US Patent 7767350 Nonaqueous electrolyte battery

A nonaqueous electrolyte battery includes: a cathode using a composite compound of lithium and transition metals as a positive active material; an anode using a negative active material capable of being doped with and doped from lithium; and a nonaqueous electrolyte interposed between the cathode and the anode. The nonaqueous electrolyte is obtained by dissolving LiMFm (M is an element selected from As, B, P and Sb, and m is an integer located within a range of 4 to 6.) and LiCnF2n+1 SO3 or LiN(CnF2n+1SO2)2 in a nonaqueous solvent including cyclic carbonate or non cyclic carbonate and having unsaturated carbonate added within a range of 0.1 volume % or more and 5 volume % or less, and the concentration of LiCnF2n+1SO3 or LiN(CnF2n+1SO2)2 is located within a range of 1 wt % or more and lower than 10 wt %. Thus, a self-discharge is suppressed and a storage property is improved.