V2O5/ZnV2O6 nano-heterojunction cathodes for high-performance Aqueous zinc ion battery

Abstract

Rechargeable aqueous zinc-ion batteries (RAZIBs) have significant energy storage potential for smart grid applications. However, challenges such as slow Zn²⁺ diffusion kinetics, limited active sites, and poor intrinsic conductivity have hindered the full exploitation of their potential. The V₂O₅/ZnV₂O₆ nano-heterojunction composite materials were synthesized as the cathode for AZIBs. The electrode achieved a high capacity and exhibited excellent rate capability and cycling stability. Specifically, at current densities of 10 A g⁻¹ and 20 A g⁻¹, the cathode maintained a specific capacity of 168.5 mA h g⁻¹ after 6000 cycles and 61.3 mA h g⁻¹ after 20 000 cycles. Detailed structural analysis revealed that the V₂O₅/ZnV₂O₆ composite consists of different crystal facets of V₂O₅ and ZnV₂O₆, which form an effective heterojunction interface network within the bulk electrode, playing a key role in its superior electrochemical performance.