Interfacial structure design enables rapid reaction kinetics for high-voltage NCM 613 cathodes

A fundamental challenge in the advancement of advanced battery materials is the need to achieve a balance between electrode structural integrity and interfacial charge transfer kinetics via the modification of the electrode interface. In this study, we propose an interfacial reconstruction of LiNi 0.6 Co 0.1 Mn 0.3 O 2 (NCM 613) by wet coating Nb 2 O 5 and high-temperature annealing treatment, and successfully doped the electrode surface with the construction of Nb 5+ and LiNbO 3 fast ion channels. Combined with in-situ analysis and density functional theory (DFT) calculations to provide a comprehensive understanding of the electrochemical behavioural relationships between Li, O and Nb, the resulting structure accelerates the charge transfer kinetics at the electrode interface, resulting in fast Li + migration and high ionic conductivity. Furthermore, the doping of the surface with Nb 5+ also serves to mitigate the occurrence of lattice distortion and the release of lattice oxygen from the electrode during Li + insertion/extraction. Consequently, the modified NCM 613 displays high Li-ion conductivity (15.11 S m −1 ), prolonged cycle stability at high voltages (4.5 V, 175.40 mAh g −1 ), and the assembled Li||NCM 613 pouch cell (0.5 Ah) demonstrated a capacity retention of 75.16 % after 100 cycles of cycling at 0.5 C. This in situ surface modification strategy offers a viable approach for the development of advanced cathode materials with practical applications.