| Abstract Scope |
Clean energy technologies are essential for decarbonization and sustainability, which calls for foundational knowledge about the structure-property relationship of the underpinning energy materials. Transmission electron microscopy (TEM) is an indispensable methodology to characterize materials structures and compositions at the atomic scale as well as to observe dynamic material transformations during the relevant (electro)chemical reactions and associated phase transitions. Herein, we present a systematic exploration of in-situ TEM studies for Li-ion batteries (LIBs) and sodium-ion batteries, focusing on solid-state reactions through intercalation, alloying, and conversion reaction mechanisms. We fundamentally elucidated the root causes for substantial differences in reaction mechanisms, pathways, and kinetics between lithiation and sodiation processes. The knowledge learned from in-situ TEM will provide valuable insights into understanding the reaction mechanisms and kinetics, further guiding the advancement of LIBs and beyond-Li technologies. |