Synthesis and Characterization of Cu- and Co-Doped Bi4V2O11 for Intermediate-Temperature Solid Oxide Fuel Cell Electrolytes by Carbonate Coprecipitation

Bi2MexV1xO5:53x=2 (Me = Cu; 0 x 0:2) powders were prepared by the ammonium carbonate coprecipitation method. The starting salts were bismuth nitrate, copper nitrate, cobalt nitrate, and vanadium sulphate. The thermal decomposition of Bi2MexV1xO5:53x=2 precursors was completed at about 500 C. The crystallite structure, surface morphology, and ionic conductivity of the prepared powders and pellets were examined using X-ray diffractometry, field emission scanning electron microscopy, and an impedance analyzer, respectively. The average particle sizes of the Bi2Cu0:1V0:9O5:35 and Bi2Co0:1V0:9O5:35 powders were 10–50nm. The tetragonal structure (� -phase) appeared at sintering temperatures higher than 700 C and the peak intensity increased at higher sintering temperatures. The ionic conductivities of the Bi2Cu0:1V0:9O5:35 and Bi2Co0:1V0:9O5:35 pellets sintered at 800 C showed the highest values of 6:8 10 2 Scm 1 at 700 C and 9:1 10 2 Scm 1 at 700 C, respectively. The optimum concentration of the Cu and Co dopants in Bi2MexV1xO5:53x=2 was determined to be 0.1. The results of this study demonstrated that the ammonium carbonate coprecipitation process could be used as an economical method for the preparation of Bi2MexV1xO5:53x=2 electrolytes for intermediate-temperature solid oxide fuel cells. # 2011 The Japan Society of Applied Physics