Application of tri (alkylamino) phosphonic compound, lithium ion battery, electrolyte and electrolyte additive

Abstract

The invention relates to application of a tri (alkylamino) phosphonic compound, a lithium ion battery, an electrolyte and an electrolyte additive. The tri (alkylamino) phosphonic compound has a structure shown in a general formula (I), wherein R1-R6 are respectively selected from atom-substituted or non-substituted naphthenic base or halogen atom-substituted or non-substituted alkyl having 1-5 C atoms. P atoms in the tri (alkylamino) phosphonic compound can be combined with halide ions such as chloride ions or bromide ions, the problem that the halide ions such as the chloride ions or the bromide ions acts with an Al positive electrode collector to form [AlCl4]<-> or [AlBr4]<-> so as to cause corrosion acceleration of an oxide layer Al2O3 is prevented; and moreover, the tri (alkylamino) phosphonic compound shows alkalescence, a certain neutralization effect on a slight amount of HF generated by decomposition is achieved, so that the problem of corrosion of an electrolyte lithium salt on an aluminum foil of the positive electrode collector is prevented, and the cycle property of the lithium ion battery is further improved.

Description

technical field [0001] The invention relates to the technical field of batteries, in particular to the application of a tri(alkylamino)phosphine compound, a lithium ion battery and its electrolyte and electrolyte additives. Background technique [0002] At present, the lithium-ion battery electrolyte is mainly composed of lithium hexafluorophosphate, carbonate solvent and additives. Since lithium hexafluorophosphate is unstable above 55°C, it is easy to decompose to form LiF and PF 5 These decomposition products, which in turn react with solvents to produce highly toxic species, or initiate solvent polymerization. Lithium hexafluorophosphate has the disadvantage of thermal instability, its PF 6 - The solvation of anions in carbonate-based aprotic solvents is also poor, so PF 6 - Anions are highly sensitive to trace amounts of water or alcohol, and are prone to react to generate HF, which affects battery performance and safety. Therefore, especially for large batteries ...

AI Technical Summary

Problems solved by technology

Lithium hexafluorophosphate has the disadvantage of thermal instability, its PF 6 - The solvation of anions in carbonate-based aprotic solvents is also poor, so PF 6 - Anions are highly sensitive to trace amounts of water or alcohol, and are prone to react to produce HF, which affects battery performance and safety

However, LiFSI also has a serious problem in practical application. When used as the main lithium salt, the trace amount of HF produced by the decomposition of LiFSI and the residual chloride or bromide ions in the LiFSI production process will corrode the Al positive current collector, thereby affecting the battery life. Core performance and safety

Therefore, it is urgent to provide a lithium-ion battery electrolyte to solve the problem of corrosion of the Al positive current collector caused by the trace amount of HF decomposed by the electrolyte lithium salt or the residual chloride or bromide ions in the production process of the electrolyte lithium salt.

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