Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (05): 953-958.doi: 10.3866/PKU.WHXB201302254

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

Dense 5%Al3+-Doped SnP2O7-SnO2 Composite Ceramic for Application in Intermediate Temperature Fuel Cell

DENG Xu-Li, ZHAO Dong-Mei, DING Zuo-Long, MA Gui-Lin   

  1. Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China
  • Received:2012-12-20 Revised:2013-02-25 Published:2013-04-24
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20771079) and Priority Academic Program Development of Jiangsu Higher Education Institutions, China.

Abstract:

Dense non-doped and 5% (molar fraction) Al3+-doped SnP2O7-SnO2 composite ceramics were prepared by reacting non-doped and 5% Al3+-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% Al3+-doped SnP2O7-SnO2 composite ceramic were higher than the conductivities of the non-doped SnP2O7-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% Al3+-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 mW·cm-2 at 200℃ and 82.3 mW·cm-2 at 250℃. Such good performance is related to the high conductivity and sufficient density of the composite ceramic electrolyte as well as the low interfacial polarization resistance of the cell.

Key words: SnP2O7, Composite ceramic, Electrolyte, Conductivity, Fuel cell

MSC2000: 

  • O646