Polymer electrolyte membrane composition

Fedkiw Jr PS. Preparing in situ electrocatalytic films in solid polymer electrolyte membranes, composite microelectrode structures produced thereby and chloralkali process utilizing the same. United States patent US 4959132. 1990 Sep 25. 

Jiang, J. and Kucernak, A. 2005. Solid polymer electrolyte membrane composite microelectrode investigations of fuel ceU reactions. II Voltammetric study of methanol oxidation at the nanostructured platinum microelectrode Nafion membrane interface. 

Kamarajugadda, S., and Mazumder, S. Numerical investigation of the effect of cathode catalyst layer structure and composition on polymer electrolyte membrane fuel cell performance. Journal of Power Sources 2008 183 629-642. Krishnan, L., Morris, E. A., and Eisman, G. A. Pt black polymer electrolyte-based membrane-based electrode revisited. Journal of the Electrochemical Society 2008 155 B869-B876. 

Kamarajugadda, S., and Mazumder, S. Numerical investigation of the effect of cathode catalyst layer structure and composition on polymer electrolyte membrane fuel cell performance. Journal of Power Sources 2008 183 629-642. 

Song, M. K., Kim, Y. T. and Rhee, H. W. 2001. Composite polymer electrolyte membranes for high PEMFC performance. Proceedings of Electrochemical Society Meeting, San Francisco, CA. 

Cho, E. A., U. S. Jeon, H. Y. Ha, et al. 2004. Gharacteristics of composite bipolar plate for polymer electrolyte membrane fuel cells. Journal of Power Sources 125 178-182. 

Physical models of fuel cell operation contribute to the development of diagnoshc methods, the rational design of advanced materials, and the systematic ophmization of performance. The grand challenge is to understand relations of primary chemical structure of materials, composition of heterogeneous media, effective material properties, and performance. For polymer electrolyte membranes, the primary chemical structure refers to ionomer molecules, and the composition-dependent phenomena are mainly determined by the uptake and distribuhon of water. 

Figure 11.21 Long-term performance of a composite solid polymer electrolyte membrane consisting of 80 wt% AgBF4 dissolved in a propylene oxide copolymer matrix. Feed gas, 70 vol% ethylene/30 vol% ethane at 50 psig permeate pressure, atmospheric [33,61]...

The SECM capacity for rapid screening of an array of catalyst spots makes it a valuable tool for studies of electrocatalysts. This technique was used to screen the arrays of bimetallic or trimetallic catalyst spots with different compositions on a GC support in search of inexpensive and efficient electrocatalytic materials for polymer electrolyte membrane fuel cells (PEMFC) [126]. Each spot contained some binary or ternary combination of Pd, Au, Ag, and Co deposited on a glassy carbon substrate. The electrocatalytic activity of these materials for the ORR in acidic media (0.5 M H2S04) was examined using SECM in a rapidimaging mode. The SECM tip was scanned in the x—y plane over the substrate surface while electrogenerating 02 from H20 at constant current. By scanning... 

The key achievements at Ballard (Wilkinson 1998)15 are low Pt loading (1 mg cm-2) in 50-kW fuel cell power plants, and that of a power-to-weight ratio of 1 kW/kg. The development of the solid polymer electrolyte membrane was by no means in a final state in the late 1990s. The quality of the membrane controls the highest current density at which the cell is viable. There are open areas, too, with regard to the composition (as apart from the loading and particle size) of the catalyst a PtRu alloy... 

Wolf, H. and Willert-Porada, M., Electrically conductive LCP-carbon composite with low carbon content for bipolar plate application in polymer electrolyte membrane fuel cell, J. Power Sources, 153, 41, 2006. 

The material of PtRu alloy exhibits good properties for CO tolerance in polymer electrolyte membrane fuel cells (PEMFC) [68] and has been studied extensively in recent years [69]. Particular interest has been focused on the application of the PtRu alloy materials as anodes in methanol fuel cells (MFC) for electric vehicles [70]. The most convenient way to alter the surface composition of a PtRu alloy is to employ the electrochemical co-deposition method in the preparation of the alloy. Richcharz and co-workers have studied the surface composition of a series of PtRu alloys using X-ray photoelectron spectroscopy (XPS) and low-energy ion spectroscopy (LFIS)... 

Polymer-electrolyte fuel cells (PEFC and DMFC) possess a exceptionally diverse range of applications, since they exhibit high thermodynamic efficiency, low emission levels, relative ease of implementation into existing infrastructures and variability in system size and layout. Their key components are a proton-conducting polymer-electrolyte membrane (PEM) and two composite electrodes backed up by electronically conducting porous transport layers and flow fields, as shown schematically in Fig. 1(a). 

Concentration of HI over Hix solution by polymer electrolyte membrane electrodialysis was investigated using galvanodynamic and galvanostatic polarisation method. For this purpose, Hix solution with sub-azeotrope composition (HI L HjO = 1.0 0.5 5.8) was prepared. It was noticed that the electrical energy demand for electrodialysis of Hix solution decreases with increasing temperature. From the experimental results, it is concluded that the system resistance crucially affects the electrodialysis cell overpotential and hence the optimisation of cell assembly as well as the selection of low resistance materials should be carried out in order to obtain high performance electrodialysis cell. 

The PEM cell electrodes are composites consisting of nanoparticles of a Pt-based catalyst deposited on graphite. These are embedded in a polymer electrolyte membrane having a perfluoroethylene backbone (-- F2C—Cp2 r) with attached sulfonic acid groups (RS03 ) that play a key role in ferrying protons from anode to cathode. 

K.M. Nouel and PS. Fedkiw, Nafion based composite polymer electrolyte membrane, Electrochim. Acta, 1998, 43, 2381-2387. 

Quintus, M, Composite Electrodes and Membranes for Polymer Electrolyte Membrane Fuel Cells, PhD Thesis, University of Stuttgart, 2002, urn nbn de bsz 93-opus-12074 A, Dillon, K,M, Jones, T,A, Bekkedahl, C,H, Kiang, D,S, Bethune, M,J, Heben, Nature 386, 1997,377... 

M. Deka, A. K. Nath, and A. Kumar, Effect of dedoped (insulating) polyaniline nanofibers on the ionic transport and interfacial stability of poly(vinylidene fluoride-hexafluoropropylene) based composite polymer electrolyte membranes, J. Membrane Set, ill, 188-194 (2009). 

R. M. Formato, R. F. Kovar, P. Osenar, N. Landrau, and L. S. Rubin. Composite solid polymer electrolyte membranes. US Patent 7 052793, assigned to Foster-MUler, Inc. (Waltham, MA), May 30, 2006. 

This polymer membrane normally consists of an ion exchange polymer or a composite made from a chemically and thermally stable polymer containing an ion conducting liquid having a high boiling point. Polymer electrolyte membranes are made from the following classes of polymers. 

Anis A, Banthia AK, Bandyopadhyay S (2008) Synthesis and characterization of polyvinyl alcohol copolymer/phosphomolybdic acid-baed crosslinked composite polymer electrolyte membranes. J Power Sources 179 69-80... 

Park, K.T., Jnng, U.H., Choi, D.W., Chun, K., Lee, H.M. and Kim, S.H. 2008. ZrOj-SiOy Nafion composite membrane for polymer electrolyte membrane fuel cells operation at high temperature and low humidity. 177(2) 247—253. 

Figure 6.18 Loss of resistance as function of time of a pure (PEO)s Nal polymer electrolyte membrane and of a (PEO)8NaI.10 w/o P-AlxO composite membrane at temperatures above the amorphous transition. From ref [38].

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