33. Failure Probability of Solid Oxide Fuel Cells

  1. Narottam P. Bansal
  1. JÜRgen Malzbender,
  2. Rolf W. Steinbrech and
  3. Lorenz Singheiser

Published Online: 26 MAR 2008

DOI: 10.1002/9780470291245.ch33

Advances in Solid Oxide Fuel Cells: Ceramic Engineering and Science Proceedings, Volume 26, Number 4

Advances in Solid Oxide Fuel Cells: Ceramic Engineering and Science Proceedings, Volume 26, Number 4

How to Cite

Malzbender, J., Steinbrech, R. W. and Singheiser, L. (2005) Failure Probability of Solid Oxide Fuel Cells, in Advances in Solid Oxide Fuel Cells: Ceramic Engineering and Science Proceedings, Volume 26, Number 4 (ed N. P. Bansal), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470291245.ch33

Author Information

  1. Forschungszentrum Jülich GmbH Institute for Materials and Processes in Energy Systems 52425 Jülich, Germany

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2005

ISBN Information

Print ISBN: 9781574982343

Online ISBN: 9780470291245

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Keywords:

  • solid oxide fuel cells;
  • weibull statistics;
  • materials;
  • thermo-mechanical reliability;
  • modulus of rupture

Summary

The failure probability of anode supported solid oxide fuel cells (SOFCs) was analyzed combining experimental results of residual and fracture stress measurements. Oxidized and reduced anode/electrolyte half-cells composed of standard Ni and yttria stabilized zirconia materials were tested. The residual stresses were derived from the temperature dependence of unconstrained cell curvature. The fracture stress (modulus of rupture) was determined in bending tests at room and operation relevant temperature (800°C). The room temperature results revealed a high compressive residual stress in the electrolyte (∼ 430 MPa) and a low average tensile stress in the anode (∼ 9 MPa). The fracture stresses varied between ∼ 115 MPa for the oxidized anode at room temperature and ∼ 67 MPa for the reduced anode at 800°C. Thermal cycling and stack operation time did not influence the results significantly. Based on Weibull statistics a modulus of ∼ 13 was determined and the influence of the cell size was elaborated. The critical stress in stack operation is discussed for different failure probabilities