本論文實驗量測棋盤式(pin-type)雙極板尺寸效應對固態氧化物燃料電池(solid oxide full cell, SOFC)性能之影響。採用單電池堆配合不同流道尺寸設計的Crofer-22-APU雙極板，藉此探討雙極板流道尺寸效應對電池性能及其物理化學反應機制和劣化程度的影響。量測方法有二，含單電池堆電壓-電流密度之極化曲線量測與電化學阻抗頻譜量測，所探討的尺寸參數包含：(1)雙極板格狀凸出物(pin)寬度與流道寬度之和(Wpitch = Wpin + Wchannel)和(2)Wpin與Wpitch 的比值( f = Wpin/Wpitch)。結果顯示，在相同實驗操作條件下，電池輸出功率密度會隨Wpitch值減少而增加，這是因為當Wpitch值減少時，電池反應氣體較易擴散至pin下方多孔性電極，進而減少電池濃度損失；相反地，電池輸出功率密度卻會隨f值減少而減少，這是由於當Wpin值小於3 mm時，濃度損失幾乎不會隨f 值減少而變化，但卻會使雙極板與電極間的接觸電阻大幅增加，進而使歐姆損失大幅增加。當單電池堆在負載電壓下(0.8 V、0.6 V)，我們發現極化阻抗可被大幅度地減少，而歐姆阻抗則幾乎沒有變化。綜合而論，在電池堆實際操作條件下，如何設計棋盤式流道尺寸使電池堆具有較低之歐姆阻抗為設計之首要，故我們找到優化流道尺寸為Wpitch = 4 mm和f = 0.66。此研究結果應有助於提升棋盤式SOFC電池性能及壽命。

This study aims to investigate the size effect of pin-type interconnectors on the performance of solid oxide fuel cell (SOFC). Using the SOFC single-cell stacks, we apply Crofer-22-APU pin-type interconnectors with various sizes to investigate the size effect on the cell performance and its corresponding physical and chemical reaction mechanisms as well as the related cell degradation. Two different measurements are carried out, including the voltage-current density polarization curves (PC) and the electrochemical impedance spectroscopy (EIS), which the key parameters for the study of the size effect are the interconnect pin width (Wpin), the channel width (Wchannel), the pitch width (Wpitch = Wpin+Wchannel), and a fraction ratio between Wpin and Wpitch (f = Wpin/Wpitch). Results show that the cell power density increases as values of Wpitch decrease, by which all other experimental conditions are kept constant. This power increase is because the reactants are more easier to diffuse into the porous electrode under the bottom of the pin when decreasing Wpitch, and thus the cell concentration losses can be reduced. On the other hand, the cell power density decreases with decreasing f. This is because when Wpin is smaller than 3 mm, the decrease of f has little influences on the concentration losses, but it has strong influence on the contact resistances between the interconnector and the electrode so that a significant increase of the ohmic losses is found. We found that the polarization resistance decreases under the load voltages (0.8 V and 0.6 V), while the ohmic resistance remains almost unchanged. Finally, a combination of Wpitch = 4 mm and f = 0.66 is proposed to obtain a better cell performance. These results should be useful for the improvement of cell performance and longevity of pin-type planar SOFCs.

[1]Gregor, H., Fuel cell technology hand book, CRC Press, Germany, 2003.
[2]Stambouli, A.B. and Traversa, E., Solid oxide fuel cells (SOFCs): a review of an environmentally clean and efficient source of energy, Renew. Sust. Energ. Rev. Vol. 6, pp. 433-455, 2002.
[3]方良吉等編著，2010年能源產業技術白皮書，第一版，經濟部能源局，台北市，民國九十九年。
[4]Huang, C.M., Shy, S.S. and Lee, C.H., On flow uniformity in various interconnects and its influence to cell performance of planar SOFC, J. Power Sources, Vol. 183, pp. 205-213, 2008.
[5]Huang, C.M. Shy, S.S., Huang, S.C. and Lee, C.H., Performance measurements of a single-cell stack using various designs of flow distributors for planar SOFC, ECS Transactions, Vol. 25, Issue 2, pp. 221-230, 2009.
[6]Huang, C.M., Shy, S.S., Li, H.H. and Lee, C.H., The impact of flow distributors on the performance of planar solid oxide fuel cell, J. Power Sources, Vol. 195, pp. 6280-6286, 2010
[7]黃家明，「平板式固態氧化物燃料電池流場板與陽極微結構之優化設計與實作測試」，國立中央大學，博士論文，民國九十九年。
[8]黃士峻，「平板式SOFC單電池堆性能量測：棋盤狀流道尺寸效應」，國立中央大學，碩士論文，民國九十八年。
[9]Yamamoto, O., Solid oxide fuel cells: fundamental aspects and prospects, Electrochim. Acta, Vol. 45, pp. 2423–2435, 2000.
[10]Vielstich, W., Lamm, A. and Gasteiger, H. A., Handbook of fuel cells : fundamentals, technology, and applications, John Wiley and Sons Ltd., West Sussex, 2003
[11]Mogensen, M., Sammes, N. M. and Tompsett, G. A., Physical, chemical and electrochemical properties of pure and doped ceria, Solid State Ionics, Vol. 129, pp. 63-94, 2000.
[12]Zhu, B., Yang, X.T., Xu, J., Zhu, Z.G., Ji, S.J., Sun, M.T. and Sun, J.C., Innovative low temperature SOFCs and advanced materials, J. Power Sources, Vol. 118, pp. 47–53, 2003.
[13]Kato, H., Kudo, T., Naito, H. and Yugami, H., Electrical conductivity of Al-doped La1-xSrxScO3 perovskite-type oxides as electrolyte materials for low-temperature SOFC, Solid State Ionics, Vol. 159, pp. 217- 222, 2003.
[14]Shaula, A.L., Kharton, V.V., Waerenborgh, J.C., Rojas, D.P. and Marques, F.M.B. Oxygen ionic and electronic transport in apatite ceramics, J. Eur. Ceram. Soc., Vol. 25, pp. 2583-2586, 2005.
[15]Park, J. H. and Blumenthal, R. N., Electronic Transport in 8 Mole Percent Y2O3-ZrO2, J. Electrochem. Soc., Vol. 136, Issue 10, pp. 2867-2876, 1989.
[16]Singhal, S. C. and Kendall, K., High temperature solid oxide fuel cells: fundamentals, design and applications, Elsevier Science, Kidlington, 2003
[17]Sun, C. and Stimming, U., Recent anode advances in solid oxide fuel cells, J. Power Sources, Vol. 171, pp. 247-260, 2007.
[18]Clemmer, R. M.C. and Corbin, S. F., The influence of pore and Ni morphology on the electrical conductivity of porous Ni/YSZ composite anodes for use in solid oxide fuel cell applications, Solid State Ionics, Vol. 180, pp. 721-730, 2009.
[19]Haanappel, V.A.C., Mertens, J., Rutenbeck, D., Tropartz, C., Herzhof, W., Sebold, D. and Tietz, F., Optimisation of processing and microstructural parameters of LSM cathodes to improve the electrochemical performance of anode-supported SOFCs, J. Power Sources, Vol. 141, pp. 216-226, 2005.
[20]de Boer, B., Gonzalez, M., Bouwmeester, H.J.M. and Verweij, H., The effect of the presence of fine YSZ particles on the performance of porous nickel electrodes, Solid State Ionics, Vol. 127, pp. 269-276, 2000.
[21]Mogensen, M., Jensen, K. V., Jørgensen, M. J. and Primdahl, S., Progress in understanding SOFC electrodes, Solid State Ionics, Vol. 150, pp. 123-129, 2002.
[22]Jeon, D. H., Nam, J. H. and Kim, C. J., Microstructural optimization of anode-supported solid oxide fuel cells by a comprehensive microscale model, J. Electrochem. Soc., Vol. 153, pp. A406-A417, 2006.
[23]Matus, Y. B., De Jonghe, L. C., Jacobson, C. P. and Visco, S. J., Metal-supported solid oxide fuel cell membranes for rapid thermal cycling, Solid State Ionics, Vol. 176, pp. 443-449, 2005.
[24]Panteix, P. J., Baco-Carles, V., Tailhades, Ph., Rieu, M., Lenormand, P., Ansart, F. and Fontaine, M. L., Elaboration of metallic compacts with high porosity for mechanical supports of SOFC, Solid State Sci., Vol. 11, pp. 444-450, 2009.
[25]Pyke, S. H., Howard, P. J. and Leah, R. T., Planar SOFC technology: stack design and development for lower cost and manufacturability, DTI Research Report, DTI/Pub-URN 02/1350, 2002.
[26]Haanappel, V. A. C. and Smith, M. J., A review of standardising SOFC measurement and quality assurance at FZJ, J. Power Sources, Vol. 171, pp. 169-178, 2007.
[27]Krishnan, V. V., McIntosh, S., Gorte, R. J. and Vohs, J. M., Measurement of electrode overpotentials for direct hydrocarbon conversion fuel cells, Solid State Ionics, Vol. 166, pp. 191-197, 2004.
[28]Lin, Y., Zhan, Z., Liu, J. and Barnett, S. A., Direct operation of solid oxide fuel cells with methane fuel, Solid State Ionics, Vol. 176, pp. 1827-1835, 2005.
[29]Aguilar, L., Zha, S., Cheng. Z., Winnick, J. and Liu, M., A solid oxide fuel cell operating on hydrogen sulfide (H2S) and sulfur-containing fuels, J. Power Sources, Vol. 135, pp. 17-24, 2004.
[30]Sasaki, K., Susuki, K., Iyoshi, A., Uchimura. M., Imamura, N., Kusaba, H., Teraoka, Y., Fuchino, H., Tsujimoto, K., Uchida, Y. and Jingo, N., H2S poisoning of solid oxide fuel cells, J. Electrochem. Soc., Vol. 153, Issue 11, pp. A2023-A2029, 2006.
[31]Taherparvar, H., Kilner, J. A., Baker, R. T. and Sahibzada, M., Effect of humidification at anode and cathode in proton-conducting SOFCs, Solid State Ionics, Vol. 162-163, pp. 297-303, 2003.
[32]Sakai, N., Yamaji, K., Horita, T., Xiong, Y. P., Kishimoto, H., Brito, M. E. and Yokokawa. H., Effect of water on electrochemical oxygen reduction at the interface between fluorite-type oxide-ion conductors and various types of electrodes, Solid State Ionics, Vol. 174, pp. 103-109, 2004.
[33]Xue, L. A., Barringer, E. A., Cable, T. L., Goettler, R. W. and Kneidel, K. E., SOFCo planar solid oxide fuel cell, Int. J. Appl. Ceram. Technol., Vol. 1, Issue 1, pp. 16-22, 2004.
[34]Liu, H. C., Lee, C. H., Shiu, Y. H., Lee, R. Y. and Yan, W. M., Performance simulation for an anode-supported SOFC using Star-CD code, J. Power Source, Vol. 167, pp. 406-412, 2007.
[35]Laurencin, J., Lefebvre-Joud, F. and Delette, G., Impact of cell design and operating conditions on the performances of SOFC fuelled with methane, J. Power Source, Vol. 177, pp. 355-368, 2008.
[36]Andreassi, L., Rubeo, G., Ubertini, S., Lunghi, P. and Bove, R., Experimental and numerical analysis of a radial flowsolid oxide fuel cell, Int. J. Hydrogen. Energ., Vol. 32, pp. 4559-4574, 2007.
[37]Bedogni, S., Campanari, S., Iora, P., Montelatici, L. and Silva, P., Experimental analysis and modeling for a circular-planar type IT-SOFC, J. Power Source, Vol. 171, pp. 617-625, 2007.
[38]Larrain, D., Van herle, J., Maréchal, F. and Favrat, D., Generalized model of planar SOFC repeat element for design optimization, J. Power Source, Vol. 131, pp. 304-312, 2004.
[39]Sulzer Hexis, Inc.; http://www.hexis.com/.
[40]Liu, S., Song, C. and Lin, Z., The effects of the interconnect rib contact resistance on the performance of planar solid oxide fuel cell stack and the rib design optimization, J. Power Sources, Vol. 183, pp. 214-225, 2008.
[41]Tanner, C. W. and Virkar, V., A simple model for interconnect design of planar solid oxide fuel cells, J. Power Sources, Vol. 113, pp. 44-56, 2003.
[42]Ferguson, J. R., Fiard, J. M. and Herbin, R., Three-dimensional numerical simulation for various geometries of solid oxide fuel cells, J. Power Sources, Vol. 58, pp. 109-122, 1996.
[43]Yakabe, H. and Sakurai, T., 3D simulation on the current path in planar SOFCs, Solid State Ionics, Vol. 174, pp. 295-302, 2004.
[44]Lin, Z., Stevenson, J. W. and Khaleel, M. A., The effect of interconnect rib size on the fuel cell concentration polarization in planar SOFCs, J. Power Sources, Vol. 117, pp. 92-97, 2003.
[45]Li, P.W., Kotwal, A., Sepulveda, J.L., Loutfy, R.O. and Chang, S., An easy-to-approach and comprehensive model for planar type SOFCs, Int. J. Hydrogen. Energ., Vol. 34, pp. 6393-6406, 2009.
[46]Ji, Y., Yuan, K., Chung, J. N. and Chen, Y. C., Effects of transport scale on heat/mass transfer and performance optimization for solid oxide fuel cells, J. Power Sources, Vol. 161, pp. 380-391, 2006.
[47]Gazzarri, J.I. and Kesler, O., Short-stack modeling of degradation in solid oxide fuel cells: Part I. Contact degradation, J. Power Sources, Vol. 176, pp. 138-154, 2008.
[48]Huang, S. C., Huang, C. M. and Shy, S. S., Numerical and experimental studies on effects of various sizes of pin-type flow distributors to cell performance of a single planar SOFC stack, 16th Computational Fluid Dynamics in Forum, Yilan, Taiwan, 2009.
[49]Huang, Q.A., Hui, R., Wang, B. and Zhang, J., A review of AC impedance modeling and validation in SOFC diagnosis, Electrochem. Acta, Vol. 52, pp. 8144-8164, 2007.
[50]Kim, C.H., Pyun, S.L. and Kim, J.H., An investigation of the capacitance dispersion on the fractal carbon electrode with edge and basal orientations, Electrochem. Acta, Vol. 48, pp. 3455-3463, 2003.
[51]Jorcin, J.B., Orazem, M.E., Pébére, N. and Tribollet, B., CPE analysis by local electrochemical impedance spectroscopy, Electrochem. Acta, Vol. 51, pp. 1473-1479, 2006.
[52]Leonide, A., Sonn, V., Weber, A. and Ivers-Tiffée, E., Evaluation and modeling of the cell resistance in anode-supported solid oxide fuel cells, J. Electrochem. Soc., Vol. 155, pp. B36-B41, 2008.
[53]Zhou, X. -D., Pederson, L. R., Templeton, J. W. and Stevenson, J. W., Electrochemical performance and stability of the cathode for solid oxide fuel cells: I. Cross validation of polarization measurements by impedance spectroscopy and current-potential sweep, J. Electrochem. Soc., Vol. 157, Issue 2, pp. B220-B227, 2010.
[54]Barfod, R., Mogensen, M., Klemensø, T., Hagen, A., Liu, Y.L. and Hendriksen, P.V., Detialed characterization of anode-supported SOFCs by impedance spectroscopy, J. Electrochem. Soc., Vol. 154, pp. B371-B378, 2007.
[55]ThyssenKrupp VDM; http://www.thyssenkrupp-vdm-fareast.com/.
[56]Kumtek International Co., Ltd.; http://www.kumtek.com.tw/.
[57]Jørgensenz, M. J. and Mogensen, M., Impedance of solid oxide fuel cell LSM/YSZ composite cathodes, J. Electrochem. Soc., Vol. 148, Issue 5, pp. A433-A442, 2001.
[58]Primdahl, S. and Mogensen, M., Gas diffusion impedance in characterization of solid oxide fuel cell anodes, J. Electrochem. Soc., Vol. 146, Issue 8, pp. 2827-2833, 1999.
[59]Primdahl, S. and Mogensen, M., Gas conversion impedance: A test geometry effect in characterization of solid oxide fuel cell anodes, J. Electrochem. Soc., Vol. 145, Issue 7, pp. 2431-2437, 1998.