Stability of a Solid Oxide Cell Stack under Direct Internal-reforming of Hydrogen-blended Methane

Yafei Tang, Key Laboratory of Advanced Fuel Cells and Electrolyzers cell Technology of Zhejiang Province, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang, 315201
Anqi Wu, Key Laboratory of Advanced Fuel Cells and Electrolyzers cell Technology of Zhejiang Province, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang, 315201
Beibei Han, Key Laboratory of Advanced Fuel Cells and Electrolyzers cell Technology of Zhejiang Province, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang, 315201
Hua Liu, Zhejiang Qiming Electric Power Group CO.LTD, Zhoushan, Zhejiang 316099, China
Shanjun Bao, Zhejiang Qiming Electric Power Group CO.LTD, Zhoushan, Zhejiang 316099, China
Wanglin Lin, Ocean Research Center of Zhoushan, Zhejiang University, Zhoushan, Zhejiang 316021, China
Ming Chen, Department of Energy Conversion and Storage, Technical University of Denmark (DTU), Lyngby, Denmark
Wanbing Guan, Key Laboratory of Advanced Fuel Cells and Electrolyzers cell Technology of Zhejiang Province, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang, 315201
Subhash C. Singhal, Key Laboratory of Advanced Fuel Cells and Electrolyzers cell Technology of Zhejiang Province, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang, 315201

Abstract

In this work, the long-term stability of a direct internal-reforming solid oxide fuel cell stack (IR-SOFC stack) using hydrogen-blended methane steam reforming are investigated. The stack is operated for about 3000 h, with a degradation rate of about 2.3%·kh-1; the voltage of the two cells in the stack increase 3.38 mV·kh-1 and 3.78 mV·kh-1, respectively. The area specific resistance of the three metal interconnects in the stack increase by 0.276 Ω·cm2, 0.254 Ω·cm2, and 0.249 Ω·cm2, respectively. The results prove the stability of the flat-tube solid oxide fuel cell stack during long-term operation. The degradation of the stack is caused by segregation of Cr on the surface of metal interconnects and the formation of SrCrO4 insulating phase in the current collecting layer of the cathode, which result in an increase in the interfacial resistance and decrease the stack performance. The long-term performance of a flat-tube IR-SOFC stack can be further improved by suitably coating the metal interconnect surface. This work provides theoretical and experimental reference for the application of hydrogen-blended methane steam reforming in flat-tube IR-SOFC stacks.