Enhancement of the electrochemical properties of the nickel-rich cathode material LiNi_0.815Co_0.15Al_0.035O₂ by WO₃ coating

LiNi_0.815Co_0.15Al_0.035O₂ (NCA) has attracted a lot of attention owing to its high specific capacity and low cost. The problems of capacity loss and interface side reaction during the long cycle hinder the application of NCA cathode materials. In this work, WO₃-coated LiNi_0.815Co_0.15Al_0.035O₂ cathode materials were successfully prepared, which greatly improved the electrochemical properties of the NCA. Results of XRD show that the WO₃ coating has no significant effect on the structure of the NCA samples. Results of XPS show that WO₃ coating is beneficial to reduce the content of residual alkali substance on the surface of the NCA. In addition, the first discharge specific capacity of NCA@2wt%WO₃ is 174.96 mAh g ^− 1 at a current density of 1.0 C, with a capacity retention rate of 89.94% after 200 cycles. The discharge specific capacity of NCA@2wt%WO₃ is 137.74 mAh g ^− 1 at 5.0 C. The coating of WO₃ effectively improves the electrochemical performance of NCA cathode materials.