Durability Test of Anode-Supported Solid Oxide Fuel Cell Under Diverse Load Conditions

Abstract

Solid oxide fuel cells (SOFCs) provide an appealing electrochemical devices to convert chemical energy into electrical power with high efficiency and negligible carbon emissions. For utilizing in a wide spectrum of applications, SOFCs need to prove the operational stability over 40,000 h with less than 10% of power decay [1]. The performance deteriorations of SOFCs are induced by complex factors such as redox cycle [2], carbon deposition [3], S poisoning [4], and Cr poisoning. Therefore, understanding of fundamental degradation mechanisms under various operating conditions are important to improve the lifetime of SOFCs. For past few decades, the durability study of SOFCs has carried out under prolonged periods of time in mainly ‘laboratory conditions’, i.e. constant current operations, well controlled fuel composition, and low level of impurities [5,6]. However, the real operating conditions normally include harsh conditions such as temperature fluctuations, current fluctuations, and fuel and air stop. Especially, the different load conditions can result in accelerating the degradation of cell components because of the local potential and temperature changing. In this research, systematic durability investigations of anode-supported SOFCs are performed under a wide range of operating conditions including load cycle and load trip. In order to understand degradation mechanisms of the cell, various electrochemical investigations are performed such as the current-voltage polarization and electrochemical impedance spectroscopy. The morphology and microstructure of anode-supported cell are examined using field emission scanning electron microscoy and electron probe X-ray microanalyzer. References Y.-S. Chou, J.W. Stevenson, J.-P. Choi, J. Power Sources 250 (2014) 166–173.T. Klemensø, C. Chung, P.H. Larsen, M.Mogensen, J. Electrochem. Soc. 152 (2005) A2186–A2192.Mai, M. Becker, W. Assenmacher, F. Tietz, D. Hathiramani, E. Ivers-Tiffee, D. Stöver, W. Mader, Solid State Ionics 177 (2006) 1965–196H. Yokokawa, T. Horita, K. Yamaji, H. Kishimoto, T. Yamamoto, M. Yoshikawa, Y. Mugikura, K. Tomida, Fuel Cells 13 (2013) 526–535.Hagen, J.V.T. Høgh, R. Barfod, J. Power Sources 300 (2015) 223–228.H. Yokokawa, ECS Trans. 35 (2011) 207–216.T.-H. Lee, K.-Y. Park, J.-T. Kim, Y. Seo, K.B. Kim, S.-J. Song, B. Park, J.-Y. Park, J. Power Sources 276 (2015) 120–132.