Electrochemical activation strategies of a novel high entropy amorphous V-based cathode material for high-performance aqueous zinc-ion batteries. Issue 34 (20th August 2021) - Zhang, Shangshang
Abstract : Two electrochemical activation strategies induce the activation of the amorphous high entropy V x O y @C as a high-performance cathode material for AZIBs. Abstract : V-based materials are widely applied as cathode materials for aqueous zinc-ion batteries because the high potential of V 5+ provides a thermodynamic basis for the transition of Zn 2+ . The isotropy of high entropy amorphous vanadium oxide not only avoids the performance degradation caused by the broken crystal structure, but also offers more active sites and improves the solid-state solubility and transfer kinetics of Zn 2+ . Herein, a high entropy amorphous vanadium oxide@carbon matrix (V x O y @C) was obtained via a simple coprecipitation method. Two electrochemical activation strategies could induce the activation of amorphous V x O y @C as a high-performance cathode material for aqueous zinc-ion batteries (AZIBs). After electrochemical activation, the amorphous V x O y @C exhibited a high specific capacity of 399.1 mA h g −1, high rate capability of 314.1 mA h g −1 at 2.0 A g −1 and excellent cycling stability for up to 300 cycles with a specific capacity retention of 91.8%. It was proven that the amorphous lump of V x O y @C transforms into an amorphous fibrous material accompanied by an increase in the valency of V. With the insertion of Zn 2+, the fibrous materials would be reversibly converted into a lamellar structure.