High-Performance LiNiO2 Cathodes through Microstructural Engineering

Abstract

LiNiO2 (LNO) is a promising high-capacity cathode, but its practical application is hindered by severe structural and microstructural instability. Herein, we develop a two-step calcination strategy that decouples lithiation from Ta introduction. This approach promotes the segregation of a Ta-rich phase at grain boundaries, producing nanosized, radially aligned primary particles that mitigate strain and suppress microcracking. It also preserves a layered–rocksalt nanostructured multiphase that reversibly transforms into a layered–spinel-like state during charging, which may contribute to structural stability and Li-ion transport. The optimized TS-Ta-LNO delivers 252.7 mAh g–1 and retains 88.4% of its capacity after 100 cycles. Furthermore, a TS-Ta-LNO/Li-metal pouch cell maintains stable voltage profiles under an electric vertical take-off and landing dynamic-load protocol, demonstrating its potential for high-energy, high-power batteries.