Performance evaluation of Ca2.9−xBi0.1PrxCo4O9−δ cathode for anode-supported intermediate temperature solid oxide fuel cells

Abstract

The Ca2.9−xBi0.1PrxCo4O9−δ (CBPxC, x = 0–0.6) oxides were prepared by sol–gel method, as the potential cathode of anode-supported intermediate temperature solid oxide fuel cells (IT-SOFCs). The electrochemical performance test showed that the CBPxC oxide sintered at 700 °C for 10 h could form a single-phase crystal structure, and when the doping ratio of Pr ion was x = 0.4, the CBPxC cathode on the SDC electrolyte sintered at 950 °C for 5 h obtained the minimum interface polarization resistance (about 0.406 Ω·cm2 at 800 °C). Meanwhile, on the basis of the above conditions, we had fabricated Ni0.95Cu0.05Ox-SDC/SDC/CBP0.4C single cell with the optimized CBPxC (x = 0.4) cathode, in which the SDC electrolyte thickness was 55.6 μm. The maximum power densities of the single cell reached 0.705 W/cm2 and 0.570 W/cm2 at 800 °C and 750 °C, the corresponding polarization resistances were 0.051 Ω·cm2 and 0.153 Ω·cm2, respectively. This suggested that CBP0.4C was a very promising cathode material for IT-SOFCs.