Structural and Electrochemical Properties of Nanosize Layered Li[Li[sub 1/5]Ni[sub 1/10]Co[sub 1/5]Mn[sub 1/2]]O[sub 2]

The Li [ Li 1 / 5 Ni 1 / 10 Co 1 / 5 Mn 1 / 2 ] O 2 cathode material was synthesized using a sol-gel method. The Li [ Li 1 / 5 Ni 1 / 10 Co 1 / 5 Mn 1 / 2 ] O 2 was formed with typical hexagonal structure. The discharge capacity of Li [ Li 1 / 5 Ni 1 / 10 Co 1 / 5 Mn 1 / 2 ] O 2 delivered 190 mAh/g at the first cycle. But the discharge capacity gradually increased with cycle number to be 231 mAh/g after 13th cycle and reached 229 mAh/g after 40 cycles with capacity fading ratio of 0.014 %/cycle. The oxidation states of Ni and Co were 2+ and 3+, respectively, while Mn was in the 4+ oxidation state in the Li [ Li 1 / 5 Ni 1 / 10 Co 1 / 5 Mn 1 / 2 ] O 2 . But the oxidation state of Mn was reversibly changed between 4+ and 3+ after the first cycle.