TY - JOUR
T1 - Suppression of Leakage Current in Proton-Conducting BaZr0.8Y0.2O3-δ Electrolyte by Forming Hole-Blocking Layer
AU - Matsuzaki, Yoshio
AU - Tachikawa, Yuya
AU - Baba, Yoshitaka
AU - Sato, Koki
AU - Kojo, Gen
AU - Matsuo, Hiroki
AU - Otomo, Junichiro
AU - Matsumoto, Hiroshige
AU - Taniguchi, Shunsuke
AU - Sasaki, Kazunari
N1 - Publisher Copyright:
© 2020 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited.
PY - 2020/1/5
Y1 - 2020/1/5
N2 - 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 BaZr0.8Y0.2O3-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.
AB - 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 BaZr0.8Y0.2O3-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.
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U2 - 10.1149/1945-7111/ab904f
DO - 10.1149/1945-7111/ab904f
M3 - Article
AN - SCOPUS:85084760336
VL - 167
JO - Journal of the Electrochemical Society
JF - Journal of the Electrochemical Society
SN - 0013-4651
IS - 8
M1 - 084515
ER -