Method for stabilizing LiPF₆, electrolyte solution for nonaqueous secondary batteries having excellent thermal stability, and nonaqueous secondary battery having excellent thermal stability

摘要

A method for stabilizing a solution that contains LiPF₆ by increasing thermal stability of LiPF₆ without changing the structure thereof; an electrolyte solution for nonaqueous secondary batteries, which has increased thermal stability; and a nonaqueous secondary battery which has increased thermal stability. The solution containing LiPF₆ contains a phosphoric acid ester amide in such an amount that the molar ratio of the phosphoric acid ester amide relative to LiPF₆ is 0.001-2.