Innermost Ion Association Configuration Is a Key Structural Descriptor of Ionic Liquids at Electrified Interfaces

Kaustubh S. Panse, Haiyi Wu, Shan Zhou, Fujia Zhao, Narayana R. Aluru, Yingjie Zhang

Research output: Contribution to journalArticlepeer-review

Abstract

The structure of electric double layers (EDLs) is crucial for all types of electrochemical processes. While in dilute solutions EDL structure can be approximately treated within the Gouy-Chapman-Stern regime, in highly ionic electrolytes the description of EDL has been largely elusive. Here we study the EDL structure of an ionic liquid on a series of crystalline electrodes. Through molecular dynamics (MD) simulations, we observe strong intermolecular interaction among cations and anions and propose that the cation-anion association structure at the innermost layer is a key descriptor of the EDL. Using our recently developed electrochemical 3D atomic force microscopy (EC-3D-AFM) technique, we confirm the theoretical prediction and further find that the width of the first EDL is an experimental gauge of the ion association structure in that layer. We expect such ion association descriptors to be broadly applicable to a large range of highly ionic electrolytes on various electrode surfaces.

Original languageEnglish (US)
Pages (from-to)9464-9472
Number of pages9
JournalJournal of Physical Chemistry Letters
Volume13
Issue number40
DOIs
StatePublished - Oct 13 2022
Externally publishedYes

ASJC Scopus subject areas

  • General Materials Science
  • Physical and Theoretical Chemistry

Fingerprint

Dive into the research topics of 'Innermost Ion Association Configuration Is a Key Structural Descriptor of Ionic Liquids at Electrified Interfaces'. Together they form a unique fingerprint.

Cite this