(255a) Fabrication of PBI Based Composite Membrane for Application in High Temperature Polymer Electrolyte Membrane Fuel Cells

Recently, the area of fuel cells have received increased attention from many researchers. One of those type is high temperature polymer electrolyte membrane fuel cells (HT-PEMFC), which utilizes phosphoric acid as a medium for proton conducting over conventional water. One of the main polymer series used for this application is polybenzimidazole (PBI). It has the necessary thermal and chemical stability, as well as affinity towards phosphoric acid, allowing it to be an excellent candidate for HT-PEMFC. Though it has the ability to surpass conventional low temperature PEMFC, one of its current limiting factor is its conductivity, which the basic PBI shows lower values (~0.1S/cm or less). To overcome this, PBI based composite membranes were developed for their application in HT-PEMFC by introducing Al-Si nanoparticles. The fillers were created via metal grafting the silica nanoparticle to improve its affinity towards phosphoric acid, one of the determining factors in performance of the membrane. A series of membrane containing different amount of filler was fabricated in order to study its effect on the membrane. Its basic characteristics were studied via thermogravimetric analysis (TGA), scanning electron microscope (SEM) and universal testing machine (UTM). Its performance as a PEM was studied via its phosphoric acid doping level, proton conductivity and a single cell test by fabrication of MEA.