This study used correlative X-ray and neutron computed tomography (CT), along with a virtual unrolling technique, to create 4D images of lithium-ion battery operation. The research revealed how lithium distribution, electrolyte consumption, and electrode degradation (like cracking) change during battery discharge, highlighting a more active lithium intercalation at the outer electrode windings due to less compression.

The authors declare no competing interests, but funding was provided by institutions with interests in battery technology, including the Faraday Institution and the National Renewable Energy Laboratory. This could potentially influence research priorities and interpretation of results, though there is no direct indication of bias in the presented work.

This study uses a novel combination of advanced imaging techniques (X-ray and neutron CT) coupled with a virtual unrolling method to provide a detailed 4D visualization of the processes occurring within a lithium-ion battery during discharge. The correlative approach and the unrolling technique offer valuable insights into the complex interplay of chemical and mechanical changes, going beyond what is achievable with traditional methods. While the limited sample size (two cells) and challenges in distinguishing lithium from electrolyte pose some limitations, the study presents valuable methodological advancements and provides a strong foundation for future research in this area.