Fundamental Investigations into Na+ Behavior in Aqueous and Non-Aqueous Electrolytes

Abstract

Sodium ion batteries present a meaningful opportunity to apply knowledge gained from lithium ion batteries. In order to produce functional sodium ion batteries that present real advantages compared to today’s commercial lithium ion batteries, the sodium ion and its interactions in solution must be exploited. From previous work on the subject, our work has shown fundamental differences in the solvation of Na+ as compared to Li+. Specifically, we were able to show that Na+ experiences weaker attractive forces and longer bond lengths between itself and its solvent molecules in organic and aqueous solution, which affects contact ion pairing and aggregation behavior. In this work, we will explore the relationship between ion-solvent interactions as they relate to the transference number and electrochemical stability of sodium organic and aqueous electrolytes. Ion interaction has a significant effect on the reduction potential of both solvent molecules and anions, and so there may be opportunities to take advantage of Na+ to affect both transference number and stability with the goal of producing effective electrolytes for sodium ion batteries.