Polymer electrolyte membrane materials

Polymer electrolyte membrane materials and their properties... 

For both DMFC systems for light traction and for DMFC systems for portable applications, Nafion is still the standard membrane material. A general overview of the polymer electrolyte membrane materials, their modifications, and their function can be found in. [107] and with the focus on the DMFC operation in [108]. 

D. S. Kim, Ph.D. Thesis, Novel polymer electrolyte membrane materials Candidates for proton exchange membrane fuel cell. Hanyang University, Seoul, Korea, 2005. 

Schonberger, F., Kerres, J. (2007) Novel multiblock-co-ionomers as potential polymer electrolyte membrane materials. Journal of Polymer Science Part A Polymer Chemistry,... 

Design parameters of the anode catalyst for the polymer electrolyte membrane fiiel cells were investigated in the aspect of active metal size and inter-metal distances. Various kinds of catalysts were prepared by using pretreated Ketjenblacks as support materials. The prepared electro-catalysts have the morphology such as the sizes of active metal are in the range from 2.0 to 2.8nm and the inter-metal distances are 5.0 to 14.2nm. The electro-catalysts were evaluated as an electrode of PEMFC. In Fig. 1, it looked as if there was a correlation between inter-metal distances and cell performance, i.e. the larger inter-metal distances are related to the inferior cell performance. 

D. Wilkinson, D. Thompsett, "Materials and Approaches for CO and CO2 Tolerance for Polymer Electrolyte Membrane Fuel Cells," Proceedings of the Second International Symposium on New Materials for Fuel Cell and Modern Battery Systems, pp. 266-285, (Montreal, Quebec, Canada, July 6-10, 1997). 

D. P. Wilkinson and D. Thompsett. In Materials and approaches for CO and CO2 tolerance for polymer electrolyte membrane fuel cells, ed. O. Savadogo and P. R. Roberge, 266. Montreal Ecole Polytechnique de Montreal, 1997. 

Li, Q., He, R., Jensen, J. O. and Bjerrum, N. J. 2003. Approaches and recent deyel-opment of polymer electrolyte membranes for fuel cells operating aboye 100°C. Chemistry of Materials 15 4896 915. 

Wang, H., and J. A. Turner. 2004. Investigation of a duplex stainless steel as polymer electrolyte membrane fuel cell bipolar plate material. Journal of Power Sources. 128 193-200. 

The materials of greatest interest in view of fundamental understanding and design are the polymer electrolyte membrane and the catalyst layers. They fulfill key functions in the cell and at the same time offer the most compelling opportunities for innovation through design and integration of advanced materials. 

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. 

Because of its lower temperature and special polymer electrolyte membrane, the proton exchange membrane fuel cell (PEMFC) is well-suited for transportation, portable, and micro fuel cell applications. But the performance of these fuel cells critically depends on the materials used for the various cell components. Durability, water management, and reducing catalyst poisoning are important factors when selecting PEMFC materials. 

Stephen J. Paddison received a B.Sc.(Hon.) in Chemical Physics and a Ph.D. (1996) in Physical/Theoretical Chemistry from the University of Calgary, Canada. He was, subsequently, a postdoctoral fellow and staff member in the Materials Science Division at Los Alamos National Laboratory, where he conducted both experimental and theoretical investigations of sulfonic acid polymer electrolyte membranes. This work was continued while he was part of Motorola s Computational Materials Group in Los Alamos. He is currently an Assistant Professor in the Chemistry and Materials Science Departments at the University of Alabama in Huntsville, AL. Research interests continue to be in the development and application of first-principles and statistical mechanical methods in understanding the molecular mechanisms of proton transport in fuel-cell materials. 

Polymer electrolyte membrane and solid oxide fuel cells demonstration of systems and development of new materials. Activity leader National Research Council (CNR). Estimated activity cost 14 million. 

Proton exchange membrane (pem) fuel cells, also known as polymer electrolyte membrane fuel cells, have a plastic electrolyte. The membrane material most widely used in pems is produced by DuPont and looks like the plastic wrap used for storing foods. The word proton refers to the hydrogen ion that passes through the polymer membrane. 

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 development of conventional room-temperature hydrides based on interme-tallic compounds led to a large number of storage materials exhibiting very favorable sorption enthalpies with values of around 25 kj (mol H2), which can be operated in combination with conventional (80 °C operation temperature) polymer electrolyte membrane (PEM) fuel cells. However, their gravimetric storage capacity is limited to less than 3 wt.% H2. 

Wang, H., Sweikart, M.A., and Turner, J.A., Stainless steel as bipolar plate material for polymer electrolyte membrane fuel cells, J. Power Sources, 115, 243, 2003. 

Weil, K.S. et al., Boronization of nickel and nickel clad materials for potential use in polymer electrolyte membrane fuel cells, Sutf. Coatings TechnoL, 201,4436, 2006. 

Among the proton-conducting membranes Nation or Nafion-like sulfonated perfluorinated polymers should also be mentioned. These materials are used for polymer electrolyte membrane (PEM) fuel cells, and in addition to being chemically very stable, they exhibit high proton conductivity at temperatures lower than 100°C. It is believed that permeability and thermal stability may be increased if tailor-made lamellar nanoparticles are added to a proton conducting polymer. 

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