Effect of Contaminants on the Performance of a Proton Exchange Membrane Fuel Cell

The overall cost and performance of proton exchange membrane fuel cells (PEMFCs) are an issue of tradeoffs, and the optimal design depends on the application. For example, avoiding degradation via contamination by using expensive materials increases the initial cost to produce the system, but it can extend life and improve the overall performance. This may be desirable where reliability is paramount. In contrast, using less expensive materials reduces the initial cost, but at the expense of the life-time cost of the system and reduced performance.

During this study, a systematic and collaborative investigation was conducted to understand, characterize, and quantify the degradation mechanisms due to contaminants that arise from components that make up the fuel-cell system. Initially, the key contaminants that leach out of commercial assembly-aid materials were identified and screened for their detrimental effect on fuel-cell component performance (e.g. catalyst activity, membrane conductivity). Then, model compounds were selected and in-depth parametric studies were performed. In total, four model compounds in the assembly aid materials have been selected to study the degradation mechanisms, and the impact to PEMFC performance and durability of each compound was evaluated by in-situ infusion tests and in-situ membrane resistance tests. The results from these parametric studies were then used to develop mathematical models to quantify the performance loss and recovery of the fuel cell.