(364b) Computational Study of Solvation, Dynamics and Energetics of Electrolytes for Multivalent Batteries

Authors: 
Rajput, N. N., Lawrence Berkeley National Laboratory
Qu, X., Lawrence Berkeley National Laboratory
Persson, K., Lawrence Berkeley Lab

Increasing demand of high energy density and high capacity batteries require development beyond Li-ion technology, such as multivalent batteries, and innovations in electrodes and electrolytes, alike. Magnesium has been considered as one of the most promising materials for multivalent batteries not only because it’s cheaper than Li but because it could theoretically provide at least twice the energy density as compared to the Li-ion batteries that are currently being used in electric vehicles and other electronic devices. However development and commercialization of Mg batteries require not only improved electrode discovery and development but also novel electrolytes which are compatible with the Mg metal as conventional electrolytes fail to penetrate the Mg metal passivation layer. Thus a fundamental understanding of molecular level properties of these electrolytes is required to improve the electrochemical stability and the charge transfer properties.  In this work, we present classical molecular dynamics simulations coupled with ab initio calculations for Mg salts in various solvents. We present structure, dynamics and energetics of Mg electrolytes benchmarked against available experimental results. We observed significant change in the properties of Mg electrolytes as compared to Li electrolytes in terms of mobility as well as desolvation of the ions at the electrode interface.