質子交換膜燃料電池於運作過程中，往往不當的操作行為將會產生電池堆性能下降與各級電池之電壓分佈不均的問題。此外，日後燃料電池將朝向系統整合，故整體系統體積勢必需有效降低，且為了減少額外消耗之電功，使燃料電池整體發電效率提升，所以本研究將陰極增濕之方法，由需耗電的氣泡式增濕器改為薄膜式增濕器，此法不但縮小系統體積，且減少周邊系統的耗電量，但對於性能提升上與氣泡式相較之下並無太大差異，但可使輸出之功率較為穩定。
本研究為反應面積120cm2之五級質子交換膜燃料電池堆，根據交流阻抗技術與極化曲線之診斷方法，探討操作參數為輸出電流、電池溫度、空氣當量比與增濕溫度等，觀察電池堆與各級電池之性能與阻抗影響，由實驗結果得知，當利用氣泡式增濕器時，一旦電池溫度大於增濕溫度時，提升空氣當量比與電池溫度將會導致電池性能降低與各級電池之電壓分佈不均問題，且不利於接近中央電池之性能；若陰極改以薄膜式增濕器時，增濕效果將隨輸出電流、空氣當量比與電池溫度增加而提升。

The proton exchange membrane fuel cell (PEMFC) is one of the most promising alternative energy devices. It has attracted lots of public attention due to its high energy efficiency and zero emissions. The research and development of fuel cells was also very vigorous in the past two decades. However, an improper operation condition may cause a drop of the stack performance and a decrease of the voltage uniformity of each individual cell. In order to reduce the volume of the fuel cell system and to reduce the power consumption of components, the membrane-type humidifier was used at cathode instead of the bubble-type humidifier. The results showed that the performance of the membrane-type humidifier was close to that of the bubble-type humidifier, and the stack power using the membrane-type humidifier was more stable than that using bubble-type humidifier.
In this study, a 5-cell PEMFC stack with 120 cm2 of the reactive area was made. The stack performance and the resistance at different operation conditions
, including cell temperatures, dew points, air stoichiometric ratios and currents, were studied in this work. From the results of polarization curve tests and EIS tests, increasing the air stoichiometric ratio and cell temperature resulted in a decrease of the stack performance and a decrease of the voltage uniformity of each individual cell when the bubble-type humidifier was used and the cell temperature was greater than the dew point. Furthermore, the equivalent dew point for the membrane-type humidifier increased with the increase of currents, air stoichiometric ratios and cell temperatures.

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