Simulating Structure and Diffusivity in the Inorganic Components of the Cathode Electrolyte Interface
Eshton Liu
Department of Chemistry & Biochemistry
Faculty Supervisor: Nicole Adelstein
Conventional organic electrolytes in Li-ion batteries have an electrochemical window that is too narrow, leading to a decomposition at the cathode and anode surfaces, especially at high voltages. The breakdown of the electrolyte leads to the formation of cathode-electrolyte interface (CEI). These interfaces are multicomponent, 3-dimensional heterogeneous structures that span from a few nanometers to micrometers. To understand the atomic-scale impact of the interfaces’ structure and chemistry on function we have run molecular dynamics simulations of the Li-ion diffusivity in the most likely components: LiF, Li2CO3, Li2O, and their mixtures. We extract Li-ion diffusivity and the activation energy for Li-ion transport using machine learning force fields from the individual components of the interface and explicit interfaces.
This work was sponsored by the Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Office and was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
This work was supported in part by the U.S. Department of Energy, Office of Science, Office of Workforce Development for Teachers and Scientists (WDTS) under the Visiting Faculty Program (VFP).