Credit: Image courtesy of Advanced Energy Materials
Atomic force microscopy (AFM) can measure atomic-scale height variations on the surface of a material. This investigation has developed AFM techniques to study silicon (Si) battery electrode materials during charge-discharge cycling (left). The design of the thin film electrode allows the measurement of growth of the surface interface layer (SEI) (purple region in the right image) during the cycling; this approach allows extraction of the interface thickness from the overall electrode volume change (tan).