Anode-supported thin-film fuel cells operated in a single chamber configuration 2T-I-12

The performance characteristics of anode-supported, thin-film, single chamber fuel cells (SCFCs) have been investigated. Cells, in which Ni+Sm _0.15Ce_0.85O₂ (Samaria doped ceria, SDC) served as the anode and SDC as the electrolyte, were fabricated by dry pressing. High quality, bilayer structures with electrolyte thicknesses as small as 10 μm were prepared with excellent reproducibility. The cathode, 70 wt.% Sm _0.5Sr_0.5CoO₃+30% SDC, was deposited by a spray method. The cells were operated in a dilute propane+oxygen mixture. The influence of environmental temperature, gas composition and flow rate on the fuel cell performance were investigated. At low temperatures, fuel cell power output was limited primarily by poor catalytic activity at the anode whereas at high temperatures it was limited primarily by high catalytic activity of the cathode towards propane oxidation. Thus, intermediate temperatures are optimal for maximizing power densities. An increase in fuel flow rate led to an increase of the fuel cell temperature due to exothermal partial oxidation on the anode, producing a complex response in fuel cell power output. Under optimized gas compositions and flow conditions, a peak power density of ∼210 mW/cm² was obtained.