Surface modification of Ni-rich LiNi_0.8Co_0.1Mn_0.1O₂ with perovskite LaFeO₃ for high voltage cathode materials

Ni-rich LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) is regarded as a potential cathode material due to its higher capacity. However, the severe capacity fading which occurs above 4.2 V vs. Li/Li⁺ needs to be addressed to enhance the electrochemical performance. Herein, we report the surface modification of NCM811 cathodes with a perovskite material, i.e., lanthanum iron oxide (LaFeO₃), which has drawn attention for various research areas due to its non-toxicity, electric conductivity, chemical stability, and low cost and systematically investigate the influence of the LaFeO₃ coating on NCM811. The LaFeO₃ coating layer significantly protects the cathode material from corrosion due to the HF formation and restrains the dissolution of other ions into liquid electrolyte during high voltage charge-discharge processes. Even after 80 cycles, 0.5 wt% LaFeO₃-coated NCM811 cathode material shows about 13% higher cycling stability when compared to the bare NCM811 and other ratios of coated materials. Furthermore, the 0.5 wt% LaFeO₃-coated NCM811 delivers excellent rate capability and demonstrates improved structural stability at 4.6 V vs. Li/Li⁺ under high voltage conditions with Ni-rich cathode active materials.