Exfoliated graphite nanoplatelets–V2O5 nanotube composite electrodes for supercapacitors

Exfoliated graphite nanoplatelet (xGnP) and V ₂ O ₅ nanotube (VNT) composite electrodes were fabricated and tested as electrodes for supercapacitors. Enhancement of the electrochemical performance of the composite over its component materials was demonstrated using cyclic voltammetry (CV), constant current charge/discharge testing and electrochemical impedance spectroscopy in aqueous and organic electrolytes. The calculated specific capacitance of the composite was 35Fg ⁻¹ in the aqueous electrolyte and 226Fg ⁻¹ in the organic electrolyte at a scan rate of 10mVs ⁻¹ using a three-electrode system. Asymmetric coin cell devices were fabricated using activated carbon cloth as the positive electrode and xGnP–VNT composite as the negative electrode. The energy and power densities in 1M LiTFSI were 28Whkg ⁻¹ and 303Wkg ⁻¹ , respectively, at a discharge current density of 250mAg ⁻¹ .