Open AccessImproved Redox Cycling Durability in Alternative Ni Alloy-Based SOFC Anodes
Author(s) -
Yusuke Ishibashi,
Kenichi Matsumoto,
Shotaro Futamura,
Yuya Tachikawa,
Junko Matsuda,
Stephen Matthew Lyth,
Yusuke Shiratori,
Shunsuke Taniguchi,
Kazunari Sasaki
Publication year - 2020
Publication title -
journal of the electrochemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.258
H-Index - 271
eISSN - 1945-7111
pISSN - 0013-4651
DOI - 10.1149/1945-7111/abac87
Subject(s) - materials science , anode , cermet , oxide , alloy , oxidizing agent , nickel , redox , electrochemistry , solid oxide fuel cell , chemical engineering , metallurgy , electrode , chemistry , ceramic , organic chemistry , engineering
Repeated reduction and oxidation of metallic nickel in the anodes of solid oxide fuel cell (SOFC) causes volume changes and agglomeration. This disrupts the electron conducting network, resulting in deterioration of the electrochemical performance. It is therefore desirable to develop more robust anodes with high redox stability. Here, new cermet anodes are developed, based on nickel alloyed with Co, Fe, and/or Cr. The stable phases of these different alloys are calculated for oxidizing and reducing conditions, and their electrochemical characteristics are evaluated. Whilst alloying causes a slight decrease in power generation efficiency, the Ni-alloy based anodes have significantly improved redox cycle durability. Microstructural observation reveals that alloying results in the formation of a dense oxide film on the surface of the catalyst particle (e.g. Co-oxide or a complex Fe–Ni–Cr oxide). These oxide layers help suppress oxidation of the underlying nickel catalyst particles, preventing oxidation-induced volume changes/agglomeration, and thereby preserving the electron conducting pathways. As such, the use of these alternative Ni-alloy based cermets significantly improves the redox stability of SOFC anodes.