Elucidating Interfaces in Solid State Batteries Using Advanced Scanning Transmission Electron Microscopy (STEM)

Designing next-generation energy storage systems, such as solid-state batteries, faces numerous challenges, many of which are related to interfaces. Elucidating interfacial phenomena 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 <i>in situ</i> 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 interfacial ion transport behavior, and (3) map space charge region at solid-solid interfaces. Perspectives for the future advancements of these new STEM techniques for research into emerging energy materials and systems will also be provided.