Effects of fluorosilicone rubbers on electrochemical performance and durability of proton exchange membrane fuel cell

초록

Gasket is a sealing material in proton-exchange membrane fuel cells (PEMFC) to prevent leakage and to prevent mixing of hydrogen and oxygen. Silicone is an ideal candidate for gasket of PEMFC because of its excellent chemical stability and heat resistance. However, contaminants eluted from the silicone gasket can greatly affect the electrochemical performance and durability of PEMFC. Therefore, in this work, a silicone gaskets containing fluorine groups were synthesized to give the gasket the characteristics of high acid resistance and low ion leaching, and the effect of the fluorine group content on the acid resistance and ion elution properties of the gasket will be investigated. Electrochemical performance tests will be performed to investigate the effect of fluorine group content on the performance of PEMFC. Weight loss of the samples will be monitored. Optical microscopy will be used to observe the surface change of the sample under an acidic environment and the mechanical strength will be measured to confirm the acid resistance. In addition, inductively coupled plasma will be employed to investigate silicone leachants eluted from the sample according to the content of fluorine groups, and Fourier transform infrared spectroscopy will be used to investigate changes in the surface chemistry of samples before and after exposure to the PEMFC environment. It is expected that the silicone gasket containing fluorine groups will have better acid resistance and ion leaching properties compared to general silicone gaskets, and the higher the content of fluorine groups, the more pronounced such tendency will be.