Abstract The content of Polytetrafluoroethylene (PTFE) is the key factor to determine the hydrophobicity and heat transfer characteristics of the gas diffusion layer (GDL), which directly affects the performance of the proton exchange membrane fuel cell (PEMFC). The PTFE content of GDL materials changes due to the complex and variable working conditions and the accumulation of working hours in fuel cells. In order to study the effect of PTFE content and external load on the thermal conductivity of GDL materials, a new method based on Fiber Bragg Grating (FBG) sensing technology was proposed to measure the thermal conductivity of GDL materials. The thermal conductivity of GDL materials with different PTFE content was measured by FBG temperature sensor, and the effect of different PTFE content on the performance of fuel cell was studied. The experimental results show that the hydrophobicity of GDL material increases with the increase of PTFE content, and different PTFE content of GDL materials have different effects on the performance of PEMFC. The difference of thermal conductivity of GDL material with different PTFE content can be measured by using FBG sensing measurement technology, which reflects the change of GDL material properties due to the difference of PTFE content in the GDL material. The results of this study provide guidance for the method of detecting the change of internal material characteristics of PEMFC.

中文翻译：

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不同PTFE含量的GDL特性及其对PEMFC性能的影响研究

摘要 聚四氟乙烯（PTFE）的含量是决定气体扩散层（GDL）疏水性和传热特性的关键因素，直接影响质子交换膜燃料电池（PEMFC）的性能。GDL材料的PTFE含量由于复杂多变的工作条件以及燃料电池工作时间的累积而发生变化。为了研究PTFE含量和外载荷对GDL材料热导率的影响，提出了一种基于光纤布拉格光栅（FBG）传感技术测量GDL材料热导率的新方法。采用FBG温度传感器测量了不同PTFE含量的GDL材料的热导率，研究了不同PTFE含量对燃料电池性能的影响。实验结果表明，GDL材料的疏水性随着PTFE含量的增加而增加，不同的GDL材料的PTFE含量对PEMFC性能的影响不同。利用FBG传感测量技术可以测量不同PTFE含量的GDL材料的热导率差异，它反映了GDL材料中PTFE含量的差异引起的GDL材料性能的变化。本研究结果为检测PEMFC内部材料特性变化的方法提供指导。利用FBG传感测量技术可以测量不同PTFE含量的GDL材料的热导率差异，它反映了GDL材料中PTFE含量的差异引起的GDL材料性能的变化。本研究结果为检测PEMFC内部材料特性变化的方法提供指导。利用FBG传感测量技术可以测量不同PTFE含量的GDL材料的热导率差异，它反映了GDL材料中PTFE含量的差异引起的GDL材料性能的变化。本研究结果为检测PEMFC内部材料特性变化的方法提供指导。