摘要 |
Provided are a cathode active material and a secondary battery both having a higher capacity and superior cycle characteristics and capable of obtaining a sufficient discharge capacity during large current discharge. A cathode (21) and an anode (22) with a separator (23) in between are spirally wound. The cathode (21) comprises a highly stable complex oxide LixNi1-y-zMnyMIzO2 and a highly conductive complex oxide LisMII1.t. uMntMIIIuO2. Each of MI and MIII includes at least one kind selected from the group consisting of elements in Group 2 through Group 14, and MII includes at least one kind selected from the group consisting of Ni and Co, and the values of x, y, z, s, t and u are within a range of 0.9</=x<1.1, 0.25</=y</=0.45, 0.01</=z</=0.30, 0.9</=s<1.1, 0.05</=t</=0.20, and 0.01</=u</= 0.10, respectively. The highly stable complex oxide in which an amount of substitution of a different element is larger and the highly conductive complex oxide in which an amount of substitution of a different element is smaller are mixed, so superior cycle characteristics and a sufficient discharge capacity during large current discharge can be achieved. <IMAGE> |