Tuning the Hydrophobic Component in Reinforced Poly(arylimidazolium)-Based Anion Exchange Membranes for Alkaline Fuel Cells

Abstract

A series of imidazolium-based aromatic copolymers were synthesized using fluorinated and non-fluorinated hydrophobic monomers. The quaternized copolymers were reinforced with the plasma-treated porous polyethylene substrate to provide flexible, homogeneous membranes. Crosssectional SEM images revealed a triple-layer structure. The reinforced membranes exhibited phase-separated morphology as confirmed through TEM images. Among the membranes, QQP-MEIm-PE-containing quinquephenylene hydrophobic groups exhibited the most balanced properties (ion conductivity, mechanical strength, and alkaline stability). In particular, QQP-MEIm-PE exhibited excellent elongation properties with 24 MPa maximum stress and 205% elongation at break. A single H 2 /O 2 fuel cell using the QQP-MEIm-PE membrane (1.26 meq g −1 ) and non-PGM-(Fe−N−C) cathode achieved 222 mW cm −2 , which accounted for 888 mW mg −1 Pt at 560 mA cm −2 . Reasonable durability was confirmed with the membrane in the operating fuel cell.

Effect of Radical‐Mediated Cross‐Linking on Partially Fluorinated Aromatic Anion Exchange Membranes and their Applications in Alkaline Water Electrolysis Cells

“…Membrane Characterization: The detailed procedures for the membrane's characterization such as TEM, titration (for IEC), water absorbability, swelling ratio, hydroxide ion conductivity, alkaline stability, universal stress-strain (S-S) curves, and DMA was described in our previous articles. [11,[28][29][30] Preparation of Membrane Electrode Assembly: A modified procedure to that in the literature was used. [25] The anode catalyst ink was prepared from homemade catalyst Ni-Co oxide (Ni 0.8 Co 0.2 O) [23] and in-house binder (QPAF-4, IEC = 1.5 meq g À1 ) [31] using methanol and pure water as solvents.…”

“…The detailed procedures for the membrane's characterization such as TEM, titration (for IEC), water absorbability, swelling ratio, hydroxide ion conductivity, alkaline stability, universal stress–strain (S–S) curves, and DMA was described in our previous articles. [ 11,28–30 ]…”

Aryl ether-free polymer electrolytes for electrochemical and energy devices

“…A general synthetic scheme of polyaromatics used in AEPs, utilizing Ni(0)-promoted coupling reactions, is shown in Scheme 11a. [188][189][190][191][192][193][194][195][196][197][198][199][200][201][202][203] Typically, pre-aminated, tertiary amino group-containing aromatic monomers and hydrophobic aromatic monomers are copolymerized. The polymerization reaction usually proceeds rapidly and quantitatively within 3-8 hours at 80 1C in polar aprotic solvents such as DMSO and DMAc.…”

Robust poly(p‐phenylene oxide) anion exchange membranes reinforced with pore‐filling technique for water electrolysis

“…Polyethylene (PE) is a commonly used substrate due to its porous structure and good chemical resistance. 19,20 Wang and coworkers reinforced poly(fluorenylco-terphenyl piperidinium)-based AEM using highdensity PE. They used EtOH as an assistant cosolvent to enhance the penetration efficiency of the polymer solution.…”

“…The organic composite membrane can be less expensive and offer improved performance. Polyethylene (PE) is a commonly used substrate due to its porous structure and good chemical resistance 19,20 . Wang and coworkers reinforced poly(fluorenyl‐co‐terphenyl piperidinium)‐based AEM using high‐density PE.…”