Development of a High-Performance Proton Exchange Membrane: From Structural Optimization to Quantity Production

Abstract

Quantity production of low-cost and high-performance proton exchange membranes (PEMs) used in hydrogen fuel cells is the centerpiece step toward the hydrogen future. Herein, we developed a facile synthesis approach for this task. The prepared PEM breaks through the unfavorable trade-off between thermal-dimensional stability and proton conductivity due to the adequately designed hierarchical polymer structure composed of flexible ionic side-chains anchored onto twisted rigid backbone. Microscale topology structure analyses and molecular dynamics simulations indicate that the hydrated ionic groups self-assemble to form well-connected proton nanochannels. More importantly, the quantity production of the PEM is allowed with a pilot-scale production line. The PEM reaches a peak power density of 1.2 W cm–2 under the realistic low fuel gas flow in a single-cell of H2/O2 fuel cell. Additionally, the PEM maintains profitable fuel cell performance under lower relative humidity (1.1 and 0.9 W cm–2 peak power density at 80 and 60% relative humidity, respectively). In short, we report that a canonical form from the structural optimization of a PEM to the pilot-scale production in which the micromorphology-proton conduction relationship is fully explored.