2016/04/26 by Andreas Härtel, Sela Samin, René van Roij +1 · 20 citations
Chemical Engineering · Chemistry · Engineering · Physics and Astronomy · #Capacitance #Charge (physics) #Density functional theory #Dielectric #Dielectric materials and actuators #Electrostatics and Colloid Interactions #Ionic bonding #Ionic liquids properties and applications #Molecular dynamics #Perpendicular #Planar #cond-mat.soft
paper · pdf · doi:10.1088/0953-8984/28/24/244007
published in Journal of Physics Condensed Matter 28(24), 244007 (IOP Publishing)
openalex publication_date 2016/04/26 · arxiv created 2016/04/27 · arxiv updated 2016/04/28 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The ongoing scientific interest in the properties and structure of electric double layers (EDLs) stems from their pivotal role in (super)capacitive energy storage, energy harvesting, and water treatment technologies. Classical density functional theory (DFT) is a promising framework for the study of the in- and out-of-plane structural properties of double layers. Supported by molecular dynamics simulations, we demonstrate the adequate performance of DFT for analyzing charge layering in the EDL perpendicular to the electrodes. We discuss charge storage and capacitance of the EDL and the impact of screening due to dielectric solvents. We further calculate, for the first time, the in-plane structure of the EDL within the framework of DFT. While our out-of-plane results already hint at structural in-plane transitions inside the EDL, which have been observed recently in simulations and experiments, our DFT approach performs poorly in predicting in-plane structure in comparison to simulations. However, our findings isolate fundamental issues in the theoretical description of the EDL within the primitive model and point towards limitations in the performance of DFT in describing the out-of-plane structure of the EDL at high concentrations and potentials.