LITHIUM SECONDARY BATTERY USING IONIC LIQUID

A flame-retardant lithium secondary battery is provided that has better battery performance and higher safety than conventional batteries. The lithium secondary battery uses a positive electrode that includes a positive electrode active material of the general formula (1) below, and a nonaqueous electrolytic solution in which an ionic liquid that contains bis(fluorosulfonyl)imide anions as an anionic component is used as the solvent, LiNi x Mn y O 4 (1). In the formula (1), x and y are values that satisfy the relations x + y = 2, and x:y = 27.5:72.5 to 22.5:77.5.