Determining the formulation and fabrication of high rigidity composite plates for use in the end plates of PEM fuel cells

One of the most important parts in fuel cells is the end plates, which withstand the pressure caused by the reactions inside the cells and have the task of clamping the plates. As a result, these plates must be able to withstand a high bending force [۱]. Therefore, the flexural modulus parameter is very important in the construction of these plates. In this paper, we have taken an important step in lightening and increasing the special flexural modulus of these plates by building polymer composite plates and replacing them with heavy steel plates. These composite plates were made by vacuum bag method and made of epoxy resin (to be compatible with the almost acidic atmosphere of the fuel cell) and carbon and glass fibers. These plates were made in four formulations with different arrangement angles of unidirectional fibers (۰ degrees in one direction, ۰,۹۰ degrees in ۲ directions). Then the three-point bending test of these plates were investigated to calculate the flexural modulus and the specific flexural modulus. One of the heavy parts in fuel cells is their end plates, which are made from steel to withstand high pressure and corrosion protection. Polymer composites are materials that are composed of resins and fibers or polymer nanoparticles and bring amazing properties. Due to the low weight of composites, modulus to weight ratio (specific modulus) of these materials are significantly superior to metallic materials [۲]. In this project, our goal is to build and replace light composite plates instead of heavy steel plates. First, studies are done to achieve how these plates are made and then efforts are made to produce and industrialize these plates.Unidirectional glass fibers ۲۸۰ g, unidirectional carbon fibers ۲۰۰ g and laminating resin epoxy (Tg۸۰ ° C with ۱۵% hardener) were purchased from Aladdin Chemistry Co., Ltd, China. ۴ composite plates with the optimum percentage of resin and fibers (۶۰% fibers and ۴۰% resin) were made using vacuum bag method.Three-point bending test was taken from ۴ composites and the flexural modulus was calculated for each specimen (Table ۱). As can be seen, the carbon / epoxy specimen (۰,۰) has the highest modulus. The specific bending modulus of this sample, according to the specific gravity of steel (۷.۸۷) and the composite sample (۱.۵۵) is much higher than steel. Also, changing the thickness of composites is much easier and has a longer range than metals. Bending test diagrams are also visible for a carbon/epoxy sample and a glass/epoxy sample. (Fig ۱ and Fig ۲) In this study, we succeeded in making polymer composite sheets that have a bending modulus close to metals and a special bending modulus much higher than metals. The results of this research are much lighter end plates, with much lower manufacturing costs and cheaper and easier machining process