Non-destructive measurement of in-operando lithium concentration in batteries via x-ray Compton scattering

TL;DR

This paper introduces a non-destructive x-ray Compton scattering technique to measure lithium concentration in working batteries, enabling safe and efficient in-operando analysis of battery health and performance.

Contribution

It presents a novel application of high-energy x-ray Compton scattering combined with computational modeling to quantify lithium distribution in closed electrochemical cells.

Findings

Shape parameter S is linearly proportional to lithium concentration.

Method successfully applied to LixMn2O4 cathodes.

Demonstrated effectiveness in a commercial lithium coin battery.

Abstract

Non-destructive determination of lithium distribution in a working battery is key for addressing both efficiency and safety issues. Although various techniques have been developed to map the lithium distribution in electrodes, these methods are mostly applicable to test cells. Here we propose the use of high-energy x-ray Compton scattering spectroscopy to measure the local lithium concentration in closed electrochemical cells. A combination of experimental measurements and parallel first-principles computations is used to show that the shape parameter S of the Compton profile is linearly proportional to lithium concentration and thus provides a viable descriptor for this important quantity. The merits and applicability of our method are demonstrated with illustrative examples of LixMn2O4 cathodes and a working commercial lithium coin battery CR2032.