Towards Principles of Electronic Structure Modeling of Battery Interfaces

Battery Interfaces affect charge/discharge rates, cycle life, safety, and many other aspects of battery operations. Electronic structure modeling should significantly accelerate the understanding and design of such interfaces. Due to their complexity and the lack of established, guiding principles governing such modeling efforts, most research groups working in this area apply different models and sets of approximations, making it difficult for the experimental or casual theoretical reader to understand how different modeling approaches fit together (or not). For example, the calculation and control of voltages in DFT settings remain active research topics. In this presentation, we propose key scientific principles involved in battery interface modeling, how they relate to principles in other electrochemical disciplines, and the differences between cathodes and anodes. We emphasize the need to deal with the “dirty” nature of realistic battery electrode surfaces (covered by multi-layer surface SEI or CEI films), the need to go beyond the “initial’ stages of surface film growth, the focus on kinetics rather than thermodynamics, the almost inevitable presence of overpotentials on metallic electrode models, and the choice of DFT functionals when dealing with electrolyte oxidation on cathode surfaces.<br/><br/>This article has been authored by an employee of National Technology & Engineering Solutions of Sandia, LLC under Contract No. DE-NA0003525 with the U.S. Department of Energy (DOE). The employee owns all right, title and interest in and to the article and is solely responsible for its contents. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this article or allow others to do so, for United States Government purposes. The DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan https://www.energy.gov/downloads/doe-public-access-plan. This paper describes objective technical results and analysis. Any subjective views or opinions that might be expressed in the paper do not necessarily represent the views of the U.S. Department of Energy or the United States Government.