干旱区生态环境知识资源中心(Arid): Effect of ionic conductivity of zirconia electrolytes on polarization properties of various electrodes in SOFC

Arid

DOI	10.2172/460189
报告编号	CONF-961107--Absts.
来源ID	OSTI_ID: 460189
	Effect of ionic conductivity of zirconia electrolytes on polarization properties of various electrodes in SOFC
	Watanabe, Masahiro; Uchida, Hiroyuki; Yoshida, Manabu [Yamanashi Univ., Kofu (Japan)]
英文摘要	Solid oxide fuel cells (SOFCs) have been intensively investigated because, in principle, their energy conversion efficiency is fairly high. Lowering the operating temperature of SOFCs from 1000{degrees}C to around 800{degrees}C is desirable for reducing serious problems such as physical and chemical degradation of the constructing materials. The object of a series of the studies is to find a clue for achieving higher electrode performances at a low operating temperature than those of the present level. Although the polarization loss at electrodes can be reduced by using mixed-conducting ceria electrolytes, or introducing the mixed-conducting (reduced zirconia or ceria) laver on the conventional zirconia electrolyte surface, no reports are available on the effect of such an ionic conductivity of electrolytes on electrode polarizations. High ionic conductivity of the electrolyte, of course, reduces the ohmic loss. However, we have found that the IR-free polarization of a platinum anode attached to zirconia electrolytes is greatly influenced by the ionic conductivity, {sigma}{sub ion}, of the electrolytes used. The higher the {sigma}{sub ion}, the higher the exchange current density, j{sub 0}, for the Pt anode in H{sub 2} at 800 {approximately} 1000{degrees}C. It was indicated that the H{sub 2} oxidation reaction rate was controlled by the supply rate of oxide ions through the Pt/zirconia interface which is proportional to the {sigma}{sub ion}. Recently, we have proposed a new concept of the catalyzed-reaction layers which realizes both high-performances of anodes and cathodes for medium-temperature operating SOFCs. We present the interesting dependence of the polarization properties of various electrodes (the SDC anodes with and without Ru microcatalysts, Pt cathode, La(Sr)MnO{sub 3} cathodes with and without Pt microcatalysts) on the {sigma}{sub ion} of various zirconia electrolytes at 800 {approximately} 1000{degrees}C.
出版年	1996
报告类型	Technical Report
语种	英语
国家	美国
来源学科分类	30 DIRECT ENERGY CONVERSION ; 36 MATERIALS SCIENCE ; SOLID ELECTROLYTE FUEL CELLS ; PERFORMANCE ; ZIRCONIUM OXIDES ; IONIC CONDUCTIVITY ; YTTRIUM OXIDES ; YTTERBIUM OXIDES ; SCANDIUM OXIDES ; ANODES ; CATHODES ; CURRENT DENSITY ; EFFICIENCY ; ELECTROCHEMISTRY ; POLARIZATION
URL	http://www.osti.gov/scitech/servlets/purl/460189
资源类型	科技报告
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/266867
推荐引用方式 GB/T 7714	Watanabe, Masahiro,Uchida, Hiroyuki,Yoshida, Manabu [Yamanashi Univ., Kofu . Effect of ionic conductivity of zirconia electrolytes on polarization properties of various electrodes in SOFC,1996.