Standard Article

Factors limiting the low temperature operation of SOFCs

Advances in Electrocatalysis, Materials, Diagnostics and Durability

Materials for high temperature fuel cells

Novel materials

  1. J. David Carter,
  2. T. A. Cruse,
  3. B. J. Ingram,
  4. M. Krumpelt

Published Online: 15 DEC 2010

DOI: 10.1002/9780470974001.f500040

Handbook of Fuel Cells

Handbook of Fuel Cells

How to Cite

Carter, J. D., Cruse, T. A., Ingram, B. J. and Krumpelt, M. 2010. Factors limiting the low temperature operation of SOFCs. Handbook of Fuel Cells. .

Author Information

  1. Argonne National Laboratory, Argonne, IL, USA

Publication History

  1. Published Online: 15 DEC 2010

Abstract

Over the history of solid oxide fuel cell (SOFC) development, many investigators have sought to reduce the operating temperature. In this article, we present and discuss factors that lead to a lower limit on the effective operating temperature of these fuel cells. Among these factors, the cathode polarization resistance and fuel oxidation on the anode show the greatest effects on limiting low-temperature operation. The strontium-doped lanthanum manganite cathode is limited to ≥800 °C for 0.6 W cm−2 at 0.85 V. Mixed-ionic and electronic conducting materials are more active and can operate at ∼750 °C, but they are more prone to interact with the yttria-stabilized zirconia (YSZ) electrolyte. Modified Ni-based/YSZ anodes operating on carbonaceous fuels have a thermodynamic temperature limit of 500 °C because of carbon formation in the absence of steam, but also need to have their power densities improved to operate below 650 °C. The electrolyte resistance is not a significant factor for 8 mol% YSZ being able to operate as low as 530 °C, and for other electrolytes at even lower temperatures. Also, the electrical resistance of the interconnect, including that of the protective scale on metallic interconnects, becomes significant at temperatures below 600 °C. Cell geometry is another factor that limits low-temperature operation, favoring planar over other stack designs.

Keywords:

  • low-temperature SOFC;
  • cost;
  • design;
  • cathode;
  • electrolyte;
  • anode;
  • interconnect;
  • seal