Oxygen vacancy H2V3O8 nanowires as high-capacity cathode materials for aqueous zinc-ion batteries

Abstract H 2 V 3 O 8 has been regarded as a compelling cathode material for aqueous zinc-ion batteries (AZIBs) owing to its elevated theoretical capacity, abundance of vanadium valence states, and advantageous layered configuration. Nonetheless, the intrinsically low conductivity and sluggish ionic reaction kinetics of H 2 V 3 O 8 result in undesirable, constraining its broader implementation in AZIBs. In this study, a facile hydrothermal approach was utilized to prepare H 2 V 3 O 8 nanowires with an abundance of oxygen vacancies. The combination of nanowire nanostructure and oxygen vacancies of the H 2 V 3 O 8 offer improved ion diffusion kinetics and enhanced electronic conductivity, leading to a superior improved electrochemical performance. Particularly, the H 2 V 3 O 8 nanowire cathodes with the optimal oxygen vacancy concentration (HVO-20) exhibit a specific capacity of 461.7 mAh g − 1 at 0.3 A g − 1 and exceptional cycle life of 198.8 mAh g − 1 after 1000 cycles at 1.0 A g − 1 . The investigation unveils the impact of oxygen vacancy vanadium-based oxides on the performance of AZIBs, presenting a viable strategy for advanced cathode materials in AZIBs.