Unveiling the potential of surface–beneath region doping by induced-diffusion in nickel-rich single crystal cathode for high-performance lithium-ion batteries

Abstract

A critical challenge associated with Ni-rich single-crystal cathode materials is the significant degradation of their structural integrity caused by cation mixing during high-temperature sintering. To address this issue, we propose an effective strategy of uniformly doping Zn ions into the region below the surface of Ni0.90Co0.07Mn0.03OH2 using polyvinyl pyrrolidone. This approach enables the localized concentration of Zn ions in the near-surface region, which can effectively reduce the degree of Li/Ni mixing and improve the surface and thermal stability of the material under high-state-of-charge conditions. We observed that the near-surface region doped sample with 1 wt% Zn (SC-NCM90@Zn1) demonstrated superior rate performance (100.01 mA h g−1 at 10C) and excellent capacity retention (87.71% after 100 cycles) compared with those of Pristine SC-NCM90 (LiNi0.90Co0.07Mn0.03O2). Overall, this study provides a design approach for enhancing the performance of Ni-rich single-crystal cathode materials for Li-ion batteries.