一步法合成La0.4Sr0.6Co0.2Fe0.7Nb0.1O3-δ-Gd0.2Ce0.8O2-δ对称电极应用于SOFC性能研究

Co-synthesis of La0.4Sr0.6Co0.2Fe0.7Nb0.1O3-δ-Gd0.2Ce0.8O2-δ symmetrical electrode for SOFC performance study

摘要:

一步法合成La0.4Sr0.6Co0.2Fe0.7Nb0.1O3-δ-Gd0.2Ce0.8O2-δ（LSCFN-CGO）混合电导对称电极，并采用La0.8Sr0.2Ga0.83Mg0.17O3-δ（LSGM）作为电解质制备了结构为LSCFN-CGO||LSGM||LSCFN-CGO的对称电池。分别使用X射线衍射仪（XRD）和扫描电子显微镜（SEM）对LSCFN-CGO粉体物相及电极微观结构进行分析。一步法制得的LSCFN-CGO电极粉体为纯相，LSCFN钙钛矿相与CGO萤石相具备极好的化学相容性，且烧结得到了良好微观结构的对称电极。采用H2（3% H2O），C3H8（3% H2O）为燃料气测试电池性能，850 ℃电池最大功率密度可分别达980 mW/cm2 和 869 mW/cm2。稳定性测试在C3H8（3% H2O）气氛中0.3 A/cm2的恒流放电条件下进行，全程共420 h，衰减较小，期间进行8次电极氧化还原循环，对称电极具有理想的碳基燃料下氧化还原再生能力。实验结果表明采用一步法合成混合电导电极是一种简便、优化的电极制备方法，具有广阔的应用前景。

Abstract:

In this paper, one step method was investigated to prepare La0.4Sr0.6Co0.2Fe0.7Nb0.1O3-δ-Gd0.2Ce0.8O2-δ (LSCFN-CGO) compound symmetrical electrode, La0.8Sr0.2Ga0.83Mg0.17O3-δ (LSGM) was used as electrolyte and symmetrical cells with a con?guration of LSCFN-CGO||LSGM||LSCFN-CGO were successfully fabricated. Phase-analysis and electrode microstructure of LSCFN-CGO were examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). LSCFN-CGO was identified to be pure phase and perovskite structured LSCFN chemically compatible with ?uorite structured CGO. Using H2 (3% H2O) and C3H8 (3% H2O) as fuel for the cell, the maximum power densities were 980 mW/cm2 and 869 mW/cm2 at 850 ℃. Moreover, the long-term stability of the cell is demonstrated to be stable for 420 h under constant current of 0.3 A/cm2 using C3H8 (3% H2O) as fuel, 8 redox cycles were carried out, and the symmetrical electrode had ideal redox regeneration ability under carbon-based fuel. Results show that, one step method is a facile and optimized electrode fabrication procedure and owns promising application prospects.