| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress drop in capacity or high-rate discharge characteristics after charge-discharge cycles in a nonaqueous electrolyte battery using a positive active material obtained by mixing a lithium-manganese composite oxide having spinel structure and a lithium-transition metal composite oxide. <P>SOLUTION: The nonaqueous electrolyte secondary battery is equipped with a positive electrode 1, a negative electrode 2, a separator 3 placed between the positive electrode 1 and the negative electrode 2, and a nonaqueous electrolyte. A mixture of the lithium-manganese composite oxide having spinel structure represented by a composition formula of Li<SB>1+z</SB>Mn<SB>2</SB>O<SB>4</SB>(0≤z≤0.2) and the lithium-transition metal composite oxide represented by a composition formula of LiNi<SB>1-x-y</SB>Co<SB>x</SB>Mn<SB>y</SB>O<SB>2</SB>(0.5<x+y<1.0, 0.1<y<0.6) is used in a positive active material, and low crystalline carbon-covered graphite obtained by covering a part or the whole of the surface of a first graphite material acting as a core material with a second carbon material having lower crystallinity than that of the first graphite material is used in a negative active material. Insertion and separation of lithium ions in the positive active material and the negative active material are smoothly performed. <P>COPYRIGHT: (C)2004,JPO |
