Sulfonated Graphene–Nafion Composite Membranes for Polymer Electrolyte Fuel Cells Operating under Reduced Relative Humidity

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• 作者：Akhila Kumar Sahu ; Kriangsak Ketpang ; Sangaraju Shanmugam ; Osung Kwon ; Sangcheol Lee ; Hasuck Kim
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：July 28, 2016
• 年：2016
• 卷：120
• 期：29
• 页码：15855-15866
• 全文大小：789K
• 年卷期：0
• ISSN：1932-7455

文摘

Sulfonic acid-functionalized graphene (S-graphene) is employed as a promising inorganic filler as well as a solid acid proton conducting medium to realize a composite membrane with Nafion for polymer electrolyte fuel cell (PEFC) applications under reduced relative humidity (RH). The functionalization of graphene is performed by sulfonic acid-containing aryl radicals to increase the number of sulfonate groups per unit volume of a domain. A Nafion–S-graphene composite membrane is obtained by embedding S-graphene in Nafion, which provides high absorption of water and fast proton-transport across the electrolyte membrane under low RH values. The proton conductivity of the Nafion–S-graphene (1%) composite membrane at 20% RH is 17 mS cm^–1, which is five times higher than that of a pristine recast Nafion membrane. PEFCs incorporating the Nafion–S-graphene composite membrane deliver a peak power density of 300 mW cm^–2 at a load current density of 760 mA cm^–2 while operating at optimum temperature of 70 °C under 20% RH and ambient pressure. By contrast, operating under identical conditions, a peak power density of 220 mW cm^–2 is achieved with the pristine recast Nafion membrane. The Nafion–S-graphene composite membrane could be used to address many critical problems associated with commercial Nafion membranes in fuel cell applications.