Patent ID: 7833677

Claim:
A nonaqueous electrolyte battery, comprising a negative electrode and a positive electrode that comprises or can occlude and release lithium, a lithium salt-containing ionic liquid, wherein said ionic liquid comprises a cation represented by formula (1): A + -(CH 2 ) n —(CF 2 ) m —CF 3 (1) wherein A + represents an imidazolium structure represented by formula (2): wherein R 1 , R 3 , and R 4 each independently represent a substituent having 8 or less carbon atoms and comprising at least one element selected from the group consisting of carbon, hydrogen, and oxygen, R 2 represents a substituent having 1 or more and 8 or less carbon atoms and comprising at least one element selected from the group consisting of carbon, hydrogen, and oxygen, n is an integer of 2 or more and 10 or less, and m is an integer of 1 or more and 12 or less.