In situ electrochemically activated V2O3@MXene cathode for a super high-rate and long-life Zn-ion battery.

The development of a high specific capacity and stable vanadium-based cathode material is very attractive for aqueous zinc-ion batteries (ZIBs). Herein, an in situ electrochemically oxidized cathode is fabricated based on a V2O3@MXene cathode for Zn-ion storage. V2O3@MXene undergoes a phase transition to Zn3(OH)2V2O7·2H2O and ZnyVOz on the first charge, thus allowing for the subsequent insertion/de-insertion of zinc ions, which can be regulated by the amount of H2O in the electrolyte. The MXene in the composite was also beneficial to electron transfer and cycling stability. V2O3@MXene delivered a high capacity of 450 mA h g−1 at 0.2 A g−1, ultra-high-rate performance and cycling stability as well as high energy density. [ABSTRACT FROM AUTHOR]