A Core‐Shell Perovskite Composite Air Electrode With Thermal‐Expansion Offset and Mechanical Support Functions for Highly Durable Reversible Protonic Ceramic Cells

(DP-SFZW) shell. Both SP-SFZW and DP-SFZW serve as oxygen catalysts, while DP-SFZW shell additionally acts as a thermal expansion suppressor and mechanical support structure, effectively mitigating electrode cracking and delamination from other cell components during RPCC operation. Consequently, the composite electrode demonstrates comparable catalytic activity to SF, coupled with significantly enhanced durability. This work illustrates a novel approach for developing robust RPCCs air electrode.