Synthesis and electrochemical characteristics of Li\\r sub/1.2sub\\r (Ni\\r sub/0.2sub\\r Mn\\r sub/0.6sub\\r )\\r sub/xsub\\r (Co\\r sub/0.4sub\\r Mn\\r sub/0.4sub\\r )\\r sub/ysub\\r (Ni\\r sub/0.4sub\\r Mn\\r sub/0.4sub\\r )\\r sub/1−x−ysub\\r O\\r sub/2sub\\r (0 ≤ x + y ≤ 1) cathode materials for lithium ion batteries