Synthesis of γ‐Bi 2 O 3 /YSZ composite powders using a facile precipitation method

Abstract

Low melting point and high ionic conductivity of γ-Bi2O3 make it a promising additive to decrease the sintering and operation temperatures of yttria stabilized zirconia (YSZ)-based electrolyte for solid oxide fuel cell application. Herein, γ-Bi2O3/YSZ composite powders with good uniformity and precise control of morphology and phase were successfully synthesized via a low cost chemical precipitation method. Both the concentration of NaOH solution and the reactant adding sequence affect the morphology and synthesis of γ-Bi2O3/YSZ composite powders. When the concentration of NaOH was in the range of 1.25–1.875 M, tetrahedron γ-Bi2O3/YSZ powders were synthesized. While, cubic structural γ-Bi2O3/YSZ powders were obtained when adding Bi3+ and YSZ suspension into 1.5 M NaOH solution. The addition of YSZ facilitates the fabrication of γ-Bi2O3 and widens its process window to a higher NaOH concentration. Thus synthesized γ-Bi2O3/YSZ composite powders effectively decrease the sintering temperature of YSZ to 1050°C due to the uniform distribution of γ-Bi2O3 inside YSZ powders. This work provides a facile method to fabricate γ-Bi2O3/YSZ composite powder with controlled morphology and phase, which will promote the mass production of low cost YSZ-based electrolyte for SOFC applications.