Getting intimate: A 3D interconnected Bi0.5Sr 0.5FeO3-ð (BSF)-Ag electrocatalyst is prepared from a BSF-AgNO3 core-shell precursor in one step. The nanometer-sized Ag enhances the sintering process, enabling an optimum cathode microstructure and good cathode-to-electrolyte attachment upon firing at 850°C. A solid-oxide fuel cell based on this cathode shows a near 100% peak power density enhancement at 550°C.