A non-aqueous electrolyte rechargeable battery including: (a) a positive
electrode capable of charging and discharging lithium; (b) a negative
electrode capable of charging and discharging lithium; (c) a separator or
a lithium ion conductive layer interposed between the positive electrode
and the negative electrode; and (d) a lithium ion conductive non-aqueous
electrolyte, wherein the positive electrode contains a mixture of a first
positive electrode active material and a second positive electrode active
material, the first positive electrode active material includes lithium
oxide containing manganese, the lithium oxide further contains aluminum
and/or magnesium, and the second positive electrode active material
includes Li.sub.xCo.sub.1-y-zMg.sub.yAl.sub.zO.sub.2 where
1.ltoreq.x.ltoreq.1.03, 0.005.ltoreq.y.ltoreq.0.1 and
0.001.ltoreq.z<0.02.