Fig. 3: Cryo-TEM experiments reveal densely-packed Li0 deposits protected by uniform SEI.

a Representative cryogenic scanning transmission electron microscopy (Cryo-TEM) images showing the smooth chunk morphology of the deposited Li0 with PCE. The images were obtained in high-angle annular dark-field (HAADF) mode. b High-angle annular dark-field STEM (HAADF-STEM) image, and energy-dispersive spectroscopic (EDS) maps of the deposited Li0 with the PCE electrolyte. The result shows that a thin and uniform layer of solid electrolyte interface (SEI) enriched in C, N, O, F, and S forms on the Li0 surface. c Atomic-resolution Cryo-TEM image showing the structure of the Li0 deposit. The Li0 (110) spacing is indicated in the inset. d Electron diffraction pattern (EDP) of Li0 deposit. The Bragg spots and diffraction rings corresponding to Li0 and Li2O respectively are indicated by arrows. e Atomic-resolution Cryo-TEM image showing the SEI on the surface of the Li0 deposit. The SEI comprises nano-sized domains (e.g., Li2O indicated by dash circles) with varied crystallographic orientations.