V2O5/MnO2 Nanostructured Electrodes for High-Energy-Density Supercapacitors

Transition metal oxides, owing to their fascinating and unique properties, are anticipated to revolutionize future energy storage technologies. Among them, V2O5 and MnO2 are two of the most promising pseudocapacitive materials, known for their high theoretical capacitance, low cost, and ease of synthesis. Hybrid nanostructures combining these two metal oxides can further enhance the electrochemical performance through synergistic interactions. Morphology engineering of active materials is a proven strategy for developing high-performance supercapacitor electrodes. In this work, we present a facile method for synthesizing of V2O5/MnO2 hybrid electrodes by the direct chemical deposition of MnO2 onto V2O5. The MnO2 produced using this approach forms a unique interconnected flower-like morphology, leading to significantly enhanced electrochemical performance compared to electrodes composed of bare metal oxides. The optimized electrode achieves a high capacitance of 394.5 F g(-1) at 0.5 A g(-1) within an extended potential window of 2 V. Moreover, a symmetric supercapacitor fabricated by using this electrode and an aqueous electrolyte exhibits an enhanced energy density of 82 Wh kg(-1) at a specific power of 2000 W kg(-1). Also, to address commercial application requirements, a symmetric device using organic electrolyte was also developed, demonstrating excellent rate capability and cycling stability. These findings highlight the potential of V2O5/MnO2 hybrid nanostructures as outstanding candidates for next-generation, high-performance, and sustainable energy storage technologies.