• Journal of the Korean Electrochemical Society
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• v.13 no.2
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• pp.81-88
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• 2010

Small size polymer electrolyte membrane fuel cell (PEMFC) stacks were prepared using carbon composite and graphite bipolar plates and their performances were evaluated on reactant gas and operating time. In comparison to single cell and stack, it was identified that home-made bipolar plate was well-designed to maximize stack performance as high as that of single cell. During long-term operation, the performances of stacks using two different kinds of bipolar plates were compared. The decrease of performance in both stacks was accelerated with increasing load current. It was observed from stack test that the stack performance using carbon composite bipolar plate was very similar to that using graphite bipolar plate.

• Korean Chemical Engineering Research
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• v.61 no.4
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• pp.517-522
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• 2023

A chemical/mechanical durability test of polymer membrane evaluation method is used in which air and hydrogen are supplied to the proton exchange membrane fuel cell (PEMFC) and wet/dry is repeated in the open circuit voltage (OCV) state. In this protocol, when wet/dry is repeated, voltage increase/decrease is repeated, resulting in electrode degradation. When the membrane durability is excellent, the number of voltage changes increases and the evaluation is terminated due to electrode degradation, which may cause a problem that the original purpose of membrane durability evaluation cannot be performed. In this study, the same protocol as the department of energy (DOE) was used, but oxygen was used instead of air as the cathode gas, and the wet/dry time and flow rate were also increased to increase the chemical/mechanical degradation rate of the membrane, thereby shortening the durability evaluation time of the membrane to improve these problems. The durability test of the Nafion 211 membrane electrode assembly (MEA) was completed after 2,300 cycles by increasing the acceleration by 2.6 times using oxygen instead of air. This protocol also accelerated degradation of the membrane and accelerated degradation of the electrode catalyst, which also had the advantage of simultaneously evaluating the durability of the membrane and the electrode.