TY - JOUR
T1 - High power-density single-chamber fuel cells operated on methane
AU - Shao, Zongping
AU - Mederos, Jennifer
AU - Chueh, William C.
AU - Haile, Sossina M.
N1 - Funding Information:
The authors gratefully acknowledge Dr. Shaomin Liu (formerly of Caltech) for providing a portion of the BSCF powder used in this work, Dr. Ma Chi for assistance with acquisition of scanning electron microscopy images and Prof. Janet Hering for providing access to surface area analysis instrumentation. This work was funded by the Defense Advanced Research Projects Agency, Microsystems Technology Office. Additional support was provided by the National Science Foundation through the Caltech Center for the Science and Engineering of Materials.
PY - 2006/11/8
Y1 - 2006/11/8
N2 - Single-chamber solid oxide fuel cells (SC-SOFCs) incorporating thin-film Sm0.15Ce0.85O1.925 (SDC) as the electrolyte, thick Ni + SDC as the (supporting) anode and SDC + BSCF (Ba0.5Sr0.5Co0.8Fe0.2O3-δ) as the cathode were operated in a mixture of methane, oxygen and helium at furnace temperatures of 500-650 °C. Because of the exothermic nature of the oxidation reactions that occur at the anode, the cell temperature was as much as 150 °C greater than the furnace temperature. Overall, the open circuit voltage was only slightly sensitive to temperature and gas composition, varying from ∼0.70 to ∼0.78 V over the range of conditions explored. In contrast, the power density strongly increased with temperature and broadly peaked at a methane to oxygen ratio of ∼1:1. At a furnace temperature of 650 °C (cell temperature ∼790 °C), a peak power density of 760 mW cm-2 was attained using a mixed gas with methane, oxygen and helium flow rates of 87, 80 and 320 mL min-1 [STP], respectively. This level of power output is the highest reported in the literature for single chamber fuel cells and reflects the exceptionally high activity of the BSCF cathode for oxygen electro-reduction and its low activity for methane oxidation.
AB - Single-chamber solid oxide fuel cells (SC-SOFCs) incorporating thin-film Sm0.15Ce0.85O1.925 (SDC) as the electrolyte, thick Ni + SDC as the (supporting) anode and SDC + BSCF (Ba0.5Sr0.5Co0.8Fe0.2O3-δ) as the cathode were operated in a mixture of methane, oxygen and helium at furnace temperatures of 500-650 °C. Because of the exothermic nature of the oxidation reactions that occur at the anode, the cell temperature was as much as 150 °C greater than the furnace temperature. Overall, the open circuit voltage was only slightly sensitive to temperature and gas composition, varying from ∼0.70 to ∼0.78 V over the range of conditions explored. In contrast, the power density strongly increased with temperature and broadly peaked at a methane to oxygen ratio of ∼1:1. At a furnace temperature of 650 °C (cell temperature ∼790 °C), a peak power density of 760 mW cm-2 was attained using a mixed gas with methane, oxygen and helium flow rates of 87, 80 and 320 mL min-1 [STP], respectively. This level of power output is the highest reported in the literature for single chamber fuel cells and reflects the exceptionally high activity of the BSCF cathode for oxygen electro-reduction and its low activity for methane oxidation.
KW - Ceria electrolyte
KW - Methane
KW - Single chamber fuel cell
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U2 - 10.1016/j.jpowsour.2006.07.003
DO - 10.1016/j.jpowsour.2006.07.003
M3 - Article
AN - SCOPUS:33750001418
SN - 0378-7753
VL - 162
SP - 589
EP - 596
JO - Journal of Power Sources
JF - Journal of Power Sources
IS - 1
ER -
