High-performance α-MnO2 nanowire electrode for supercapacitors

Nanowired α-MnO2 material supported on carbon fiber paper (α-MnO2/CFP) is synthesized using a facile hydrothermal method for supercapacitor electrode. The α-MnO2/CFP material is characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and BET for its composition, structure/morphology, and BET surface area. The electrochemical properties of the α-MnO2/CFP electrode are studied by cyclic voltammetry (CV), galvanostatic charge/discharge and electrochemical impedance spectroscopy (EIS) in 1M Na2SO4 solution. The porous α-MnO2/CFP material electrode shows a high specific capacitance of 251Fg−1 at the current density of 1Ag−1, and also exhibits a good rate capability and an excellent cycling stability. It is testified that even after 3000cycles, the capacitance retention of the porous α-MnO2/CFP material electrode can still maintain over 98.9% of the capacitance at the high current density of 4Ag−1, demonstrating its excellent cycling stability. The high electrochemical performance of the porous α-MnO2/CFP material nanowire electrode may be attributed to the 2×2 tunnel structure, high active surface area, and high porosity of the of α-MnO2 material.