Molecular Structure and Ion Transport Near Electrode-Electrolyte Interfaces in Lithium-Ion Batteries
Here we present molecular dynamics (MD) simulations of typical organic liquid LIB electrolytes in contact with graphite electrodes to understand the relationship between ion solvation structure and transport near the interface. Results for different graphite terminations are presented and the effect of an electric field is explored. Different prototypical organic liquids, including ethylene carbonate and ethyl methyl carbonate, are compared. We observe that anion mobility in an electric field is much greater than that for Li ions, a phenomenon due to the very different solvation structures. In addition, we observe a barrier to Li insertion into graphite when its surface is hydroxyl terminated. Furthermore, we compare the results of ab initio MD with the empirical reactive forcefield ReaxFF and the non-reactive, non-polarizable COMPASS forcefield and note differences in the predictive power of each technique.