Polarizable force fields for the Investigation of sodium-ion battery materials

Abstract

The implementation of new renewable energy sources is a necessary step toward the mitigation of the CO2 emissions and the control of climate changes. However, due to the intermittent nature of these sources, it is necessary to use energy storage technologies such as supercapacitors and batteries. The low availability of lithium on Earth makes lithium batteries, the most batteries used today, not sufficient to meet the future demand for batteries. Therefore, in recent years, much effort has been made to develop batteries of sodium-ion (SIB). Among the main limiting factors for these batteries, we can mention the formation of the solid electrolyte interface (SEI) on the anode surface, which occurs by side reactions between the electrolyte and the electrode surface. An alternative to mitigate the impacts of SEI formation is the use of electrolytes based on ionic liquids (ILs), which result in a robust SEI, which contributes to the transport of Na+ ions from the bulk region to the electrode surface. To increase the understanding of SEI formation in ILs, an atomistic investigation is needed, focusing on the interactions between ions and their transport. In this project, we propose to carry out molecular dynamics (MD) simulations using polarizable force fields for IL-based electrolytes. In addition to the MD simulations, density functional theory calculations can be carried out to complement the information obtained from the MD simulations and also to obtain different properties that influence the formation of the SEI, such as the stability of ions and the energy costs of interactions. (AU)