Membrane fuel cell, components

Modeling of Polymer Electrolyte Membrane Fuel-Cell Components... 

Sol-gel techniques have been widely used to prepare ceramic or glass materials with controlled microstructures. Applications of the sol-gel method in fabrication of high-temperature fuel cells are steadily reported. Modification of electrodes, electrolytes or electrolyte/electrode interface of the fuel cell has been also performed to produce components with improved microstructures. Recently, the sol-gel method has expanded into inorganic-organic hybrid membranes for low-temperature fuel cells. This paper presents an overview concerning current applications of sol-gel techniques in fabrication of fuel cell components. 

Sol-gel techniques have been successfidly applied to form fuel cell components with enhanced microstructures for high-temperature fuel cells. The apphcations were recently extended to synthesis of hybrid electrolyte for PEMFC. Although die results look promising, the sol-gel processing needs further development to deposit micro-structured materials in a selective area such as the triple-phase boundary of a fuel cell. That is, in the case of PEMFC, the sol-gel techniques need to be expanded to form membrane-electrode-assembly with improved microstructures in addition to the synthesis of hybrid membranes to get higher fuel cell performance. 

Proton Exchange Membrane Fuel Cells (PEMFCs) are being considered as a potential alternative energy conversion device for mobile power applications. Since the electrolyte of a PEM fuel cell can function at low temperatures (typically at 80 °C), PEMFCs are unique from the other commercially viable types of fuel cells. Moreover, the electrolyte membrane and other cell components can be manufactured very thin, allowing for high power production to be achieved within a small volume of space. Thus, the combination of small size and fast start-up makes PEMFCs an excellent candidate for use in mobile power applications, such as laptop computers, cell phones, and automobiles. 

The previous discussion asserts that design, fabrication, and implementation of stable and inexpensive materials for membranes and catalyst layers are the most important technological challenges for PEFC developers. A profound insight based on theory and modeling of the pertinent materials will advise us how fuel cell components with optimal specifications can be made and how they can be integrated into operating cells. 

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. 

The first key component of a membrane fuel cell is the membrane electrolyte. Its central role lies in the separation of the two electrodes and the transport of ionic species (e.g. hydroxyl ion, OH , in an AEM), between them. In general, quaternary ammonium groups are used as anion-exchange groups in these materials. However, due to their low stability in highly alkaline media [43,44], only a few membranes have been evaluated for use as solid polymer electrolytes in alkaline fuel cells. 

Copolymers were subsequently converted into 90-pm-thick membranes using (V-methylpyrrolidone and were used as fuel cell components. 

Proton Exchange Membrane Technology Fuel Cell Components Testing Equipment Software... 

The internal resistance of a fuel cell includes the electric contact resistance among the fuel cell components, and the proton resistance of the proton-conducting membrane. In PEMFCs, the proton resistance of the polymer electrolyte membrane contributes the most to the total ohmic resistance. 

It has been demonstrated that EIS can serve as a standard analytical diagnostic tool in the evaluation and characterization of fuel cells. Scientists and engineers have now realized that the entire frequency response spectrum can provide useful data on non-Faradaic mechanisms, water management, ohmic losses, and the ionic conductivity of proton exchange membranes. EIS can help to identify contributors to PEMFC performance. It also provides useful information for fuel cell optimization and for down-selection of the most appropriate operating conditions. In addition, EIS can assist in identifying problems or predicting the likelihood of failure within fuel cell components. 

The 3,4,5,6,7,8-hexahydro-l,2-oxathiocin 2,2-dioxide is the key component for the synthesis of a polymer used for proton exchange membrane fuel cells (PEMFCs). Membranes made with this polymer are pliant, do not expand much during wet conditions, and are chemically, hydrolytically, and thermally stable <2006USP0135702>. 

---