Figure‐of‐Merit Compatibility of Solid Oxide Fuel Cells

Solid oxide fuel cell (SOFC) is one of the most efficient energy converters which can produce electricity from reactions of gaseous chemicals. However, a high operating temperature ( T o ) of 800–1200 °C is required to achieve the highest peak performance. Such high T o triggers miscellaneous problems, that is, mechanical disintegration with further degradation of its electrical performance for a long‐term application. Despite accomplishing various approaches for the improvement of SOFC performance, the standard level to determine SOFC performance has never been achieved. To date, a quantitative analysis is only pinpointing the power output density ( P out ). The SOFC cannot be simply determined by a mere P since other parameters that is chemical stability between SOFC components, mismatch of thermal expansion coefficient, and area‐specific resistance also contribute to the mechanical durability and electrochemical stability of the SOFC. Hence, herein, a novel idea is proposed to characterize the overall performance of SOFC through the figure‐of‐merit compatibility ( χ cp ) of SOFC cells. The χ cp can reflect a level of SOFC performance, thus it can be utilized for future improvements.