"X-ray Coulomb Counting" to understand electrochemical systems

TL;DR

This paper introduces 'X-ray Coulomb Counting,' a novel method using X-ray techniques to quantify charge transfer in electrochemical systems, enhancing mechanistic understanding of reactions.

Contribution

It presents a new approach that explicitly measures charge transfer during electrochemical processes using X-ray methods, enabling detailed interpretation.

Findings

Demonstrated the method on Li-ion batteries

Enabled absolute quantification of charge transfer

Provided insights into reaction mechanisms

Abstract

Electrochemical systems are important for a sustainable and defossilized energy system of the future. While accurate and precise, the corresponding electrochemical measurements, in which many reactions may occur simultaneously, often do not contain enough information to understand the underlying mechanism and processes. This information, however, is crucial towards rational materials and devices as well as process development and for inventing innovative concepts. In this perspective, we introduce explicitly the concept of "X-ray Coulomb Counting" in which X-ray methods are used to quantify on an absolute scale how much charge is transferred into which reactions during the electrochemical measurements. This allows to interpret the electrochemical measurements in detail and obtain the desired phenomenological and mechanistic understanding. We show a few recent examples from the Li-ion battery literature in which the concept of X-ray Coulomb Counting was employed to obtain foundational understanding.