Quantification of Enhanced Ion-Pairing in Nanoconfined Electrolytes Using Valence-to-Core X-ray Emission Spectroscopy

27 December 2023, Version 1
This content is a preprint and has not undergone peer review at the time of posting.

Abstract

The increasing use of nanostructured materials in contact with aqueous solutions for various technological applications including energy storage requires an improved understanding of the effects of nanoconfinement. In this study, we use valence-to-core X-ray emission spectroscopy (VTC-XES) to quantify the effects of nanoconfinement on the evolution of local coordination structure of Zn complexes in aqueous zinc chloride systems. Recent work (Dhakal, et al., 2023) establishes the ability to quantify the Zn–Cl first shell coordination number. We find that ion pairing is enhanced in solutions under confinement in nanoporous carbon compared to their bulk counterparts, and we also find that the electrochemical voltage window (EVW) of such solutions is correlated to the extent of ion pairing. Several possible explanations for both the enhancement in ion pairing and its correlation with the EVW are discussed, with significant connection to the broader concept of water-in-salt electrolytes (WiSE).

Keywords

ion pairing
x-ray emission spectroscopy
nanoconfined solution

Supplementary materials

Title
Description
Actions
Title
SI for Dhakal et al
Description
Supplementary results in support of the main premise of the article.
Actions

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.