Double layer in ionic liquids: capacitance vs temperature

Abstract

Temperature dependence of the capacitance of the electrical double layer (EDL) in concentrated electrolytes/ionic liquids has been under debates for decades. To rationalise the capacitance vs temperature dependence, we run molecular dynamics simulations of the EDL at variable temperatures. We show that the dependence is related to the smearing of the EDL multilayer structure with increasing temperature. The results are in agreement with the recent experimental data. To explain the results, we propose a phenomenological ionic bilayer model.