Polymer electrolyte membranes cooling

In addition to the individual polymer electrolyte membrane fuel cells and their bipolar plates, special heat-exchanger plates must also be included in the battery stack. Cooling fluid is circulated through these plates in order to eliminate the heat produced during battery operation. At least one such plate must be provided for any two cells when the battery is to be operated with high current densities. These plates could also be used to warm up the battery for a cold start-up. 

The peripheral equipment needed for direct methanol fuel cells is largely analogous to that of polymer electrolyte membrane fuel cells. The mechanical basis of fuel cells and stacks on the whole consists of bipolar plates between which the sandwiched membrane-electrode assemblies are arranged. For the venting of heat, cooling plates with a circulating heat transfer agent are set up in a particular order between individual fuel cells in the stack. 

Jorissen, L., and Hartnig, C. (2009) Externally cooled high temperature polymer electrolyte membrane fuel cell stack./. Power Sources, 190, 83-85. 

Kim, C.J. (2009) Numerical study to examine the performance of multi-pass serpentine flow-fields for cooling plates in polymer electrolyte membrane fuel cells. /. Power Sources, 194 (2), 697-703. 

Jensen H-C B, KaerSK (2011) Boundary model-based reference control of blower cooled high temperature polymer electrolyte membrane fuel cells. Int J Hydrog Energy 36 5030-5037... 

There has been an accelerated interest in polymer electrolyte fuel cells within the last few years, which has led to improvements in both cost and performance. Development has reached the point where motive power applications appear achievable at an acceptable cost for commercial markets. Noticeable accomplishments in the technology, which have been published, have been made at Ballard Power Systems. PEFC operation at ambient pressure has been validated for over 25,000 hours with a six-cell stack without forced air flow, humidification, or active cooling (17). Complete fuel cell systems have been demonstrated for a number of transportation applications including public transit buses and passenger automobiles. Recent development has focused on cost reduction and high volume manufacture for the catalyst, membranes, and bipolar plates. 

Frequently, the MEA is framed by an inert and compression resistant polymer film with the function to protect the electrolyte membrane from external contaminations caused for example by cations present in the cooling water or... 

The copolymer P(VDF-HFP) can be dissolved in organic electrolyte (EC/ DEC) by heating and then coated on a microporous membrane. After cooling, a gel polymer electrolyte supported by the membrane is obtained. Its ionic conductivity at room temperature is 1.5-2 x 10 3 S/cm, with an electrochemical window up to 4.5 V. Ihe assembled batteries show excellent cycling performance. 

The copolymer PAMS (AN-MMA-St) prepared by emulsion polymerization can be dissolved in organic electrolyte by heating and then coated on both sides of a PE microporous membrane. After cooling and solidification by cross-linking, the gel polymer electrolyte that is obtained shows an ionic... 

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