Mn3O4 nanoparticles grown on surface activated graphite paper for aqueous asymmetric supercapacitors

Mn3O4 nanoparticles were anchored on the surface of oxidised graphite paper via template-free hydrothermal method. Synthesized samples were characterized using different techniques such as X-ray diffraction (XRD), Raman spectroscopy, Field Emission Scanning Electron Microscopy (FE-SEM), High Resolution Transmission Electron Microscopy (HRTEM) and X-ray Photoelectron Spectroscopy (XPS). Electrochemical capacitor behaviour was evaluated using cyclic voltammetry (CV), galvanostatic charge discharge (GCD) and electrochemical impedance spectroscopy (EIS). The binder free material was found to exhibit a specific capacitance of 471 F g(-1) at a current density of 1 mA cm(-2) in 1 M Na2SO4. Conductive additive free, Mn3O4 anchored electrode was used as positive electrode in the asymmetric cell fabrication; the asymmetric cell was tested at a potential window of 1.6 V and its performance characteristics were evaluated. The asymmetric cell delivered a maximum specific energy of 47 Wh kg(-1) at a power density of 202.5 W kg(-1) which evidenced the superior performance of the synthesized electrode material. Here in the present work, the surface oxidised graphite paper was used as an excellent current collector and active sites for anchoring Mn3O4 due to its desirable properties. (C) 2018 Elsevier B.V. All rights reserved.