Lattice-Engineering modulated band structure facilitates enhanced stability of high-voltage LiCoO2 at 4.6 V.

• The co-doping of zirconium and titanium in lithium cobalt oxide significantly enhances the diffusion kinetics of lithium ions. • The homogeneous distribution of Zr/Ti effectively suppresses structure degradation. • Synergistic interaction of Zr and Ti stabilizes lattice oxygen. Lithium cobalt oxide (LCO) cathode materials could exceed 210 mAh g−1 with excellent volumetric energy density, when operated at voltages above 4.5 V. However, the progress in the advancement of high-voltage LCO cathodes is impeded by unstable lattice oxygen loss and rapid structural degradation. Herein, we propose a modification strategy to modulate the band structure and stabilize the crystal structure of LCO through Zr/Ti dual-doping. The modified Zr/Ti-LCO demonstrates stable cycling performance at elevated cut-off voltage of 4.6 V. Uniform co-doping with zirconium and titanium suppresses the severe H1-3/O1 deleterious phase transition of LCO. By fine-tuning TM-O interactions and modulated band structure mitigate oxygen release reactivity at high voltage, achieving a delicate balance between structural integrity and electrochemical stability. Consequently, the modified Zr/Ti-LCO half-cell achieves superb capacity retention of 87.7 % after 300 cycles at 3.0–4.6 V, while the Zr/Ti-LCO||graphite pouch full-cell retains up to 85.8 % capacity after 500 cycles at 3.0–4.5 V. This study offers critical perspectives for advancing the design of high-voltage LCO cathodes. [ABSTRACT FROM AUTHOR]