Modelling electrochemical systems with finite field molecular dynamics

Physical chemistry of electric double layers and ionic solutions plays a fundamental role in energy related applications such as electrocatalysis, super-capacitors, fuel cells, lithium/sodium ion batteries. A realistic representation of these electrochemical systems requires treating electronic, structural and dynamic properties on an equal footing. Density functional theory based molecular dynamics (DFTMD) is perhaps the only approach that can provide a consistent atomistic description. However, one of the challenges in DFTMD modelling of electrochemical systems is the slow convergence of the polarization P, where P is the central quantity connecting to all electrical properties (the dielectric constant, the Helmholtz capacitance and the ionic conductivity). Here, we summarize our recent progress on developing finite field MD for computing electrical properties. Discussions on notable extensions and outlook for future works are also given.