Structural pseudo-rotation affords highly durable 4.6 V LiCoO₂

Layered lithium cobalt oxide (LiCoO₂), a key cathode material for commercial lithium-ion batteries, faces severe limitations in further enhancing its energy density and power density due to structural instability at high voltages and kinetic hysteresis at high rates. This work proposes and validates an innovative strategy utilizing a pseudo-rotation mechanism to significantly enhance the cycling stability of LCO at a high voltage of 4.6 V and high rate of 5C. Through lattice engineering via co-doping with Al, Mg, and La, a controllable local coordination reorientation (pseudo-rotation) behavior is successfully induced in LCO, where CoO₆ octahedra undergo cooperative tilting and edge-sharing reconfiguration to reverse the rock-salt degradation product back to a reconstructed spinel phase with a distinct crystallographic orientation. The aberration-corrected transmission electron microscopy (AC-TEM) analysis reveals that this mechanism effectively alleviates lattice distortion during deep delithiation and stress accumulation from detrimental phase transitions, while simultaneously promoting rapid Li⁺ diffusion kinetics under high-rate charge/discharge conditions. The modified LCO achieves an impressive capacity retention of 91.9% after 100 cycles at 4.6 V, significantly outperforming unmodified LCO. Even at a high rate of 5C, both capacity retention and rate capability are markedly improved. This study provides an effective strategy to overcome the bottlenecks of LCO for high-voltage/high-rate applications and deeply elucidates the key mechanistic role of pseudo-rotation in stabilizing layered oxide cathode materials.