Coordination Polymer-Derived Carbon-Encapsulated V2O3 Cathodes for High-Performance Aqueous Zinc-Ion Batteries

Abstract

Vanadium-based oxides show great potential as cathode candidates for aqueous Zn-ion batteries owing to their adaptable structural frameworks and substantial theoretical capacities. However, their large-scale deployment severely hindered by inherently poor electrical conductivity and vanadium dissolution. Herein, to overcome these limitations, a self-sacrificing template strategy is employed to construct a carbon-encapsulated V2O3/C composite derived from a vanadium-based coordination polymer (V-IPA) precursor. Upon controlled pyrolysis, the rod-like V-IPA precursor undergoes a topological transformation into a sheet-like V2O3/C architecture that combines abundant porosity with an integrated conductive carbon network and a high density of oxygen vacancies. These structural features synergistically promote rapid Zn2+ diffusion, enhance electron transport, and mitigate the dissolution of V during the cycling process. The optimized V2O3/C cathode displayed a remarkable initial capacity equal to 387 mAh g –1 at 20 A g –1, in addition to remarkable cyclic efficiency and higher rate capability. Detailed kinetic evaluations demonstrate that Zn2+ storage is predominantly controlled by surface capacitive processes. These findings validate coordination polymer-derived cathode materials as a promising strategy to overcome structural and cycling instability issues of vanadium-based cathodes in future energy storage devices.