fig12

Figure 12. (A) Characterization of electrolytes by ¹⁷O NMR, temperature-dependent ⁷Li NMR, and two-dimensional correlation infrared spectroscopy with different concentrations of APT additives^[116]. Reproduced from Ref.^[116] with open access from Wiley; (B) C 1s, N 1s, Li 1s, F 1s, S 2p, and O 1s recorded at the interface Li/C1C6ImTFSI-LiTFSI during the polarization at a current density of 200 μA·cm^-2 in the OXPS cell. The spectra were recorded after GEIS measurement^[120]. Reproduced from Ref.^[120] with permission from the American Chemical Society; (C) In situ electrochemical Raman spectra of LLTO and LLTO-4%LBSO in the 1 mol L^-1 LiCl aqueous solution with a 5 V forward voltage^[104]. Reproduced from Ref.^[104] with permission from Wiley. ¹⁷O NMR: Oxygen-17 nuclear magnetic resonance; APT: allyl trimethyl phosphonium bis(trifluoromethane)sulfonimide; OXPS: operando X-ray photoelectron spectroscopy; GEIS: galvanostatic electrochemical impedance spectroscopy; LLTO: Li_0.33La_0.57TiO₃.