Abstract
Understanding the interfacial reactivity of aqueous electrolytes is crucial for their use in future batteries. We investigate the reactivity of the bis(trifluoromethane)sulfonimide anion when exposed to a strongly basic medium, by means of ab initio molecular dynamics and enhanced sampling techniques. In particular, we study the nucleophilic attack by the hydroxide anion, which was proposed as a mechanism for the formation of the solid electrolyte interphase at the negative electrode with water-in-salt electrolytes. While in the gas phase we recover a stable gaseous product, namely fluoroform, we observe the formation of trifluoromethanol in strong basic conditions, which then rapidly deprotonates to form CF3O−. This anion was suggested recently as a key compound leading to the formation of a solid electrolyte interphase on an Si-C anode. Such an approach could be leveraged to discover convenient additives leading to the formation of a stable interphase.