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

C. Pean (1, 2, 3) , Benjamin Rotenberg (2, 3) , P. Simon (3, 1) , M. Salanne (2, 3, 4)

1 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux
2 PHENIX - PHysicochimie des Electrolytes et Nanosystèmes InterfaciauX
3 RS2E - Réseau sur le stockage électrochimique de l'énergie
4 MDLS - Maison de la Simulation

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.

Mots clés: Supercapacitors; Molecular dynamics simulation; Porous materials; Dynamic processes; Transport properties

Domaines: Physique [physics]

C. Pean, Benjamin Rotenberg, P. Simon, M. Salanne. Multi-scale modelling of supercapacitors: From molecular simulations to a transmission line model. Journal of Power Sources, 2016, ⟨10.1016/j.jpowsour.2016.03.095⟩. ⟨hal-01304251v1⟩