Radiation grafted membranes for superior anion exchange polymer membrane fuel cells performance

Reduction of the monomer quantities required for the preparation of radiation-grafted alkaline anion-exchange membranes

“…The TPS results ( at 60°C respectively; the increased water contents and faster ion mobilities led to the increase in conductivities at higher temperatures [37]. The high bicarbonate (and calculated hydroxide) ion conductivities in the through-plane direction of the AEMs provides evidence of an even distribution of the VBC monomer through the thickness of the AEMs, which is contrary to the observations by Mamlouk et al where an emulsion technique was used to prepare similar AEMs from ETFE preformed films but using water as the solvent [30]. ).…”

“…However, ETFE based AAEMs (with quaternary amine (TMA) functionality produced using this method) evaluated in collaboration with Mamlouk et al, exhibited extremely low through-plane conductivity with high anisotropy, resulting in them being labelled "unsuitable for fuel cell tests". This was attributed to the poor distribution of the VBC monomer through the profile of the membrane, due to the lack of polymer swelling in water and the low solubility of the VBC in water (the emulsion technique used a only 3%v/v VBC) [30]. The severe immiscibility of VBC in water (even within an emulsion based system) is proving difficult for the production of highly ionic conductive AAEMs with the pre-irradiation grafting method (that is more useful when the radiation source is not on site).…”

Manipulating Water in High-Performance Hydroxide Exchange Membrane Fuel Cells through Asymmetric Humidification and Wetproofing

“…The PPD of 737 mW cm −2 is among the highest reported (Table II). [2][3][4][5]15,16,35 Conclusions GDL wetproofing increases HEMFC hydration. This leads to a performance tradeoff: IR is lower when the electrolyte is hydrated, but too much hydration induces mass transport losses through flooding.…”

“…12 In HEMFCs the hydrogen oxidation reaction (HOR) produces water so in principle the anode is analogously susceptible to flooding; yet, while GDL thickness has been studied in the HEMFC literature, 4 there is little discussion of hydrophobic treatment or MPLs. 3,[13][14][15] Cathode drying is also a potential concern for HEMFCs because the oxygen reduction reaction (ORR) consumes water (Scheme 1).…”

A review of radiation-grafted polymer electrolyte membranes for alkaline polymer electrolyte membrane fuel cells

“…The anion conductivity reached 0.039 S cm À1 at 30 C in deionized water, and was found to increase with increasing temperature from 20 to 80 C. The membranes were tested for stability after being treated in 10 M aqueous KOH solution at 60 C for 120 h. The H 2 /O 2 fuel cell performance with these alkaline membranes at 40 C was 48 mW cm À2 at a current density of 69 mA cm À2 . Varcoe et al [176,177,188], Mamlouk et al [132,133,167], and Hasegawa et al [189] also used 60 Co as their gray source to pre-irradiate membranes when preparing radiationgrafted membranes for alkaline PEM fuel cell applications. Varcoe and Slade [110] employed an electron beam with a total dose of 7 MRad to irradiate ETFE membranes.…”