Performance stability of strontium-doped lanthanum cobaltite ceramic cathode synthesized by a wet chemical method
By Jun-Sik Park and Jiwoong Bae and Young-Beom Kim
Published in Ceramics International
2016
Abstract
Porous strontium-doped lanthanum cobaltite ( La 0 . 5 Sr 0 . 5 CoO 3 ? ? , LSC) thin film electrodes were deposited by a metal-organic chemical solution deposition method. These films were used as cathodic electrodes replacing precious metal electrodes for low-temperature solid oxide fuel cell (LT-SOFC) applications. They were characterized electrochemically and compared with devices that had platinum (Pt) cathodes. Pt was prepared by a \DC\ magnetron sputtering method and LSC-YSZ-Pt and Pt-YSZ-Pt (cathode-electrolyte-anode) \SOFC\ unit cells were fabricated. The performance of each cell was continuously evaluated under operating conditions and the performance of fuel cells with a Pt cathode was superior to those using a \LSC\ cathode at the initial stages of operation; however, the output power density started to decrease as a function of time due to the degradation that comes from the heat vulnerability of Pt. As a consequence, the performance of Pt-YSZ-Pt was significantly lower than LSC-YSZ-Pt, and the electrode resistance grew to be about four times larger compared to before operation. In contrast, neither the output power density nor the electrode resistance of LSC-YSZ-Pt changed during operation. These results imply that \LSC\ has better long-term performance stability compared to Pt and feasibility of using ceramic electrode for low-temperature solid oxide fuel cells.