As a chemical to electricity energy conversion technology, solid oxide fuel cells (SOFCs) must be operated at relatively high temperatures due to the high resistance of their electrodes. The low specific surface area caused by high sintering temperature during electrode fabrication, along with the poor catalytic ability of electrode materials, were the reason for the poor SOFC electrode performance. With the development of highly active electrode materials and new electrode synthesis methods like precursor solution infiltration, nano-sized, highly catalytically active materials like La 0.6 Sr 0.4 Co 0.8 Fe 0.2 O 3-δ (LSCF), Sm 0.5 Sr 0.5 CoO 3-δ (SSC) and Gd 0.1 Ce 0.9 O 2 (GDC) have all been successfully fabricated at relatively low temperatures. A new “nano-composite” structure for SOFC electrodes, where nano-sized electrode catalysts are added into micron-sized ionic conducting (IC) materials using precursor solution infiltration, has greatly improved the electrode performance and reduced the operating temperature for SOFCs due to the large number of active reaction sites for nano-sized electrode catalysts and the fast oxygen ion transport pathway provided by the sintered IC substrates.