Long-term operation of a proton exchange membrane fuel cell without external humidification

Abstract

Electrodes for proton exchange membrane fuel cells (PEMFCs) with a Pt loading of 0.2mgPtcm−2 were prepared by the electrospraying deposition technique and were used to build membrane electrode assemblies (MEAs). These MEAs were tested in a single-cell configuration under a non-humidified regime fed by dry H2 and dry air. Long-term runs of 1000h were performed for MEAs prepared from Pt/C catalysts with Pt percentages on the carbon support ranging from 10 to 60wt%. The MEAs reached steady-state voltages in the approximate range of 500–600mV at 200mAcm−2, ambient pressure, and a 40°C cell temperature and exhibited almost no net performance loss. An even longer durability test of an MEA prepared from 20wt% Pt/C demonstrated the suitability of the non-humidified regime for these electrosprayed electrodes. This MEA worked uninterruptedly for 5000h with performance losses of 10% and 20% after 2200 and 3800h, respectively. Moreover, an MEA prepared from the 60wt% Pt/C catalyst was subjected to a long-term run under more efficient but more challenging conditions for non-humidified PEMFCs (a higher temperature, 60°C, which favors thermal management, and a low air stoichiometry, λair=2, which leads to high air utilization). Despite these harsh operating conditions, the non-humidified fuel cell reached a relatively stable voltage (≈0.6V at 200mAcm−2) that was sustained throughout 1000h of continuous operation.