(Invited) Insight into Bulk and Interfacial Structure of Electrolytes and SEI Components from Molecular Modeling

Abstract

Obtaining fundamental understanding and ultimately controlling bulk and interfacial properties of battery electrolytes is important for increasing battery power and energy density. Molecular dynamics simulations using many-body polarizable APPLE&P force field and ab initio Born Oppenheimer Molecular Dynamics (BOMD) simulations were used to examine the relationship between the structure of lithium solvates and ion transport in a wide range of electrolytes with potential applications in lithium battery. The solvate structures are systematically examined for electrolytes doped with LiFSI, LiTFSI, LiTriflate, LiPF6 and other salts in multiple solvents. Structural properties of SEI compounds will be also discussed. Previously reported1 interfacial properties for the dilithium ethylene dicarbonate (Li2EDC) – electrolyte interface will be contrasted with the interfacial properties for the Li2EDC – LiF interface. Transport mechanism including grain-boudary diffusion in the Li2EDC – LiF composite will be discussed.