Solid oxide fuel cells (SOFCs) are highly efficient chemical to electrical energy conversion devices that have potential in a global energy strategy. The wide adoption of SOFCs is currently limited by cost and concerns about cell durability. Improved understanding of their degradation modes and mechanisms combined with reduction-oxidation stable anodes via all-ceramic-anode cell technology is expected to lead to durability improvements, while economies of scale for production will mitigate the cost of commercialization. This paper presents an Ishikawa analysis and a failure mode, mechanisms, effects, and criticality analysis (FMMECA) for all-ceramic anode-based SOFCs. FMMECA takes into account the life cycle conditions, multiple failure mechanisms, and their potential effects on fuel-cell health and safety.
Schematic representation of a solid oxide fuel cell (SOFC)
Ishikawa diagram for ceramic anodes.
To assess root cause and impact of failures, an Ishikawa analysis and a failure mode, mechanisms, effects, and criticality analysis (FMMECA) of ceramic anodes for SOFCs have been developed. It was found that anode-electrolyte interfacial delamination and cracks are the critical failure modes which can cause the abrupt failure of SOFCs. Hence, one should carefully design the ceramic anodes of SOFCs for redox cycling and thermal cycling as these are the dominant failure causes for aforementioned critical failure modes. It is worth noting that though mechanical failure due to redox cycling is still a concern with ceramic anodes, the susceptibility to the failure mode is expected to be dramatically reduced as compared to Ni-cermet cells. Additionally, these analyses can be used to develop degradation and failure test plans for ceramic anodes and to facilitate assessment of the reliability of anodes as well as the entire SOFC system. Standards organizations and industry groups can design better qualification and safety tests based on the findings of these analyses. Such assessments not only can predict a given application’s life-cycle stresses on the SOFCs, but also capture the interactions between different failure mechanisms that exacerbate failure. Improved design and testing influenced by these analyses can lead to safer and more reliable SOFC systems.
CALCE Publication:
Failure Modes, Mechanisms, Effects, and Criticality Analysis of Ceramic Anodes of Solid Oxide Fuel Cells, Nripendra K. Patel, Robert G. Utter, Diganta Das, Michael Pecht, and Sean R. Bishop, Electronics, Vol. 7, Issue 11, pp. 1-16, DOI: 10.3390/electronics7110323.
Surface Degradation of Strontium-based Perovskite Electrodes of Solid Oxide Fuel Cells, Nripendra K. Patel, Robert G. Utter, Diganta Das, and Michael Pecht, Journal of Power Sources, Volume 438, 2019, 227040, ISSN 0378-7753, DOI: 10.1016/j.jpowsour.2019.227040.
For more information on CALCE research on Solid Oxide Fuel Cells, contact Prof. Michael Pecht.
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