Compositing protonic conductor BaZr0.5Y0.5O3 (BZY) with triple conductor BaCo0.4Fe0.4Zr0.1Y0.1O3-δ (BCFZY) as electrolyte for advanced solid oxide fuel cell

Abstract BaZr0.5Y0.5O3(BZY) electrolyte exhibited enormous potential for low temperature solid oxide fuel cell (SOFC) due to its proton dominant mobile carriers rather than oxygen ions during the electrochemical process. In order to enhance the ionic conductivity, triple conductor BaCo0.4Fe0.4Zr0.1Y0.1O3-δ (BCFZY) was composited with proton conductor BZY to form semiconductor-ionic conductor composite (SIM), which was applied as electrolyte to fabricate symmetrical fuel cell. The microstructural and electrochemical properties for BZY, BCFZY and BZY-BCFZY composites were studied. After optimizing the weight ratio of composite content, the ionic conductivity and electronic conductivity reached an equilibrium state to obtain the maximum cell performance, namely the highest output of 902.5 mW cm−2 and an open circuit voltage (OCV) of 1.043 V at 550 °C. The BZY-BCFZY cell also presented decent power output at low temperature, a power density of 265.625 mW cm−2 was received even at 500 °C, demonstrating that the BZY-BCFZY composite was a potential electrolyte for low temperature SOFCs.