Interfaces

All-solid-state lithium-ion batteries (ASSLIBs) replace the liquid electrolyte with a solid electrolyte (SE). Both the electrodes and the electrolyte are solids, so the interfaces are buried. Side reactions, poor contact, and lithium dendrites are hard to see directly. Synchrotron X-rays can do diffraction, absorption spectroscopy, and imaging in the same facility, which is why they are used to watch bulk ion transport and how a solid–solid interface changes during cycling. The cases below ar...