Effect of carbon coating on electrochemical performance of Li 1.048 Mn 0.381 Ni 0.286 Co 0.286 O 2 cathode material for lithium-ion batteries

Carbon-coated layered oxide Li 1.048 Mn 0.381 Ni 0.286 Co 0.286 O 2 is prepared by combining a co-precipitation and a direct current magnetron sputtering. TEM images show that the carbon layer is relatively well coated on the surface of oxide particles. The Li 1.048 Mn 0.381 Ni 0.286 Co 0.286 O 2 /C composite delivers an initial discharge capacity of 203.2 mAh g −1 between 2.5 and 4.5 V at 0.1 C, and 94% of the initial discharge capacity can be retained after 100 cycles. Moreover, the carbon-coated oxide exhibits noticeable high-rate capacity of 145 mAh g −1 at 5 C, much higher than the pristine one (103 mAh g −1 at 5 C). The improved discharge capacity and cycle performance are attributed to the carbon coating, which protects the Li-rich cathode material from reacting with the electrolyte and retarding the incrassation of SEI film on the surface of oxide particles.