Engineered aluminum doping on VO2(B) as high-performance cathode materials for aqueous zinc-ion batteries

VO 2 (B) has emerged as a promising cathode candidate for aqueous zinc-ion batteries (ZIBs) due to its unique tunnel-structured framework that facilitates zinc ion transport. Nevertheless, practical implementation faces challenges including limited coulombic efficiency, inadequate cycling stability, and restricted rate capability, primarily attributed to poor electrical conductivity and strong Zn 2+ interionic repulsion. In this work, Al 3+ is selectively incorporated into VO 2 (B) and induced structural optimization in Al x V 1- x O 2 (B), where controlled lattice contraction and electronic structure modification near the Fermi level. Aluminum doping induces 3D morphology that enhances ion diffusion pathways and electrolyte interaction. The engineered material exhibits enhanced electrochemical kinetics through oxygen vacancy formation (providing active sites) and substantially improved pseudo-capacitive charge storage. The optimized Al 0.05 V 0.95 O 2 (B) cathode achieves a remarkable specific capacity of 364.7 mA·h·g −1 at 0.1 A/g, while maintaining 91.64 % capacity retention after 2000 cycles under high-current operation (5.0 A/g), demonstrating superior electrochemical stability.