Constructing ultra-stable and high-performance zinc-ion batteries through Mn doped vanadium oxide nanobelt cathode

Abstract

As a promising candidate to replace lithium-ion batteries, rechargeable aqueous zinc ion batteries (AZIB) are receiving increasing attention due their high energy density, high safety, low cost and environmental friendliness. In this study, metal ions may be introduced into the interlayer gap of layered vanadium oxide nanobelts through a one-step hydrothermal process, without changing their original structure. Moreover, we have demonstrated by density functional theory computations that Mn metal ions not only serve as structural pillars but also enhance the conductivity of Mn_xVO₂·0.2H₂O, facilitating the migration of Zn ions. As a result, the electrochemical performance of Mn_xVO₂·0.2H₂O as an AZIB cathode has significantly improved; after 100 cycles at 0.5 A g⁻¹, it exhibits a high reversible capacity of 350 mA h g⁻¹. With a high current density of 5 A g⁻¹, the initial capacity can still reach 295 mA h g⁻¹. This paper suggests an effective method to maximize the efficiency of AZIB electrode materials.