Polymer electrolyte membrane components

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. 

Fuel cells are the primary technology that will advance hydrogen use (DOE, 1998). Fuel cells are important as they are one component of a system that can efficiently produce electricity for many applications (Jacoby, 1999). It is also widely accepted that fuel cells are environmentally friendly (Hirschenhofer, 1997). Low temperature fuel cells, such as polymer-electrolyte-membrane (PEM) fuel cells, are being considered for many applications including electric power generation in commercial and residential buildings, automobile applications and... 

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. 

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). 

Heinzel and Konig snmmarize the impact of nanostrnctnred materials on fnel cell technology, mainly in the area of polymer electrolyte membrane fuel cells. This chapter illustrates how nanostructured materials can modify component performance snch as electrocatalyst materials and membrane. 

In last few years there has been considerable amount of activity in using ink-jet technology for printing different components of a fuel cell particularly those for polymer electrolyte membrane fuel cell (PEMFC) and direct methanol fuel cell (DMFC). The various components reported to have been printed using ink-jet are as follows ... 

The membrane in the polymer electrolyte fuel cell (PEFC) is a key component. Not by chance does the type of membrane brand the cell name - it is the most important component determining cell architecture and operation regime. Polymer electrolyte membranes are almost impermeable to gases, which is crucial for gas-feed cells, where hydrogen (or methanol) oxidation and oxygen reduction must take place at two separated electrodes. However, water can diffuse through the membrane and so can methanol. Parasitic transport of methanol (methanol crossover) severely impedes the performance of the direct methanol fuel cell (DMFC). 

A detailed cost analysis for a polymer electrolyte membrane fuel cell power plant of 5 kW was provided in 2006 by Kamarudin et al. According to their data, the total cost of such a plant will be about 1200 of which 500 is for the actual fuel-cell stack and 700 for the auxiliary equipment (pumps, heat exchangers, etc.). The cost of the fuel-cell stack is derived from the components as 55 /kW for the membranes, 52 /kW for the platinum, 128 /kW for the electrodes, and 148 /kW for the bipolar plates. 

Polymer Electrolyte membrane Fuel Cells (PEFC) are used to power uninterruptible power supplies, combined heat and power generation systems, vehicles for materials handling as well as electric vehicles, busses and light duty road vehicles. This contribution gives a short introduction into the working principles of PEFC as well as the materials and components used. 

The main component of a Polymer Electrolyte Membrane Fuel CeU (PEMFQ is the Membrane Electrode Assembly (MEA) [1,2]. The MEA is formed by a polymer membrane flanked by two electrodes. The membrane acts as the ionic conductor between the two electrodes the anode, where the fuel is oxidized, and the cathode, where the oxidant is reduced. The electrodes are formed by a porous material named Gas Diffusion Layer (GDL) with a thin layer of an electrocatalyst denominated the Catalyst Layer (CL), The electrocatalyst, responsible of driving... 

Fuel cells are power generation devices converting chemical energy into electric energy by electrochemical reactions. A typical fuel cell is comprised of two electrodes separated by an electrolyte, with a provision of reactant supply and product removal. Among various types of fuel cells, Ha-O -based polymer electrolyte membrane (PEM) fuel cells (PEMFC) have attracted special attention due to their high efficiency, low temperature operation and suitability for low to medium power generation. Basic components of a PEMFC are PEM, catalyst layer, gas diffusion layer and... 

Other important applications of poly(VPA) and its copolymers are as polymer electrolyte membranes for fuel cells,in the medical field as components in dental cements,bone reconstruction, hydrogels for drug delivery, and in ion exchange membranes. ... 

The main property of PVPA is proton conductivity. PVPA is largely used as a component in polymer electrolyte membranes obtained either by copolymerization or blending, in a low humidity environment at operating temperatures higher than 100 °C. 

Fig.l (a) Principal layout of a PEM fuel cell with the main functional components, viz. proton-conducting polymer-electrolyte membrane (PEM), catalyst layers on anode (ACL) and cathode sides (CCL), gas-diffusion layers (CDL) and flow fields (FF). (b) Disciplines in fuel cell research and how they are connected by the theory. 

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

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