Fabrication and electrochemical performance of thin-film solid oxide fuel cells with large area nanostructured membranes

• Published in: Journal of power sources Vol. 195; no. 4; pp. 1149 - 1155
• Main Authors: Johnson, Alex C., Baclig, Antonio, Harburg, Daniel V., Lai, Bo-Kuai, Ramanathan, Shriram
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.02.2010; Elsevier
• Subjects: Applied sciences; Cathodes; Channels; Covering; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Fuel cells; Lanthanum strontium cobalt iron oxide (LSCF); Membranes; Micro-fabrication; Microstructure; Nanostructure; Solid oxide fuel cell (SOFC); Solid oxide fuel cells; Thin film; Thin films; Yttria stabilized zirconia; Yttria-stabilized Zirconia (YSZ); Solid oxide fuel cell (SOFC); Microstructure; Lanthanum strontium cobalt iron oxide (LSCF); Micro-fabrication; Yttria-stabilized Zirconia (YSZ); Thin film; Cobalt oxide; Iron oxide; LSCF; Stabilized zirconia; Solid oxide fuel cell; Electrochemical characteristic; Lanthanum strontium cobalt iron oxide; Lanthanum; Nanostructured materials; Strontium oxide
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2009.08.066

Thin-film solid oxide fuel cells (SOFCs) with large (5-mm square) membranes and ultra-thin La 0.6Sr 0.4Co 0.8Fe 0.2O 3− δ (LSCF) cathodes have been fabricated and their electrochemical performance was measured up to 500 °C. A grid of plated nickel on the cathode with 5–10 μm linewidth and 25–50 μm pitch successfully supported a roughly 200-nm-thick LSCF/yttria-stabilized zirconia/platinum membrane while covering less than 20% of the membrane area. This geometry yielded a maximum performance of 1 mW cm −2 and 200 mV open-circuit voltage at 500 °C. Another approach toward realizing large area fuel cell junctions consists of depositing the membrane on a smooth substrate, covering it with a high-porosity material formed in situ, then removing the substrate. We have used a composite of silica aerogel and carbon fiber as the support, and show that this material can be created in flow channels etched into the underside of a silicon chip bonded to the top of the SOFC membrane. We anticipate these integrated fuel cell devices and structures to be of relevance to advancing low-temperature SOFCs for portable applications.