METHOD FOR PRODUCING DIFLUOROPHOSPHATE, NONAQUEOUS ELECTROLYTE SOLUTION FOR SECONDARY BATTERY AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

Disclosed is a simple method for producing a difluorophosphate, which is useful as an additive for nonaqueous electrolyte solutions for secondary batteries, by using an easily-available low-cost raw material. Specifically disclosed is a method for producing a difluorophosphate wherein a raw material salt composed of a carbonate and/or a borate is brought into contact and reacted with a raw material gas which is composed of P and F, and if necessary O. The raw material salt may be a lithium carbonate, while the raw material gas may be a substance obtained by decomposing LiPf₆. It is also possible to mix LiPf₆ and a lithium carbonate for reaction. Also disclosed is a nonaqueous electrolyte solution containing the thus-obtained reaction product.