Research And Application Of A Method To Measure The MEA Parameters Of PEMFCs

The rapid development of automobile industry is facing the serious energy crisisand environmental problems, to find new clean power is imminent. Because theproton exchange membrane fuel cell has the advantages of high energy conversionefficiency and no-pollution, it is considered to be the best choice of the futureautomotive power. Currently, most of the research of PEMFC is focus on the overallperformance of fuel cell, the research on the MEA is little. However, the MEA is themost important part to determine its performance, so it is very necessary to researchthe properties of MEA.The paper study and improve a galvanostatic method to measure the parametersof the membrane electrode, with N2and H2into both sides of the fuel cell, externalload constant current. Based on the analysis of voltage-time curve, the MEAparameters are obtained. Since the galvanostatic method is simple and practical, andthe measured results are relatively stable, it has a good application value.At the same time, the galvanostatic method is used to study the influence of thetemperature and gas relative humidity on the membrane electrode parameters, theexperimental results show that with the increase of gas relative humidity, the electricdouble layer capacitance and the electrochemical active surface increases, while thehydrogen penetration current decreases, and when the gas relative humidity reached90%, the membrane electrode parameters remain stable; with increase of temperature,the electric double layer capacitance increases, and hydrogen penetration currentand electrochemical active surface slow decline when the gas relative humidity is100%. In addition, the influences of hydrogen evolution activation method and microcurrent activation method on the performance of PEMFC are researched by using thegalvanostatic method to analysis the change of MEA parameters, results show thatboth methods can effectively improve the performance of PEMFC, reduce thehydrogen penetration current, and increase the electrochemical active surface andelectric double layer capacitor. By contrast, the effect of hydrogen evolutionactivation method is more outstanding. Hydrogen evolution activation can improve the performance of both sides, while the micro current activation can only improvethe performance of cathode.In general, the gavanostatic method can effectively measure the membraneelectrode parameters, has a strong practical value as a tool of the fuel cell research. Atthe same time, the research of hydrogen evolution activation method and microcurrent activation method by using the gavanostatic method improve ourunderstanding of activation mechanism. This work has an important significance toimprove the lifetime of PEMFC.