Growing demands for rapidly powering portable electronics and electric vehicles has triggered substantial efforts on high-energy and high power-density energy storage devices. Based on the charge storage mechanism, supercapacitors are classified into two main categories: electrical double-layer capacitors (EDLCs) and pseudocapacitors. The former store electrical energy via electrostatic accumulation of charges at the electrode/electrolyte interfaces (non-faradaic process). Pseducapacitance is based on fast and reversible redox reactions occurring at the surfaces of electroactive materials (faradaic process). Because of the difference in their energy storage mechanisms, pseducapacitors deliver higher specific capacitance and energy density than EDLCs. To further improve the performances of pseudocapacitors, numerous hybrid nanomaterials were designed by engineering electrically conductive polymers and transition metal oxides. In this report, core@shell structured V2O5@polypyrrole (PPy) nanofibers were successfully synthesized as electrode materials of supercapacitors and the optimal mass ratio of PPy on V2O5 was determined around 40% with high specific capacitances and excellent rate capability. Overcoating of PPy weakened the adherence between electroactive materials and current collector and retained the integral performances of electrodes. Respective contributions of double layer capacitance and pseudocapacitance were explored at different PPy/V2O5 ratios, further ascertaining the function of PPy shells on V2O5 nanofibers. This work lays the foundation for outperformed hybrid electrode materials in aqueous supercapacitors.

Optimal ratio of polypyrrole decoration on V<sub>2</sub>O<sub>5</sub> nanofibers as electrode materials for energy storage

247th National Meeting (2014)

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Optimal ratio of polypyrrole decoration on V2O5 nanofibers as electrode materials for energy storage

Optimal ratio of polypyrrole decoration on V₂O₅ nanofibers as electrode materials for energy storage