Enhanced Electrochemical Performance of Li [ Li0.2Ni0.2Mn0.6] O2Modified by Manganese Oxide Coating for Lithium-Ion Batteries

Li-rich layered cathode material Li[Li0.2Ni0.2Mn0.6]O2was modified by manganese oxide coating via a simple deposition and heat-treatment process. The HRTEM images and the XPS analysis demonstrated that the surface of Li[Li0.2Ni0.2Mn0.6]O2was covered by continuous manganese oxide layer, with about 10nmthickness. The electrochemical performance is improved greatly, especially the rate capability. The composite coated with 4wt%manganese oxide showed high reversible capacity of 210mAhg−1after 50cyclesat 2C(400mAg−1), compared with 77mAhg−1of the pristine. It is believed that surface modification of Li[Li0.2Ni0.2Mn0.6]O2with manganese oxide coating exhibits a convenient approach for a large-scale production.