Method of compounding conductive polypropylene-graphite composite for bipolar plates of hydrogen fuel cell

氢化物公司是加拿大市场的领先者之一，在全球范围内提供氢电解槽和燃料电池，作为化石燃料的清洁能源替代品。对于电网在非高峰时段的过剩电力，以及风力涡轮机和太阳能电池板产生的电力，氢气是最有效和最具成本效益的能源储存方式之一。氢化物公司希望用一种具有更好的电气和机械性能的热塑性-石墨复合材料来取代目前的热固性-石墨复合材料。导电复合材料必须满足美国能源部(DOE)制定的导电性和强度性能指南。这种复合材料预计含有超过80%的导电填料，主要是石墨粉、碳黑粉和碳纤维或碳纳米管，以产生协同作用，实现所需的性能。因此，本工作的主要目标是利用高剪切强度密炼机和单螺杆挤出机相结合的方法，开发适合于双极板的高性价比、高负荷的聚丙烯-石墨复合材料。该复合材料将通过两个步骤生产：a)使用高强度混合机对粉末PP和粉末填料进行密集的干法混合，b)在单螺杆挤出机中对混合混合物进行熔融处理。将使用加工和粘合促进剂来改善和达到所需的电气和机械性能。在成功生产概念验证原型后，氢基因公司将通过内部混合设施或通过分包给安大略省或加拿大其他省份现有的定制混合器来扩大此类材料的生产。NSERC Engage项目新开发的材料和工艺的成功整合将转化为氢气公司的竞争力和盈利能力。氢燃料电池市场正处于大规模需求的十字路口，成功将带来规模经济和大规模生产。

Hydrogenics Corporation, one of the Canada's market leaders in providing hydrogen electrolyzers and fuel cells world-wide as clean energy alternatives to fossil fuel. Hydrogen is one of the most efficient and cost effective energy storage for excess electricity from power grid during the off-peak hours, as well as electricity produced from wind turbines and solar panel. Hydrogenics desires to substitute the current thermoset-graphite composite material with a thermoplastic-graphite composite material, with improved electrical and mechanical properties. The conductive composite must meet the performance guidelines established by the Department of Energy (DOE), for conductivity and strength. Such a composite is expected to contain in excess of 80% of conductive filler, primarily graphite powder, carbon black powder and carbon fibre or carbon nanotubes to create synergy to achieve the desired properties. Therefore, the main objective of this work is to develop cost-effective, highly loaded polypropylene-graphite composites suitable for bipolar plates using a combination of high shear intensity mixer and single screw extruder. The composite will be produced in a two-step process: a) intensive dry blending of powder PP and powder fillers using high intensity mixer, and b) melt processing of the blended mixture in a single screw extruder. Processing and adhesion promoting aids will be used to improve and achieve the required electrical and mechanical properties. Upon successful production of proof of concept prototypes, Hydrogenics will scale up the production of such material, either through in-house compounding facility or through sub-contracting to available custom compounders in Ontario or other provinces in Canada. Successful integration of the newly developed material and process from this NSERC Engage project would translate into competitiveness and profitability of Hydrogenics. Hydrogen fuel cell market is at the crossroad of mass demand, and success will result in economy of scale and mass production.