Reinforcing effect of graphene nanoplatelets in the electrochemical behaviour of manganese oxide-based supercapacitors produced by EPD

Abstract

A simple procedure for the manufacture of metal oxide based supercapacitors consisting on the electrophoretic deposition (EPD) onto graphite paper of well-dispersed aqueous slurries of manganese oxide with graphene nanoplatelets is presented. EPD was performed using optimised slurries and depositing onto graphite paper electrodes. In order to improve manganese oxide conductivity graphene nanoplatelets (GNP) were incorporated in a concentration of 20 wt% over the MnO2 content. The evaluation of the electrochemical properties of the so prepared deposits demonstrates that the addition of GNP improves both the capacity and specific energy, with values of 158 F g−1 and 4 W h Kg−1 respectively, which represents four times the values reported for the bare manganese oxide.