Al-induced fast phase transition in vanadium oxide cathode materials for high-performance aqueous zinc-ion batteries

Abstract

Herein, Al-doped V₂O₃ nanoparticles were prepared via a sol–gel method combined with annealing treatment and applied as a cathode material for high-performance aqueous Zn-ion batteries. The doped Al acted as a pillar, effectively widening the layer spacing and significantly improving ion transport kinetics. More importantly, the presence of Al introduced additional oxygen vacancies and induced rapid structural transformation of the cathode material during the cycling process, which endowed the cathode with excellent electrochemical performance. The AlVO-0.2 cathode exhibited a highly reversible capacity of 383.5 mA h g⁻¹ at 0.1 A g⁻¹ and impressive cycle stability (335.2 mA h g⁻¹ at 3 A g⁻¹ with 95.54% capacity retention after 1000 cycles), which was superior to undoped V₂O₃ nanoparticles.