Ionic Conductivity in Laco1-XMgX03-δ: A Potential Cathode Material for Solid Oxide Fuel Cells

1995 ◽  
Vol 393 ◽  
Author(s):  
Anbin Yu ◽  
Sossina M. Haile
Keyword(s):  
Fuel Cells ◽  
Ionic Conductivity ◽  
Oxygen Vacancy ◽  
Solid Oxide Fuel Cells ◽  
Cathode Material ◽  
Triple Point ◽  
Vacancy Concentration ◽  
Solid Oxide ◽  
Oxygen Vacancy Concentration ◽  
Oxide Fuel

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.

High Throughput Screening of Materials for Solid Oxide Fuel Cells

2003 ◽  
Vol 804 ◽  
Author(s):  
John P. Lemmon ◽  
Venkatesan Manivannan ◽  
Tracey Jordan ◽  
Lamyaa Hassib ◽  
Oltea Siclovan ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Cathode Material ◽  
High Throughput ◽  
High Throughput Screening ◽  
Vacancy Concentration ◽  
Performance Testing ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
A Site

ABSTRACTState of the art commercial cathodes for solid oxide fuel cells (SOFC) include LaMnO3 with a zirconia-based electrolyte. However, the vacancy concentration in A site doped LaMnO3 is low, thus ionic conductivity is also very low (10−7 – 10−8 S/cm at 800 °C). The surface path dominates the reaction rate of the LaMnO3 cathode; therefore the optimized electrode is a porous composite material of both the cathode material and electrolyte and relies on triple-point boundaries for performance. The electrical conductivity and thermal expansion properties of this cathode material and other A3+B3+O3 perovskites can be tuned by substitution at the A and/or B site. The numerous combinations of composition, processing and microstructure needed for improved cathode performance is well suited for a high throughput screening (HTS) approach towards optimization and discovery. We present here a high throughput discovery process that includes, synthesis, performance testing and characterization techniques directed towards new low temperature SOFC cathode materials.

Oxygen vacancy-engineered cobalt-free Ruddlesden-Popper cathode with excellent CO2 tolerance for solid oxide fuel cells

2021 ◽  
Vol 497 ◽  
pp. 229872
Author(s):  
Daoming Huan ◽  
Lu Zhang ◽  
Kang Zhu ◽  
Xinyu Li ◽  
Nai Shi ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Oxygen Vacancy ◽  
Solid Oxide Fuel Cells ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Co2 Tolerance

scholarly journals A Bulk-Heterostructure Nanocomposite Electrolyte of Ce0.8Sm0.2O2-δ–SrTiO3 for Low-Temperature Solid Oxide Fuel Cells

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Yixiao Cai ◽  
Yang Chen ◽  
Muhammad Akbar ◽  
Bin Jin ◽  
Zhengwen Tu ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Ionic Conductivity ◽  
Low Temperature ◽  
Solid Oxide Fuel Cells ◽  
Short Circuit ◽  
Solid Oxide ◽  
Superior Performance ◽  
Electrode Polarization ◽  
Oxide Fuel ◽  
Ac Impedance Analysis

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.

Electrode properties of CuBi2O4 spinel oxide as a new and potential cathode material for solid oxide fuel cells

2021 ◽  
Vol 511 ◽  
pp. 230447
Author(s):  
Na Li ◽  
Liping Sun ◽  
Qiang Li ◽  
Tian Xia ◽  
Lihua Huo ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Cathode Material ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Spinel Oxide

(Bi0.15La0.27Sr0.53)(Co0.25Fe0.75)O3-δ perovskite: A novel cathode material for intermediate temperature solid oxide fuel cells

2016 ◽  
Vol 334 ◽  
pp. 137-145 ◽  
Author(s):  
Deni S. Khaerudini ◽  
Guoqing Guan ◽  
Peng Zhang ◽  
Pairuzha Xiaoketi ◽  
Xiaogang Hao ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Cathode Material ◽  
Solid Oxide ◽  
Intermediate Temperature ◽  
Oxide Fuel

scholarly journals Remarkable Ionic Conductivity in a LZO-SDC Composite for Low-Temperature Solid Oxide Fuel Cells

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2277
Author(s):  
Zhengwen Tu ◽  
Yuanyuan Tian ◽  
Mingyang Liu ◽  
Bin Jin ◽  
Muhammad Akbar ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Ionic Conductivity ◽  
Low Temperature ◽  
Solid Oxide Fuel Cells ◽  
Ionic Conduction ◽  
Open Circuit ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Open Circuit Voltages ◽  
Composite Samples

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.

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