(Bi2O3)1-x-y(Dy2O3)x(Ho2O3)y üçlü sistemin elektriksel, yapı ve termal kararlılık özelliklerinin incelenmesi

Yıl 2012, Cilt: 28 Sayı: 1, 6 - 10, 01.02.2012

Semra Durmuş Mehmet Arı

Öz

Bu çalışmanın amacı; zamanla özellikleri bozulmayan ve çalışma şartları altında iyonik iletkenliğini koruyan elektrolit/elektrolitler tespit etmektir. Bu doğrultuda, (Bi2O3)1-xy(Ho2O3)x(Dy2O3)y üçlü sistemin (x=%11, 12, 13, 14 mol ve y=% 4, 3, 2, 1 mol, katkı konsantrasyonu) numuneleri katıhal reaksiyonu ile 48 saat 750°C ısıl işleme tabi tutularak hazırlandı. Katı Oksit Yakıt Hücresi (SOFC) için en iyi katı elektrolit özelliklere sahip olabilecek numunelerin yapısal özellikleri X-ışınları difraktometresi (XRD), elektriksel özellikleri dört-nokta metodu ve termal özellikleri diferansiyel termal analiz (TG / DTA) ölçüm sistemleri ile ölçüldü. XRD ölçümleri 48 saat 750°C ısıl işlem sonucunda bütün numuneler δ- Bi2O3 fazında kararlı olduğunu gösterdi.

Anahtar Kelimeler

Katıhal reaksiyonu, Yakıt hücresi, Elektriksel iletkenlik, Dört-nokta metod

Investigation of electrical, structural and thermal stability properties of (Bi2O3)1-x-y(Dy2O3)x(Ho2O3)y ternary system

Öz

The aim of this study is to find an electrolyte which does not have any degradation in its properties with time this maybe caused either interaction between the different electrochemical cell materials or by instability of the ionic conductor under operation conditions. Accordingly, this (Bi2O3)1-x-y(Ho2O3)x(Dy2O3)y ternary system (x=11, 12, 13, 14 mol % and y=4, 3, 2, 1 mol %, dopant concentrations) sample materials were synthesized using solid state reaction method sintering each of them at 750°C for 48 hours. Structural, electrical and thermal properties of the samples which are candidate of electrolyte for solid oxide fuel cells have been evaluated by means of X-ray diffraction (XRD), four-probe method, and thermal analysis (TG / DTA). XRD measurements showed that all of the samples have stable δ- type phase which was also supported by the TG / DTA measurements.

Anahtar Kelimeler

Electrolyte, Solid state reaction, Fuel cell, Electrical conductivity, Fourprobe point method

Kaynakça

• D. Music, S. Konstantinidis and J. M. Schneider, Equilibrium structure of δ-Bi2O3 from first principle, J. Phys.: Condens. Matter, 21, 2009, 175403-175480.
• C. –Y. Hsieh, K.-Z. Fung, Crystal structure and electrical conductivity of cubic fluorite-based (YO1.5)x(WO3)0.15(BiO1.5)0.85-x (0≤x≤0.4) solid solutions, J. Solid State Electrochem, 13, 2009, 951-957.
• P.K. Cheekatamarla, M. F. Caine, and J. Cai, Internal reforming of hydrocarbon fuels in tubular solid oxide fuel cells, Internatıonal Journal of Hydrogen Energy, 33, 2008, 1853-1858.
• S.R Xiao-Feng Ye, Z.R Wang, L. Wang, X.F Xiong, T.L. Sun Wen, Use of a catalyst layer for anode-supported SOFCs running on ethanol fuel, Journal of Power Sources, 177, 2008, 419-425.
• M. Wang, and K. Woo, Impact of Sr2MnO4 preparation process on its electrical resistivity, Energy Conversion and Management, 49, 2008, 2409–2412.
• S.H. Jung, E.D. Wachsman and N. Jiang, Structural Stability and Conductivity of Cubic (WO3)x-(Dy203)y(Bi203)l.x.y, International Journal of Ionics, Volume 8, Numbers 3-4, 2002, 210-214.
• M. Benkaddour, M.C. Steil, M. Drache, and P. Conflant, The Influence of Particle Size on Sintering and Conductivity of Bi0.85Pr0.105V0.045O1.545 Ceramics, Journal of Solid State Chemistry, 155, 2000, 273-279 .
• N.M. Sammes, G.A. Tompsett, H. Nafe and F. Aldinger, Bismuth based oxide electrolytes structure and ionic conductivity, Journal of Europan Ceramic Society, 19, 1999, 1801-1826.
• N. Jiang, E.D. Wachsman and S.H. Jung, A higher conductivity Bi203-based electrolyte, Solid State İonics, 150, 3-4, 2002, 347-353.
• H.A. Harwing, On the Structure of Bismuthsesquioxide: The α, β, γ, and δ-phase, Z. Anorg. Allg. Chem., 444, 1978, 151-166.
• Watanabe, Is it possible to stabilize δ-Bi2O3 by an oxide additive, Solid State Ionics, 40-41, 1990, 889-892 .
• N. Jiang, R.M. Buchanan, F.E.G. Henn. A.F. Marshall, D.A. Stevenson, E.E. Wachsman, Aging phenomenon of stabilized bismuth oxides, Mater. Res. Bull., 29, 1994, 247-254.
• E.D. Wachsman, S. Boyapati, M.J. Kaufman, N. Jiang, Modeling of Ordered Structures of Phase-Stabilized Cubic Bismuth Oxides, J. Am. Ceram. Soc., 83, 2000, 1964-1968.
• E.D. Wachsman, G.R. Ball, N. Jiang and D.A. Stevenson, Structural and defect studies in solid oxide electrolytes, Solid State Ionics, 52, 1992, 213-218.
• S. Boyabati, E.D. Wachsman and B.C. Chakoumakos, Neutron diffraction study of occupancy and positional oxygen ions in phase-stabilized cubic bismuth oxides, Solid State Ionics, 138, 2001, 293-304.