Fig. 2
From: Reversible flowering of CuO nanoclusters via conversion reaction for dual-ion Li metal batteries
Characterization of PAN-containing CuO cathodes and PAN powder before and after cyclization at several temperatures. a N 1s X-ray photoelectron spectroscopy (XPS) profiles of CuO cathodes with non-cyclized PAN and 280 °C cyclized PAN, marked with “Raw” and “280 °C”, respectively. b Atomic composition of N-containing functional groups at different cyclization temperatures according to their N 1s XPS profiles. c Structures of C ≡ N and pyridinic-, pyrrolic-, and quaternary-N groups. d Fourier-transform infrared (FTIR) spectra of the raw and cyclized PAN powder at temperatures in the range of 150–300 °C. e Extent of ratio (EOR) of the PAN cyclization reaction calculated using FTIR data