Critical Parameters and Control Strategies for Comparable PEFC Stack Characterization

Abstract

The harmonization of PEFC test procedures is of significant interest for industry and academia and important to accelerate fuel cell development. Up to the present date, PEFC analysis has not been standardized for the stack level leading to non-comparable results. The preparation of required protocols was realized in a two-step process in the EU-funded project Stack-Test. The crucial parameters were identified and the procedure for the respective parameter variation was specified. The direction of parameter adjustment, the sensor position and the parameter control are defined in order to achieve reproducible results. Thereby, the feedback from industry and academia has been considered. For the present work, different protocols regarding stack performance and durability were applied to different 10-cell stacks. The typical test operating parameters have been varied according to the protocols. Thereby, the impact of the protocols on the test results was examined. For industry, the test duration is a further crucial parameter and should be minimized without endanger the result accuracy and reproducibility. This aspect will be demonstrated for polarization curves, the most common tool for PEFC characterization. Our results show that the comparability of the test results carried out at different facilities across Europe is greatly influenced by the applied testing protocols. In this work, we will present the validation results, identify and highlight critical parameters and sequence of examination steps. Our work clearly demonstrates the great need for harmonized test protocols and their case-dependent choice.