Back to Search
Start Over
PVA-SSA-HPA mixed-matrix-membrane electrolytes for DMFCs
- Source :
- IndraStra Global.
- Publication Year :
- 2010
-
Abstract
- Stabilized forms of heteropolyacids (HPAs), namely phosphomolybdic acid (PMA), phosphotungstic acid (PTA), and silicotungstic acid (STA), are incorporated into poly (vinyl alcohol) (PVA) cross-linked with sulfosuccinic acid (SSA) to form mixed-matrix membranes for application in direct methanol fuel cells (DMFCs). Bridging SSA between PVA molecules not only strengthens the network but also facilitates proton conduction in HPAs. The mixed-matrix membranes are characterized for their mechanical stability, sorption capability, ion-exchange capacity, and wetting in conjunction with their proton conductivity, methanol permeability, and DMFC performance. Methanol-release kinetics is studied ex situ by volume-localized NMR spectroscopy (employing point-resolved spectroscopy'') with the results clearly demonstrating that the incorporation of certain inorganic fillers in PVA-SSA viz., STA and PTA, retards the methanol-release kinetics under osmotic drag compared to Nafion, although PVA-SSA itself exhibits a still lower methanol permeability. The methanol crossover rate for PVA-SSA-HPA-bridged-mixed-matrix membranes decreases dramatically with increasing current density rendering higher DMFC performance in relation to a DMFC using a pristine PVA-SSA membrane. A peak power density of 150 mW/cm(2) at a load current density of 500 mA/cm(2) is achieved for the DMFC using a PVA-SSA-STA-bridged-mixed-matrix-membrane electrolyte. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3465653] All rights reserved.
- Subjects :
- Vinyl alcohol
Peak power densities
Ion exchange capacity
Ex situ
Ion exchange membranes
Inorganic fillers
Silicotungstic acid
Membrane electrolytes
chemistry.chemical_compound
Electrolytes
NMR spectroscopy
Methanol fuels
Nafion
Polymer chemistry
Materials Chemistry
Electrochemistry
Methanol crossover rates
Phosphotungstic acid
Methanol fuel
Sulfur compounds
Nuclear magnetic resonance spectroscopy
Osmotic drag
Release kinetics
Mixed-matrix membranes
Renewable Energy, Sustainability and the Environment
Methanol
Mechanical permeability
Condensed Matter Physics
matrix
Phosphomolybdic acid
Mechanical stability
Surfaces, Coatings and Films
Electronic, Optical and Magnetic Materials
Membrane
chemistry
Chemical engineering
Heteropoly acids
Sorption
Direct methanol fuel cells (DMFC)
Protons
Sorption capability
Methanol permeability
Ion exchange
Proton conduction
Subjects
Details
- Language :
- English
- ISSN :
- 23813652
- Database :
- OpenAIRE
- Journal :
- IndraStra Global
- Accession number :
- edsair.doi.dedup.....b505acd4b5feb10370c5f548a2fdc46a
- Full Text :
- https://doi.org/10.1149/1.3465653