Ordered mesoporous carbon/SnO2 composites as the electrode material for supercapacitors

Abstract

A series of composites as electrode materials for supercapacitors were prepared via incipient wetness impregnation method utilizing ordered mesoporous carbon (OMC) and tin (IV) oxide (SnO2) with different ratio. The structure and electrochemical properties of the OMC/SnO2 composites were characterized by XRD, TEM and cyclic voltammetry (CV). Pore characteristics were measured by nitrogen adsorption and desorption isotherms. The results show that the structure and electrochemical properties of the composites depend mainly on the loading amount of SnO2 in the ordered mesoporous carbon. The optimum amount of SnCl4 added is found to be 40 % (1.54 g ethanol-based SnCl4·5H2O added to 1 g OMC) of the saturated solution. The specific capacitance of the composite of optimum amount of SnCl4 (200 F g−1) is nearly three times of that of the pristine SnO2 (72 F g−1) at the scan rate of 5 mV s−1, and its specific capacitance is almost equal to that of the ordered mesoporous carbon (126 F g−1) at the scan rate of 200 mV s−1. Meanwhile, it has better specific volumetric energy density than OMC due to its higher density. Besides, in the potential range of 0–0.9 V the composite electrode material exhibits a stable cycle life after 500 cycles.