Bismuth and niobium co-doped barium cobalt oxide as a promising cathode material for intermediate temperature solid oxide fuel cells

作者：He Shaofei; Le Shiru^*; Guan Lili; Liu Tao; Sun Kening

来源：Journal of Power Sources, 2015, 295: 33-40.

DOI：10.1016/j.jpowsour.2015.06.134

• Solid oxide fuel cell
• Cathode
• Cubic perovskite structure
• Intermediate temperature
• Electrochemical performance

Perovskite oxides BaBi0.05Co0.95-yNbyO3-delta (BBCNy, 0 <= y <= 0.2) are synthesized and evaluated as potential cathode materials for intermediate temperature solid oxide fuel cells (IT-SOFCs). Highly charged Nb5+ successfully stabilizes the cubic perovskite structure to room temperature with Nb substituting content y > 0.1. The phase structure, thermal expansion behavior, electrical conductivity and electrochemical performance of BBCNy with cubic phase are systematically studied. The samples exhibit excellent chemical compatibility with GDC and have sufficiently high electrical conductivities. However, the thermal expansion coefficients of BBCNy samples are nearly twice those of the most commonly used electrolyte materials YSZ and GDC, which is a major drawback for application in IT-SOFCs. The polarization resistances of BBCNy with y = 0.10, 0.15 and 0.20 on GDC electrolyte are 0.086, 0.079 and 0.107 Omega cm(2) at 700 degrees C, respectively. Even though the YSZ electrolyte membrane and GDC barrier layer are approximately 50 gm and 10 gm in thickness, the highest maximum power density (1.23W cm(-2)) of the single cell Ni-YSZIYSZIGDCIBBCNom is obtained at 750 degrees C. Good long-term stability of the single cell with BBCN0.15 cathode is also demonstrated. These results demonstrate that BBCNy perovskite oxides with cubic structure are very promising cathode materials for IT-SOFCs.

• 出版日期2015-11-1
• 单位哈尔滨工业大学