Multi-scale Imaging of Solid-State Battery Interfaces: From Atomic Scale to Macroscopic Scale

The recent discovery of solid-state electrolytes with high conductivity has given rise to tremendous advances in the development of solid-state batteries. However, they still face the barrier of interfacial issues that restrict their future applications. Efforts to direct observation and analysis of solid-state battery interfaces are still lacking. Recent review articles have examined various solid-state batteries based on traditional chemical and physics insights, such as conductivity and stability. Recognizing this, here, we seek to evaluate a variety of emerging imaging techniques to understand the local interfacial structure and chemistry, with special focus on how each technique can address the key challenges at multiple interfaces from atomic scale to macroscopic scale. We assess the state-of-the-art imaging techniques and highlight new operando capabilities from cryogenic or synchrotron imaging methods to track the dynamic interface behaviors.