Experimental and theoretical investigations of transport processes in polymer electrolyte fuel cells

加拿大目前的化石燃料运输部门消耗了近30%的一次能源。聚合物电解质燃料电池（PEFC）和电池提供了替代当前交通能源系统的可行替代品。氢，由水分裂在聚合物电解质电解槽（PEE）使用来自可再生能源的电力生产，可用于PEFC为车辆提供动力。PEFC仅产生水蒸气，从而消除污染和温室气体排放。PEFC车辆已经展示了客户期望的所有属性，例如快速启动和加油，长距离和耐用性。PEE和PEFC车辆市场渗透率增加的前提是生产成本降低以及性能和耐久性改善。 为了将PEFC和PEE的成本降低到商业化目标，即，分别为30美元/kW和300美元/kW（2020年美国能源部目标），有必要改善电极中的质量传输，以实现更高的功率密度操作和使用更少的贵重催化剂。由于PEFC和PEE的材料和物理现象复杂，需要进行数值模拟分析和设计。 在燃料电池和电解槽的宏观数值模拟方面取得了显著进展。然而，这些模型不能解释PEFC和PEE中多孔复合材料的微观特征如何影响传质性能和反应。纳米尺度的成像结合统计分析，重建和模拟应该用来解释这些影响。在高电流密度下，电极中的液态水积聚也减少了向反应位点的输送，从而限制了燃料电池的最大功率。可以通过使用微制造技术（例如喷墨印刷）设计更好的传输层来最小化水积聚。上述问题、降解和材料研究对PEFC和PEE至关重要。 拟议的发现资助计划旨在开发：a）微尺度统计分析，重建和数值模型，以及非原位实验工具，以研究电极微结构对传输特性和水积聚的影响;以及B）旨在最大限度地减少水积聚的新型燃料电池架构。重点将在PEFC，然而，由于物理过程的接近性，数值和实验工具也适用于PEE。 新的数值模型和架构旨在设计具有增加的催化剂利用率和最大功率密度的电极，这可以导致更便宜和性能更好的PEFC。这项研究将有助于加拿大经济发展的基本理解，新的工具，并培训HQP保持加拿大在燃料电池的领导地位。我的软件已经在加拿大工业公司使用了。

Canada's current fossil fuelled transportation sector consumes nearly 30% of our primary energy. Polymer electrolyte fuel cells (PEFCs) and batteries present viable alternatives to replace the current transportation energy system. Hydrogen, produced by water splitting in a polymer electrolyte electrolyzer (PEE) using electricity from renewable energy sources, could be used in PEFCs to power a vehicle. PEFCs produce only water vapor thereby eliminating pollution and greenhouse gas emissions. PEFC vehicles have demonstrated all the attributes that customers expect such as quick start-up and refuelling, long range, and durability. Prerequisites for an increase in market penetration of PEE, and PEFC vehicles, are production cost reductions as well as performance and durability improvements. In order to reduce the cost of PEFCs and PEEs to commercialization targets, i.e., $30/kW and $300/kW respectively (2020 U.S. Department of Energy targets), it is necessary to improve mass transport in the electrode in order to enable higher power density operation and the use of less precious catalysts. Due to the complex materials and physical phenomena, numerical modelling is required for PEFC and PEE analysis and design. Remarkable progress has been achieved in macroscale numerical modelling of fuel cells and electrolyzers. These models however cannot account for how microscopic features in the porous composite materials in PEFCs and PEEs affect mass transport properties and reactions. Nanometer scale imaging combined with statistical analysis, reconstruction, and simulation should be used to account for these effects. At high current density, liquid water accumulation in the electrode also reduces transport to the reaction site, thereby limiting the fuel cell maximum power. Water accumulation can be minimized by designing better transport layers using micro-fabrication techniques such as inkjet printing. The issues above, degradation, and material research are critical to PEFCs and PEEs. The proposed Discovery grant program aims at developing: a) micro-scale statistical analysis, reconstruction, and numerical models, and ex-situ experimental tools to study the effect of electrode micro-structures on transport properties and water accumulation; and, b) novel fuel cell architectures that aim at minimizing water accumulation. The focus will be in PEFCs, however, due to the closeness of physical processes, the numerical and experimental tools are also applicable to PEEs. The new numerical models and architectures aim at designing electrodes with increased catalyst utilization and maximum power density which can lead to cheaper and better performing PEFCs. This research will contribute to the Canadian economy by developing fundamental understanding, novel tools, and training HQP to maintain Canada's leadership in fuel cells. My software is already in use at Canadian industries.