| 摘要 |
PROBLEM TO BE SOLVED: To improve volume energy density, and to improve a charge/discharge cycle characteristic by combining a carbon negative electrode carrying metal to be alloyed with lithium and a Mn positive electrode material having a stable crystal structure. SOLUTION: A secondary battery is composed of a positive electrode, a negative electrode and an organic electrolyte, and an inexpensive manganese- containing oxide having a stable crystal structure is used as an active material of the positive electrode. Its composition is selected from, for example, LiMn2 O4 , Li1+ xMn2-x O4-z (0<x<=0.3, and 0<=z<=2) and LixMn1-y MyO2 (0<x<=1.3, 0<=y<=1 and 0<=z<2, and M is at least one kind of B, Al, Si, Ge, Ga, Fe, Cu, Co, Mg, Ca, Ti, V, Cr, Ni, Ag, Sn and second transition metal). The negative electrode uses a carbon material carrying a fine particle of metal forming an alloy with Li on carbon capable of storing/releasing Li ions. The metal to form alloy with Li forms the alloy with Li in the atomic ratio not more than that with seven metallic atoms as a reference to a single Li atom. |
