Morphology modulation and electrochemical performance properties of Mn-decorated (NH4)2V10O25·8H2O as a cathode material for aqueous zinc-ion batteries

Abstract

Developing a structurally controlled electrode has attracted widespread attention in recent years, which is ascribed to the morphology of cathode materials having an influence on the electrochemical performance. Herein, we present Mn-decorated (NH₄)₂V₁₀O₂₅·8H₂O (NVOH) materials with a cauliflower-like, tremella-like, and purslane-like structure via a solvothermal approach. When examined as a cathode material for aqueous zinc-ion batteries (ZIBs), all three materials with different morphologies exhibited superior electrochemical performances. Especially for materials with a tremella-like structure, benefiting from the uniqueness of the porosity structure of the tremella, the active material has a larger contact area with the electrolyte, which increases the active sites and diffusion coefficient of Zn²⁺. This tremella-like NVOH delivered a high rate capability of 159 mA h g⁻¹ at 500 mA g⁻¹ together with long-term stability (85% retention after 500 cycles at 500 mA g⁻¹). This study has great significance for the exploitation of cathode electrodes of aqueous ZIBs with high reversible specific capacity and long cycle life and provides a promising candidate cathode for practical rechargeable aqueous ZIBs.