoride series batteries also have stable discharge capacity. They can still maintain good electrical properties in high temperature and high humidity environments, discharge continuously and stably, and the self-discharge rate is less than 1% / year. No heavy metals are involved in the production, use and scrapping of the battery. The physical and chemical stability of carbon fluoride materials makes lithium carbon fluoride batteries relatively safer, and they are still highly safe in the case of misuse such as short circuit, extrusion, collision, over discharge, high temperature, etc. Therefore, lithium carbon fluoride series button batteries have become the first choice for automotive (TPMS) tire pressure monitors.

[0004] However, carbon fluoride has low density, low conductivity, and strong hydrophobicity. It also generates a lot of heat during continuous high-current discharge, and the battery volume expands significantly. In a long-term high-temperature environment, the risk of battery leakage or even fire and explosion is also very high. These defects also limit its application to a certain extent. In addition, compared with lithium secondary batteries, lithium primary batteries pursue higher specific energy discharge characteristics. Making the electrolyte formula compatible with the carbon fluoride positive electrode material can maximize the energy density of carbon fluoride, which is also the current key research direction of lithium carbon fluoride batteries. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a wide-temperature lithium carbon fluoride battery electrolyte capable of improving the safety performance and power discharge performance under long-term high-temperature storage.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A lithium fluoride carbon battery electrolyte comprises an organic solvent, an electrolyte salt and an additive, wherein the electrolyte is a mixture of any one of lithium tetrafluoroborate, lithium bis(trifluoromethylsulfonyl)imide, lithium bis(fluorosulfonyl)imide, lithium trifluoromethylsulfonate and lithium difluorophosphate, and the additive comprises a silane additive, an acid anhydride additive and a phosphazene additive, wherein the mass ratio of the silane additive, the acid anhydride additive and the phosphazene additive is (1-5):(0.5-1):(3-10).

[0008] More preferably, the mass ratio of the silane additive, the acid anhydride additive and the phosphazene additive is (0.5-5):1:(3-10).

[0009] Preferably, the silane additive is one or more of difluorodiphenylsilane, tetravinylsilane, tetrakis(trimethylsilyl)silane.

[0010] Preferably, the acid anhydride additive is one or more of phthalic anhydride, citraconic anhydride, propylphosphoric anhydride, and 2,3-pyridine dianhydride.

[0011] Preferably, the phosphazene additive is ethoxypentafluorocyclotriphosphazene and / or hexa(2,2,2-trifluoroethoxy)cyclotriphosphazene.

[0012] According to some specific embodiments, the additives consist of silane additives, acid anhydride additives and phosphazene additives.

[0013] Preferably, the concentration of the electrolyte salt is 1-2 mol / L, for example, 1 mol / L, 1.1 mol / L, 1.2 mol / L, 1.3 mol / L, 1.4 mol / L, 1.5 mol / L, 1.6 mol / L, 1.7 mol / L, 1.8 mol / L, 1.9 mol / L, 2 mol / L.

[0014] Further preferably, the concentration of the lithium difluorophosphate is 0.05-0.2 mol / L, for example 0.05 mol / L, 0.06 mol / L, 0.07 mol / L, 0.08 mol / L, 0.09 mol / L, 0.1 mol / L, 0.11 mol / L, 0.12 mol / L, 0.13 mol / L, 0.14 mol / L, 0.15 mol / L, 0.16 mol / L, 0.17 mol / L, 0.18 mol / L, 0.19 mol / L, 0.2 mol / L.

[0015] Preferably, the amount of the silane additive is 0.1% to 5% of the total mass of the lithium fluoride carbon battery electrolyte, for example 0.1%, 0.5%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%.

[0016] Preferably, the amount of the acid anhydride additive is 0.1% to 3% of the total mass of the lithium fluoride carbon battery electrolyte, for example, 0.1%, 0.5%, 0.15%, 0.2%, 0.25%, 0.3%.

[0017] Preferably, the amount of the phosphazene additive is 2% to 20% of the total mass of the lithium fluoride carbon battery electrolyte, for example 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%.

[0018] Further preferably, the amount of the silane additive is 0.5% to 5% of the total mass of the lithium fluoride carbon battery electrolyte, for example, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%.

[0019] Further preferably, the amount of the acid anhydride additive is 0.5% to 1% of the total mass of the lithium fluoride carbon battery electrolyte, for example, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%.

[0020] Further preferably, the amount of the phosphazene additive is 2% to 10% of the total mass of the lithium fluoride carbon battery electrolyte, for example 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%.

[0021] Preferably, the organic solvent includes an ester solvent, an ether solvent and a sulfone solvent.

[0022] The ester solvent is a cyclic ester and / or a linear ester.

[0023] The cyclic ester solvent is one or more of ethylene carbonate, propylene carbonate and γ-butyrolactone.

[0024] The linear ester solvent is one or more of dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl butyrate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate and propyl propionate.

[0025] The ether solvent is one or more of ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, 1,4-dioxane, 1,3-dioxane, and tetrahydrofuran.

[0026] The sulfone solvent is one or more of vinyl sulfone, dimethyl sulfoxide and sulfolane.

[0027] Preferably, the mass ratio of the ester solvent, the ether solvent and the sulfone solvent is (1-5):1:(1-3), and more preferably (1.5-3.5):1:(1.5-3).

[0028] The present invention also provides a lithium carbon fluoride battery, wherein the positive electrode material is carbon fluoride, the negative electrode material is metallic lithium, and the electrolyte of the lithium carbon fluoride battery is the above-mentioned lithium carbon fluoride battery electrolyte.

[0029] Preferably, the lithium carbon fluoride battery is in the shape of a button type, a cylinder, a square or a soft pack.

[0030] The present invention also provides application of the lithium carbon fluoride battery in a tire pressure detection system.

[0031] Due to the adoption of the above technical solution, the present invention has the following advantages compared with other processes:

[0032] The electrolyte prepared by the present invention through the optimization and combination of the above-mentioned electrolyte lithium salt, functional additives and organic solvents can simultaneously meet the requirements of normal temperature discharge, high rate discharge, high and low temperature discharge performance and safety performance at high temperature after the lithium fluoride carbon battery is filled. The adjusted electrolyte salt not only has a high ionic conductivity, but the addition of lithium difluorophosphate can also reduce the battery impedance and further improve its power performance; the compound addition of the three additives is conducive to the film formation of the electrolyte on the surface of the positive and negative electrode materials, improves the stability of the electrolyte at high and low temperatures and the conductivity at low temperatures, broadens the temperature range of battery use, and also suppresses the flammability of the electrolyte, greatly improving the safety performance of the battery at high temperatures. The electrolyte of the present invention has broad application prospects in future lithium fluoride carbon batteries for tire pressure. DETAILED DESCRIPTION

[0033] Although some models of wide-temperature lithium carbon fluoride batteries currently available on the market show an operating temperature of -40℃~+85℃ or -20℃~+150℃, high and low temperature performance tests have found that at -20℃~-40℃, there is a high probability that they cannot discharge normally or can only reach a discharge capacity of 0-15% at the same rate discharge, and the rate performance is poor. In addition, the safety is poor when stored at high temperature for a long time (many commercially available lithium carbon fluoride batteries have a certain degree of leakage or explosion in the test of being stored at 125℃ for 100h).

[0034] Therefore, in order to improve the safety performance and power discharge performance of lithium carbon fluoride batteries in a high temperature environment for a long time, and to further improve the application prospects of lithium carbon fluoride batteries, the inventors have conducted long-term research and a large number of experimental verifications on the electrolyte system of lithium carbon fluoride batteries, and have made adjustments to its organic solvents, additives, and lithium salts. Through the optimization of the formula of the electrolyte system, the lithium carbon fluoride battery will not leak or explode even if it is left in a high temperature environment for a long time (125°C, 100h), and the safety performance is significantly improved. At the same time, the -40°C low-temperature discharge capacity, 85°C high-temperature discharge capacity, and 3A high-current pulse discharge capacity of the lithium carbon fluoride battery have all been significantly improved, showing a better discharge performance.

[0035] The technical scheme of the present invention and its implementation process will be further explained below in conjunction with the embodiments and comparative examples. However, the present invention is not limited to the following embodiments. The implementation conditions used in the embodiments can be further adjusted according to the different requirements of specific use, and the implementation conditions not specified are conventional conditions in the industry. The technical features involved in each embodiment of the present invention can be combined with each other as long as they do not conflict with each other.

[0036] The components of the electrolyte in the following examples and comparative examples can be obtained from commercial sources.

[0037] The electrolytes in the following examples and comparative examples were used to prepare lithium fluorinated carbon button-type CR2450 batteries for performance testing. The positive electrode of the BR2450 battery was carbon fluoride (specifically graphene fluoride), the negative electrode was metallic lithium, the nominal voltage was 3V, the nominal capacity was 650mAH, and the size was Φ24×50mm. The battery was prepared using conventional technical means in the art.

[0038] The electrolyte formulas of Examples 1 to 12 and Comparative Examples 1 to 12 are as follows:

[0039] Example 1

[0040] The present embodiment provides a lithium fluoride carbon battery electrolyte for tire pressure, which is composed of an organic solvent, an electrolyte lithium salt and an additive. The organic solvent is a mixture of propylene carbonate, ethylene glycol dimethyl ether and cyclopentane sulfone (the mass ratio of the three is 30:20:50); the electrolyte lithium salt is lithium tetrafluoroborate and lithium difluorophosphate, wherein the concentration of lithium tetrafluoroborate in the electrolyte is 1 mol / L, and the concentration of lithium difluorophosphate in the electrolyte is 0.05 mol / L; the additive is difluorodiphenylsilane, phthalic anhydride and ethoxy pentafluorocyclotriphosphazene, wherein the amount of difluorodiphenylsilane is 1% of the total mass of the electrolyte, the amount of phthalic anhydride is 0.5% of the total mass of the electrolyte, and the amount of ethoxy pentafluorocyclotriphosphazene is 5% of the total mass of the electrolyte.

[0041] Example 2

[0042] The present embodiment provides a lithium fluoride carbon battery electrolyte for tire pressure, which is composed of an organic solvent, an electrolyte lithium salt and an additive. The organic solvent is a mixture of propylene carbonate, ethylene glycol dimethyl ether and cyclopentane sulfone (the mass ratio of the three is 50:20:30); the electrolyte lithium salt is lithium di(trifluoromethylsulfonyl)imide and lithium difluorophosphate, wherein the concentration of lithium di(trifluoromethylsulfonyl)imide in the electrolyte is 1 mol / L, and the concentration of lithium difluorophosphate in the electrolyte is 0.05 mol / L; the additives are tetraethylene silane, citraconic anhydride and ethoxy pentafluorocyclotriphosphazene, wherein the amount of tetraethylene silane is 1% of the total mass of the electrolyte, the amount of citraconic anhydride is 1% of the total mass of the electrolyte, and the amount of ethoxy pentafluorocyclotriphosphazene is 5% of the total mass of the electrolyte.

[0043] Example 3

[0044] The present embodiment provides a lithium fluoride carbon battery electrolyte for tire pressure, which is composed of an organic solvent, an electrolyte lithium salt and an additive. The organic solvent is a mixture of ethylene carbonate, propylene carbonate, ethylene glycol dimethyl ether and cyclopentane sulfone (the mass ratio of the four is 8:32:15:45); the electrolyte lithium salt is lithium tetrafluoroborate and lithium difluorophosphate, wherein the concentration of lithium tetrafluoroborate in the electrolyte is 1 mol / L, and the concentration of lithium difluorophosphate in the electrolyte is 0.1 mol / L; the additive is tetrakis(trimethylsilyl)silane, propyl phosphoric anhydride and hexa(2,2,2-trifluoroethoxy)cyclotriphosphazene, wherein the amount of tetrakis(trimethylsilyl)silane is 1% of the total mass of the electrolyte, the amount of propyl phosphoric anhydride is 0.5% of the total mass of the electrolyte, and the amount of hexa(2,2,2-trifluoroethoxy)cyclotriphosphazene is 3% of the total mass of the electrolyte.

[0045] Example 4

[0046] This embodiment provides a lithium fluoride carbon battery electrolyte for tire pressure, which is composed of an organic solvent, an electrolyte lithium salt and an additive. The organic solvent is a mixture of ethylene carbonate, propylene carbonate, ethylene glycol dimethyl ether and cyclopentane sulfone (the mass ratio of the four is 8:42:15:35); the electrolyte lithium salt is lithium bis(fluorosulfonyl)imide and lithium difluorophosphate, wherein the concentration of lithium bis(fluorosulfonyl)imide in the electrolyte is 1 mol / L lithium bis(fluorosulfonyl)imide, and the concentration of lithium difluorophosphate in the electrolyte is 0.05 mol / L; the additives are tetrakis(trimethylsilyl)silane, 2,3-pyridine dianhydride and hexa(2,2,2-trifluoroethoxy)cyclotriphosphazene, wherein the amount of tetrakis(trimethylsilyl)silane is 1% of the total mass of the electrolyte, the amount of 2,3-pyridine dianhydride is 0.5% of the total mass of the electrolyte, and the amount of hexa(2,2,2-trifluoroethoxy)cyclotriphosphazene is 5% of the total mass of the electrolyte.

[0047] Example 5

[0048] The present embodiment provides a lithium fluorinated carbon battery electrolyte for tire pressure, which is composed of an organic solvent, an electrolyte lithium salt and an additive. The organic solvent is a mixture of ethylene carbonate, propylene carbonate, ethylene glycol dimethyl ether and cyclopentane sulfone (the mass ratio of the four is 8:42:15:35); the electrolyte lithium salt is lithium trifluoromethyl sulfonate and lithium difluorophosphate, wherein the concentration of lithium trifluoromethyl sulfonate in the electrolyte is 1 mol / L, and the concentration of lithium difluorophosphate in the electrolyte is 0.1 mol / L; the additive is tetrakis(trimethylsilyl)silane, 2,3-pyridine dianhydride and hexa(2,2,2-trifluoroethoxy)cyclotriphosphazene, wherein the amount of tetrakis(trimethylsilyl)silane is 1% of the total mass of the electrolyte, the amount of 2,3-pyridine dianhydride is 0.5% of the total mass of the electrolyte, and the amount of hexa(2,2,2-trifluoroethoxy)cyclotriphosphazene is 5% of the total mass of the electrolyte.

[0049] Example 6

[0050] The present embodiment provides a lithium fluoride carbon battery electrolyte for tire pressure, which is composed of an organic solvent, an electrolyte lithium salt and an additive. The organic solvent is a mixture of propylene carbonate, ethylene glycol dimethyl ether and cyclopentane sulfone (the mass ratio of the three is 50:20:30); the electrolyte lithium salt is lithium di(trifluoromethylsulfonyl)imide and lithium difluorophosphate, wherein the concentration of lithium di(trifluoromethylsulfonyl)imide in the electrolyte is 1 mol / L, and the concentration of lithium difluorophosphate in the electrolyte is 0.1 mol / L; the additive is tetrakis(trimethylsilyl)silane, citraconic anhydride and ethoxy pentafluorocyclotriphosphazene, wherein the amount of tetrakis(trimethylsilyl)silane is 0.5% of the total mass of the electrolyte, the amount of citraconic anhydride is 1% of the total mass of the electrolyte, and the amount of ethoxy pentafluorocyclotriphosphazene is 10% of the total mass of the electrolyte.

[0051] Example 7

[0052] The present embodiment provides a lithium fluoride carbon battery electrolyte for tire pressure, which is composed of an organic solvent, an electrolyte lithium salt and an additive. The organic solvent is a mixture of propylene carbonate, ethylene glycol dimethyl ether and cyclopentane sulfone (the mass ratio of the three is 50:20:30); the electrolyte lithium salt is lithium di(trifluoromethylsulfonyl)imide and lithium difluorophosphate, wherein the concentration of lithium di(trifluoromethylsulfonyl)imide in the electrolyte is 0.8 mol / L, and the concentration of lithium difluorophosphate in the electrolyte is 0.1 mol / L; the additive is tetrakis(trimethylsilyl)silane, citraconic anhydride and ethoxy pentafluorocyclotriphosphazene, wherein the amount of tetrakis(trimethylsilyl)silane is 0.5% of the total mass of the electrolyte, the amount of citraconic anhydride is 1% of the total mass of the electrolyte, and the amount of ethoxy pentafluorocyclotriphosphazene is 10% of the total mass of the electrolyte.

[0053] Example 8

[0054] The present embodiment provides a lithium fluorinated carbon battery electrolyte for tire pressure, which is composed of an organic solvent, an electrolyte lithium salt and an additive. The organic solvent is a mixture of ethylene carbonate, propylene carbonate, ethylene glycol dimethyl ether and cyclopentane sulfone (the mass ratio of the four is 8:42:15:35); the electrolyte lithium salt is lithium bis(fluorosulfonyl)imide and lithium difluorophosphate, wherein the concentration of lithium bis(fluorosulfonyl)imide in the electrolyte is 1 mol / L, and the concentration of lithium difluorophosphate in the electrolyte is 0.1 mol / L; the additive is tetrakis(trimethylsilyl)silane, 2,3-pyridine dianhydride and hexa(2,2,2-trifluoroethoxy)cyclotriphosphazene, wherein the amount of tetrakis(trimethylsilyl)silane is 1% of the total mass of the electrolyte, the amount of 2,3-pyridine dianhydride is 1% of the total mass of the electrolyte, and the amount of hexa(2,2,2-trifluoroethoxy)cyclotriphosphazene is 10% of the total mass of the electrolyte.

[0055] Example 9

[0056] The present embodiment provides a lithium fluoride carbon battery electrolyte for tire pressure, which is composed of an organic solvent, an electrolyte lithium salt and an additive. The organic solvent is a mixture of propylene carbonate, ethylene glycol dimethyl ether and cyclopentane sulfone (the mass ratio of the three is 50:20:30); the electrolyte lithium salt is lithium di(trifluoromethylsulfonyl)imide and lithium difluorophosphate, wherein the concentration of lithium di(trifluoromethylsulfonyl)imide in the electrolyte is 1.1 mol / L, and the concentration of lithium difluorophosphate in the electrolyte is 0.1 mol / L; the additive is tetrakis(trimethylsilyl)silane, citraconic anhydride and ethoxy pentafluorocyclotriphosphazene, wherein the amount of tetrakis(trimethylsilyl)silane is 1% of the total mass of the electrolyte, the amount of citraconic anhydride is 1.5% of the total mass of the electrolyte, and the amount of ethoxy pentafluorocyclotriphosphazene is 10% of the total mass of the electrolyte.

[0057] Example 10

[0058] The present embodiment provides a lithium fluorinated carbon battery electrolyte for tire pressure, which is composed of an organic solvent, an electrolyte lithium salt and an additive. The organic solvent is a mixture of ethylene carbonate, propylene carbonate, ethylene glycol dimethyl ether and cyclopentane sulfone (the mass ratio of the four is 8:32:15:45); the electrolyte lithium salt is lithium tetrafluoroborate and lithium difluorophosphate, wherein the concentration of lithium tetrafluoroborate in the electrolyte is 1 mol / L, and the concentration of lithium difluorophosphate in the electrolyte is 0.1 mol / L; the additive is tetrakis(trimethylsilyl)silane, 2,3-pyridine dianhydride and hexa(2,2,2-trifluoroethoxy)cyclotriphosphazene, wherein the amount of tetrakis(trimethylsilyl)silane is 1% of the total mass of the electrolyte, the amount of 2,3-pyridine dianhydride is 0.5% of the total mass of the electrolyte, and the amount of hexa(2,2,2-trifluoroethoxy)cyclotriphosphazene is 5% of the total mass of the electrolyte.

[0059] Embodiment 11

[0060] The present embodiment provides a lithium fluoride carbon battery electrolyte for tire pressure, which is composed of an organic solvent, an electrolyte lithium salt and an additive. The organic solvent is a mixture of propylene carbonate, ethylene glycol dimethyl ether, and cyclopentane sulfone (the mass ratio of the three is 30:20:50); the electrolyte lithium salt is lithium tetrafluoroborate and lithium difluorophosphate, wherein the concentration of lithium tetrafluoroborate in the electrolyte is 1 mol / L, and the concentration of lithium difluorophosphate in the electrolyte is 0.1 mol / L; the additive is difluorodiphenylsilane, phthalic anhydride and ethoxy pentafluorocyclotriphosphazene, wherein the amount of difluorodiphenylsilane is 2% of the total mass of the electrolyte, the amount of phthalic anhydride is 0.5% of the total mass of the electrolyte, and the amount of ethoxy pentafluorocyclotriphosphazene is 5% of the total mass of the electrolyte.

[0061] Example 12

[0062] The present embodiment provides a lithium fluorinated carbon battery electrolyte for tire pressure, which is composed of an organic solvent, an electrolyte lithium salt and an additive. The organic solvent is a mixture of propylene carbonate, ethylene glycol dimethyl ether and cyclopentane sulfone (the mass ratio of the three is 30:20:50); the electrolyte lithium salt is lithium tetrafluoroborate and lithium difluorophosphate, wherein the concentration of lithium tetrafluoroborate in the electrolyte is 1 mol / L, and the concentration of lithium difluorophosphate in the electrolyte is 0.1 mol / L; the additive is tetrakis(trimethylsilyl)silane, citraconic anhydride and hexa(2,2,2-trifluoroethoxy)cyclotriphosphazene, wherein the amount of tetrakis(trimethylsilyl)silane is 5% of the total mass of the electrolyte, the amount of citraconic anhydride is 1% of the total mass of the electrolyte, and the amount of hexa(2,2,2-trifluoroethoxy)cyclotriphosphazene is 3% of the total mass of the electrolyte.

[0063] Comparative Example 1

[0064] This comparative example provides a lithium fluoride carbon battery electrolyte for tire pressure, which is composed of an organic solvent and an electrolyte lithium salt, without adding other additives. The organic solvent is a mixture of propylene carbonate and ethylene glycol dimethyl ether (the mass ratio of the two is 30:70); the electrolyte lithium salt is lithium tetrafluoroborate, and its concentration in the electrolyte is 1 mol / L.

[0065] Comparative Example 2

[0066] This comparative example provides a lithium fluoride carbon battery electrolyte for tire pressure, which is composed of an organic solvent and an electrolyte lithium salt, without adding other additives. The organic solvent is a mixture of propylene carbonate, ethylene glycol dimethyl ether, and cyclopentane sulfone (the mass ratio of the three is 20:30:50); the electrolyte lithium salt is lithium trifluoromethanesulfonate, and its concentration in the electrolyte is 1 mol / L.

[0067] Comparative Example 3

[0068] This comparative example provides a lithium fluoride carbon battery electrolyte for tire pressure, which is composed of an organic solvent and an electrolyte lithium salt, without adding other additives. The organic solvent is a mixture of propylene carbonate, ethylene glycol dimethyl ether, and cyclopentane sulfone (the mass ratio of the three is 40:20:40); the electrolyte lithium salt is lithium bis(trifluoromethylsulfonyl)imide, and its concentration in the electrolyte is 0.8 mol / L.

[0069] Comparative Example 4

[0070] This comparative example provides a lithium fluoride carbon battery electrolyte for tire pressure, which is composed of an organic solvent, an electrolyte lithium salt and an additive. The organic solvent is a mixture of propylene carbonate, ethylene glycol dimethyl ether, and cyclopentane sulfone (the mass ratio of the three is 30:20:50); the electrolyte lithium salt is lithium tetrafluoroborate, and its concentration in the electrolyte is 1 mol / L; the additive is difluorodiphenylsilane, and its amount is 1% of the total mass of the electrolyte.

[0071] Comparative Example 5

[0072] This comparative example provides a lithium fluorinated carbon battery electrolyte for tire pressure, which is composed of an organic solvent, an electrolyte lithium salt and an additive. The organic solvent is a mixture of propylene carbonate, ethylene glycol dimethyl ether, and cyclopentane sulfone (the mass ratio of the three is 30:20:50); the electrolyte lithium salt is lithium tetrafluoroborate, and its concentration in the electrolyte is 1 mol / L; the additive is ethoxy pentafluorocyclotriphosphazene, and its amount is 1% of the total mass of the electrolyte.

[0073] Comparative Example 6

[0074] This comparative example provides a lithium fluoride carbon battery electrolyte for tire pressure, which is composed of an organic solvent, an electrolyte lithium salt and an additive. The organic solvent is a mixture of propylene carbonate, ethylene glycol dimethyl ether, and cyclopentane sulfone (the mass ratio of the three is 30:20:50); the electrolyte lithium salt is lithium tetrafluoroborate, and its concentration in the electrolyte is 1 mol / L; the additive is phthalic anhydride, and its amount is 1% of the total mass of the electrolyte.

[0075] Comparative Example 7

[0076] This comparative example provides a lithium fluorinated carbon battery electrolyte for tire pressure, which is composed of an organic solvent, an electrolyte lithium salt and an additive. The organic solvent is a mixture of propylene carbonate, ethylene glycol dimethyl ether, and 1,3-dioxolane (the mass ratio of the three is 30:20:50); the electrolyte lithium salt is lithium tetrafluoroborate, and its concentration in the electrolyte is 1 mol / L; the additive is phenoxy pentafluorocyclotriphosphazene, and its amount is 1% of the total mass of the electrolyte.

[0077] Comparative Example 8

[0078] This comparative example provides a lithium fluorinated carbon battery electrolyte for tire pressure, which is composed of an organic solvent, an electrolyte lithium salt and an additive. The organic solvent is a mixture of propylene carbonate, ethylene glycol dimethyl ether, and 1,3-dioxolane (the mass ratio of the three is 30:20:50); the electrolyte lithium salt is lithium trifluoromethanesulfonate, and its concentration in the electrolyte is 1 mol / L; the additive is citraconic anhydride, and its amount is 1% of the total mass of the electrolyte.

[0079] Comparative Example 9

[0080] This comparative example provides a lithium fluoride carbon battery electrolyte for tire pressure, which is composed of an organic solvent, an electrolyte lithium salt and an additive. The organic solvent is a mixture of propylene carbonate, ethylene glycol dimethyl ether, and cyclopentane sulfone (the mass ratio of the three is 30:20:50); the electrolyte lithium salt is lithium tetrafluoroborate and lithium difluorophosphate, wherein the concentration of lithium tetrafluoroborate in the electrolyte is 1 mol / L lithium tetrafluoroborate, and the concentration of lithium difluorophosphate in the electrolyte is 0.05 mol / L; the additive is difluorodiphenylsilane and phthalic anhydride, wherein the amount of difluorodiphenylsilane is 1% of the total mass of the electrolyte, and the amount of phthalic anhydride is 0.5% of the total mass of the electrolyte.

[0081] Comparative Example 10

[0082] This comparative example provides a lithium fluoride carbon battery electrolyte for tire pressure, which is composed of an organic solvent, an electrolyte lithium salt and an additive. The organic solvent is a mixture of propylene carbonate, ethylene glycol dimethyl ether and cyclopentane sulfone (the mass ratio of the three is 30:20:50); the electrolyte lithium salt is lithium tetrafluoroborate and lithium difluorophosphate, wherein the concentration of lithium tetrafluoroborate in the electrolyte is 1 mol / L, and the concentration of lithium difluorophosphate in the electrolyte is 0.05 mol / L; the additive is difluorodiphenylsilane, vinylene carbonate and ethoxy pentafluorocyclotriphosphazene, wherein the amount of difluorodiphenylsilane is 1% of the total mass of the electrolyte, the amount of vinylene carbonate is 0.5% of the total mass of the electrolyte, and the amount of ethoxy pentafluorocyclotriphosphazene is 5% of the total mass of the electrolyte.

[0083] Comparative Example 11

[0084] This comparative example provides a lithium fluoride carbon battery electrolyte for tire pressure, which is composed of an organic solvent, an electrolyte lithium salt and an additive. The organic solvent is a mixture of propylene carbonate, ethylene glycol dimethyl ether, and cyclopentane sulfone (the mass ratio of the three is 30:20:50); the electrolyte lithium salt is lithium tetrafluoroborate and lithium difluorophosphate, wherein the concentration of lithium tetrafluoroborate in the electrolyte is 1 mol / L, and the concentration of lithium difluorophosphate in the electrolyte is 0.05 mol / L; the additives are difluorodiphenylsilane, phthalic anhydride and ethoxy pentafluorocyclotriphosphazene, wherein the amount of difluorodiphenylsilane is 1% of the total mass of the electrolyte, the amount of phthalic anhydride is 0.5% of the total mass of the electrolyte, and the amount of ethoxy pentafluorocyclotriphosphazene is 1% of the total mass of the electrolyte.

[0085] Comparative Example 12

[0086] This comparative example provides a lithium fluoride carbon battery electrolyte for tire pressure, which is composed of an organic solvent, an electrolyte lithium salt and an additive. The organic solvent is a mixture of propylene carbonate, ethylene glycol dimethyl ether, and cyclopentane sulfone (the mass ratio of the three is 30:20:50); the electrolyte lithium salt is lithium tetrafluoroborate and lithium difluorophosphate, wherein the concentration of lithium tetrafluoroborate in the electrolyte is 1 mol / L, and the concentration of lithium difluorophosphate in the electrolyte is 0.05 mol / L; the additive is difluorodiphenylsilane, phthalic anhydride and ethoxy pentafluorocyclotriphosphazene, wherein the amount of difluorodiphenylsilane is 1% of the total mass of the electrolyte, the amount of phthalic anhydride is 5% of the total mass of the electrolyte, and the amount of ethoxy pentafluorocyclotriphosphazene is 1% of the total mass of the electrolyte.

[0087] Performance Test:

[0088] The discharge performance of the battery was tested using a Shenzhen Xinwei battery tester (5V10mA).

[0089] The 12 comparative examples and 12 examples were formulated into electrolytes according to the formulas, injected into button-type BR2450 lithium carbon fluoride batteries, and subjected to 85°C high-temperature discharge, 125°C high-temperature storage, high-current pulse discharge and -40°C low-temperature discharge tests.

[0090] The 85℃ discharge test conditions are: at 80℃, leave for 24 hours, constant current 20mA, cut-off voltage 2.0V.

[0091] The 125℃ high temperature shelf thickness test method is: place the battery in a 125℃ oven for 100 hours and observe whether the battery has leakage or explosion.

[0092] The test method for high current pulse discharge is: under normal temperature conditions, discharge at a constant current of 3A for 3s, leave for 27s, and cycle until the voltage reaches 1.8V.

[0093] The test method for low-temperature discharge is: at -40℃, leave for 24 hours, constant current 20mA, cut-off voltage 2.0V.

[0094] All comparative examples and test results are shown in Table 1.

[0095] Table 1

[0096]

[0097]

[0098] Table 1 shows that by optimizing the organic solvent, using dilithium salt (which must contain lithium difluorophosphate), combining the use of silane additives (difluorodiphenylsilane, tetraethylenesilane or tetrakis(trimethylsilyl)silane), anhydride additives (phthalic anhydride, citraconic anhydride, propylphosphoric anhydride or 2,3-pyridine dianhydride) and phosphazene additives (ethoxypentafluorocyclotriphosphazene or hexa(2,2,2-trifluoroethoxy)cyclotriphosphazene), and controlling the compounding ratio and dosage of these three types of additives, it is possible to improve the conductivity of the electrolyte while forming a stable SEI film, improve the power characteristics of the battery, and still have good discharge performance under a wide temperature range, which can meet the use needs of lithium fluoride carbon batteries for tire pressure in special fields. At the same time, the compounding of the three additives also greatly suppresses the risk of battery fire and explosion, and greatly improves the safety of the battery under long-term high-temperature storage.

[0099] The above detailed description of the present invention is intended to enable persons familiar with the art to understand the contents of the present invention and implement them. It does not limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A lithium fluoride carbon battery electrolyte, comprising an organic solvent, an electrolyte salt and an additive, characterized in that: The electrolyte is a mixture of any one of lithium tetrafluoroborate, lithium bis(trifluoromethylsulfonyl)imide, lithium bis(fluorosulfonyl)imide, lithium trifluoromethylsulfonate and lithium difluorophosphate, and the additives include silane additives, acid anhydride additives and phosphazene additives, and the mass ratio of the silane additives, the acid anhydride additives and the phosphazene additives is (1-5): (0.5-1): (3-10).

2. The lithium fluoride carbon battery electrolyte according to claim 1, characterized in that: The silane additive is one or more of difluorodiphenylsilane, tetraethylenesilane, and tetrakis(trimethylsilyl)silane; The acid anhydride additive is one or more of phthalic anhydride, citraconic anhydride, propylphosphoric anhydride, and 2,3-pyridine dianhydride; The phosphazene additive is ethoxy pentafluorocyclotriphosphazene and / or hexa(2,2,2-trifluoroethoxy)cyclotriphosphazene.

3. The lithium fluoride carbon battery electrolyte according to claim 1, characterized in that: The additives consist of silane additives, acid anhydride additives and phosphazene additives.

4. The lithium fluoride carbon battery electrolyte according to claim 1, characterized in that: The concentration of the electrolyte salt is 1-2 mol / L.

5. The lithium fluoride carbon battery electrolyte according to claim 1 or 4, characterized in that: The concentration of the lithium difluorophosphate is 0.05-0.2 mol / L.

6. The lithium fluoride carbon battery electrolyte according to claim 1, characterized in that: The amount of the silane additive is 0.1% to 5% of the total mass of the lithium fluoride carbon battery electrolyte; The amount of the acid anhydride additive is 0.1% to 3% of the total mass of the lithium fluoride carbon battery electrolyte; The amount of the phosphazene additive used is 2% to 20% of the total mass of the lithium fluorinated carbon battery electrolyte.

7. The lithium fluoride carbon battery electrolyte according to claim 6, characterized in that: The amount of the silane additive is 0.5% to 5% of the total mass of the lithium fluorinated carbon battery electrolyte; The amount of the acid anhydride additive is 0.5% to 1% of the total mass of the lithium fluoride carbon battery electrolyte; The amount of the phosphazene additive is 2% to 10% of the total mass of the lithium fluorinated carbon battery electrolyte.

8. The lithium fluoride carbon battery electrolyte according to claim 1, characterized in that: The organic solvent includes ester solvents, ether solvents and sulfone solvents. The ester solvent is one or more of ethylene carbonate, propylene carbonate, γ-butyrolactone, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl butyrate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, and propyl propionate; The ether solvent is one or more of ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, 1,4-dioxane, 1,3-dioxane, and tetrahydrofuran; The sulfone solvent is one or more of vinyl sulfone, dimethyl sulfoxide and sulfolane.

9. The lithium fluoride carbon battery electrolyte according to claim 1, characterized in that: The mass ratio of the ester solvent, the ether solvent and the sulfone solvent is (1-5):1:(1-3).

10. A lithium carbon fluoride battery, wherein the positive electrode material is carbon fluoride and the negative electrode material is metallic lithium, characterized in that: The electrolyte of the lithium fluorinated carbon battery is the lithium fluorinated carbon battery electrolyte according to any one of claims 1 to 9.

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