Single Electrode Capacitances of Porous Carbons in Neat Ionic Liquid Electrolyte at 100°C: A Combined Experimental and Modeling Approach

Abstract

Supercapacitors are promising devices for energy storage. Being able to measure and predict their performances is a key step in order to optimize them. In the present study, we propose an original methodology to calculate the capacitance of a single nanoporous carbon electrode in contact with an ionic liquid, using molecular dynamics simulations. The results are compared to experimental electrochemical measurements conducted on the same systems at high temperature (close to 100$\,^{\circ}$C). The two approaches are in qualitative agreement and show that, in the case of a butyl-methylimidazolium hexafluorophosphate electrolyte combined with a carbide-derived carbon with an average pore size of 0.9 nm, the positive electrode capacitance is fairly larger than the negative one.