Open AccessSuppression of Leakage Current in Proton-Conducting BaZr0.8Y0.2O3−δ Electrolyte by Forming Hole-Blocking Layer
Author(s) -
Yoshio Matsuzaki,
Yuya Tachikawa,
Yoshitaka Baba,
Koki Sato,
Gen Kojo,
Hiroki Matsuo,
Junichiro Otomo,
Hiroshige Matsumoto,
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/ab904f
Subject(s) - electrolyte , oxide , materials science , leakage (economics) , electrochemistry , solid oxide fuel cell , analytical chemistry (journal) , proton , inorganic chemistry , electrode , chemistry , chromatography , economics , metallurgy , macroeconomics , physics , quantum mechanics
Solid oxide fuel cells (SOFCs) with proton-conducting solid electrolyte, instead of the oxide-ion conducting solid electrolyte have attracted attentions because of their high potential to reduce operating temperatures and to enhance the electrical efficiencies of SOFCs. In addition, the proton-conducting SOFCs with multistage electrochemical oxidation configuration will be promising technology for critically-high electric efficiencies. However, it is known that there are non-negligible charge -carriers other than protons in typical proton-conducting solid oxide electrolytes at relatively high temperatures. The existence of the partial conductivities of holes and/or electrons will cause the internal leakage current that consumes fuel but never generates any electrical power output. The higher ratio of the leakage current to external current will more deteriorate the electrical efficiency. In this study, the effects of blocking -layers formed on the air side surface of base electrolyte layer consisting of BaZr 0.8 Y 0.2 O 3− δ (BZY82) for suppressing the leakage current have been investigated by using electrochemical parameters of the partial conduction of the materials. The chemical potential profile and leakage current showed large dependence on the material of the blocking-layer. Lanthanum tungstate was found to play a role as unique and strong blocking-layer against the leakage current.