| 摘要: | 本研究使用脈衝雷射沉積法(Pulsed Laser Deposition, PLD)製備Pt奈米顆粒並應用於燃料電池陰陽極端之觸媒層，結合直通流道板及自製微孔層並滴塗含有二氧化鈰顆粒的Nafion薄膜(Dropcasted Nafion film)將質子交換膜直接滴塗於觸媒層上，在膜內增加質子通道，提升質子與水的傳導能力，並增加膜內保水性、降低自由基所造成的降解，提升膜的耐久性。
本研究先進行燃料電池流道結構的優化，3x3單區及三區的性能比較，並將實驗室學姊在5x5流道減薄的優化結果應用在適合脈衝雷射沉積製程的3x3流道中。減薄發泡材流場具有較寬的進出氣口可改善流體分布均勻性並降低壓降，顯示經過改良之流道，亦可有效提高電池之性能。
過去實驗室皆是使用39BC碳紙進行研究，可以適用於滴塗膜燃料電池製程，但因為目前此型號已停產，須尋找替代產品。而39BB碳紙因為裂縫較大、裂縫表面積占比較高其裂縫寬度較39BC大、裂縫表面積占比也較39BC高，經測試不適用於滴塗膜燃料電池，需自製微孔層。在成功製作出微孔層後，將造孔劑加入MPL漿料中，再利用高溫的方式，在烤乾微孔層的同時，將分布在其中的造孔劑去除，藉此留下多孔隙的結構，增進氣體傳輸效率，使得性能可以提升。
並透過比較二氧化鈰的摻雜量，在相同的操作溫度及溫度下，因二氧化鈰有好的吸水特性，使得膜能更有效的吸收水分。由於水分在膜中的分布改變，水傾向膜的方向集中，不會積聚於觸媒層，減緩觸媒層的水淹現象，可以提高電池的開路電壓及功率密度。
;This study employed the Pulsed Laser Deposition (PLD) method to prepare Pt nanoparticles for application in the catalyst layer of fuel cell anode and cathode. By combining a straight-through flow plate with a self-made microporous layer, a Nafion thin film containing cerium dioxide particles was drop-casted on the catalyst layer. This approach increased proton conduction and water transport within the membrane, improved water retention, and reduced degradation caused by free radicals, thereby enhancing the durability of the membrane.
In this study, the optimization of the fuel cell flow channel structure was conducted. The performance of 3x3 single-area and three-area configurations was compared. The optimization results obtained from thinning the 5x5 flow channel in a previous experiment by a senior researcher in the laboratory were applied to the 3x3 flow channel suitable for the pulsed laser deposition process. Thinning the foamed material in the flow field resulted in wider inlet and outlet openings, improving the uniformity of fluid distribution and reducing pressure drop. These modifications demonstrated the effective enhancement of the fuel cell performance.Previous studies in the lab utilized 39BC carbon paper, which was suitable for drop-casting membrane fuel cell fabrication. However, as this model is no longer in production, an alternative product needed to be identified. 39BB carbon paper had larger cracks and higher crack surface area compared to 39BC, rendering it unsuitable for drop-casting membrane fuel cells. Therefore, a self-made microporous layer was developed. After successfully fabricating the microporous layer, a pore-forming agent was added to the MPL slurry. Through a high-temperature process, the pore-forming agent was removed, leaving a porous structure that improved gas transport efficiency and enhanced performance.
Furthermore, the doping level of cerium dioxide was compared. At the same operating temperature and humidity, the good water-absorbing properties of cerium dioxide enabled the membrane to effectively absorb moisture. The change in water distribution within the membrane concentrated water towards the center, preventing flooding of the catalyst layer and improving reaction efficiency, thereby increasing the fuel cell′s current density. |
