LiPF6 stabilization method, electrolyte solution for non-aqueous secondary battery excellent in thermal stability, and non-aqueous secondary battery excellent in 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.