Oxygen vacancy-rich Co-doped V₂O₅ as a high-performance cathode for aqueous zinc-ion batteries

Developing high-performance cathode materials is crucial for advancing aqueous zinc-ion batteries (AZIBs). In this work, we report a Co-doped V₂O₅ (CoVO) material engineered with abundant oxygen vacancies (O_d-CoVO) via a simple calcination process. Structural analyses confirm that cobalt is substitutionally incorporated without disrupting the V₂O₅ crystal framework, while oxygen vacancies are successfully introduced to modulate the electronic environment. The combined effects of cobalt doping and oxygen vacancies enhance electronic conductivity, provide additional Zn²⁺ adsorption sites, and facilitate ion diffusion. As a result, the O_d-CoVO electrode delivers a high specific capacity, excellent rate performance, and outstanding long-term cycling stability compared to pristine CoVO. These findings demonstrate that defect engineering offers a promising pathway for optimizing vanadium-based cathodes for next-generation AZIBs.