Low overvoltage mechanism of high ionic conducting cathode for solid oxide fuel cell

Electrochemical characteristics of three types of La1-xSrxCoO3 (LSC) and La1-xSrxMnO3 (LSM) electrodes, (dense, porous, and porous/dense double layer) were measured. The dense layers of LSC and LSM were prepared by laser ablation and the porous layers were prepared by tape-casting. Electrochemical measurements (ac impedance and dc polarisation measurements) revealed that surface area is an important factor for the reaction rate on the LSC electrode, while the electrode/electrolyte boundary structure is important on the LSM electrode. These results indicate that high performance electrodes can be obtained using a high ionic conductor electrode with a large surface area. 5 refs.