Ursula Franklin MSE GRADUATE SEMINAR ​​​​​​: Computational Design of New Materials for use in Solid State Batteries

Solid state electrolyte batteries provide a noticeable advantage over conventional liquid batteries due to their improved safety. In particular, lithium ion solid state batteries have shown exceptional strides in recent years as their cycling performance and electrical capacities have started to approach those of conventional counterparts. In the discovery of these new compounds, Density Functional Theory (DFT) and Ab-Initio Molecular Dynamics (AIMD) are useful tools as they remove the need for a physical laboratory, thus saving time and resources. In addition to this, it has been shown recently that dopants can be used to increase the ionic conductivity of many compounds and this has opened a large field of potential study in doped solid-state electrolytes.

This study takes this computational approach to determine the electronic properties for a variety of compounds, including the Li6PS5X argyrodite series and the Li3SBF4 anti-perovskite series using DFT and AIMD. These compounds have previously been shown to have exceptional long term cycling as well as high discharge capacities. Additionally, they have been experimentally determined to have relatively high ionic conductivities, in the range of mS/cm at room temperature, which has been shown to be linked to improved battery performance. Following this, this study explores the benefits of varying dopants in these compounds and the role they may play in increasing the ionic conductivity of these compounds.