致密的5%Al^3＋掺杂的SnP_2O_7-SnO_2复合陶瓷在中温燃料电池中的应用(英文)

Dense 5% Al^(3+) -Doped SnP_2O_7-SnO_2 Composite Ceramic for Application in Intermediate Temperature Fuel Cell

首先制备了未掺杂和5%(摩尔分数)Al3+掺杂SnO2的多孔性基片,然后将基片与85%的H3PO4在600°C下反应,分别得到了致密的未掺杂和5%Al3+掺杂的SnP2O7-SnO2复合陶瓷样品.采用X射线衍射(XRD),扫描电子显微镜(SEM)和X射线能量色散谱(EDS)测试方法对样品进行了表征,采用电化学阻抗谱法(EIS)测试了样品在中温(100-250°C)下,湿润空气和湿润氢气气氛中的电导率.结果表明,在湿润空气和湿润氢气中,5%Al3+掺杂的SnP2O7-SnO2复合陶瓷样品的电导率均高于未掺杂的SnP2O7-SnO2复合陶瓷样品的电导率,且该复合陶瓷样品在湿润空气和湿润氢气中250°C下,电导率分别达到最大值:4.30×10-2和6.25×10-2S·cm-1,高于至今报道的SnP2O7-SnO2基复合陶瓷及SnP2O7基陶瓷在类似条件下的电导率.以5%Al3+掺杂的SnP2O7-SnO2复合陶瓷样品(厚度:1.45mm)为电解质,多孔性铂为电极组装成的氢气/空气燃料电池具有良好的中温电池性能,175、200、250°C的最大输出功率密度分别为52.0、61.9、82.3mW·cm-2.良好的中温电池性能与该复合陶瓷电解质较高的电导率和致密度及该燃料电池较低的界面极化电阻有关.

Dense non-doped and 5% （molar fraction） Al^3＋-doped SnP2OT-SnO2 composite ceramics were prepared by reacting non-doped and 5% AI3＋-doped SnO2 porous substrates, respectively, with 85% H3PO4 solution at 600 ℃. The composite ceramics were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and energy-dispersive spectroscopy （EDS）. Their conductivities in the intermediate temperature range of 100-250 ℃ in wet air and wet H2 atmospheres were measured by electrochemical impedance spectroscopy （EIS）. The conductivities of the 5% AI3＋-doped SnP2O7-SnO2 composite ceramic were higher than the conductivities of the non-doped SnP2OT-SnO2 composite ceramic and reached 4.30×10^-2 S.cm-1 in wet air and 6.25×10^-2 S.cm-1 in wet H2 at 250 ℃. These values are higher than those of the SnP2O7-SnO2 based composite ceramic and SnP2O7--based ceramics under similar conditions. An H2/air fuel cell containing the 5% AP＊-doped SnP2O7-SnO2 composite ceramic as an electrolyte （thickness： 1.45 mm） and porous platinum as electrodes exhibited satisfactory cell performance. The maximum output power densities of this cell were 52.0 mW. cm-2 at 175 ℃, 61.9 roW. cm-2 at 200 ℃ and 82.3 mW-cm-2 at 250 ℃. Such good performance is related to the high conductivity and sufficientdensity of the composite ceramic electrolyte as well as the low interracial polarization resistance of the cell.