Proton exchange membrane bipolar plates

Figure 4.1 shows a schematic of a typical polymer electrolyte membrane fuel cell (PEMFC). A typical membrane electrode assembly (MEA) consists of a proton exchange membrane that is in contact with a cathode catalyst layer (CL) on one side and an anode CL on the other side they are sandwiched together between two diffusion layers (DLs). These layers are usually treated (coated) with a hydrophobic agent such as polytetrafluoroethylene (PTFE) in order to improve the water removal within the DL and the fuel cell. It is also common to have a catalyst-backing layer or microporous layer (MPL) between the CL and DL. Usually, bipolar plates with flow field (FF) channels are located on each side of the MFA in order to transport reactants to the... 

T. Matsuura, M. Kato, and M. Hori. Study on metallic bipolar plate for proton exchange membrane fuel cell. Journal of Power Sources 161 (2006) 74-78. 

In PEMFCs working at low temperatures (20-90 °C), several problems need to be solved before the technological development of fuel cell stacks for different applications. This concerns the properties of the components of the elementary cell, that is, the proton exchange membrane, the electrode (anode and cathode) catalysts, the membrane-electrode assemblies and the bipolar plates [19, 20]. This also concerns the overall system vdth its control and management equipment (circulation of reactants and water, heat exhaust, membrane humidification, etc.). 

Besmann, T.M. et al., Carbon/carbon composite bipolar plate for proton exchange membrane fuel cells, J. Electrochem. Soc., 147, 4083, 2000. 

Kim M, Yu HN, Lim JW, Lee DG (2012) Bipolar plates made of plain weave carbon/epoxy composite for proton exchange membrane fuel cell. Int J Hydrogen Energy 37 4300 308... 

T. M. Besmann et al., Carbon/Carbon Composite Bipolar Plate for Proton Exchange Membrane Fuel Cells, Journal of The Electrochemical Society, 147(11), 4083-4086 (2000). 

Kinumoto, T., Nagano, K., Tsumura, T., and Toyoda, M. (2010) Thermal and electrochemical durability of carbonaceous composites used as a bipolar plate of proton exchange membrane fuel cell. 

Brady MP, Wang H, Turner JA, Meyer HM, More KL, Tortorelli PF, McCarthy BD (2010) Pre-oxidized and nitrided stainless steel alloy foil for proton exchange membrane fuel cell bipolar plates Part 1. Corrosion, interfacial contact resistance, and surface structure. J Power Sources 195 5610-5618... 

Stack Components In collaboration with partners, research and develop technologies to overcome the most critical technical hurdles for polymer electrolyte fuel cell stack components for both stationary and transportation applications. Critical technical hurdles include cost, durability, efficiency, and overall performance of components such as the proton exchange membranes, oxygen reduction electrodes, advanced catalysts, bipolar plates, etc. 

Figure 7.7. Schematic diagram of an MEA structure. BP - bipolar plate GDL - gas diftusion layer ACL - anode catalyst layer CCL - cathode catalyst layer PEM - proton exchange membrane.

The design of a PEM-type electrolyzer is relatively simple. As Figure 2.10 illustrates, it comprises a stack of elementary cells connected in a series by bipolar plates. Each cell comprises two electrodes separated by a Proton Exchange Membrane (PEM). Each electrode is made up of a thin catalytic layer which is the site of the oxidation (anode) or reduction reaction (cathode), and layers of porous materials which act as current distributors/receivers depending on the electrode in question. In general, this porous material will be incompressible (titanium) at the anode and compressible (carbon) at the cathode in order to add mechanical flexibility when the whole ensemble is compressed. 

Cho, K. H., Lee, S. B., Lee, W. G. et al. 2009. Improved corrosion resistance and interfacial contact resistance of 316L stainless-steel for proton exchange membrane fuel cell bipolar plates by chromizing surface treatment. Journal of Power Sources 187 318-323. 

Heo, S. I., Oh, K. S., Yun, J. C. et al. 2007. Development of preform moulding technique using expanded graphite for proton exchange membrane fuel cell bipolar plates. Journal of Power Sources 171 396-403. 

Hou, M., Fu, Y., Lin, G. et al. 2009. Optimized Gr-nitride film on 316L stainless steel as proton exchange membrane fuel cell bipolar plate. International Journal of Hydrogen Energy 34 453—458. 

Joseph, S., McClure, J. C., Chianelli, R. et al. 2005. Conducting polymer-coated stainless steel bipolar plates for proton exchange membrane fuel cells (PEMFG). International Journal of Hydrogen Energy 30 1339-1344. 

Brady, M.P, K. Weisbrod, I. Paulauskas et al. 2004. Preferential thermal nitridation to form pin-hole free Cr-nitrides to protect proton exchange membrane fuel cell metallic bipolar plates. Scripta Materialia 50 1017-1022. 

Electrically conductive BMC with a proprietary conductive fiUer is developed for proton exchange membrane (PEM) fuel ceU conductive plates for passenger cars. Bulk Molding Compounds Inc. vinyl ester compounds are molded into PEM fuel cell plates. Premix subsidiary Quantum Composites Pemtex BMC formulations are co-developed for fuel cell plates with Ferromatik MHacron and Apex Plastics technology. The conductive, corrosion-resistant composite is injection molded into bipolar plates for PEM fuel cells. ... 

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