An engineer designs a solid-oxide fuel cell (SOFC) stack operating at 800°C. Which risk increases as the operational enthalpy deviates negatively from the design value?

💡 Explanation

Negative deviation in operational enthalpy results in a temperature drop, which induces thermal stress within the ceramic components of the SOFC; because the thermal expansion coefficients of the different layers do not match, the stresses increase. Therefore, cracking probability increases, rather than the oxygen vacancies, Nernst potential, or electrode resistance being the primary concern.

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