Integrating Experiment with Theory to Determine the Structure of Electrode-Electrolyte Interfaces

TL;DR

This paper introduces a combined experimental and theoretical approach using 3D-AFM imaging and molecular dynamics simulations to accurately determine the atomic-scale structure of electrode-electrolyte interfaces, advancing understanding in electrochemical systems.

Contribution

It proposes an integrated method that combines 3D-AFM imaging with molecular dynamics simulations for detailed EDL structure analysis, overcoming limitations of existing techniques.

Findings

Demonstrates feasibility of joint experiment-theory approach

Provides atomic-scale insights into EDL structures at various electrodes

Highlights potential for high-throughput EDL characterization

Abstract

Electrode-electrolyte interfaces are crucial for electrochemical energy conversion and storage. At these interfaces, the liquid electrolytes form electrical double layers (EDLs). However, despite more than a century of active research, the fundamental structure of EDLs remains elusive to date. Experimental characterization and theoretical calculations have both provided insights, yet each method by itself only offers incomplete or inexact information of the multifaceted EDL structure. Here we provide a survey of the mainstream approaches for EDL quantification, with a particular focus on the emerging 3D atomic force microscopy (3D-AFM) imaging which provides real-space atomic-scale EDL structures. To overcome the existing limits of EDL characterization methods, we propose a new approach to integrate 3D-AFM with classical molecular dynamics (MD) simulation, to enable realistic, precise, and high-throughput determination and prediction of EDL structures. As examples of real-world application, we will discuss the feasibility of using this joint experiment-theory method to unravel the EDL structure at various carbon-based electrodes for supercapacitors, batteries, and electrocatalysis. Looking forward, we believe 3D-AFM, future versions of scanning probe microscopy, and their integration with theory offer promising platforms to profile liquid structures in many electrochemical systems.