A highly conductive electrolyte for molten oxide fuel cells

2017 ◽  
Vol 53 (3) ◽  
pp. 565-568 ◽  
Author(s):  
V. V. Belousov ◽  
S. V. Fedorov

A gas-tight and ductile solid/liquid δ-Bi2O3–0.2 wt% B2O3 electrolyte with the highest oxygen ionic conductivity is developed for molten oxide fuel cells (MOFCs).

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.


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.


1995 ◽  
Vol 393 ◽  
Author(s):  
Anbin Yu ◽  
Sossina M. Haile

ABSTRACTA serious concern with present designs of solid oxide fuel cells is the requirement that “triple-point junctions” exist, sites at which the cathode, electrolyte and oxidizing gas are in simultaneous contact. Only at these junctions can the cathode catalyze the reduction of oxygen into 0= ions and initiate their subsequent transport through the electrolyte. Enhanced ionic conductivity in the cathode material may increase the surface area over which reduction can take place and relax the triple-point constraint. To this end, we have examined the electrical and structural properties of LaCo1-xMgx03-δ materials under various atmospheres. Oxygen ion transport in this and related ABO3 perovskites takes place via oxygen vacancy migration. We have opted to investigate the effect of Mg doping on the transition metal site in an effort to maintain a significant oxygen vacancy concentration in oxidizing atmospheres (as would be encountered during fuel cell operation) and to isolate the effects of A- and B-site doping.


Author(s):  
F. Tsai ◽  
J. M. Cowley ◽  
S. S. Jiang ◽  
J. B. Wagner

Calcia stabilized zirconia(CSZ) and ceria(CeO2) doped with rare-earth oxides have been used as electrolytes in solid oxide fuel cells(SOFC). Such ceramics are usually good ionic conductors for oxygen ions at elevated temperatures. A few studies have attempted to correlate the microstructures with ionic conductivity. It was suggested that the grain boundaries play a role in depressing the ionic conductivity. In their study, it was found that continuous “thick” boundary layers of secondary phases existed on the grain boundaries and blocked ion transport.In the present studies, high resolution transmission electron microscopy has been used to investigate the microstructures of grain boundaries in zirconia doped with calcia (ZrO2 + 13%CaO) and ceria ceramics doped with calcia (CeO2 + 10% CaO). The ceramics was made in our Solid State Ionics Laboratory. Transport number measurements on zirconia samples showed that the transport number tO2- =1 from PO2 = 10-17 atm to PO2 =1 atm.


2015 ◽  
Vol 49 ◽  
pp. 90-96 ◽  
Author(s):  
Chuangang Yao ◽  
Junling Meng ◽  
Xiaojuan Liu ◽  
Xiong Zhang ◽  
Xiliang Liu ◽  
...  

2013 ◽  
Vol 242 ◽  
pp. 455-463 ◽  
Author(s):  
Qing Su ◽  
Daeil Yoon ◽  
Aiping Chen ◽  
Fauzia Khatkhatay ◽  
Arumugam Manthiram ◽  
...  

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