S. Schweizer, J.-R. Hill, L. Subramanian
Keywords: simulation, molecular dynamics, density functional, electrode-electrolyte interactions
Summary:Powerful energy storage technologies are key to meet the ever increasing demand in energy in a sustainable manner. Electrochemical double layer capacitors (EDLCs), which are also known as supercapacitors, are energy storage elements which are ideally suited for applications that require high power density and a long life cycle such as electric vehicles, backup systems, or portable electronic devices. Molecular modeling can be leveraged to gain crucial information of the storage processes in EDLCs for improving and tuning the performance. We present computational studies on carbon-based EDLC systems showing how morphological realistic structures of the carbon electrode can be modeled efficiently using molecular dynamics. A detailed analysis of the structural properties of the porous carbon matrix and a comparison with experimental data including adsorption isotherms will be provided demonstrating the validity of the models. In addition, the influence of structural modifications and of the local environment on electrode-electrolyte interactions has been examined using density functional theory. Our findings indicate that the interaction between electrolyte molecules and electrode material can be linked to the performance of carbon-based EDLCs and represents thus a valuable descriptor for virtual screening experiments geared to optimizing EDLC-based energy storage systems.