Resonant inelastic X-ray scattering for studying materials for renewable energy conversion and storage.

Renewable energy conversion and storage technologies, including batteries, fuel cells, and electrolyzers, have garnered global attention. Electrode materials are crucial in determining the performance and lifespan of the corresponding devices. Transition metals and light elements are key components in electrode materials, enabling efficient energy conversion by directly providing active sites or indirectly optimizing material electronic structures. To understand the relationship between electronic structures and device performance, advanced techniques like X-ray absorption spectroscopy (XAS) have been developed. Recently, resonant inelastic X-ray scattering (RIXS) features coupled with X-ray emission spectra (XES) have emerged as a complementary tool, providing additional insights into material electronic structures. This review focuses on recent advances in using XES, particularly RIXS, for studying energy conversion and storage materials, highlighting the unique features and potential of RIXS for electronic structure characterization and quantitative analysis. This work aims to stimulate interests in utilizing RIXS features in the field of energy conversion and storage.