Proton-conductive membranes, fuel cells

Hiibner, G. and Roduner, E. 1999. EPR investigation of HO radical initiated degradation reactions of sulfonated aromatics as model compounds for fuel cell proton conducting membranes. Journal of Materials Chemistry 9 409- 18. 

PEM Proton-exchange-membrane fuel cell (Polymer-electrolyte-membrane fuel cell) Proton- conducting polymer membrane (e.g., Nafion ) H+ (proton) 50-80 mW (Laptop) 50 kW (Ballard) modular up to 200 kW 25-=45% Immediate Road vehicles, stationary electricity generation, heat and electricity co-generation, submarines, space travel... 

Direct-methanol fuel cell Proton- conducting polymer membrane H+ (proton) 80-100... 

Figure 29. Conductivity of some intermediate-temperature proton conductors, compared to the conductivity of Nafion and the oxide ion conductivity of YSZ (yttria-stabilized zirconia), the standard electrolyte materials for low- and high-temperature fuel cells, proton exchange membrane fuel cells (PEMFCs), and solid oxide fuel cells (SOFCs).

The proton conductivity of the sulfonated PES is above 0.08 S cm , which is in the range needed for high-performance fuel cell proton exchange membranes and... 

Research has been conducted and is currently being conducted into several types of fuel cells, such as alkaline fuel cells, proton exchange membrane (PEM) fuel cells, phosphoric acid fuel cells, molten carbonate fuel cells, solid oxide fuel cells, and so forth. Some of them are already commercialized, whereas others are close to commercialization. They are expected to find applications in almost every energy utilizing plant and/or device, from power plants to cars and homes, from laptop computers to mobile phones. 

Ren, X. Springer, T. E. and Gottesfeld, S. (1998). Direct Methanol Fuel Cell Transport Properties of the Polymer Electrolyte Membrane and Cell Performance. Vol. 98-27. Proc. 2nd International Symposium on Proton Conducting Membrane Euel Cells. Pennington, NJ Electrochemical Society. 

S. R. Narayanan, A. Kindler, B. Jeffries-Nakamura, W. Chun, H. Frank, M. Smart, S. Surampudi, and G. Halpert, in Proc. of the First International Symposium on Proton Conducting Membrane Fuel Cells, Ed. by S. Gottesfield, G. Halpert, and A. R. Landgrebe, The Electrochemical Society, Pennington, NJ, PV 95-23, 1995, pp. 261-266. 

A.R. Landgrebe, S. Gottesfeld, First International Symposium on Proton Conducting Membrane Fuel Cells, Chicago, h. Proceedings Vol. 95-23, The Electrochemical Society, Inc., Pennington, N.J., 1995. 

Kreuer, K. D. 2001. On the development of proton conducting membranes for hydrogen and methanol fuel cells. Journal of Membrane Science 185 29-39. 

Asano, N., Aoki, M., Suzuki, S., Miyatake, K., Uchida, H. and Watanabe, M. 2006. Aliphatic/aromatic polyimide ionomers as a proton conductive membrane for fuel cell applications. Journal of the American Chemical Society 128 1762-1769. 

Jeske, M., Soltmann, C., Ellenberg, C., Wilhelm, M., Koch, D. and Grathwohl, G. 2007. Proton conducting membranes for the high temperature-polymer electrolyte membrane-fuel cell (HT-PEMFC) based on functionalized polysiloxanes. 

Allcock, H. R., Hofmann, M. A., Ambler, C. M., Lvov, S. N., Zhou, X. Y., Chalkova, E. and Weston, J. 2002. Phenyl phosphonic functionalized poly(aryloxyphosphanes) as proton-conducting membranes for direct methanol fuel cells. Journal of Membrane Science 201 47-54. 

Dobrovolskii, Y. A., A. E. Ukshe, A. V. Levchenko, et al. 2007. Materials for bipolar plates for proton-conducting membrane fuel cells. Russian Journal of General Chemistry 4 752-765. 

Allcock et al. also have investigated the use of phosphonated polyphosphazenes as potential membrane materials for use in direct methanol fuel cells (Figure A2) Membranes were found to have lEC values between 1.17 and 1.43 mequiv/g and proton conductivities between 10 and 10 S/cm. Methanol diffusion coefficients for these membranes were found to be at least 12 times lower than that for Nafion 117 and 6 times lower than that for a cross-linked sulfonated polyphosphazene membrane. 

Wnek, G. E. Rider, J. N. Serpico, J. M. Einset, A. G. Proceedings of the First International Symposium on Proton Conducting Membrane Fuel Cells, Electrochemical Society 1995 p 247. 

One of the most important parts of the fuel cell is the electrolyte. For polymer-electrolyte fuel cells this electrolyte is a single-ion-conducting membrane. Specifically, it is a proton-conducting membrane. Although various membranes have been examined experimentally, most models focus on Nafion. Furthermore. it is usually necessary only to modify property values and not governing equations if one desires to model other membranes. The models presented and the discussion below focus on Nafion. 

The purpose of the present review is to summarize the current status of fundamental models for fuel cell engineering and indicate where this burgeoning field is heading. By choice, this review is limited to hydrogen/air polymer electrolyte fuel cells (PEFCs), direct methanol fuel cells (DMFCs), and solid oxide fuel cells (SOFCs). Also, the review does not include microscopic, first-principle modeling of fuel cell materials, such as proton conducting membranes and catalyst surfaces. For good overviews of the latter fields, the reader can turn to Kreuer, Paddison, and Koper, for example. 

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