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

点击翻译按钮获取中文摘要

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.