Investigation of layered double hydroxide (LDH) Nafion-based nanocomposite membranes for high temperature PEFCs. (15th May 2015)

• Record Type: Journal Article
• Authors: Angjeli, Kristina; Nicotera, Isabella; Baikousi, Maria; Enotiadis, Apostolos; Gournis, Dimitrios; Saccà, Ada; Passalacqua, Enza; Carbone, Alessandra
• Is Part Of: Energy conversion and management. Volume 96(2015)
• Page Start: 39
• Page End: 46
• Publication Date: 2015-05-15
• Subjects: LDH -- Nafion composites -- NMR diffusion -- Proton conductivity -- PEMFCs; Direct energy conversion -- Periodicals; Energy storage -- Periodicals; Energy transfer -- Periodicals; Énergie -- Conversion directe -- Périodiques; Direct energy conversion; Periodicals; 621.3105
• DOI: 10.1016/j.enconman.2015.02.064
• Languages: English
• ISSNs: 0196-8904

Abstract

Highlights: Evaluation of LDHs with different interlayer anions ( CO 3 2 -, ClO 4 -, NO 3 - ). Composite Nafion membranes were prepared by a standardized casting method. Study of water transport properties in the polymeric membranes by an NMR technique. Improved capability to coordinate water molecules in composites membranes. NLDH-NO3 reaches the best performance (0.22 W cm −2 ) at 100 °C and 50%RH. Abstract: Hydrogen/air Polymer Electrolyte Fuel Cell (PEFC) are highly attractive as energy source for mobile applications, improving electrochemical kinetics rates, waste heat recovery and overcoming catalyst tolerance for reformed hydrogen at operating temperatures above 80 °C. Layered double hydroxide (LDH) nanoparticles with Mg 2+ /Al 3+ metal cations (metal ratio 2:1) and different countervailing anions ( CO 3 2 -, ClO 4 -, NO 3 - ) in the interlayer space were synthesized and tested as fillers for the creation of hybrid Nafion nanocomposites using a standardized casting method. The development of such nanocomposites will lead to a highly efficient H2 /air polymer electrolyte fuel cell operating at high temperatures. The produced hybrid membranes were characterized by a combination of powder X-ray diffraction, FTIR spectroscopy, and thermal analysis (DTA/TGA) that revealed the creation of homogeneous exfoliated nanocomposites. The water-transport properties were investigated by NMR spectroscopy (diffusion and relaxation time). Interlayer anions affect the lambda value (mol H2 O/mol SO3 H) showing better hydration with higher values compared to recast Nafion. Fuel cell tests performed in drastic conditions (1.5 abs. bar and 50% RH) at 100 °C highlighted the influence of the different interlayer anions in composite membranes. A good performance was obtained for membranes containing LDH- ClO 4 - with a power density of 300 mW cm −2 at 0.6 V at 100 °C.