Effect of MgO and TiO2 Coating on the Electrochemical Performance of Li-Rich Cathode Materials for Lithium-Ion Batteries

0.5Li 2 MnO 3 ·0.5LiNi 0.5 Mn 0.3 Co 0.2 O 2 cathode materials with nano-MgO and nano-TiO 2 coating layers are synthesized via a facile approach. These nanocoating layers with a thickness of ≈20 nm are homogeneously coated on the surface of the materials. With the nano-MgO and nano-TiO 2 coating layers, the modified materials deliver excellent electrochemical performance. Nano-MgO-coated and nano-TiO 2 -coated Li-rich materials exhibit 147.56 and 137.96 mAh g −1 after 100 cycles at 1C rate and deliver 156.13 and 130.69 mAh g −1 at 2C rate, respectively, in the voltage range of 2.0–4.8 V. The materials with nano-MgO and nano-TiO 2 coating layers also show a high discharge voltage retention of more than 90% after 50 cycles, low impedance for Li + migration, and high diffusion coefficients of the lithium ions. Nano-MgO and nano-TiO 2 coating layers help decrease the content of Li 2 CO 3 on the surface of the materials and suppress side reactions. Thus, these materials play a significant role in strengthening the electrochemical performance of Li-rich cathode materials.