Isocyanate electrolyte additive containing sulfonamide structure group and application thereof

Abstract

The invention relates to an isocyanate electrolyte additive containing a sulfonamide structure group. The structural formula of the electrolyte additive is shown as a formula I, wherein R1 and R2 are the same or different; R1 and R2 are respectively and independently selected from methyl, ethyl, butyl, methoxyl, methanesulfonyl, ethanesulfonyl, fluorosulfonyl, trifluoromethanesulfonyl, perfluoroethanesulfonyl, benzenesulfonyl, alkyl-containing benzenesulfonyl, cyanogen-containing / fluorine-containing benzenesulfonyl and alkoxy-containing benzenesulfonyl, and R1 and R2 can be linked to form one of a five-membered ring or a six-membered ring. According to the electrolyte additive, sulfonyl and isocyanate structural groups are organically combined together, so that the electrolyte additive has high thermal stability, can play a role of an electrolyte stabilizer, and avoids high-temperature discoloration and acid value increase of an electrolyte. When the electrolyte containing the novel additive provided by the invention is applied to the battery, the high-temperature circulation and high-temperature storage performance is improved, and relatively low impedance is embodied.

Description

technical field [0001] The invention relates to an isocyanate electrolyte additive containing a sulfonamide structural group and an application thereof, belonging to the technical field of lithium battery nonaqueous electrolyte additives. Background technique [0002] Since the commercialization of lithium secondary batteries, due to its high specific energy and good cycle performance, it has been widely used in digital, energy storage, power, military aerospace and communication equipment and other fields. Compared with other secondary batteries, lithium secondary batteries have the advantages of high working voltage, long cycle life, low self-discharge rate, environmental friendliness, and no memory effect. [0003] In lithium-ion batteries, the oxidative decomposition of the electrolyte deteriorates battery performance, and is often accompanied by the dissolution of metal ions during cycling and high-temperature storage, resulting in a serious decline in battery performan...

AI Technical Summary

Problems solved by technology

1,3-Propane sultone (PS) and ethylene sulfate (DTD) are representative additives containing sulfur elements respectively, which have the effect of reducing battery impedance and film-forming additives, but 1,3-Propane sultone (PS ) is controlled by EU regulations, and its use is limited. Vinyl sulfate (DTD) has poor thermal stability. If there is no stabilizer, it will lead to deterioration of the acid value and chromaticity of the electrolyte, thereby affecting the high temperature performance of the battery

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