Additive for non-aqueous liquid electrolyte, non-aqueous liquid electrolyte secondary cell and non-aqueous liquid electrolyte electric double layer capacitor

摘要

The present invention provides an additive for a non-aqueous electrolytic solution including a phosphazene derivative which is solid at 25° C. and represented by the following formula (1): (PNR2)n formula (1) wherein R represents a monovalent substituent or a halogen atom; and n represents a number of 3 to 6. More particularly, the present invention provides a non-aqueous electrolytic solution secondary cell and a non-aqueous electrolytic solution electric double layer capacitor which contain the additive for the non-aqueous electrolytic solution, which have excellent self-extinguishability or flame retardancy, and resistance to deterioration, and which have low internal resistance and excellent conductivity due to low viscosity of the non-aqueous electrolytic solution.