Mechanical Properties of Scandia Stabilised Zirconia with Alumina Addition

2008 ◽  
Vol 385-387 ◽  
pp. 441-444
Author(s):  
Wakako Araki ◽  
Hiroyuki Norigoe ◽  
Tadaharu Adachi

Zirconium oxide doped with scandium oxide is one of the most promising materials for electrolytes of solid oxide fuel cells because of its high ionic conductivity. In this study, temperature dependence of mechanical property, especially strength, of 9 mol% scandia doped zirconia polycrystalline samples with 0 to 30 wt% of alumina additions was examined at temperatures from 293 to 1273 K. Ionic conductivity was also measured by AC impedance analysis. From both mechanical and electrical standpoints, the experimental results were discussed in terms of alumina addition.

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Yixiao Cai ◽  
Yang Chen ◽  
Muhammad Akbar ◽  
Bin Jin ◽  
Zhengwen Tu ◽  
...  

AbstractSince colossal ionic conductivity was detected in the planar heterostructures consisting of fluorite and perovskite, heterostructures have drawn great research interest as potential electrolytes for solid oxide fuel cells (SOFCs). However, so far, the practical uses of such promising material have failed to materialize in SOFCs due to the short circuit risk caused by SrTiO3. In this study, a series of fluorite/perovskite heterostructures made of Sm-doped CeO2 and SrTiO3 (SDC–STO) are developed in a new bulk-heterostructure form and evaluated as electrolytes. The prepared cells exhibit a peak power density of 892 mW cm−2 along with open circuit voltage of 1.1 V at 550 °C for the optimal composition of 4SDC–6STO. Further electrical studies reveal a high ionic conductivity of 0.05–0.14 S cm−1 at 450–550 °C, which shows remarkable enhancement compared to that of simplex SDC. Via AC impedance analysis, it has been shown that the small grain-boundary and electrode polarization resistances play the major roles in resulting in the superior performance. Furthermore, a Schottky junction effect is proposed by considering the work functions and electronic affinities to interpret the avoidance of short circuit in the SDC–STO cell. Our findings thus indicate a new insight to design electrolytes for low-temperature SOFCs.


2010 ◽  
Vol 58 (7) ◽  
pp. 2504-2509 ◽  
Author(s):  
M. Morales ◽  
J.J. Roa ◽  
X.G. Capdevila ◽  
M. Segarra ◽  
S. Piñol

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2277
Author(s):  
Zhengwen Tu ◽  
Yuanyuan Tian ◽  
Mingyang Liu ◽  
Bin Jin ◽  
Muhammad Akbar ◽  
...  

Recently, appreciable ionic conduction has been frequently observed in multifunctional semiconductors, pointing out an unconventional way to develop electrolytes for solid oxide fuel cells (SOFCs). Among them, ZnO and Li-doped ZnO (LZO) have shown great potential. In this study, to further improve the electrolyte capability of LZO, a typical ionic conductor Sm0.2Ce0.8O1.9 (SDC) is introduced to form semiconductor-ionic composites with LZO. The designed LZO-SDC composites with various mass ratios are successfully demonstrated in SOFCs at low operating temperatures, exhibiting a peak power density of 713 mW cm−2 and high open circuit voltages (OCVs) of 1.04 V at 550 °C by the best-performing sample 5LZO-5SDC, which is superior to that of simplex LZO electrolyte SOFC. Our electrochemical and electrical analysis reveals that the composite samples have attained enhanced ionic conduction as compared to pure LZO and SDC, reaching a remarkable ionic conductivity of 0.16 S cm−1 at 550 °C, and shows hybrid H+/O2− conducting capability with predominant H+ conduction. Further investigation in terms of interface inspection manifests that oxygen vacancies are enriched at the hetero-interface between LZO and SDC, which gives rise to the high ionic conductivity of 5LZO-5SDC. Our study thus suggests the tremendous potentials of semiconductor ionic materials and indicates an effective way to develop fast ionic transport in electrolytes for low-temperature SOFCs.


2004 ◽  
Vol 2 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Ke An ◽  
Kenneth L. Reifsnider

Solid oxide fuel cells (SOFCs) are expected to be a future power source. Simulation analyses of SOFCs can help to understand well the interactive functions among the multiphysics phenomena in the SOFC system. A three-dimensional multiphysics finite-element model was used to simulate the performance of a half-cell SOFC with (Pr0.7Sr0.3)MnO3±δ∕8mol% yttria-stabilized zirconia (8YSZ) composite cathode on one side of the 8YSZ electrolyte before and after aging. Multiphysics phenomena in the SOFC were considered in the modeling. The current/voltage curves simulated matched the experimental data before and after aging. The average current density was found to have a linear relationship to the logarithm of the effective exchange current density. The effect of the effective ionic conductivity of the composite cathode was more apparent for small total effective ionic conductivity values than for large ones.


Author(s):  
A. Walter ◽  
R. Xu ◽  
G. Jursich ◽  
C.G. Takoudis

Thin films of yttria-stabilized zirconium oxide (YSZ) were successfully deposited using atomic layer deposition (ALD) for use in solid oxide fuel cells (SOFCs). YSZ was deposited on p-Si(100) by ALD using Tris(isopropyl-cyclopentadienyl)yttrium [(iPrCp)3Y] and tris(dimethylamino)cyclopentadienylzirconim [ZyALD] as metal precursors and ozone as oxidant. The normalized ALD cycle ratio of yttria cycles / total cycles used in making these films was varied to investigate the tunability of this process. Spectral ellipsometry was used to measure the thickness of the films. X-ray photoelectron spectroscopy (XPS) analyses were used to evaluate the composition and binding environments of as-deposited YSZ films. The normalized cycle ratio and the yttrium atomic percentage (Y atoms / metal atoms) have a linear relationship with a strong correlation, implying excellent tunability for this process. The binding environment analyses determine the oxidation state of the metals and show that decreasing the cycle ratio decreases the extent of yttrium hydroxidation.


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