Electrochemically Induced Metal-Organic-Framework-Derived Amorphous V₂ O₅ for Superior Rate Aqueous Zinc-Ion...

The electrochemical performance of vanadium-oxide-based cathodes in aqueous zinc-ion batteries (ZIBs) depends on their degree of crystallinity and composite state with carbon materials. An in situ electrochemical induction strategy was developed to fabricate a metal-organic-framework-derived composite of amorphous V₂ O₅ and carbon materials (a-V₂ O₅ @C) for the first time, where V₂ O₅ is in an amorphous state and uniformly distributed in the carbon framework. The amorphous structure endows V₂ O₅ with more isotropic Zn²⁺ diffusion routes and active sites, resulting in fast Zn²⁺ transport and high specific capacity. The porous carbon framework provides a continuous electron transport pathway and ion diffusion channels. As a result, the a-V₂ O₅ @C composites display extraordinary electrochemical performance. This work will pave the way toward design of ZIB cathodes with superior rate performance.