Method for Producing Difluorophosphate, Non-Aqueous Electrolyte for Secondary Cell and Non-Aqueous Electrolyte Secondary Cell

摘要

A difluorophosphate effective as an additive for a nonaqueous electrolyte for secondary battery is produced by a simple method from inexpensive common materials. The difluorophosphate is produced by reacting lithium hexafluorophosphate with a carbonate in a nonaqueous solvent. The liquid reaction mixture resulting from this reaction is supplied for providing the difluorophosphate in a nonaqueous electrolyte comprising a nonaqueous solvent which contains at least a hexafluorophosphate as an electrolyte lithium salt and further contains a difluorophosphate. Also provided is a nonaqueous-electrolyte secondary battery employing this nonaqueous electrolyte.