MIL-47(V) Derived V2O5@Carbon Core-Shell Microcuboids with Oxygen Vacancies as Advanced Conversion Cathodes for High-Performance Zinc-Ion Batteries

Vanadium pentoxide (V2O5) has been considered one of the most promising cathodes for zinc-ion batteries (ZIBs) due to its outstanding theoretical capacity (589 mAh g(-1)). However, it remains great challenge to achieve the high capacity, limited to the poor electronic conductivity and sluggish ionic diffusion kinetics of V2O5. Herein, a controllable strategy is proposed to synthesize V2O5@carbon core-shell microcuboids with oxygen vacancies (V2O5-x@CCSMs) derived from MIL-47(V) used for cathodes of ZIBs. The obtained V2O5-x@CCSMs cathode delivers high capacities of 485.4 and 392.1 mAh g(-1) at 0.1 and 2.0 A g(-1), respectively. The superior electrochemical performances originate from the nano-sized particles of V2O5, oxygen vacancies and carbon shell. Further, ex-situ XRD indicates V2O5 undergoes a shrinking core model conversion reaction at initial cycling to a new phase of Zn3V2O7(OH)(2) center dot 2H(2)O, which is an ideal host for Zn2+. Our work offers an innovative strategy to develop high-capacity cathode in ZIBs.

Automated summary

This study proposes a new strategy to synthesize high-capacity V2O5 cathodes, successfully preparing V2O5-x@CCSMs with superior electrochemical performance, providing a new approach for the development of zinc-ion batteries.