Bio-analogue l-lysine lined arrangement on nanofibers with superior proton-conduction for proton exchange membrane

Manipulating nanophase-separation behavior and constructing ion-channels is of great challenge for optimizing proton transport. Herein, a novel strategy is demonstrated for constructing long-range and consecutive proton-conducting channels by immobilizing bio-analogue l -lysine onto surface of hydrolyzed polyacrylonitrile (PAN) nanofibers (L/P NFs), combing the superiority of the hydrophilicity 3D network structure (3DNWS) of hydrolyzed PAN NFs and the function of l -lysine as proton-conductors. The hybrid proton exchange membranes (PEMs) are fabricated by filling the inter-fiber voids of L/P NFs with Nafion matrix . The acid–base ion-channels formed between –SO 3 H of Nafion and –NH 2 of L/P NFs may offer the abundant hydrogen-bonded networks for proton hopping. The results show L@Nafion hybrid PEMs can reach 0.263 S/cm (80 °C, 100% relative humidity) proton conductivity and 122.82 mW/cm 2 power density for fuel-cell performance. Besides, the preponderance of 3DNWS of L/P NFs can considerably facilitate the thermal and dimensional stability as well as restrict methanol crossover for hybrid PEMs. This approach brings a unique vision for preparing high-performance PEMs for direct methanol fuel cells.