NONAQUEOUS ELECTROLYTIC SOLUTION FOR POWER STORAGE DEVICE, AND POWER STORAGE DEVICE

A nonaqueous liquid electrolyte includes a solute, a nonaqueous solvent, and an isophorone diisocyanate component. The isophorone diisocyanate component includes a cis-isophorone diisocyanate compound and a trans-isophorone diisocyanate compound. The mass ratio cis/trans of the cis-isophorone diisocyanate compound to the trans-isophorone diisocyanate compound is 35/65 or more and 96/4 or less.