To improve a positive electrode active material, in a nonaqueous electrolyte secondary battery using an inexpensive lithium-containing transition metal composite oxide as the positive electrode active material to improve output characteristics in various temperature conditions so that the battery can be suitably used as a power source for a hybrid car or the like.
The nonaqueous electrolyte secondary battery includes a positive electrode 11 containing positive electrode active material, a negative electrode 12 containing negative electrode active material, and a nonaqueous electrolyte 14 prepared by dissolving a solute to a nonaqueous solvent. As the positive electrode active material, a lithium-containing transition metal composite oxide to which niobium is added is used, the lithium-containing transition metal composite oxide having a layered structure represented by the formula: Li1+xNiaMnbCocO2+d (where x, a, b, c and d satisfy relations of x+a+b+c=1, 0.7≤a+b, 0<x≤0.1, 0≤c/(a+b)<0.35, 0.7≤a/b≤2.0, and -0.1≤d≤0.1). Further, the surface of the positive electrode active material is preferably coated with an amorphous carbon material.
OKITA KAZUNARI
NAKAGAWA HIROSHI
FUJIMOTO HIROYUKI
YADA CHIHIRO
SUZUKI AKIHIRO
TODE SHINGO
KIDA YOSHINORI
Hiroshi Kakutani