Improving the Supercapacitor Performance by Dispersing SiO2 Microspheres in Electrodes

This paper describes a simple, reproducible, and scalable procedure for the preparation of a SiO2-containing supercapacitor with high cycle stability. A carbon mesoporous material (CMM) with a high specific surface area, CMK-3, was adopted as an electric double-layer capacitor (EDLC) active material for the preparation of electrodes for the supercapacitor. The optimized SiO2 content decreased as the microsphere diameter decreased, and the optimal specific capacitance was obtained with 6 wt % SiO2 microspheres (100 nm size). The capacitance improved from 133 to 298 F/g. The corresponding capacitance retention rate after 1000 cycles increased from 68.04 to 91.53%. In addition, the energy density increased from 21.05 to 26.25 Wh/kg with a current density of 1 A/g. Finally, similar results based on active carbon, CeO2/CMK-3, and graphene/CNT/MnOv composite electrodes demonstrated that the proposed method exhibits wide compatibility with diverse electrode materials.