Multi-scale modelling of supercapacitors: From molecular simulations to a transmission line model

• Published in: Journal of power sources Vol. 326; pp. 680 - 685
• Main Authors: Pean, C., Rotenberg, B., Simon, P., Salanne, M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-09-2016; Elsevier
• Subjects: Chemical Sciences; Dynamic processes; Material chemistry; Molecular dynamics simulation; Physics; Porous materials; Supercapacitors; Transport properties; Supercapacitors; Transport properties; Molecular dynamics simulation; Dynamic processes; Porous materials
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2016.03.095

We perform molecular dynamics simulations of a typical nanoporous-carbon based supercapacitor. The organic electrolyte consists in 1-ethyl-3-methylimidazolium and hexafluorophosphate ions dissolved in acetonitrile. We simulate systems at equilibrium, for various applied voltages. This allows us to determine the relevant thermodynamic (capacitance) and transport (in-pore resistivities) properties. These quantities are then injected in a transmission line model for testing its ability to predict the charging properties of the device. The results from this macroscopic model are in good agreement with non-equilibrium molecular dynamics simulations, which validates its use for interpreting electrochemical impedance experiments.
•Model supercapacitors are simulated under constant applied potential conditions.•The results are injected in a transmission line model.•The predicted charging plots agree very well with non-equilibrium MD.