Abstract
This paper presents a comprehensive analysis of the performance of high temperature polymer electrolyte membrane fuel cells (HT-PEMFCs). A single cell is characterized at different operating temperatures, \(\hbox {H}_2\) partial pressures, and \(\hbox {H}_2\) flow rates. The cell efficiencies are calculated from the measured data and analyzed. The electrochemical impedance spectra (EIS) of the cell are obtained under different conditions, and the processes that contribute to the overall cell resistance are identified using the distribution of relaxation times (DRT) analysis. An equivalent circuit model (ECM) is then proposed based on the DRT analysis and used to model the EIS data. The efficiency analysis shows higher cell efficiencies at lower \(\hbox {H}_2\) flow rates. Maximum efficiencies are observed in the same potential window where the power density peaks. The DRT analysis reveals the presence of four distinct processes. The proposed ECM, based on the DRT analysis, shows that the model-fitted resistances and the DRT peaks exhibit the same trends when changing the operating parameters.
Graphical Abstract
