Revealing the Intrinsic Origin for Performance-Enhancing V2O5 Electrode Materials.

Revealing the intrinsic origin is critical for developing performance-enhancing V2O5 battery-type electrode materials. In this work, ultralong single-crystal V2O5 wires (W-V2O5) and V2O5 plate particles (P-V2O5) with similar physicochemical properties were compared to investigate the possible stimulative factors for pseudocapacitive enhancement. Our results indicate that besides the most-discussed specific surface area (or nanostructure), the enhanced electronic conductivity, the controllable interlamellar spacing distance, and the ion-transporting route as intrinsic origin also greatly affect their pseudocapacitive enhancement. First, the ultralong single-crystal wire structure can apparently enhance the electrons transport; second, the unique [001] facet orientation along the wire direction enlarges the interlamellar spacing distance and shortens the Li+ inserting route, thus facilitating the redox reactions by providing fast channels for charge carrier intercalation. Thus W-V2O5 showed much higher capacitance, better rate, and cycling capability than those of P-V2O5. This new insight presented here provides guidance for the design of V2O5 electrode materials and opens new opportunities in the development of high-performance battery-type electrode materials.