i am currently doing a study on fuel cell membrane for my thesis. I would like to get a detail explanation on Nafion Polymer Membrane. Thank you
Nafion? is a sulfonated tetrafluorethylene copolymer discovered in the late 1960s by Walther Grot of DuPont de Nemours. It is the first of a class of synthetic polymers with ionic properties which are called ionomers. Nafion's unique ionic properties are a result of incorporating perfluorovinyl ether groups terminated with sulfonate groups onto a tetrafluoroethylene (Teflon) backbone. Nafion has received a considerable amount of attention as a proton conductor for proton exchange membrane (PEM) fuel cells because of its excellent thermal and mechanical stability. The chemical basis of Nafion's superior conductive properties remain a focus of research. Protons on the SO3H (sulfonic acid) groups hop from one acid site to another. Pores allow movement of cations but the membranes do not conduct anions or electrons. Nafion can be manufactured with various cationic conductivities.
A polymer electrolyte membrane for a fuel cell, which restrains a crossover phenomenon of fuel and a decomposition of a polymer membrane over platinum, and shows outstanding power output and performance characteristics during operation of the fuel cell, and a method for producing the same. The method comprises the steps of blending a polymer matrix with a fluorinated ionomer of 3 to 50 wt % based on a weight of a polymer to produce a blended polymer solution; casting the blended polymer solution into a polymer membrane; and coating the fluorinated ionomer on both sides of the polymer membrane to produce a composite membrane. The polymer electrolyte membrane has advantages in that the fuel cell using the polymer electrolyte membrane, which has high energy efficiency, can be inexpensively produced, and so the fuel cell can be applied in various applications such as a power source of a nonpolluting car, on-site generation of electricity, an electric power source of a spacecraft, a portable energy source, and an energy source for military purpose. An all-solid-state supercapacitor is fabricated and optimized using a Nafion[R] membrane and an ionomer. The device shows good capacitance (ca. 200 Fg[-1]) as demonstrated by cyclic voltammograms (CVs) and charge-discharge curves. The supercapacitor exhibits a relatively stable capacitance during 10,000 cycles of operation. A hybrid system comprising a direct methanol fuel cell (DMFC) and an all-solid-state supercapacitor has been designed and tested. It is confirmed that the power discharged by the supercapacitor is transferred effectively to the DMFC. The power of the hybrid is immediately improved by 30% compared with that of a DMFC alone operating at 25 C. The possibilities of using this system for high energy and high instantaneous power devices and integrated fabrication processes are discussed
