| 摘要 |
PROBLEM TO BE SOLVED: To provide a nonaqueous secondary battery having high capacity and excellent cycle life and stability formed by using a specific composition as a positive electrode material having, and a double-structure graphite particles coated with an amorphous carbon layer and graphitized meso-carbon micro- beads as a negative electrode material. SOLUTION: A positive electrode contains, as a positive electrode active material, a lithium - manganese - nickel composite oxide expressed by a composition formula Lia Mnb Nic Md O2 , where M is at least one kind of element selected from a group comprising Co, Al and Fe, 1<=a<=1.1, 0.3<=b<0.5, 0.3<=c<0.5, 0<d<=0.3 and b+c+d=1. A negative electrode contains, as a negative electrode active material, a mixture comprising double-structure graphite particles prepared by coating the surfaces of graphitic particles having 0.34 nm or less of a spacing (d002) of the (002) face by an X-ray wide-angle diffraction method with an amorphous carbon layer having 0.34 nm or more of the spacing, and graphitized meso-carbon micro-beads. |
