کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1281973 | 1497538 | 2013 | 9 صفحه PDF | دانلود رایگان |
La2−xSrxCoO4−δ (x = 0.9, 1.0, 1.1) compounds with Ruddlesden-Popper K2NiF4-type structure have been investigated as potential cathode materials for IT-SOFC application. Materials have been prepared by citrate-nitrate combustion method. Structural evolution analysed by XRD shows a shortened Co–O–Co bond length within the perovskite layer as Sr substitution increases, while the interlayer distance at the same time increases. An oxygen stoichiometry close to 4 has been found for all compositions at room temperature. Thermal expansion coefficients have been obtained from temperature-dependent XRD analysis and show large values (>20 × 10−6 K−1) compared to the currently utilized electrolyte materials. Electrochemical characterisation has been performed by means of impedance spectroscopy on symmetric cells with CGO electrolyte. Pure electrodes have a high Area Specific Resistance, probably due to limited oxygen ion diffusion. By using composite electrode (50 wt.% CGO), an Area Specific Resistance of 0.25 Ω cm2 is obtained at approximately 700 °C for all the three compounds suggesting promising electrochemical properties for IT-SOFCs.
► La2−xSrxCoO4−δ cathode materials for solid oxide cells are studied.
► The oxygen stoichiometry at rom temperature is close to 4.
► Thermal expansion is greater than 20 × 10−6 K−1
► Pure electrode materials present a high Area Specific Resistance.
► Composite electrodes show a low ASR of 0.25 Ω.cm2 at 700 °C.
Journal: International Journal of Hydrogen Energy - Volume 38, Issue 7, 7 March 2013, Pages 3064–3072