Correlative electron and X-ray microscopy: a new lens for sodium-ion battery research

Abstract Sodium-ion batteries (SIBs) are emerging as a promising alternative to lithium-ion technology, with the first commercial cells now available. Understanding their structure and degradation mechanisms is crucial for further development. This study presents a correlative approach combining X-ray and electron microscopy to achieve multi-scale imaging of SIB materials. X-ray microscopy enables non-destructive 3D analysis of electrode architecture, while electron microscopy provides high-resolution insights into particle morphology, interfaces, and failure modes. By integrating these techniques, we establish a comprehensive workflow for analyzing structural and chemical changes. Our results offer one of the first in-depth imaging and analysis of commercial SIB materials and provide valuable feedback for material optimization. This correlative methodology sets a new standard for battery research, advancing the development of next-generation sodium-ion energy storage solutions.