Patent ID: 8795544

Claim:
A power storage device comprising: a positive electrode; a negative electrode; a separator; an electrolyte salt; and a room-temperature ionic liquid represented by a general formula (G1) wherein R 2 represents an alkyl group having 1 or 2 carbon atoms, wherein one of R 1 , R 3 to R 5 represents an alkyl group having 1 or 2 carbon atoms, wherein the other two of R 1 , and R 3 to R 5 represent hydrogen atoms, wherein A − represents a univalent imide anion selected from (C n F 2n+1 SO 2 ) 2 N − (n=0 to 4), (C m F 2m+1 SO 3 ) − (m=0 to 4), and CF 2 (CF 2 SO 2 ) 2 N − and wherein the electrolyte salt includes a lithium ion.