Integrated Surface Modulation of Ultrahigh Ni Cathode Materials for Improved Battery Performance

Ni-rich layered cathodes with ultrahigh nickel content (>= 90%), for example LiNi0.9Co0.1O2 (NC0.9), are promising for next-generation high-energy Li-ion batteries (LIBs), but face stability issues related to structural degradation and side reactions during the electrochemical process. Here, surface modulation is demonstrated by integrating a Li+-conductive nanocoating and gradient lattice doping to stabilize the active cathode efficiently for extended cycles. Briefly, a wet-chemistry process is developed to deposit uniform ZrO(OH)(2) nanoshells around Ni0.905Co0.095(OH)(2)(NC0.9-OH) hydroxide precursors, followed by high temperature lithiation to create reinforced products featuring Zr doping in the crust lattice decorated with Li2ZrO3 nanoparticles on the surface. It is identified that the Zr4+ infiltration reconstructed the surface lattice into favorable characters such as Li+ deficiency and Ni3+ reduction, which are effective to combat side reactions and suppress phase degradation and crack formation. This surface control is able to achieve an optimized balance between surface stabilization and charge transfer, resulting in an extraordinary capacity retention of 96.6% after 100 cycles at 1 C and an excellent rate capability of 148.8 mA h g(-1) at 10 C. This study highlights the critical importance of integrated surface modulation for high stability of cathode materials in next-generation LIBs.

Automated summary

In this study, surface modulation was used to stabilize the Ni-rich layered cathode and improve its cycle stability and rate capability. A wet-chemistry process was developed to deposit uniform ZrO(OH)(2) nanoshells and Li2ZrO3 nanoparticles on the surface of Ni0.905Co0.095(OH)(2)(NC0.9-OH) hydroxide precursors. This surface control technique achieved an optimized balance between surface stabilization and charge transfer, resulting in exceptional capacity retention and rate capability.