Simulation methods for chemically specific modeling of electrochemical interfaces

Abstract

We present progress in simulation of electrochemical interfaces. The problem is one of a larger class of materials related simulation challenges in which one needs to couple calculations spanning about 10 orders of magnitude in length and time scale in order to produce macroscopic predictions. Generally, methods within each scale are available but robust and reliable methods for coupling one scale to another are not. We discuss methods for coupling the electronic structure scale to the atomic scale and the atomic scale to higher length scales. At the electronic scale, quantum chemical, Hartree-Fock based methods and solid-state, density functional methods, while working from the same principles, are both useful in the appropriate electrochemical context. To study oxides, methods in which tight binding molecular dynamics models are fitted to plane wave local density electronic structure results with applications to titania and other rutile structure oxides are described in more detail. At the higher scale, we discuss progress on renormalization of molecular dynamics to permit it to be used on longer time and length scales in the context of studies of polymer electrolytes of interest in battery development programs.