Method for preparing perfluor alkyl ethide phosphite ester

Abstract

The invention discloses a method for preparing perfluor alkyl ethide phosphite ester with better inflaming retarding effect, lower viscosity, and better electrochemical stability, which comprises the following steps: (1) phosphorus trichloride and perfluor alkyl ethanol are fully reacted according to the mol ratio of 1:2-1:9 within minus 30 DEG C to 100 DEG C; generated primary product is an acid mixture of perfluor alkyl ethide phosphite ester; (2) the acid mixture is fully neutralized by using alkaline matter with minus 30 DEG C to 100 DEG C of neutral temperature to ensure that the PH value of a neutralized solution is more than 7, and then the solution is filtered to remove impurities; filtrate is collected; (3) the filtrate is distilled in subpressure under minus 0.05Mpa to minus 0.1Mpa; distillation with more than 99% of contents of perfluor alkyl ethide phosphite ester is collected; (4) distillation with more than 99% of contents is dehydrated with a molecular sieve under minus50 DEG C to minus 100 DEG C, thus obtaining perfluor alkyl ethide phosphite ester with the contents of 99%, which can be used as flame retardant of lithium ion battery electrolyte.

Description

technical field [0001] The invention relates to a preparation method of a perfluoroalkyl ethyl phosphite that can be used as a flame retardant for a lithium-ion battery electrolyte. Background technique [0002] The huge application prospects of large-capacity lithium-ion power batteries have attracted the attention of many scientists. However, one of the obstacles to the development of large-capacity lithium-ion power batteries is safety issues, especially under abuse (such as thermal shock, overcharge, overdischarge, short circuit, etc.), there are often safety hazards such as fire and explosion. In order to develop high-capacity lithium-ion batteries, safety issues must be solved, and the purpose of adding flame retardant additives is to improve the safety performance of batteries. When the flame retardant additive is heated, it releases free radicals with flame retardant properties, which can capture hydrogen radicals or hydroxyl radicals in the gas phase, thereby preve...

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Problems solved by technology

[0010] However, according to the current research results, the flame retardant additives used have electrochemical instability or other unfavorable physical and chemical properties - such as high melting point, high viscosity, etc., which will have a certain negative impact on the performance of lithium-ion batteries