Highly porous terpolymer-MOF composite electrode material for high performance supercapattery devices

Abstract

• MOF based electrode material for supercapattery devices. • High specific capacity of 200C/g and high specific capacitance of 285F/g. • Supercapattery formed by coupling activated carbon with battery grade electrode (MOF//AC). • High power density of 1600 W/kg and high energy density of 38.5 W h/kg. Supercapattery a renowned energy storage device that comprises of the features of the battery and supercapacitor at a time. This unique combination leads to the formation of such device that can deliver high energy density with no compromise on the power density. Here, we have reported a unique class of material known as metal organic frame works (MOF) for the application of energy storage devices. MOF comprises of exceptional properties such as high surface area, excellent chemical stability and high porosity. The material was synthesized via hydrothermal route in three steps. The structure, morphology, surface area, porosity and crystallinity of the synthesized material were carried out through Tunneling Electron Microscopy, Scanning Electron Microscopy, X-ray diffraction and Brunauer-Emmett-Teller. In order to investigate the energy storage application, the electrochemical characterization was carried out in three-electrode assembly and the material express excellent performance by showing a battery graded nature with specific capacity of 199.8 C/g. To further investigate the application in energy storage field a supercapattery was formed as a real device by coupling activated carbon as a cathode with MOF as an anode separated by porous membrane. This asymmetric assembly expresses a specific capacity of 171.15 C/g and embraces an outstanding rate capability of 69% at 2.0 A/g. Furthermore, this supercapattery delivers tremendous energy density of 38.05 Wh.kg −1 with an admirable power density of 1600 W.kg −1 . At last the supercapattery reliability was investigated through cyclic charge discharge and the device has shown exceptional stability by sustaining its capacity of 100% even after 1000 consecutive charge discharge cycles.