MEMS Seminar: Emerging Scanning Transmission Electron Microscopy (STEM) for Energy Materials Research

An ever-increasing societal demand calls for sustainable solutions to converting and storing energy. However, designing next-generation energy conversion and storage systems, such as solid-state batteries and fuel cells, faces numerous challenges, many of which are related to interfaces. Elucidating interfacial phenomena in these energy systems requires knowledge, not only of atomic-scale structure and chemistry but also of correlated local charge distribution and ion transport that are difficult to probe with existing characterization techniques. Several emerging scanning transmission electron microscopy (STEM) techniques, such as four-dimensional (4D)-STEM, monochromated EELS (electron energy loss spectroscopy), atomic-scale cryogenic and in situ environmental microscopy, allow the behavior of electrons, ions, and atoms to be probed, opening opportunities to tackle complex dynamic interfacial questions. In this talk, I will demonstrate how we advance and utilize these techniques to (1) reveal the origin of unexpected dendrite growth within all-solid-state batteries, (2) probe local ion transport behavior at interfaces and grain boundaries, and (3) map charge density in electrides and interfaces in heterogeneous catalysts. Perspectives for the future advancements of these new STEM techniques for research into emerging energy and quantum materials will also be provided.