Oxygen Vacancy-Rich Co-Doped V2O5 as a High-Performance Cathode for Aqueous Zinc-Ion Batteries

Abstract

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 (Od -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 Od -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.