Nb and Pd co-doped La0.57Sr0.38Co0.19Fe0.665Nb0.095Pd0.05O3-δ as a stable, high performance electrode for barrier-layer-free Y2O3-ZrO2 electrolyte of solid oxide fuel cells
Nb and Pd co-doped La0.57Sr0.38Co0.19Fe0.665Nb0.095Pd0.05O3-δ as a stable, high performance electrode for barrier-layer-free Y2O3-ZrO2 electrolyte of solid oxide fuel cells
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Nb和Pd共掺杂La0.57Sr0.38Co0.19Fe0.665Nb0.095Pd0.05O3-delta作为固体氧化物燃料电池无阻挡层Y2O3-ZrO2电解质的稳定、高性能电极
DOI：
10.1016/j.jpowsour.2017.12.066
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发表时间：
2018-02-28
影响因子：
9.2
通讯作者：
Jiang, San Ping
中科院分区：
文献类型：
--
作者：
Chen, Kongfa;He, Shuai;Jiang, San Ping
La0.6Sr0.2Co0.2Fe0.8O3-δ（LSCF）是中温固体氧化物燃料电池（IT-SOFC）中研究最多的高性能阴极，但锶在电极/电解质界面的偏析和迁移是限制LSCF阴极电催化活性和稳定性的关键问题。在此，我们报告了Nb和Pd共掺杂的LSCF（La0.57Sr0.38Co0.19Fe0.665Nb0.095Pd0.05O3-delta，LSCFNPd）钙钛矿作为稳定和活性阴极在无阻挡层的阳极支撑的氧化钇稳定的氧化锆（YSZ）电解质电池上使用直接组装方法而无需在高温下预烧结。该电池在750 ℃下的峰值功率密度为1.3 W cm-2，在500 mA cm-2和750 ℃下极化175 h时稳定性良好，无退化。微观和光谱分析表明，电化学极化促进了Pd/PdO纳米粒子在操作过程中电极/电解质界面的形成和出溶。在LSCF的B-位中的Nb掺杂显著减少了Sr表面偏析，增强了阴极的稳定性，而脱溶的PdJPdO纳米颗粒增加了氧还原反应的电催化活性。本研究为开发具有高活性和高稳定性的钴酸盐基钙钛矿阴极开辟了一条新的途径。
La0.6Sr0.2Co0.2Fe0.8O3-delta (LSCF) is the most intensively investigated high performance cathode for intermediate temperature solid oxide fuel cells (IT-SOFCs), but strontium segregation and migration at the electrode/electrolyte interface is a critical issue limiting the electrocatalytic activity and stability of LSCF based cathodes. Herein, we report a Nb and Pd co-doped LSCF (La0.57Sr0.38Co0.19Fe0.665Nb0.095Pd0.05O3-delta, LSCFNPd) perovskite as stable and active cathode on a barrier-layer-free anode-supported yttria-stabilized zirconia (YSZ) electrolyte cell using direct assembly method without pre-sintering at high temperatures. The cell exhibits a peak power density of 1.3 W cm(-2) at 750 degrees C and excellent stability with no degradation during polarization at 500 mA cm-2 and 750 degrees C for 175 h. Microscopic and spectroscopic analysis show that the electrochemical polarization promotes the formation of electrode/electrolyte interface in operando and exsolution of Pd/PdO nanoparticles. The Nb doping in the B-site of LSCF significantly reduces the Sr surface segregation, enhancing the stability of the cathode, while the exsoluted PdJPdO nanoparticles increases the electrocatalytic activity for the oxygen reduction reaction. The present study opens up a new route for the development of cobaltite-based perovskite cathodes with high activity and stability for barrier-layer-free YSZ electrolyte based IT-SOFCs.