Indirect state-of-charge determination of all-solid-state battery cells by X-ray diffraction.

Determining the state-of-charge of all-solid-state batteries via both ex situ and operando X-ray diffraction, rather than by electrochemical testing (may be strongly affected by electrically isolated/inactive material, irreversible side reactions, etc.), is reported. Specifically, we focus on bulk-type cells and use X-ray diffraction data obtained on a liquid electrolyte-based Li-ion cell as the reference standard for changes in lattice parameters with (de)lithiation.