Excellent high-rate cyclic performance of LiNi0.8Co0.1Mn0.1O2 cathodes via dual Li2SiO3/PPy coating

LiNi0.8Co0.1Mn0.1O2 (NCM811) has garnered significant research attention as a high-power battery cathode for electric vehicles. However, low-rate capability and poor cyclic performance limit the widespread applications of NCM cathodes. Although surface coating is an effective strategy to suppress these drawbacks, single-phase coating does not meet the application requirements. Herein, Li2SiO3 and PPy are used to prepare dual coating and improve both rate capability and cyclic performance. Results reveal that Li2SiO3/PPy-coated NCM811 exhibits a specific discharge capacity of 145.1 mAh/g and capacity retention of 96.4% after 100 charge/discharge cycles at 10 C. Various analytical and electrochemical characterization techniques demonstrate that Li2SiO3 in the inner layer is helpful to enhance Li+ diffusion coefficient and PPy in the outer layer is conducive to improve electronic transmission and decrease polarization. Besides, the dual-phase coating can alleviate adverse side reactions at the interface by acting as a strong barrier between the cathode and electrolyte.