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

Quantity production of low-cost and high-perform-ance proton exchange membranes (PEMs) used in hydrogen fuelcells is the centerpiece step toward the hydrogen future. Herein, wedeveloped a facile synthesis approach for this task. The preparedPEM breaks through the unfavorable trade-offbetween thermal-dimensional stability and proton conductivity due to theadequately designed hierarchical polymer structure composed offlexible ionic side-chains anchored onto twisted rigid backbone.Microscale topology structure analyses and molecular dynamicssimulations indicate that the hydrated ionic groups self-assemble toform well-connected proton nanochannels. More importantly, thequantity production of the PEM is allowed with a pilot-scaleproduction line. The PEM reaches a peak power density of 1.2 Wcm-2under the realistic low fuel gasflow in a single-cell of H2/O2fuel cell. Additionally, the PEM maintains profitable fuel cellperformance under lower relative humidity (1.1 and 0.9 W cm-2peak 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 themicromorphology-proton conduction relationship is fully explored.

Automated summary

This study presents a facile synthesis approach for producing low-cost and high-performance proton exchange membranes (PEMs) used in hydrogen fuel cells. The prepared PEM breaks the trade-off between thermal-dimensional stability and proton conductivity by utilizing a hierarchical polymer structure consisting of flexible ionic side-chains anchored onto a twisted rigid backbone. Microscale topology structure analyses and molecular dynamics simulations reveal the formation of well-connected proton nanochannels through self-assembly of the hydrated ionic groups. Moreover, the PEM can be produced in large quantities using a pilot-scale production line and exhibits excellent fuel cell performance under low relative humidity conditions.