Evaluation of La–Sr–Co–Fe–O perovskites for solid oxide fuel cells and gas separation membranes

Oxygen transport in Ce0.8Gd0.2O2−-based composite membranes

“…4), predominantly p-type electronic, is sufficiently close to the literature results [27,28]. The estimated apparent activation energy for the total conductivity is 12.2 F 0.2 kJ/mol (Table 3), also in good agreement with the literature (13.5 kJ/mol [28] (Fig.…”

“…The thermal expansion coefficient of Ce 0.8 Gd 0.2 O 2 À d averaged at 300 -1270 K was reported to be 12.5 Â 10 À 6 K À 1 [26], while the corresponding value for La 0.8 Sr 0.2 Fe 0.8 Co 0.2 O 3 À d was found equal to 14.8 Â 10 À 6 K À 1 [27] and 15.4 Â 10 À 6 K À 1 [28]. Along with experimental uncertainty and possible effects of ceramic microstructure on thermal expansion, this difference is due to the narrower temperature range used in the present work.…”

Porous La0.6Sr0.4CoO3−δ thin film cathodes for large area micro solid oxide fuel cell power generators

“…However, only few results have been reported on µSOFC performance using ceramic electrodes [29][30][31][32]. [33][34][35]) together with the large mismatch in the thermal expansion coefficient of LSC vs. YSZ (TEC LSC = 23 ppm/K; TEC YSZ = 11 ppm/K [36][37][38]) limit its applicability at high operating temperatures or in devices involving high T fabrication steps (T>700ºC). In this sense, alternative electrolytes or barrier diffusion layers are sometimes introduced between the electrolyte and the cathode for reducing these effects but still degradation by detachment is present [39][40][41].…”

“…30% ensuring good percolation, large Triple-Phase-Boundary (TPB) lengths and reasonable diffusion of gas species. Presumably, the observed porosity helps to balance the big difference in thermal expansion coefficient (TEC) reported for both materials, avoiding Sr segregation [37,38,44] and limiting the presence of significant stresses in the final multi-layer. [6] showed that so deposited YSZ layers present less than 5%vol.…”

Tracking of high-temperature thermal expansion and transport properties vs. oxidation state of cobalt between +2 and +3 in the La2Co1+z(Ti1−xMgx)1−zO6-system

“…x-ray absorption spectroscopy shows only LS and HS Co 3+ in LaCoO 3 up to 650 K. 8 Temperatureinduced spin state transitions of Co 3+ resulted in high thermal expansion coefficients (TEC) of cobaltites (e.g. TEC LaCoO 3 ≈21 ppm/K 9,10 ) and significantly hamper their use in various hightemperature electrochemical devices. Therefore, it is of great interest to study the influence of the oxidation state of cobalt on high-temperature thermal expansion and electronic conductivity properties of Co-containing perovskites.…”