Monoclinic Silver Vanadate (Ag_0.33V₂O₅) as a High-Capacity Stable Cathode Material for Aqueous Manganese Batteries

Aqueous rechargeable metal batteries have recently garnered considerable attention owing to their low cost, sufficient capacity, and the use of non-flammable water-based electrolytes. Among them, manganese batteries are particularly favored because of their stability, abundance, affordability, and high energy density. Despite their advantages, Mn storage host structures remain underexplored. Therefore, developing innovative host materials is crucial for advancing this field. In this paper, the study reports for the first time, the use of Ag_0.33V₂O₅ as a cathode material in aqueous manganese batteries. The study explains the displacement/intercalation behavior of manganese and silver using electrochemical, structural, and spectroscopic analyses. Additionally, it is shown that cation (Ag⁺, Mn²⁺, H⁺) diffusion pathways can be simulated using diffusion-barrier calculations. Finally, the study demonstrates high-performance manganese batteries that exhibit a remarkable reversible capacity of ≈261.9 mAh g⁻¹ at a current of 0.1 A g⁻¹ and an excellent cycle retention of 69.1% after 2000 cycles at a current density of 1.5 A/g. The findings of this study contribute to the advancement of aqueous manganese battery technology, offering a promising pathway for developing safer, more cost-effective, and high-performance energy storage systems.