Mn2+-intercalated hydrated vanadium oxide with tunable spacing for high-performance zinc-ion batteries

Abstract

Despite the attractive capacity and multivalent nature of vanadium-based oxides for zinc-ion storage, severe challenges of low conductivity and structural instability continue to limit their practical application. Here, a Mn²⁺-intercalated hydrated vanadium oxide (MVOH) cathode is synthesised via a facile one-step hydrothermal method. The introduced Mn²⁺ effectively expands the interlayer spacing, tailors the material's morphology and electronic environment, and increases the specific surface area. This integrated modification synergistically enhances interfacial contact, provides more active sites, and improves ion diffusion kinetics. The optimized MVOH electrode exhibits a superior specific capacity of 474.6 mAh g⁻¹ under 0.5 A g⁻¹ current density, while demonstrating remarkable long-term cycling stability by maintaining 250.8 mAh g⁻¹ following 3000 charge–discharge cycles at 5 A g⁻¹. These findings underscore a viable intercalation methodology toward synthesizing resilient, high-capacity cathodes for aqueous zinc-ion energy storage devices.