Study on the characteristics of GDL with different PTFE content and its effect on the performance of PEMFC

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.