Graphene/Carbon Nanotube/MnO2 Nanocomposite Based Asymmetric Pseudocapacitors

Abstract

Graphene/carbon nanotubes (CNTs)/manganese oxide (MnO2) nanocomposites plus CNTs (in short, GMC+C) and graphene/CNTs hybrid (in short, GC) thin-film electrodes are fabricated by electrophoretic deposition (EPD). Aqueous electrolyte-based asymmetric pseudocapacitors exhibiting a cell voltage of 1.8 V is successfully prepared using GMC+C nanocomposite as cathode and GC nanocomposite as anode. The asymmetric pseudocapacitor possesses superior performance with a maximum energy density of 204.12 Wh kg(-1). The asymmetric cell configuration exhibits excellent cycling stability with 91% of the specific capacitance maintained after 5,000 cycle tests. These results indicate that our designed asymmetric pseudocapacitors are appropriate for practical applications.