Salt-template synthesis of mesoporous carbon monolith for ionogel-based supercapacitors

Abstract

Mesoporous carbon monoliths (MCM) were prepared by using soluble salt as templates. During the synthesis, a freeze-drying process enables a surface coating of self-assembled Na2SiO3 salt particles with sucrose, which is further transformed into carbon by heat treatment. After removal of the salt templates by washing, MCM were obtained. MCM samples exhibit high specific surface area together with high mesoporous volume, whose pore sizes can be tuned from 10 to 30 nm by adjusting the ratio between salt and carbon sources. MCM materials were further used as electrodes in combination with ionogel electrolyte to assemble a solid-state supercapacitor. In this configuration, MCM electrodes show capacitance as high as 75 F g−1 and good rate performance thanks to the carbon monolith pore size selected.