Microstructure-regulated V 2 O 3 cathodes for high-rate and durable aqueous Zinc-ion batteries

Abstract

Vanadium (III) oxide (V2O3) has emerged as a promising cathode material for aqueous zinc-ion batteries owing to high theoretical capacity based on reversible two-electron redox chemistry. However, the cycling stability and reaction kinetics are highly sensitive to its microstructural characteristics, which remain insufficiently understood. Here, we report a facile and scalable synthesis of V2O3 via combining oil-bath reaction and controlled calcination process, enabling precise regulation of particle morphology and microstructure through calcination time. Systematic microstructural evolution is correlated with Zinc-ion storage behavior, revealing that optimized architectures effectively promote ion transport kinetics and structural stability. Coupled with a high-concentration water-in-salt electrolyte to suppress parasitic reactions, the optimized V2O3 cathode delivers a high specific capacity of 453.8 mA h g -1 at 0.05 A g -1 , exceptional rate capability with 180 mA h g -1 retained at 10 A g -1 , and prolonged cycling stability of 210 mAh g -1 after 1000 cycles at 1 A g -1 . This work elucidates the underlying structure-property relationship governed by microstructure but also provides valuable insights into the design of highperformance cathode materials for advanced energy storage systems.