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 233^rd Electrochemical Society Meeting.

References:

1. P. Iamprasertkun, A. Krittayavathananon, A. Seubsai, N. Chanlek, P. Kidkhunthod, W. Sangthong, S. Maensiri, R. Yimnirun, S. Nilmoung, P. Pannopard, S. Ittisanronnachai, K. Kongpatpanich, J. Limtrakul, M. Sawangphruk, Sci. Rep. 6, 37560; doi: 10.1038/srep37560 (2016).
2. M. Toupin, T. Brousse, D. Be´langer, Chem. Mater.16 3184 (2004).
3. Y. Zhang, G. Li, Y. Lv, L. Wang, A. Zhang, Y. Song, B. Huang, International J. Hydrogen Energy 36 11760 (2011).