Thermal Expansion Matching as a Key Criterion for Developing High‐Performance Mn‐based Mullite Cathodes in SOFCs

and maintained stable operation for 300 h. DFT further revealed that GDC addition facilitated interfacial charge transfer and shortened Mn-Mn dimers, explaining the enhanced catalytic activity. This cathode material selection strategy, prioritizing TEC matching as the primary principle, provides a new insight into SOFC cathode development.