Preparation and characterization of Sm and Ca co-doped ceria-La0.6Sr0.4Co0.2Fe0.8O3-δ semiconductor-ionic composites for electrolyte-layer-free fuel cells
Preparation and characterization of Sm and Ca co-doped ceria-La0.6Sr0.4Co0.2Fe0.8O3-δ semiconductor-ionic composites for electrolyte-layer-free fuel cells
复制标题
无电解质层燃料电池Sm、Ca共掺杂二氧化铈-La0.6Sr0.4Co0.2Fe0.8O3-δ半导体-离子复合材料的制备及表征
DOI：
10.1039/c6ta05763b
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发表时间：
2016-01-01
影响因子：
11.9
通讯作者：
Zhu, Bin
中科院分区：
文献类型：
--
作者：
Wang, Baoyuan;Wang, Yi;Zhu, Bin
采用共沉淀法合成了一系列Sm和Ca共掺杂的氧化铈Ca0.04Ce0.96-xSmxO 2-delta（x = 0，0.09，0.16和0.24）（SCDC）。对材料的形貌、组成、晶体结构和电化学性能进行了表征。结果表明，Sm和Ca共掺杂比单一Ca掺杂样品的离子电导率有所提高。在600 ℃时，Ca0.04Ce0.80Sm0.16O2-δ的离子电导率最高，为0.039 S cm（-1），其最佳离子电导率可以通过氧空位的耦合效应和掺杂离子半径与临界半径的失配来解释。半导体La0.6Sr0.4Co0.2Fe0.8O3-δ（LSCF）与SCDC复合后，其离子电导率显著提高，600 ℃时LSCF-SCDC复合材料的离子电导率高达0.188 S cm（-1），是纯SCDC的4倍。使用透射电子显微镜和光谱方法，我们检测到在LSCF-SCDC界面区域的氧富集和LSCF-SCDC和LSCF-LSCF晶界中的氧空位的耗尽被显着减轻，这导致了掺杂离子LSCF-SCDC复合材料的离子电导率的增强。由LSCF-SCDC超导体-离子膜制造的无电解质层燃料电池（EFFC）表现出优异的性能，例如，使用LSCF-Ca 0. 04 Ce 0. 80 Sm 0. 16 O2-delta（SCDC 2）在550 ℃下的814 mW cm（-2）。
A series of Sm and Ca co-doped ceria, i.e. Ca0.04Ce0.96-xSmxO2-delta (x = 0, 0.09, 0.16, and 0.24) (SCDC), were synthesized by a co-precipitation method. Detailed morphology, composition, crystal structure and electrochemical properties of the prepared materials were characterized. The results revealed that Sm and Ca co-doping could enhance the ionic conductivity in comparison with that of single Ca-doped samples. The composition as Ca0.04Ce0.80Sm0.16O2-delta exhibited a highest ionic conductivity of 0.039 S cm(-1) at 600 degrees C in comparison with the rest of the series, and the optimal ionic conductivity can be interpreted by the coupling effect of oxygen vacancies and mismatch between the dopant ionic radius and critical radius. Composite formation between the semiconductor La0.6Sr0.4Co0.2Fe0.8O3-delta (LSCF) and the as-prepared SCDC contributed to a remarkable improvement in the ionic conductivity, an unexpectedly high ionic conductivity of 0.188 S cm(-1) was obtained for LSCF-SCDC composites at 600 degrees C, which was four times higher than that of pure SCDC. Using transmission electron microscopy and spectroscopy approaches, we detected an enrichment of oxygen in the LSCF-SCDC interface region and a depletion of oxygen vacancies in LSCF-SCDC and LSCF-LSCF grain boundaries was significantly mitigated, which resulted in the enhancement of ionic conductivity of semiconductor-ionic LSCF-SCDC composites. The electrolyte-layer-free fuel cell (EFFC) fabricated from the LSCF-SCDC semiconductor-ionic membrane demonstrated excellent performances, e.g. 814 mW cm(-2) at 550 degrees C for using the LSCF-Ca0.04Ce0.80Sm0.16O2-delta (SCDC2).