Co-precipitation process as an effective and viable route for proton-conducting solid oxide fuel cell applications.

BaCe 0.7 Zr 0.1 Y 0.1 Yb 0.1 O 3-δ (BCZYYb) is one of the most popular electrolyte materials in proton ceramic fuel cells (PCFCs). The synthesizing method and properties of BCZYYb powders have a significant impact on the sintering activity of electrolyte materials. In this work, the BCZYYb electrolyte was synthesized by ammonium bicarbonate co-precipitation method (CPT), and was compared with the powder produced by solid-state reaction (SSR) and sol-gel (SG) methods. XRD results show the BCZYYb powder synthesized by the CPT method belongs to orthorhombic crystal system with a space group of Pmcn (No. 62) and the refined lattice parameters are a = 8.774 Å, b = 6.173 Å, and c = 6.203 Å. In humid air atmosphere, the total conductivity at 650 °C and the activation energy for the BCZYYb powder prepared via the CPT method was 2.1 × 10−2 S cm−1 and 0.46 eV, respectively, as compared with 1.9 × 10−2 S cm−1 and 0.45 eV for the SSR method, and 1.8 × 10−2 S cm−1 and 0.44 eV for the SG method. Under similar testing conditions, the measured peak power densities were 0.51, 0.35, and 0.40 W cm−2 at 650 °C for the anode supported PCFCs using electrolyte powder prepared via CPT, SSR and SG methods, respectively, which proves the CPT method is an effective and viable route for PCFCs applications. • BCZYYb powders are successfully prepared by CPT, SG, and SSR methods. • The CPT method shows better conductivity and performance than the other methods under similar testing conditions. • A 600-h test showed the cell with electrolyte prepared by the CPT method has a good long-term stability. [ABSTRACT FROM AUTHOR]