3D study achieves ‘Holy Grail’ of solid–liquid battery interfaces

A research team at the University of Illinois Urbana-Champaign has achieved a breakthrough in understanding the solid–liquid interfaces within lithium-metal batteries by using three-dimensional atomic force microscopy (3D-AFM) to visualize the structure of electrical double layers (EDLs) at realistic, uneven electrode surfaces. Unlike previous models that assumed flat interfaces, this study revealed that EDLs dynamically reorganize around microscopic surface clusters during the early stages of battery charging. The researchers identified three universal EDL response patterns—bending, breaking, and reconnecting—driven primarily by the physical geometry of the electrode surface rather than the specific chemistry of the electrolyte. This discovery, published in the Proceedings of the National Academy of Sciences, fills a critical knowledge gap in electrochemistry by linking nanoscale surface morphology to the behavior of liquid electrolytes and ultimately to battery performance. The ability to directly observe and categorize EDL behavior on heterogeneous surfaces not only advances fundamental understanding but also has practical implications for designing faster, more durable lithium