Fig. 5. The composition characterization of CEI/SEI. XPS spectra of (a) C 1s, (b) O 1s, (c) F 1s, and (d) P 2p of NVP cathodes in three different electrolytes. XPS spectra of (e) C 1s, (f) O 1s, (g) F 1s, and (h) P 2p of HC anodes in three different electrolytes.