陽極電極壓力對直接甲醇燃料電池之性能影響

Influence of Anode Electrode Pressure on the Performance of Direct Methanol Fuel Cell

徐志豪(Chih-Hao Hsu)

指導教授 ： 蘇春熺

國立臺北科技大學/機電學院/機電整合研究所/碩士(2010年)

摘要

隨著能源價格上升，且需求量不斷增加，因此替代能源成為新的發展方向，直接甲醇燃料電池(Direct Methanol Fuel Cell)可成為小型電子產品之替代能源。燃料電池組裝時，受到螺栓施加壓力不平均而導致集電板變形，這些變形將影響到電池之發電效能。本研究主要探討施加不同壓力於陽極MEA時變形量對於效能之影響與利用CCD影像估算甲醇消耗量。實驗將分為三個部分，首先，利用ANSYS模擬當改變陽極電集位置時MEA的變形量；第二部分為量測其電池功率效能，此部分可以分為改變陽極集電位置以及施加不同壓力於陽極集電位置，並探討溫度變化對於電池效能之影響；最後為利用CCD (Charge Coupled Detector) 擷取電化學反應所生成之二氧化碳氣泡影像，並利用氣泡面積估算甲醇消耗量。
由模擬結果可以得到擺放於中央位置的變形量較為均勻，其餘位置所得之變形分析結果較為不均勻；陽極集電位置在靠近陰極集電端之效能較佳，遠離陰極集電端則效能較低；施加較高壓力於陽極MEA上，電池量測效能較佳，最高功率密度可達1.18 mW．cm-2，當溫度增加時量測效能之最高功率密度為2.06 mW．cm-2，增加率為75 %。由交流阻抗測得阻值受到壓力增加而有減少之趨勢，當施加壓力為1.55 N．mm-2阻抗為0.65 Ω，施加壓力為1.35 N．mm-2阻抗為1.93 Ω；最後經由CCD量測甲醇消耗量之結果，越高負載之電流密度，所消耗之甲醇較多，使用之時間縮短，因為高電流密度電化學反應較劇烈，因此較容易造成甲醇毒化及消耗等問題產生，因此所提供效能之時間較短。

關鍵字

直接甲醇燃料電池 ； 二氧化碳 ； 介面壓力 ； 螺栓壓力

並列摘要

The price of energy was increased and consumes more than before. So many researchers want to find new energy to replace oil. Direct Methanol Fuel Cell (DMFC) will become the best option of portable electronic products. The miniature DMFC and air-breathing DMFC has become recently the major design concepts of DMFC stacks development. This paper aim at the effect of assembles DMFC, because the different machine bolts force to pressure DMFC structure. Inadequate clamping pressure may lead to leakage of fuel cell, high electric impedance and malfunction of the fuel cell. In order to treat about fuel cell capability under different coefficients in the anode collection, include anode place、anode pressure and temperature of DMFC. In the experiment, it used ANSYS’s Workbench software to simulate different places of anode collection and different pressures of anode collection. A charge coupled detector (CCD) camera was used to take images of carbon dioxide (CO2) during operation of DMFC. To measure volume of carbon dioxide (CO2) created at anodic of direct methanol fuel cell (DMFC) using image processing. For DMFC in order to explore relation between current output and as-imaged carbon dioxide (CO2) volume at 25 °C.
The simulation results can know that the current collectors placed at the central location of the deformation is more uniform than the other position results from more uniform deformation. Current collector exert high pressure on the anode of the MEA can measure better battery performance. The maximum power density was 1.18 mW. cm-2. When the temperature increases to 50 C, the maximum power density measure was 2.06 mW.cm-2, increase the rate of 75%. Impedance measured resistance has decrease in the trend because the pressure of increasing. When the pressure is 1.55 N.mm-2 resistance of 0.65 Ω, pressure to 1.35 N.mm-2 resistance of 1.93 Ω.

並列關鍵字

Direct Methanol Fuel Cell ； CO2 ； Clamping Pressure ； Bolt-Clamping

參考文獻

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