NONAQUEOUS ELECTROLYTE ADDITIVE, NONAQUEOUS ELECTROLYTE, AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

The present invention pertains to a nonaqueous electrolyte additive capable of improving the safety and battery properties of a nonaqueous electrolyte secondary battery, and more specifically pertains to a nonaqueous electrolyte additive comprising a phosphazene compound represented by general formula (1), (NPR2)n... (1) (in the formula, each R independently represents fluorine or a secondary or tertiary branched alkoxy group substituted by fluorine, at least one of the Rs represents the secondary or tertiary branched alkoxy group substituted by fluorine, and n is 3-14).