气候变化领域集成服务门户(CCPortal): Non-fluorinated pre-irradiation-grafted (peroxidated) LDPE-based anion-exchange membranes with high performance and stability

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DOI	10.1039/c7ee02053h
	Non-fluorinated pre-irradiation-grafted (peroxidated) LDPE-based anion-exchange membranes with high performance and stability
	Wang L.; Brink J.J.; Liu Y.; Herring A.M.; Ponce-González J.; Whelligan D.K.; Varcoe J.R.
发表日期	2017
ISSN	17545692
起始页码	2154
结束页码	2167
卷号	10 期号:10
英文摘要	Radiation-grafted anion-exchange membrane (RG-AEM) research has predominantly focused on the chemical stability of the polymer-bound positively-charged head-groups that enable anion conduction. The effect of the backbone polymer chemistry, of the precursor film, on RG-AEM stability has been studied to a lesser extent and not for RG-AEMs made from pre-irradiation grafting of polymer films in air (peroxidation). The mechanical strength of polymer films is generally weakened by exposure to high radiation doses (e.g. from a high-energy e--beam) and this is mediated by chemical degradation of the main chains: fluorinated films mechanically weaken at lower absorbed doses compared to non-fluorinated films. This study systematically compares the performance difference between RG-AEMs synthesised from a non-fluorinated polymer film (low-density polyethylene-LDPE) and a partially-fluorinated polymer film (poly(ethylene-co-tetrafluoroethylene)-ETFE) using the peroxidation method (pre-irradiation in air using an e--beam). Both the LDPE and ETFE precursor films used were 25 μm in thickness, which led to RG-AEMs of hydrated thicknesses in the range 52-60 μm. The RG-AEMs (designated LDPE-AEM and ETFE-AEM, respectively) all contained identical covalently-bound benzyltrimethylammonium (BTMA) cationic head-groups. An LDPE-AEM achieved a OH- anion conductivity of 145 mS cm-1 at 80 °C in a 95% relative humidity environment and a Cl- anion conductivity of 76 mS cm-1 at 80 °C when fully hydrated. Alkali stability testing showed that the LDPE-AEM mechanically weakened to a much lower extent when treated in aqueous alkaline solution compared to the ETFE-AEM. This LDPE-AEM outperformed the ETFE-AEM in H2/O2 anion-exchange membrane fuel cell (AEMFC) tests due to high anion conductivity and enhanced in situ water transport (due to the lower density of the LDPE precursor): a maximum power density of 1.45 W cm-2 at 80 °C was achieved with an LDPE-AEM alongside a Pt-based anode and cathode (cf. 1.21 mW cm-2 for the benchmark ETFE-AEM). The development of more mechanically robust RG-AEMs has, for the first time, led to the ability to routinely test them in fuel cells at 80 °C (cf. 60 °C was the prior maximum temperature that could be routinely used with ETFE-based RG-AEMs). This development facilitates the application of non-Pt catalysts: 931 mW cm-2 was obtained with the use of a Ag/C cathode at 80 °C and a Ag loading of 0.8 mg cm-2 (only 711 mW cm-2 was obtained at 60 °C). This first report on the synthesis of large batch size LDPE-based RG-AEMs, using the commercially amenable peroxidation-type radiation-grafting process, concludes that the resulting LDPE-AEMs are superior to ETFE-AEMs (for the intended applications). © The Royal Society of Chemistry.
英文关键词	Alkaline fuel cells; Alkalinity; Cathodes; Chemical stability; Degradation; Electrodes; Ethylene; Fluorine containing polymers; Fuel cells; Grafting (chemical); Hydration; Ion exchange membranes; Ions; Irradiation; Oxidation; Platinum; Polymers; Radiation; Semiconducting films; Silver; Stability; Anion exchange membrane; Anion-exchange membrane fuel cells; Aqueous alkaline solutions; Benzyltrimethylammonium; Chemical degradation; Fluorinated polymers; Maximum power density; Partially fluorinated; Polymer films; catalyst; conductivity; degradation; film; fuel cell; membrane; oxidation; performance assessment; polymer; relative humidity
语种	英语
来源期刊	Energy & Environmental Science
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/190395
作者单位	Department of Chemistry, University of Surrey, Guildford, GU2 7XH, United Kingdom; Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, CO 80401, United States
推荐引用方式 GB/T 7714	Wang L.,Brink J.J.,Liu Y.,et al. Non-fluorinated pre-irradiation-grafted (peroxidated) LDPE-based anion-exchange membranes with high performance and stability[J],2017,10(10).
APA	Wang L..,Brink J.J..,Liu Y..,Herring A.M..,Ponce-González J..,...&Varcoe J.R..(2017).Non-fluorinated pre-irradiation-grafted (peroxidated) LDPE-based anion-exchange membranes with high performance and stability.Energy & Environmental Science,10(10).
MLA	Wang L.,et al."Non-fluorinated pre-irradiation-grafted (peroxidated) LDPE-based anion-exchange membranes with high performance and stability".Energy & Environmental Science 10.10(2017).