The advent of diverse battery chemistries necessitates the development of novel diagnostic techniques to investigate their degradation. Due to its sensitivity to light elements and ability to distinguish between 3d transition metals, operando neutron diffraction is well-suited to study the crystallographic transformations in battery materials and their associated degradation pathways. However, it is currently not used academically due to limited data quality and time resolution, and the lack of a cost-effective electrochemical cell that can be reproducibly fabricated at the laboratory scale with benchmarked performance. Here, using the high-resolution cold-neutron diffractometer, WISH, we demonstrate that neutron diffraction can be performed in operando on laboratory-scale 70-mAh single-layer pouch cells without any modification, deuteration or isotope enrichment, cycled under practically relevant conditions. This advances the battery diagnostics toolkit beyond X-ray techniques and permits continuous academic investigations of established, and next-generation technologies like lithium-metal, anode-free and lithium-sulphur batteries for further development.
Menon et al. (Sun,) studied this question.