Electrochemical performance and stability of Ni_1-xCo_x-based cermet anode for direct methane-fuelled solid oxide fuel cells

¹ Program of Petrochemistry, Chulalongkorn University, Thailand & Program of Materials Science, Nagaoka University of Technology, Japan
² Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
³ Department of Materials Science and Technology, Nagaoka University of Technology, Nagaoka, Niigata, Japan

^a Corresponding author: sato@analysis.nagaokaut.ac.jp

Abstract

Carbon deposition on Ni-based anode is well-known as a major barrier for the practical use and commercialization of hydrocarbon-fuelled solid oxide fuel cells (SOFCs). In this work, Co alloying in Ni-YSZ was studied as an alternative anode material for using CH₄ as a fuel. The Ni-YSZ and Ni-Co alloyed-YSZ were prepared by the traditional impregnation method without further mixing processes. After sintering and reduction in H₂ atmosphere, the introduced Co can completely dissolved into the Ni lattice and changed the morphology with an increase in the Ni-YSZ grain size and showed a better uniform microstructure. The Co alloying also enhanced the electrochemical performance under CH₄ fuel by reducing the resistance and anodic overvoltage. Moreover, the Co addition enhanced the stability of the cell with CH₄ a constant load current of 80 mA for 60 h. This performance related to the carbon deposition on the anode surface. The Co alloying showed a high efficiency to suppress the carbon deposition and improved the electrochemical performance of an SOFC cell operating under CH₄ fuel.