Cation-Dependent Solvation Behavior of Aqueous Triflate Electrolytes

06 May 2024, Version 1
This content is a preprint and has not undergone peer review at the time of posting.

Abstract

We investigated trends in the cation-dependent solvation behavior and electrochemical stability of aqueous electrolytes with ten trifluoromethanesulfonate (OTf) salts (Li+, Na+, K+, NH4+, NMe3Et+, Mg2+, Zn2+, Ca2+, Ba2+, and Al3+). Our findings show that electrochemical stability is predicted well by the pH of the electrolyte with kinetic limitations associated with concentration against hydrogen evolution playing an insignificant role when the solvent-to-anion ratio exceeds the coordination number. Furthermore, the abundance of contact ion pairs is generally inversely related to the charge density of the cation, except when the cation and anion have similar solvation enthalpies (e.g., Na+ and OTf-). These trends in cation-dependent solvation, solubility, proton activity, and electrochemical stability provide helpful guidance regarding the design of electrolytes for beyond-lithium energy storage technologies.

Comments

Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.