Achieving high-rate performance and voltage stability in Li-rich layered oxide cathodes with dual-metal doping

Li-rich layered oxides (LLOs) cathodes exhibit high specific capacities (>250 mAh·g −1 ), yet their practical application is hindered by inherent structural instability and low ionic conductivity. This study proposes a trace dual-metal doping strategy (0.2 wt% Zr and 0.1 wt% Al) to enhance the structural stability and Li  +  transport efficiency of Li 1.2 Ni 0.16 Co 0.16 Mn 0.48 O 2 . Combined in-situ X-ray diffractions and density functional theory calculations reveal that Zr 4+ and Al 3+ doping at 3b sites suppresses lattice expansion along the c -axis (Δ c reduced by 6.9 %) and strengthens the metal-oxygen bond, thereby mitigating Li/Ni cation mixing and oxygen loss during cycling. The optimized [email protected] sample achieves a capacity retention of 80.8 % after 500 cycles at 9.5 mg cm −2 loading, with a total discharge voltage decay of 0.78 V after 500 cycles. Additionally, it delivers a high-rate capacity of 136 mAh·g −1 at 5C. This work provides new insights into synergistically optimizing structural stability while maintaining electrochemical performance through dual-metal doping.