Ce0.8Sm0.2O1.9 decorated with electron-blocking acceptor-doped BaCeO3 as electrolyte for low-temperature solid oxide fuel cells. (20th February 2017)

• Record Type: Journal Article
• Authors: Gong, Zheng; Sun, Wenping; Cao, Jiafeng; Shan, Duo; Wu, Yusen; Liu, Wei
• Is Part Of: Electrochimica acta. Volume 228(2017)
• Page Start: 226
• Page End: 232
• Publication Date: 2017-02-20
• Subjects: Composite electrolyte -- Solid oxide fuel cells -- In-situ reaction -- Open circuit voltage -- Mixed ion conductor; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2017.01.065
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlights: BCS-SDC composite electrolytes were synthesized by in-situ solid-state reaction. The SDC nanoparticles are partly coated by a thin layer of BaCe1-x Smx O3-δ . The effect of BCS content in composites on cell performances was investigated. Introduction a small amount of BCS into SDC is beneficial to cell performances. Abstract: A series of composites with nominal compositions of BaCe0.8 Sm0.2 O3-δ (BCS)-Ce0.8 Sm0.2 O1.9 (SDC) (20:80, 35:65, 50:50, 65:35 wt.%) are synthesized by a modified citric acid-nitrate sol-gel combustion method and evaluated as the electrolytes for low-temperature solid oxide fuel cells (SOFCs). The TEM results show that doped BaCeO3 decorated SDC particles are formed after calcining at 1000 °C for 3 h. X-ray diffraction results reveal that the composites are only composed of BaCeO3 -based and SDC phases without any other impurity phases. Besides, BaCeO3 -based phase is uniformly distributed in the sintered electrolytes according to EDS element mapping. The open cell voltages (OCVs) of the single cells increase gradually with increasing the proportion of BaCeO3 -based phase, and are higher than those for bare SDC-based cells. Besides, the power performances of the cells are superior to SDC-based cells when BaCeO3 -based phase is lower than 35 wt.%. Electrochemical impedance spectroscopy analysis indicates that, in addition to blocking electronic current leakage, BaCeO3 -based phase would induce higher ohmic and polarization resistance, which is detrimental to power performance. Further specific effort should be focused on synthesizing uniform SDC@BCS core-shell electrolyte powders and minimizing the proportion of BCS phase towards high-performance SOFCs with high OCVs.