Research on the structure-performance relationship of thermal reduced graphene oxide based supercapacitors

摘要

The electrochemical performance of RGO-based super-capacitors are highly dependent on the exfoliation and surface functionalization degree of RGO, which of them contributes to the capacitance and pseudo-capacitance of the electrode materials respectively. In this work, a series of tRGO samples were fabricated as the raw material of graphite oxide (GO) by thermal expansion method through precisely controlling its thermal expansion temperature. It is founded that the specific capacitance of tRGO gradually decreased with the increasing of the thermal treatment temperature. Especially, the tRGO fabricated by the lowest heat treatment temperature (150 degrees C) exhibited the largest specific capacitance (326 Fg(-1)) for three-electrode with the loading of 1.5 mg in 6 M KOH electrolyte. Based on the optimized result of tRGO-150, which exhibited the specific capacitance of 202 Fg(-1) for the two-electrode symmetrical capacitor with the loading of 7.3 mg. The heat treatment temperature has the greatest influence on the C=O than electrical conductivity and pore structure, thereby determine the specific capacitance for tRGO based super-capacitors.