Investigation of La_0.65Ca_0.35FeO_3−δ as a Co-Free Cathode for Protonic Ceramic Fuel Cells with Yb-Doped BaZrO₃ Electrolyte

Although cobalt-containing cathode materials are widely used in protonic ceramic fuel cells (PCFCs) because of its high catalytic activity, cobalt diffuses into the proton-conducting electrolyte, thereby decreasing the power generation performance. To achieve a higher power generation performance in PCFCs with a cobalt-free cathode, we fabricate anode-supported PCFCs using BaZr 0.8 Yb 0.2 O 3– δ as the electrolyte, and composite cathodes of La 0.65 Ca 0.35 FeO 3− δ (LCaF) and BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3− δ (BZCYYb). The mixing weight ratios of LCaF and BZCYYb are varied to 80:20, 70:30, 60:40, 50:50, and 30:70. The PCFC with LCaF–BZCYYb (60:40) composite cathode exhibits the highest power generation performance in the operating temperature range of 500–700 °C with a maximum power density (MPD) of 0.41 W cm −2 at the operating temperature of 600 °C. This MPD value is higher than that obtained in our previous study using a PCFC with a La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3− δ –BZCYYb composite cathode.