Molecular Dynamics Simulations of Lithium Ion Transport through Solid Electrolyte Interface Layer

Monday, 29 May 2017: 14:20
Prince of Wales (Hilton New Orleans Riverside)
A. Muralidharan (Tulane University), M. Chaudhari, S. Rempe (Sandia National Laboratories), and L. R. Pratt (Tulane University)
Lithium ion transport through solid electrode interface (SEI) layer is elusive to molecular simulation studies due to lack of composition information and force field parameters available for organic SEI layer. Last decade, dilithium diethylene carbonate (Li2EDC) was suggested as the primary component of SEI layer using experiments and quantum mechanical simulations. We applied classical, non-polarizable OPLS-AA force field parameters to model SEI layer of Li2EDC molecules. Long time-scale molecular simulations at various temperatures (333, 500, 700K) were performed to calculate structural and transport properties of lithium ion in EDC. Vibrational power spectral analysis suggested two prominent modes of lithium vibrations at frequencies 400 and 650 cm-1 in EDC and pure ethylene carbonate solvents. These vibrational modes were further confirmed in Gaussian electronic structure calculations results. Self part of time dependent correlation function calculated using van Hove function confirm that EDC is crystalline compared to pure ethylene carbonate.

Sandia National Laboratories (SNL) is a multi-mission laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's (DOE) National Nuclear Security Administration under Contract DE-AC04-94AL85000.