Optimization of porous carbon nanofiber/MnO2 electrode-based supercapacitor performance using γ-cyclodextrin: Effects of graphene and MnCl2 contents

We systematically evaluate the influence of graphene and MnCl2 contents on the structure and capacity of gamma-cyclodextrin/graphene-based carbon nanofibers and MnO2(PCMG). The PCMG electrodes are stable long-term and had good capacitances, e.g., up to 236 Fg(-1) at 1 mA cm(-2) and 25.5 Wh kg(-1) at 400Wkg(-1). The electrochemical performance is maximized by the synergistic effect between the pseudocapacity of MnO2 wellembedded in the fiber and the electric double layer capacity induced by the well-developed surface pores.