Electrode reaction of Sr1−xLaxCo0.8Fe0.2O3−δ with x=0.1 and 0.6 on Ce0.9Gd0.1O1.95 at 600≤T≤800 °C

Electrode/Electrolyte Interphase Characterization in Solid Oxide Fuel Cells

“…2 are equal for both materials. In addition, a higher ASRw is expected for a thicker cathode [54], contrary to the observed in Figure 6. Consequently, the ASRw difference can be mainly attributed to the difference in interfacial contact area (S).…”

Nano-sized Pr0.8Sr0.2Co1-xFexO3 powders prepared by single-step combustion synthesis for solid oxide fuel cell cathodes

“…5(f)). The 45°degree straight line behavior is characteristic of semi-infinite diffusion and was successfully fitted with a Warburg element [36]. EIS plots with similar shape were attributed to Gerischer impedance due to a co-limited reaction regime where both kinetics and transport determine the electrode characteristics [1].…”

AC Impedance Characterisation of a La0.8Sr0.2Co0.2Fe0.8O3–δ Electrode

“…As shown in the figures, depending on temperature and P O 2 the impedance characteristics are determined by up to three different processes, corresponding to three partially overlapping depressed arcs in the Nyquist plots, such as gas diffusion, adsorption and surface exchange, bulk or surface diffusion and charge transfer steps [1,4,5,14,15]. The degree of overlapping of the corresponding arcs in the Nyquist plots and their relative contribution to the apparent polarisation resistance also depend on temperature and P O 2 .…”

“…The high frequency arc can be related to ionic diffusion in the electrode on the basis of the weak dependence (Figure 8a) of R À1 p;HF on P O 2 [5,15,29], assuming that by decreasing P O 2 from 100 to 0.7 kPa the mixed conducting electrode oxygen deficiency and, thus, the concentration of oxygen vacancies carrying the oxide ion current does not increase significantly [30,31]. The average activation energy value of 1.57 eV corresponding to the high frequency step is in reasonable agreement with the activation energy value of ∼1.9 eV reported for oxygen self-diffusion in La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-d [7,32], in view of the difference in composition.…”