- 學位論文
質子交換膜燃料電池膨脹石墨/粉末狀環氧樹脂/碳纖維雙極板製程與性質之研究
Study on the Manufacture Process and Property of Expandable Graphite/Powder Epoxy/Carbon Fiber Bipolar Plate for PEMFC
摘要
質子交換膜燃料電池是一種將燃料和氧化劑中的化學能直接或間接轉換成電能的發電裝置。相較於熱機或二次電池，質子交換膜燃料電池具有較高的能量轉換率。燃料電池中雙極板主要功用在分配燃料與氧化劑給MEA，並有串聯單電池之作用。 本研究以粉末狀熱固性環氧樹脂與膨脹石墨均勻混合後再添加碳纖維材料經由熱壓成型。以瞭解碳纖維類型對導電複合板之機械、電導、氣密及熱傳導等重要性質的影響。實驗結果顯示：短纖維含量在超過13.5%後，除抗壓能力外，其他性質明顯下降；碳纖維平面編織布數量增加，複合板的抗拉強度、抗壓能力有很好提升效果；三維編織碳纖維對於熱傳導有提升效果，但是氣密性會下降；碳纖維編織布預浸材可加強碳纖維與膨脹石墨的結合力，對於抗拉強度、氣密性有良好提升效果；製作加入碳纖維編織布之複合雙極板進行電池測試，加入五片碳纖維編織布最大電流密度2080 mA/cm2比放置一片碳纖維編織布最大電流密度2240mA/cm2低。
並列摘要
PEMFC is an electrical device which directly converts chemical energy of fuel and oxidant to electricity. Compare with a heat engine or a rechargeable battery, PEMFC has high efficiency of energy transform. The main capability of a bipolar in fuel cell is to distribute fuel and oxidant to the membrane electrode and to provide electrically connection between neighboring single cells. In this research, the composite plates are made of mixture which include expandable graphite、powder Epoxy and carbon fiber by hot-press process. The purpose of this paper is to study the influence of type of carbon fiber(short carbon fiber、plain weave carbon fiber、three-dimensional structure carbon fiber、plain weave carbon fiber prepreg) on the mechanical and electrical properties of the expanded graphite bipolar plates made by hot-press method. All properties decrease when content of short carbon fiber is over 13.5%. The type of plain weave carbon fiber can promote mechanical property. The type of three-dimensional structure carbon fiber can improve heat conduction property, but permeability is so bad. Plain weave carbon fiber prepreg enhance the binding force of expandable graphite and carbon fiber, it promote permeability. The manufacture condition of bipolar is expandable graphite and 30% powder Epoxy and add in 5 pieces(1 piece) plain weave carbon fiber. The characteristic IV curves and IP curves of the fuel cells are obtained from the single fuel cell tests. The results of add in 5 pieces plain weave carbon fiber that the great current density of 2080 mA/cm2 occurs at 0.3 V, and the highest power density of 759 mW/cm2 occurs at 0.5 V. The results of add in 1 pieces plain weave carbon fiber that the great current density of 2240 mA/cm2 occurs at 0.3 V, and the highest power density of 807 mW/cm2 occurs at 0.4 V.