Department of Physics, Harbin Institute of Technology, 92 Xi Dazhi Street, Harbin, Heilongjiang, 150001, P.R. China.
Shenzhen Key Laboratory of New Lithium-ion Batteries and Mesoporous Materials, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong, China.
ChemSusChem. 2018 Jan 10;11(1):254-263. doi: 10.1002/cssc.201701638. Epub 2017 Nov 29.
The Nb-doped lanthanum strontium ferrite perovskite oxide La Sr Fe Nb O (LSFNb) is evaluated as an anode material in a solid oxide fuel cell (SOFC). The effects of Nb partial substitution in the crystal structure, the electrical conductivity, and the valence of Fe ions are studied. LSFNb exhibits good structural stability in a severe reducing atmosphere at 800 °C, suggesting that high-valent Nb can effectively promote the stability of the lattice structure. The concentration of Fe increases after Nb doping, as confirmed by X-ray photoelectron spectroscopy. The maximum power density of a thick Sc-stabilized zirconia (ScSZ) electrolyte-supported single cell reached 241.6 mW cm at 800 °C with H as fuel. The cell exhibited excellent stability for 100 h continuous operation without detectable degeneration. Scanning electron microscopy clearly revealed exsolution on the LSFNb surface after operation. Meanwhile, LSFNb particles agglomerated significantly during long-term stability testing. Impedance spectra suggested that both the LSFNb anode and the (La Sr ) MnO /ScSZ cathode underwent an activation process during long-term testing, through which the charge transfer ability increased significantly. Meanwhile, low-frequency resistance (R ) mainly attributed to the anode (80 %) significantly increased, probably due to the agglomeration of LSFNb particles. The LSFNb anode exhibits excellent anti-sulfuring poisoning ability and redox stability. These results demonstrate that LSFNb is a promising anode material for SOFCs.
掺铌镧锶铁氧体钙钛矿氧化物 LaSrFeNbO（LSFNb）被评估为固体氧化物燃料电池（SOFC）中的阳极材料。研究了 Nb 在晶体结构、电导率和 Fe 离子价态中的部分取代的影响。LSFNb 在 800°C 的恶劣还原气氛中表现出良好的结构稳定性，表明高价 Nb 可以有效地促进晶格结构的稳定性。X 射线光电子能谱证实，Nb 掺杂后 Fe 的浓度增加。以 H 2 为燃料时，在 800°C 下，具有厚 Sc 稳定氧化锆（ScSZ）电解质支撑的单电池的最大功率密度达到 241.6 mW cm -2 。该电池在 100 h 的连续运行中表现出优异的稳定性，没有可检测到的退化。扫描电子显微镜清楚地揭示了操作后 LSFNb 表面的出溶。同时，LSFNb 颗粒在长期稳定性测试中明显聚集。阻抗谱表明，LSFNb 阳极和（LaSr）MnO/ScSZ 阴极在长期测试中都经历了一个活化过程，通过该过程，电荷转移能力显著提高。同时，低频电阻（R）主要归因于阳极（80%）显著增加，可能是由于 LSFNb 颗粒的聚集。LSFNb 阳极具有优异的抗硫化中毒能力和氧化还原稳定性。这些结果表明 LSFNb 是 SOFC 的一种有前途的阳极材料。
