fig3

Figure 3. SEM images of (A) pristine LiCoO₂, (B) cycled LiCoO₂ electrode collected from cell operated in LiDFOB + DMS/HFE/FEC and (C) LiPF₆ + EC/DMC electrolyte. High-resolution XPS spectra of Li anodes after cycling in both electrolytes: (D) Li 1s, (E) C 1s and (F) O 1s. High-resolution XPS spectra of LiCoO₂ cathode after cycling in both electrolytes: (G) Li 1s, (H) C 1s and (I) O 1s. Nyquist plots of LiCoO₂||Li cell recorded with (J) LiDFOB + DMS/HFE/FEC and (K) LiPF₆ + EC/DMC electrolytes. (L) Comparison of R_int values extracted by equivalent circuit fitting based on the EIS spectra.