La0.4Sr0.6Co0.2Fe0.7Nb0.1O3-δ电极应用于YSZ基对称SOFC性能研究

La0.4Sr0.6Co0.2Fe0.7Nb0.1O3-δ Electrodes for YSZ-based Symmetrical SOFC

摘要:

采用固相法合成了钙钛矿型氧化物La0.4Sr0.6Co0.2Fe0.7Nb0.1O3-δ(LSCFN)，并采用流延-丝印法制备了以8mol%Y2O3稳定ZrO2(YSZ）为电解质、Gd0.1Ce0.9O2-δ(GDC)为隔离层、LSCFN同时做阴极和阳极的对称固体氧化物燃料电池。利用X射线衍射对电极材料进行了物相及化学相容性分析，用扫描电镜表征了对称电池的微观形貌。分别以湿H2(3％H2O)和湿CH4(3％H2O)为燃料气，空气为氧化气测试了单电池的电化学性能，并在850℃湿CH4下进行了电池的稳定性测试。结果表明：LSCFN与GDC具有良好的化学相容性。以湿H2和湿CH4为燃料气的单电池在850℃时最大功率密度分别为254 mW cm-2，105 mW cm-2。在100 h的CH4稳定性测试中性能无明显衰减，具有良好的稳定性。因此LSCFN是很有前景的可应用于YSZ电解质的对称电极材料。

Abstract:

La0.4Sr0.6Co0.2Fe0.7Nb0.1O3-δ(LSCFN)，a perovskite oxide materials, have been synthesized by the solid state reaction method .The electrolyte-supported symmetrical solid oxide fuel cells were fabricated by tape-casting and screen-printing procedure using YSZ as electrolyte, GDC as interlayer and LSCFN as both anode and cathode. The crystal structure and chemical stability were examined by X-ray diffraction (XRD) and microstructure was inspected by scanning electron microscopy (SEM). The electrical properties of single cell were tested by using humidified 3% H2 and CH4 as fuel respectively, ambient air as oxidant and tested the stability in humidified 3% CH4 at 850℃.The results show that LSCFN appeared to be chemically compatible with GDC to at least 1400℃. The maximum power density was 254 mW cm-2 and 105 mW cm-2 in humidified H2 and CH4 at 850℃, respectively. Stable performance was sustained for at least for 100 h operating in humidified CH4. These results suggest that the LSCFN can potentially serve as an electrode for symmetrical SOFCs with YSZ electrolyte.