fig4

Figure 4. (A) SEM image of Li metal anode before cycling; (B) SEM image of Li metal anode after Li|BC/ZIF-67@Li₂TiO₃|Cu battery cycle; (C) SEM image of Li metal anode after Li|BC/ZIF-67|Cu battery cycle; (D) SEM image of Li metal anode after Li|BC|Cu battery cycle; (E) TEM image of the deposited Li metal anode after cycling in a Li|BC/ZIF-67@Li₂TiO₃|Cu cell; (F) Localized magnified image of the selected area in (E); (G) HRTEM of the selected region in (F); (H) HAADF-STEM image of the Li metal anode after cycling in a Li|BC/ZIF-67@Li₂TiO₃|Cu cell; the insert is energy-dispersive spectroscopic (EDS) maps of F, C, and N; (I) XANES and (J) the Fourier transform EXAFS for Co-K edge of Co-foil, ZIF-67 powder, and BC/ZIF-67@Li₂TiO₃ electrolyte before and after cycling; (K) Wavelet transform of the Co K-edge EXAFS signals for the BC/ZIF-67@Li₂TiO₃ electrolyte. BC: Bacterial cellulose; ZIF-67: zeolitic imidazolate framework-67; XANES: X-ray absorption near-edge structure; SEM: scanning electron microscope; TEM: transmission electron microscopy; HRTEM: high-resolution transmission electron microscopy; HAADF-STEM: high-angle annular dark-field scanning transmission electron microscopy; EXAFS: extended X-ray absorption fine structure.