Fig. 2: Spectroscopic characterizations of SPEEK-Li.
From: An ultrathin ionomer interphase for high efficiency lithium anode in carbonate based electrolyte
a XRD pattern; FTIR spectra of SPEEK and SPEEK-Li within different wavenumber ranges, b 4000–500 cm−1 and c 1300–500 cm−1; d XPS spectrum of Li in SPEEK-Li.
