Research On The Physical Durability Of Proton Exchange Membrane

Proton exchange membrane fuel cell (PEMFC), which can directly turn thechemical energy of the fuel into electricity, is a kind of application prospect is verybroad energy conversion device, and has the characteristics such as high energyconversion rate and free pollution. When fuel cells are working, proton exchangemembrane is required to conduct proton and separating polar reaction gas (hydrogenand oxygen or air). During the long-term operation, proton exchange membrane isunder a high temperature, high humidity and pressure environment. The PEMs’stability has essential influence on the electrochemical properties and service life ofPEMFCs. Based on the operation environment, proton exchange membrane’sphysical mechanical performance was studied under the different conditions,including the physical performance degradation in the fuel cell membrane electrodematerials’ preparation and normal use. The main results are listed as following:(1) The compression test results of proton exchange shows that the protonexchange membrane will be compressed under the pressure, and the deformation ismore apparent by the temperature rise. The morphology of membrane is relativelystable, to ensure enough mechanical strength in use process.(2) Under the condition of different fixed, the membranes also have differentdeformation by the pressure act. When using the sealing gasket on the both sides ofthe membrane, membrane is crumpled at the contact parts between the middle partand sealing gasket. Fixed by carbon papers and sealing washers, the membranes havea uniform deformation after compression. The membranes have a mainly deformationof thickness more than in plane position, by the edges are fixed.(3) Loop tensile test is used to study the long-term stability of the protonexchange membrane under low stress. The experimental results showed that with theincrease of cycling times, membrane will produce a certain amount of elongation, andthe internal structure also have small changes. The material of membrane becomefragility, even produce irreversible plastic deformation. Along with the increase ofloading rate, the membrane’s elongation increases further, has a large residualdeformation, and more obvious cracks inside. If sustained, it will lead to the failure phenomenon of membrane.