Synthesis and thermal expansion property of (Ba0.5Sr0.5)0.9Bi0.1Co0.8Fe0.2O3−δ cathode materials for IT-SOFCs

Abstract

Perovskite cathode material, (Ba_0.5Sr_0.5)_0.9Bi_0.1Co_0.8Fe_0.2O_3−δ (BSBCF-0.1), was synthesized by a combined citrate–EDTA complexing method for intermediate temperature solid oxide fuel cells. Bi was successfully added to the perovskite structure. A small amount of Bi could enter into the A-site of the perovskite structure, and ionic Bi would enter the B-site of the BSCF structure when the concentration was larger than 0.1. Thermal expansion coefficient (TEC) of BSBCF-0.1 is lower than that of undoped BSCF in the working temperature range. The decreased TEC of BSBCF may be more suitable for the thermal compatibility of cell components. The maximum power density is 220 and 270 mW cm⁻² at 600 and 650 °C, respectively. The result suggested that the perovskite BSBCF material could be considered as the cathode for IT-SOFCs.