Electron Beam-Induced Artifacts in SEI Characterization: Evidence from Controlled-Dose Diffraction Studies

Abstract

Solid electrolyte interphases (SEIs) directly influence Li-metal battery performance. Recent studies have characterized SEI structures using cryogenic electron microscopy but have failed to carefully consider the effect of the electron dose. We investigated this issue using selected-area electron diffraction and scanning electron nanobeam diffraction. Our findings indicate that SEIs are largely amorphous and that they are extremely beam-sensitive and thus prone to beam-induced artifacts. We show that controlled-flux scanning electron beam techniques, particularly nanobeam diffraction, allow observation of intact SEI structures. This approach enables accurate characterization without introducing artifacts, advancing our understanding and optimization of these crucial interfaces in Li-metal battery systems.