4D imaging of lithium-batteries using correlative neutron and X-ray tomography with a virtual unrolling technique

Ralf F Ziesche,Nikolay Kardjilov,Daniel Baum,Thomas M M Heenan,Donal P Finegan,Paul R Shearing,Alessandro Tengattini,Winfried Kockelmann,Tobias Arlt,Ingo Manke,Henning Markötter,Dan J L Brett

doi:10.1038/s41467-019-13943-3

Abstract

The temporally and spatially resolved tracking of lithium intercalation and electrode degradation processes are crucial for detecting and understanding performance losses during the operation of lithium-batteries. Here, high-throughput X-ray computed tomography has enabled the identification of mechanical degradation processes in a commercial Li/MnO2 primary battery and the indirect tracking of lithium diffusion; furthermore, complementary neutron computed tomography has identified the direct lithium diffusion process and the electrode wetting by the electrolyte. Virtual electrode unrolling techniques provide a deeper view inside the electrode layers and are used to detect minor fluctuations which are difficult to observe using conventional three dimensional rendering tools. Moreover, the ‘unrolling’ provides a platform for correlating multi-modal image data which is expected to find wider application in battery science and engineering to study diverse effects e.g. electrode degradation or lithium diffusion blocking during battery cycling.

Highlights

In recent years, the advancement of X-ray computed tomography (CT) capabilities have facilitated a broadening of our understanding of battery materials and devices, with studies spanning multiple length scales, from nanometre to millimetre, and multiple time scales from kilohertz to microhertz[1]
We extend our previous study to evaluate the Li distribution in the MnO2 cathode of a commercial CR2 Li-ion primary cell from Duracell[26] using both X-ray and neutron CT
X-ray and neutron imaging were performed to study the Li intercalation, morphology changes and degradation processes in two different commercial CR2 Li/manganese dioxide cells discharged under identical conditions as described in the Methods/Experimental section

Summary

Introduction

The advancement of X-ray computed tomography (CT) capabilities have facilitated a broadening of our understanding of battery materials and devices, with studies spanning multiple length scales, from nanometre to millimetre, and multiple time scales from kilohertz to microhertz[1]. While the majority of these studies have utilised X-ray CT, there is growing interest in the application of neutron imaging for battery applications; the complementarities of X-ray and neutron imaging, which are sensitive to electron and nuclear density, respectively, provide significant opportunities for correlative studies. X-ray CT is leveraged to identify features that are beyond the resolution capability of neutron CT, whereas neutron CT, being highly sensitive to Li, is utilised to track the spatial dynamics of light components such as: the Li metal, Li ions, Li salt and the hydrogen in the electrolyte, as well as formed gases

Methods

Results

Conclusion