Structural stability and interface optimization for enhancing high-voltage electrochemical performance of the...

Nickel-rich layered oxides are considered promising cathode candidates for high-energy-density lithium-ion batteries (LIBs) because of their high operating voltage and specific capacity. However, their practical application under high voltage conditions (≥4.5 V vs. Li⁺/Li) is severely limited by pronounced structural degradation and interfacial instability. Herein, a high-voltage nickel-rich cathode with improved structural robustness and interfacial stability was developed through surface engineering. A NASICON-type Li_1.3La_0.3Ti_1.7(PO₄)₃ layer was uniformly coated on LiNi_0.83Co_0.11Mn_0.06O₂ particles, which effectively suppresses lattice distortion and abrupt volume variation induced by deep delithiation under high-voltage conditions. Furthermore, Li_1.3La_0.3Ti_1.7(PO₄)₃ serves as a fast Li⁺ conductor, promoting rapid interfacial lithium-ion transport and preventing excessive interfacial impedance growth. The coating further inhibits electrolyte oxidation and transition-metal dissolution, stabilizing the cathode-electrolyte interface. As a result, the modified cathode delivers a high discharge capacity of 178.8 mAh g^-1 at 10 C and maintains 89.21% capacity retention after 100 cycles at 1 C within a 2.7-4.5 V voltage range. This study presents a simple and efficient surface modification strategy for constructing nickel-rich cathode materials suitable for high-voltage and high-energy-density LIBs.