| 摘要 |
PROBLEM TO BE SOLVED: To inhibit the degradation of a battery and to enhance preservation characteristic by providing a positive electrode containing a manganese oxide or complex oxides of lithium and manganese, a negative electrode composed chiefly of a material capable of being doped and undoped with lithium metal, a lithium alloy, or lithium, and a nonaqueous electrolyte obtained by the dissolving of an electrolyte in a nonaqueous solvent containing a phosphoric ester compound. SOLUTION: The phosphoric ester represented by the formula is used and preferably contained in a nonaqueous solvent by not less than 3 vol.% to not more than 20 vol.%. In the formula, R1 , R2 , and R3 are each an alkyl group or aryl group. For example, triethyl phosphate, triphenyl phosphate, ethyldimethyl phosphate, and the like are used, with trimethyl phosphate being particularly desirable. An electrolytic solution contains LiBF4 as an electrolyte, and a manganese oxide or complex oxides of lithium and manganese for use in the positive electrode should preferably have a spinel type crystalline structure. A phosphoric ester compound inhibits the elution of Mn in the positive electrode material into the nonaqueous electrolyte. |
