Single chamber solid oxide fuel cells with integrated current-collectors

Abstract

Single chamber solid oxide fuel cells (SC-SOFCs) based on the system Sm 0.5Sr 0.5CoO 3− δ /Ce 0.9Gd 0.1O 1.95/Ni–Ce 0.8Gd 0.2O 1.90 were investigated. Pt-meshes that were embedded in both electrodes were used as current collectors in order to achieve low overpotentials. The cells generated 271 mW/cm 2 at 500 °C and 468 mW/cm 2 at 600 °C on a gas mixture of methane and air (CH 4/O 2 = 1.6) with a total flow of 1500 ml/min. The air flow was varied (260, 780, 1120, and 1340 ml/min) while the flow of methane was kept at 380 ml/min. It was found that the open circuit voltage (OCV) and the maximum power density ( P max) were strongly dependent on the airflow and the operating temperature. The influences of Palladium-addition to the anode as well as Co-doping of the electrolyte on the OCV and P max have been studied and compared to an unmodified cell. Pd-containing anodes allow for higher power outputs at low airflow. The presence of Co in the electrolyte raises the OCV but decreases the maximum power density.