In Situ Multiresolved Optical Imaging at Electrochemical Interfaces

Electrochemical technologies underpin the paradigm shift toward sustainable energy including in electrolyzers and batteries. To date, critical processes such as interfacial degradation, active species transport, and phase transitions or mechanisms occurred at electrochemical interfaces remain poorly understood. Existing in situ techniques are unable to fully resolve these nanoscopic, spatially heterogeneous, multiscale, dynamic phenomena in real time. To tackle these challenges, in situ multiresolved optical imaging is emerging as a new frontier for unveiling detailed structure–property–activity relationships at complex interfaces with higher spatiotemporal resolutions. In this concept, we will highlight how synergistically combining multimodal imaging approaches (e.g., super‐resolution, confocal, and wide‐field) can connect macroscopic electrochemical behavior with nanoscale interfacial dynamics (cross‐scale correlations), owing to their noninvasive nature, diverse spectroscopic principles, excellent sensitivity, and sufficient spatial and temporal resolution. The key examples are presented to unveil strong potential of these in situ multiresolved optical imaging approaches in batteries and electrocatalysis. Finally, we present the outlook of future development of in situ multiresolved optical imaging that holds strong potential in accelerating materials discovery for diverse energy applications.