In situ electrochemical activation enabling high-performance cathodes for aqueous zinc-ion batteries

Abstract

Vanadium pentoxide (V₂O₅) is a promising cathode material for aqueous zinc-ion batteries (AZIBs), but its structural instability and poor intrinsic electronic conductivity lead to poor cycling stability and rate performance. This work utilizes an in situ electrochemical activation strategy, converting inactive vanadium carbide particles into carbon-incorporated amorphous V₂O₅·3H₂O nanosheets through a solid–liquid–solid phase transformation process. Compared with crystalline V₂O₅·3H₂O, the carbon-incorporated amorphous V₂O₅·3H₂O exhibits a superior specific capacity (593.2 mA h g⁻¹ at 0.1 A g⁻¹), rate capability (412.3 mA h g⁻¹ at 5 A g⁻¹), and cycling stability (>90% capacity retention after 1700 cycles at 3 A g⁻¹), originating from the synergistic effects of enhanced structural stability and boosted kinetics for charge transfer and Zn²⁺/H⁺ intercalation. This work establishes an effective approach to unlock the electrochemical potential of metal carbides for AZIBs, highlighting in situ phase engineering as a critical and enabling strategy for future energy storage materials.