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Download fileConstruction of Proton Transport Highways Induced by Polarity-Driving in Proton Exchange Membranes to Enhance the Performance of Fuel Cells
journal contribution
posted on 19.08.2021, 16:09 authored by Jialin Li, Xuzhou Tian, Chunlei Xia, Yuting Duan, Yi-nan Sun, Binghui Liu, Liming Wu, Chunyu Ru, Shi-Tong Zhang, Chengji ZhaoThe
approach to constructing proton transport channels via direct
adjustments, including hydrophilia and analytical acid concentration
in hydrophilic domains, has been proved to be circumscribed when encouraging
the flatter hydrophilic–hydrophobic microphase separation structures
and reducing conductivity activation energy. Here, we propose a constructive
solution by regulating the polarity of hydrophobic domains, which
indirectly varies the aggregation and connection of hydrophilic ion
clusters during membrane formation, enabling orderly self-assembly
and homogeneously distributed microphase structures. Accordingly,
a series of comb-shaped polymers were synthesized with diversified
optimization, and more uniformly distributed ion cluster lattices
were subsequently observed using high-resolution transmission electron
microscopy. Simultaneously, combining with density functional theory
calculations, we analyzed the mechanism of membrane degradations caused
by hydroxyl radical attacks. Experimental results demonstrated that,
facilitated by proper molecule polarity, beneficial changes of bond
dissociation energy could extend the membrane lifetime more than the
protection from side chains near ether bonds, which were deemed to
reduce the probability of attacks by the steric effect. With the optimal
strategy chosen among various trials, the maximum power density of
direct methanol fuel cell and H2/air proton exchange membrane
fuel cell was enhanced to 95 and 485 mW cm–2, respectively.
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Keywords
proton transport channelsmembrane formationExperimental resultstheory calculationsmolecule polarityion cluster latticesmicrophase structuresProton Exchange Membranescomb-shaped polymersbond dissociation energysteric effectether bondsmembrane lifetimeion clustersconductivity activation energytransmission electron microscopypower densityacid concentrationside chainsmembrane degradationsmethanol fuel cellProton Transport Highways InducedFuel Cells