電泳沉積法製備固態氧化物燃料電池

Abstract

固態氧化物燃料電池(Solid Oxide Fuel Cell；SOFC)由於擁有高能量轉換效率以及多種燃料選擇性的一種潔淨發電裝置，故發展日趨重要。但是，發展SOFC卻受制於相當高的操作溫度與生產成本，導致必須發展降低成本的製程方式。在SOFC中，高溫離子傳導性影響電池效能，所以如何製備緻密固態電解質薄膜就相對的重要。本研究採取電泳沉積法(Electrophretic Deposition；EPD)來製備SOFC，電泳沉積法具備相當多的優勢，如裝置簡易、可進行不同形狀的沉積、大規模的製備以及可藉由電壓的調控來得到孔洞性或緻密性的結構等。 研究分三主軸進行，首先探討電泳沉積法懸浮液的特性以及燒結行為對固態電解質微結構的影響，並進一步選擇出最佳的調控條件來進行製備SOFC。第二部分則嘗試使用電泳共沉積與一步燒結法分別製備以釔穩定氧化鋯(YSZ)與釤摻雜氧化鈰(SDC)為電解質的三層SOFC結構，並對燒結過後的全電池進行微結構的研究，進一步探討電泳共沉積與一步燒結之可行性。最後，使用電泳單層電解質層的方式進行製備SOFC，經高溫燒結後進行微結構分析以及電化學量測。

Solid oxide fuel cells (SOFCs) have received significant attention recently since their characteristic high efficiency for energy conversion and multiple fuel selections promise to be a clean electric power generation approach. However, the application of SOFCs is limited by the excessive operation temperature and relatively high system cost because of the high operation temperature. Therefore, current research interests have devoted to reducing the operation temperature as well as developing an inexpensive fabrication method. In the general, the ionic conductivity in the solid electrolyte plays a critical role in determining the operation temperature of a SOFC. In order to reduce the operation temperature, it is necessary to achieve a thinner and denser electrolyte film. To achieve this goal, we selected the electrophretic deposition (EPD) approach to fabricate the SOFC structure because the EPD is long established as a powerful tool for forming complex ceramics in diverse shapes and on various substrates. Also, the application of EPD to fabricate SOFCs has been demonstrated by previous research. This research is divided into three parts. First, we discussed the EPD suspension properties, the microstructure after sintering, and the optimized conditions to fabricate SOFCs. In the second part, we tried to fabricate the tri-layer structure by Co-Deposition and One Step Sintering method. Meanwhile, we discussed the microstructure after sintering and the feasibility of this method. Finally, a Step-by-Step method was performed to fabricate SOFCs. The electrochemical analysis was conducted and the microstructure after sintering was investigated.