Investigations of the ex situ ionic conductivities at 30°C of metal-cation-free quaternary ammonium alkaline anion-exchange membranes in static atmospheres of different relative humidities

被引:122
作者
Varcoe, John R. [1 ]
机构
[1] Univ Surrey, Dept Chem, Guildford GU2 7XH, Surrey, England
关键词
D O I
10.1039/b615478f
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
This article presents the first systematic study of the effect of Relative Humidity ( RH) on the water content and hydroxide ion conductivity of quaternary ammonium-based Alkaline Anion-Exchange Membranes (AAEMs). These AAEMs have been developed specifically for application in alkaline membrane fuel cells, where conductivities of > 0.01 S cm(-1) are mandatory. When fully hydrated, an ETFE-based radiation-grafted AAEM exhibited a hydroxide ion conductivity of 0.030 +/- 0.005 S cm(-1) at 30 degrees C without additional incorporation of metal hydroxide salts; this is contrary to the previous wisdom that anion-exchange membranes are very low in ionic conductivity and represents a significant breakthrough for metal-cation-free alkaline ionomers. Desirably, this AAEM also showed increased dimensional stability on full hydration compared to a Nafion (R)- 115 proton-exchange membrane; this dimensional stability is further improved ( with no concomitant reduction in ionic conductivity) with a commercial AAEM of similar density but containing additional cross-linking. However, all of the AAEMs evaluated in this study demonstrated unacceptably low conductivities when the humidity of the surrounding static atmospheres was reduced (RH=33-91%); this highlights the requirement for continued AAEM development for operation in H-2/air fuel cells with low humidity gas supplies. Preliminary investigations indicate that the activation energies for OH (-) conduction in these quaternary ammonium-based solid polymer electrolytes are typically 2 - 3 times higher than for H+ conduction in acidic Nafion (R)- 115 at all humidities.
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页码:1479 / 1486
页数:8
相关论文
共 26 条
[1]   Characterization and use of anionic membranes for alkaline fuel cells [J].
Agel, E ;
Bouet, J ;
Fauvarque, JF .
JOURNAL OF POWER SOURCES, 2001, 101 (02) :267-274
[2]   Relationship between pressure drop and cell resistance as a diagnostic tool for PEM fuel cells [J].
Barbir, F ;
Gorgun, H ;
Wang, X .
JOURNAL OF POWER SOURCES, 2005, 141 (01) :96-101
[3]   Ionic conductivity of proton exchange membranes [J].
Beattie, PD ;
Orfino, FP ;
Basura, VI ;
Zychowska, K ;
Ding, JF ;
Chuy, C ;
Schmeisser, J ;
Holdcroft, S .
JOURNAL OF ELECTROANALYTICAL CHEMISTRY, 2001, 503 (1-2) :45-56
[4]   Development of electrocatalysts for solid alkaline fuel cell (SAFC) [J].
Coutanceau, C ;
Demarconnay, L ;
Lamy, C ;
Léger, JM .
JOURNAL OF POWER SOURCES, 2006, 156 (01) :14-19
[5]   Effect of membrane characteristics and humidification conditions on the impedance response of polymer electrolyte fuel cells [J].
Freire, TJP ;
Gonzalez, ER .
JOURNAL OF ELECTROANALYTICAL CHEMISTRY, 2001, 503 (1-2) :57-68
[6]   Composite anion exchange membrane for alkaline direct methanol fuel cell: Structural and electrochemical characterization [J].
Huang, AB ;
Xia, CY ;
Xiao, CB ;
Zhuang, L .
JOURNAL OF APPLIED POLYMER SCIENCE, 2006, 100 (03) :2248-2251
[7]   Quaternized polyethersulfone Cardo anion exchange membranes for direct methanol alkaline fuel cells [J].
Li, L ;
Wang, YX .
JOURNAL OF MEMBRANE SCIENCE, 2005, 262 (1-2) :1-4
[8]   Preliminary study on direct alcohol fuel cells employing anion exchange membrane [J].
Ogumi, Z ;
Matsuoka, K ;
Chiba, S ;
Matsuoka, M ;
Iriyama, Y ;
Abe, T ;
Inaba, M .
ELECTROCHEMISTRY, 2002, 70 (12) :980-983
[9]   Mechanisms of ion and water transport in perfluorosulfonated ionomer membranes for fuel cells [J].
Saito, M ;
Arimura, N ;
Hayamizu, K ;
Okada, T .
JOURNAL OF PHYSICAL CHEMISTRY B, 2004, 108 (41) :16064-16070
[10]   Tangential and normal conductivities of Nafion® membranes used in polymer electrolyte fuel cells [J].
Silva, RF ;
De Francesco, A ;
Pozio, A .
JOURNAL OF POWER SOURCES, 2004, 134 (01) :18-26