Modeling and diagnostics of degradation phenomena in catalyst layers of polymer electrolyte fuel cells

以可持续和对环境负责的方式确保未来的能源需求已成为全球最优先关注的问题。世界各地的大量研究计划探索将聚合物电解质燃料电池(PEFC)作为汽车交通、便携式应用和住宅动力装置的有前途的电源。无与伦比的热力学效率、高能量密度以及与氢的理想兼容性使PEFC成为应对全球能源挑战的主要解决方案。尽管有了这些资产和PEFC最近的成功演示，工业界已经确定了燃料电池必须克服的一些障碍，才能成功地作为商业产品的动力源。这些因素包括但不限于电压效率、功率密度、工作范围灵活性、功能材料成本、燃料灵活性和水处理。此外，燃料电池还需要满足对性能稳定性和可靠性的严格要求。目前，燃料电池行业未能提供目标应用所需的寿命。由于这些技术障碍，近年来人们对了解和减缓燃料电池的降解过程产生了极大的兴趣。西蒙·弗雷泽大学和巴拉德电力系统公司的这项合作的目标是开发基于建模的预测能力，以预测PEFC中的降解现象(老化)。这项工作在建立材料的复杂形态、燃料电池设计参数、全球运行条件、燃料电池运行的故障模式和降解的物理机制之间的关系方面将是独一无二的。首先，我们将重点介绍阴极催化剂层，因为它会导致大部分电池电压损失。首先，我们将利用现象学方法对已定义的结构变化对业绩下降的影响进行合理化。此后，我们努力对潜在的退化机制有一个详细的物理理解。

Securing the future energy needs in a sustainable and environmentally responsible way has become the highest priority global concern. Enormous research programs worldwide explore polymer electrolyte fuel cells (PEFC) as promising power sources for vehicular transportation, portable applications, and residential power units. Unrivaled thermodynamic efficiencies, high energy densities, and ideal compatibility with hydrogen render PEFC a primary solution to the global energy challenge. In spite of these assets and recent successful demonstrations of PEFC, industry has identified a number of hurdles that fuel cells must overcome in order to succeed as power sources in commercial products. These include but are not limited to voltage efficiency, power density, operational range flexibility, cost of functional materials, fuel flexibility, and water handling. Moreover, fuel cells need to fulfill rigorous requirements on stability and reliability of performance. At present, the fuel cell industry fails short in providing required lifetimes for targeted applications. Due to these technological barriers, enormous interest in recent years has focused on understanding and mitigating degradation processes in fuel cells. The objective of this collaboration between Simon Fraser University and Ballard Power Systems is to develop modeling-based predictive capabilities for degradation phenomena (ageing) in PEFC. This work will be unique in establishing relations between complex morphologies of materials, fuel cell design parameters, global operating conditions, failure modes of fuel cell operation and physical mechanisms of degradation. Initially, we will focus on the cathode catalyst layer, since it incurs the majority of the cell voltage losses. First, we will utilize phenomenological approaches to rationalize effects of defined structural changes on performance degradation. Thereafter, we strive towards a detailed physical understanding of underlying degradation mechanisms.