LSGMC5含量对于二甲醚燃料电池复合Ni-Fe阳极性能的影响

Effects of the Concentration of LSGMC5 on the Performance of Ni-Fe Composite Anodes for Dimethyl Ether Fuel Cells

用浸渍法制备了掺杂不同质量分数的La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(0.15)Co_(0.05_O_(3-δ)(LSGMC5)粉末的Ni8-Fe2-LSGMC5复合阳极,并采用交流阻抗和直流极化技术考察了以氢气和二甲醚为燃气时该复合阳极的电化学性能及相应电池的功率输出特性.结果表明,在电极中掺入LSGMC5粉末,能显著地改善电极的形貌和电极/电解质界面结构,减小欧姆电阻和极化电阻.电极中LSGMC5粉末含量对于氢气及二甲醚电化学氧化性能的影响显著不同.以二甲醚为燃气时,电极极化电阻随LSGMC5粉末含量的增加而减小,其中LSGMC5掺杂量为30%的复合阳极具有最高的电化学性能,相应电池在1073、1023、973K时的输出功率分别为1.00、0.61、0.40W·cm^(-2);以氢气为燃气时,LSGMC5掺杂量为20%的复合阳极具有最好的电化学性能,随着LSGMC5掺杂量的进一步增加,电极极化电阻显著增大.

Ni8-Fe2-LSGMC5 composite anodes doped with various amounts of La0.8Sr0.2Ga0.8,g0.15Co0.05O3-δ （LSGMC5） were prepared by using the impregnation method. The electrochemical properties of the anodes and the power generation characteristics of corresponding cells were studied by alternating current （AC） impedance spectrometry and direct current （DC） polarization using hydrogen and dimethyl ether as fuels, respectively. The results showed that the introduction of LSGMC5 powders into the Ni-Fe anodes improved the structure of the anodes and the anode/ electrolyte interfaces significantly, which decreased the Ohmic resistance of the cell and the polarization resistance of the anodes. The LSGMC5 powders in the composite anodes showed different effects on the electro-catalytic oxidation of hydrogen and dimethyl ether （DME）. The polarization resistance of the anode decreased with increasing concentration of LSGMC5, and the anode containing 30% LSGMC5 powder showed the best electrochemical properties when using DME as a fuel. The maximum power densities of the cell in DME based on the anode containing 30% LSGMC5 powder reached 1.00, 0.61, and 0.40 W·cm ^2 at 1073, 1023, and 973 K, respectively. The anode doped with 20% LSGMC5 powder had the best electrochemical properties when using H2 as a fuel, with the further increase in the amount of LSGMC5 powder the polarization resistance increased quickly.