Electrolyte and lithium ion battery

Abstract

The invention relates to the field of lithium ion batteries, and discloses an electrolyte which comprises a high-temperature organic solvent, a positive and negative electrode protection additive andan electrolyte lithium salt, wherein the high-temperature organic solvent comprises the following components in parts by weight of 5-30 parts of ethylene carbonate, 5-30 parts of propylene carbonate,5-30 parts of diethyl carbonate, 5-50 parts of propyl propionate and 1-10 parts of fluorobenzene; the positive and negative electrode protection additive comprises the following components in parts byweight of 0.2 to 5 parts of ethylene sulfate, 0.2 to 5 parts of fluoroethylene carbonate, 0.2 to 5 parts of difluoroethylene carbonate, 0.2 to 5 parts of a dinitrile organic matter, 0.2 to 3 parts oflithium difluorophosphate, 0.2 to 5 parts of diethylene glycol dipropionitrile ether, 0.2 to 3 parts of lithium fluorosulfonyl imide, 0.1 to 2 parts of 1-propyl phosphoric anhydride, 0.5 to 20 partsof 1, 1, 2, 2-tetrafluoroethyl-2, 2, 3, 3-tetrafluoropropyl ether, 0.1 to 2 parts of lithium oxalyldifluoroborate and 0.1 to 1 part of methylene methanedisulfonate. The electrolyte is excellent in high-temperature resistance, enables the lithium ion battery with high energy density to normally work at the temperature of 70 DEG C or above, and can keep the relatively better endurance.

Description

technical field [0001] The invention relates to the field of lithium ion batteries, in particular to an electrolyte solution and a lithium ion battery. Background technique [0002] With the rapid development of portable electronic products, lithium-ion batteries that provide energy for their work have also penetrated into every corner of our lives. Some in-vehicle and outdoor products exposed to direct sunlight will be challenged by high temperature conditions during placement or work. Although general lithium-ion batteries can withstand use in a relatively high temperature environment, due to the limitation of the key material in lithium-ion batteries-electrolyte, its upper limit temperature is limited to below 60°C. [0003] However, the temperature of the above-mentioned electronic products that are on-board or exposed to direct sunlight will rise to 70° C. or higher if they are stored for a long time under strong sunlight in summer. Under such temperature conditions, ...

AI Technical Summary

Problems solved by technology

Although general lithium-ion batteries can withstand the use of relatively high temperature environments, due to the limitation of the key material in lithium-ion batteries-electrolyte, the upper limit temperature is limited below 60°C

[0003] However, the temperature of the above-mentioned electronic products that are on-board or exposed to direct sunlight will rise to 70°C or higher if they are stored for a long time under strong sunlight in summer

Under such temperature conditions, the performance of the lithium battery will be greatly affected, and even more serious, the lithium battery will be bulged by strong heat and break the electrical appliances, and the battery itself may leak and catch fire.

Therefore, the current commercial lithium-ion batteries have higher requirements on the use environment, which limits their application in higher temperature environments.

Although there are some lithium batteries on the market that can meet the application of 70°C environment, but these are the cathode materials with relatively low voltage, low energy density and poor battery life.

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