Rationally designed freestanding peapod-like carbon-coated V2O3 nanowire film cathodes enable highly stable aqueous zinc-ion batteries

Abstract

Aqueous zinc-ion batteries (AZIBs) utilizing vanadium-based oxide cathode materials exhibit considerable potential for large-scale energy storage applications, attributed to their high theoretical capacity, intrinsic safety, and environmental advantages. However, the relatively sluggish kinetics and irreversible structural degradation lead to rapid capacity fading, which presents a substantial challenge for the transition from laboratory-scale research to industrial application. Herein, we propose a synergistic inhibition strategy combining physical barrier and chemical anchoring effects to enhance the stability of V₂O₃. To this end, peapod-like carbon-coated V₂O₃ nanowires (P-V₂O₃@C) are rationally designed and successfully synthesized as a high-performance freestanding film cathode material by hydrothermal treatment and in situ carbothermal reduction reaction. This unique peapod-like carbon-coated nanostructure not only suppresses vanadium dissolution intermediates through the synergistic effect of the carbon layer as a physical barrier and V–C bonds with chemical anchoring functionality, but also provides optimized transport pathways and additional intercalation sites for electrons and ions, thereby enhancing the reaction kinetics and improving the cycling stability of P-V₂O₃@C. Consequently, the AZIBs with the P-V₂O₃@C film electrode exhibit a remarkable specific capacity (406 mAh g⁻¹ at 0.1 A g⁻¹), excellent high-rate capability (160 mAh g⁻¹ at 5 A g⁻¹), and outstanding long-term stability (87.3% capacity retention under 6000 cycles at 5 A g⁻¹). This work offers a versatile strategy and new insights for the development of advanced transition metal (vanadium, manganese, etc.) based oxide cathode materials for high performance AZIBs.