Electrochemical activation of vanadium-based cathodes in aqueous zinc-ion batteries: Advances, challenges and prospects

Despite being considered as potential cathodes for aqueous zinc ion batteries (AZIBs), vanadium-based compounds still exhibit certain limitations including sluggish kinetics, inadequate electronic conductivity, structural instability, and vanadium dissolution. The electrochemical activation (ECA) strategy induced the reconstruction or transformation of vanadium-based materials into a host framework conducive to Zn2+ storage, thereby improving zinc storage performance. However, the investigation of ECA in vanadium-based materials has primarily focused on enhancing performance, while the exploration of underlying mechanisms remains inadequate. Herein, the ECA process of vanadium-based materials in AZIBs was comprehensively reviewed. The mechanism of electrochemically induced phase transformation is proposed firstly, followed by a comprehensive discussion on the impact of activation parameters, electrolyte composition, and material composition on the activation process. Subsequently, the properties of the activated vanadium-based materials to improve their electrochemical properties were analyzed. Finally, this work highlights the prevailing challenges and prospects of ECA, aiming to provide a timely summary and novel insights into the ECA of vanadium-based materials in AZIBs.