Following the lithium-ion battery analyses, we extended our investigation to impedance data acquired from a protonic ceramic fuel cell. The measurements were conducted on a symmetric cell configuration, employing Ba 0.95 La 0.05 FeO 3-δ electrodes and a samarium-doped ceria electrolyte. The cell was operated at 500 • C under varying oxygen partial pressures (pO 2 ), specifically at 21%, 40%, 60 %, 80 %, and 100 % . Nyquist plots of the experimental impedance spectra are presented in Figure (a). Applying the same DRT deconvolution methodology as used for the battery data (Section 3.2.1), we recovered the DRTs, which are visualized as contour plots in Figure (c). Notably, we observed a consistent trend of decreasing characteristic relaxation timescales with increasing oxygen partial pressure (Figure (c)). This inverse relationship aligns with previously reported findings in the literature , suggesting that higher oxygen partial pressures facilitate faster electrochemical processes within the fuel cell. Moreover, the DRT model accurately regressed the experimental impedance spectra, as evidenced in