High-performance polymer electrolyte membranes incorporated with 2D silica nanosheets in high-temperature proton exchange membrane fuel cells

Silica nanosheets (SN) derived from natural vermiculite (Verm) were successfully incorporated into polyethersulfone-polyvinylpyrrolidone (PES-PVP) polymer to fabricate high-temperature proton exchange membranes (HT-PEMs). The content of SN filler was varied (0.1-0.75 wt%) to study its influence on proton conductivity, power density and durability. Benefiting from the hydroxyl groups of SN that enable the formation of additional proton-transferring pathways, the inorganic-organic membrane displayed enhanced proton conductivity of 48.2 mS/cm and power density of 495 mW/cm(2) at 150 degrees C without humidification when the content of SN is 0.25 wt%. Furthermore, exfoliated SN (E-SN) and sulfonated SN (S-SN), which were fabricated by a liquid-phase exfoliation method and silane condensation, respectively, were embedded in PES-PVP polymer matrix by a simple blending method. Due to the significant contribution from sulfonic groups in S-SN, the membrane with 0.25 wt% S-SN reached the highest proton conductivity of 51.5 mS/cm and peak power density of 546 mW/cm(2) at 150 degrees C, 48% higher than the pristine PES-PVP membranes. Compared to unaltered PES-PVP membrane, SN added hybrid composite membrane demonstrated excellent durability for the fuel cell at 150 degrees C. Using a facile method to prepare 2D SN from natural clay minerals, the strategy of exfoliation and functionalization of SN can be potentially used in the production of HT-PEMs. (C) 2021 The Authors. Published by ELSEVIER B.V. and Science Press on behalf of Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences.

Automated summary

By incorporating silica nanosheets (SN) into PES-PVP polymer matrix, the high-temperature proton exchange membrane showed enhanced proton conductivity and power density, demonstrating the potential of using SN in HT-PEMs production.