Effect of Graphene Oxide on Electrochemical Behavior of MnO2/GO Supercapacitor

Abstract

Supercapacitors have received a lot of attention due to their high-power performance, long cycle life low maintenance, and for applications in hybrid electric vehicles, portable electronic devices, and power back-up devices [1-3]. Various researchers studied MnO2 cathode materials for application in electrochemical capacitors, because of its low cost and natural abundance [2, 3]. However, MnO2 has limited electrochemical performance because of its poor conductivity and low surface area. To improve the electrochemical performances of MnO2, we have synthesized MnO2/graphene oxide (GO) nanocomposite with varying concentration of GO (0.4 mg/ml and 0.8 mg/ml). GO/MnO2 nanocomposite was synthesized by adding KMnO4 in a solution of water and ethanol (3:1), containing desired amount of GO. The brown precipitates were obtained after a continuous stirring for 1 hr. The precipitate was washed and dried to obtain the GO/MnO2 nanocomposites. The electrodes were prepared by spreading a slurry of GO/MnO2 powder, carbon black, PTFE binder (80:15:5 weight ratio) onto Ni mesh. The electrochemical characterizations were carried out in an aqueous solution of 1M Na2SO4. The charge discharge studies were carried out between 100 mA/g to 5A/g current range. The discharge capacities were found to be 230 F/g and 105 F/g at a current of 100 mA/g and 5A/g, respectively for 20mg GO. The detailed results will be presented at the 233rd Electrochemical Society Meeting.