Cathodic nanoporous CNT functional interlayer as a performance and durability boosting agent for proton exchange membrane fuel cells to operable at 120 degrees C

Abstract

In proton exchange membrane fuel cells (PEMFCs), securing sufficient hydration in perfluorosulfonic acid (PFSA) membrane is considered an indicator of performance and durability. Here, we present a straightforward yet effective strategy that sandwiches the nanoporous carbon nanotube (CNT) sheet between the cathodic gas diffusion backing layer (GDBL) and bipolar plate (BP) of a conventional membrane electrode assembly (MEA). CNT sheets are synthesized through the cost-effective direct spinning method. The carbon source, winding rates, and the number of layers are varied to tailor the thickness and nanoporous morphology of the CNT sheets (5, 15, and 30 mu m). CNT interlayer MEAs are evaluated for their performance in various temperature and relative humidity (RH), ranges of 80-120 degrees C and 25-100% RH. With these nanoporous CNT sheets, reactants disperse homogeneously, enhancing membrane hydration and interfacial contact, thereby fulfilling superior performance compared to conventional under entire conditions. Among CNT interlayers, the 30 mu m records a 115.4% enhanced peak power density (0.28 W cm(-2)) and 89.2% extended durability (similar to 187 h) than conventional under 120 degrees C and 25% RH. Our strategy delivers a broader perspective of PEMFCs and other fuel cell types based on their ease of production and reproducibility.