燃料電池為21世紀極需發展之新能源科技，其具有高能量轉換效率及低污染之優點，其中固態氧化物燃料電池(SOFC)由於其效率高，所以相當適合做為中小型分散式發電系統，傳統SOFC之設計採用厚膜式(150μm)的YSZ固態電解質當支撐Cell基材，在其兩側塗上薄層的兩電極，為求固態電解質層具有足夠之離子導電度，需在900~1000℃之高溫操作，高溫操作溫度會造成材料及週邊設備之選擇性受限、電極產生燒結之現象、電極與電解質間發生反應、及運轉週期所產生之熱應力等問題，故降低操作溫度為現階段SOFC研究發展之重要課題。
本研究利用電泳沉積法製備YSZ電解質薄膜，因其具製程簡易、設備成本低、產品外型限制少及適合商業化大量生產等優點，於前人的相關研究中，利用電泳沉積法可成功的將YSZ薄膜被覆在LSM基材及Ni-YSZ基材上，但在電泳被覆後將YSZ生胚薄膜進行燒結時會有高電阻第二相之生成及Ni氧化為NiO之問題產生。
為避免電極與電解質之間於薄膜燒結時產生反應及簡化製程，故本研究以LixNi2-xO2取代傳統燃料電池陽極材料之NiO，藉由鋰離子之添加使陽極基材在室溫下具足夠之導電性，以達成電泳沉積YSZ薄膜之目的。利用電泳沉積法可在LixNi2-xO2-YSZ電極基板上沉積厚度約20μm之YSZ電解質薄膜，並且探討電泳懸浮液中碘電解質添加量、外加電壓、沉積時間等參數對於薄膜沉積重量及沉積品質之影響。
由於本研究以LixNi2-xO2取代傳統SOFC陽極材料之NiO，故對於LixNi2-xO2氧化物作還原氣氛下之熱處理，結果於800℃、20%的氫氣氣氛下還原24小時後，LixNi2-xO2可還原為金屬鎳，且陽極基材(LixNi2-xO2-YSZ)經過還原步驟後，符合SOFC所需之多孔性電極材料，另外研究陽極基板材料(LixNi2-xO2-YSZ)與電解質材料(8YSZ)升溫燒結行為，知鋰含量之增加會造成LixNi2-xO2-YSZ基材之燒結溫度之降低，且升溫燒結時體積變化量隨鋰含量之增加而增加，低鋰含量x=0.2之LixNi2-xO2-YSZ基材具有與薄膜材料YSZ最接近之熱膨脹行為。

Yttria-stabilized Zirconia (YSZ) is the most commonly used electrolyte material for Solid Oxide Fuel Cells (SOFCs) because of its unique combination of properties such as high chemical and thermal stability and pure ionic conductivity over a wide range of conditions. The oxide-ion conductivity of YSZ is poor; Therefore, the high operation temperature (900-1000℃)is required for an SOFC. Due to the high operation temperature (900-1000℃) the material demand upon SOFC components are quite stringent. Currently, the goal of SOFC development is to decrease the operating temperature, so that the material selection for cell construction will be easier. The operating temperature can be decreased by lowering the electrolyte resistance either by decreasing the electrolyte thickness or with alternative materials of higher ionic conductivity at lower temperatures.
The electrophoretic deposition (EPD) is a colloidal fabrication process and has advantage of short formation times, little restriction in the shape of substrates, simple deposition apparatus, and for mass production. Therefore, the EPD method is seen as a low-cost method for preparing electrolyte thin films for SOFC. In the past , the preparation of YSZ film on a porous LaMnO3-based oxide and nickel-Y2O3-stabilized ZrO2 substrates were investigated using EPD to produce SOFCs. However YSZ reacts easily with the LaMnO3-based cathode oxide to form an La2Zr2O7 phase when sintering of the green film , and the resulting poorly conducting La2Zr2O7 compound at the electrolyte/cathode interface is undesirable for SOFCs. Therefore, sintering YSZ film on a porous LaMnO3-based oxide substrate is more difficult than sintering on an anode substrate.
In this study, LixNi2-xO2-YSZ was used to replace LaMnO3-based oxide substrate to avoid the reaction between electrode and electrolyte when sintering the YSZ film. YSZ films with thickness of about 20μm have been successfully prepared on LixNi2-xO2-YSZ substrate via EPD process. Dense and crack-free YSZ film can be obtained when the green film was sintered at 1400℃ for 2h.
LixNi2-xO2 was reduced to metallic Nickel by a heat treatment in 20% H2, 80% Ar2 atmosphere at 800℃ for 24h. Subsequently, LixNi2-xO2-YSZ substrate became a porous material after reducing. From the thermal expansion analysis it was observed, the sintering temperature of LixNi2-xO2-YSZ substrate was decreased and dimensional change increased when the amount of Li was increased. The thermal expansion behavior of Li0.2Ni1.8O2-YSZ is close to that of YSZ electrolyte.

[1] S.C. Singhal, “Science and Technology of Solid Oxide Fuel Cells,” MRS Bulletin, March 2000.
[2] N. Q. Minh, “Ceramic Fuel Cell,” J.Am.Ceram. Soc.,76 [3] 563-588, 1993.
[3] A.O.Isenberg, in: J.D.E. McIntyre, S. Srinsvan, F.G. Will (Eds), Proc.Symp.Electrode Materials Processes for Energy Coversion and Storage, Vol. 77, Electrochemical Society, Pennington, NJ, 1977, p.572.
[4] U. Pal, S.C. Singhal, J. Electrochem. Soc. 137 (1990) 2937.
[5] J.P. Dekker, V.E.J van Dieten, J. Schoonman, Solid State Ionics 47 (1991) 331.
[6] A.C. Jones, Chem. Vap. Deposition 4 (1998) 169.
[7] K.-W. Chour, H. Chen, R. Xu, Thin Solid Films 304 (1997) 106.
[8] K. Honegger, E. Batawi, C. Sprecher, and R. Diethelm, in U. Stimming, S. C. Singhal, H. Tagawa, W.Lehnert (Eds.), Proceedings of the Fifth International Symposium on Solid Oxide Fuel Cells, 1997, p. 321.
[9] T. Nakayama, H. Tajiri, K. Hiwatashi, H. NishiYama, S. Kojima, M. Aizawa, K. Eguchi, and H. Tagawa, W.Lehnert (Eds.), Proceedings of the Fifth International Symposium on Solid Oxide Fuel Cells, 1997, p. 187.
[10] M. Cassidy, K. Kendall, C. Lindsay, in: B. Thorstensen(Ed.), Proc. 2nd European Solid Oxide Fuel Cell Forum, European SOFC Forum, Oberrohrdorf, Switzerland, 1996, p. 667.
[11] J.Will, Porous support structures and sintered thin film electrolytes for solid oxide fuel cells, Diss. ETH No. 12876, ETH, Zurich, 1998.
[12] Z. Peng and M. Liu, “Preparation of Dense Platinum-Yttria Stabilized Zirconia and Yttria Stabilized Zirconia Films on Porous La0.9Sr0.1MnO3(LSM) Substrates,” J. Am. Ceram. Soc., 84 [2] 283-88 (2001).
[13] P. Sarkar and P. S. Nicholson, “Electrophoretic Deposition (EPD): Mechanism, Kinetics, and Application to Ceramic,” J. Am. Ceram. Soc., 79 1987-2002 (1996).
[14] T. Ishihara. K. Sato, and Y. Takita, “Electrophoretic Deposition of Y2O3-Stabilized ZrO2 Electrolyte Films in Solid Oxide Fuel Cells.” J. Am. Ceram. Soc. 79 [4] 913-19 (1996).
[15] T. Ishihara, K. Shimose, T. Kudo, H. Nishiguchi, T. Akbay, and Y. Takita, “Preparation of Yttria-Stabilized Zirconia Thin Film on Strontium-Doped LaMnO3 Cathode Substrates via Electrophoretic Deposition For Solid Oxide Fuel Cells.” J. Am. Ceram. Soc. 83 [8] 1921-27 (2000).
[16] F. Chen, M. Liu, “Preparation of yttria-stabilized zirconia thin film on La0.85Sr0.15MnO3 and LSM-YSZ substrates using an electrophoretic deposition (EPD) process.” J. Eur. Ceram. Soc., 21 127-134 (2001).
[17] K. Kobayashi, I. Takahashi, M. Shiono, M. Dokiya “ Supported Zr(Sc)O2 SOFCs for reduced temperature prepared by electrophoretic deposition.”, Solid State Ion. 152-153 (2002) 591-596.
[18]李邦哲譯, ”燃料電池”, 台灣經濟研究月刊,p72-74
[19]呂承頤, “燃料電池在太空之應用,” 能源、資源與環境, vol.3, No.1, 1990 p2-6
[20] K. Kordesch and G. Simader, in:Fuel cells and their applications. pp.51-166 .
[21] S.C. Singhal, “Status of Solid Oxide Fuel Cell Technology,”
[22] D.H Archer, J.J. Alles, W.A. English, L. EliKan, E.F. Sverdrup, R.L.Zahradnik, in:Westinghouse Solid-Electrolyte Fuel Cell, Fuel Cell Systems, pp332-342.
[23] F. F.Reuss, “Notice sur un nouvel Effet de 1¢electricite gavanique,” Mem. Soc. Imp. Natur. Moscou, 2 (1809) 327-37
[24] H. C. Hamaker, “Physical ”, 4 (1937) 1058- 64
[25] Y. Hirata. A. Nishimoto. And Y. Ishihara. “Forming of Alumina Powder by Electrophoretic Deposition,” Seramikusu Kyukai Ronbunshi, 99. 108 (1991).
[26] J.Will, A. Mitterdorfer, C. Kleinlogel, D. Perednis, L. J. Gauckler “Fabrication of thin electrolyte for second-generation solid oxide fuel cells” , Solid State Ion. 131 (2000) 79-96.
[27] A. Rougier, P. Gravereau and C. Delmas, “Optimization of the composition of the Li1-zNi1+zO2 electrode materials: structural, magnetic, and electrochemical studies.” J. Electrochem. Soc. 143 (1996) 1168.