Studies on the Cell Reversal of Proton Exchange Membrane Fuel Cell

Abstract: The paper uses the exchange mesh method simulation battery instead extremely mechanism, and uses in for the first time the series accumulator cell law use cell test system simulation voltaic pile some Shan Chifan the extremely phenomenon, obtained the proton exchange membrane fuel cell voltaic pile flooding electrode to have directed the rebellion extremely as well as the gas chemistry measurement compared to insufficiency when directs the rebellion extremely when to the fuel cell electricity catalyst injury and the influence, the experiment obtains, because the electrochemical process occupied the major effect factor, after the open-circuit voltage did not have the change instead extremely, the counter- pole pair proton exchange membrane degeneration might neglect nearly, but had the fatal injury to the electricity catalyst performance.Paper through analysis proton exchange membrane fuel cell conduction mechanism and instead extremely mechanism, basis voltaic pile model, first passage analogous circuit design research analysis flooding electrode and gas insufficient these two kind of typical instead extremely phenomena. Through the new flow field design, to guarded against the flooding electrode to do the thorough research, conducted the research compared with the liquid water existence quantity to the fuel cell electricity generation performance and the electrochemistry performance, further has proven the liquid water to the fuel cell limiting current influence. Through after instead extremely the catalyst and the CCM test analysis, further discovered the counter- pole pair proton exchange membrane the injury is extremely weak, but the electricity catalyst particle size remarkably increases, catalytic activity area reduction. This research has the important inspiration to the thorough understanding fuel cell mechanism and the electricity catalyst expiration protection. Also the research discovered that, (1) because the negative pole liquid water existence causes partially instead extremely, to fuel cell performance existence negative influence. Displaysespecially when the big electric current, production liquid water more and more many, at the same time needs to proliferate the response gas quantity actually more and more greatly in the gas phase and the electrolyte contact surface, the negative pole liquid water existence has increased the oxygen mass transfer resistance, because the oxygen the solubility is minimum in the water, therefore the liquid water existence serious histamine reflection gas mass transfer, reduces the fuel cell the electrochemistry performance;The flooding electrode mainly occurs in the negative pole side, is small to the battery anode influence. Moreover the back row falls the liquid water the battery performance not to have after instead extremely too changes, even the performance has the rise in the short time, namely this time is small to the electricity catalyst influence.(2) the fuel cell flow field design might reduce in some kind of degree or avoids flood the electrode occurrence, the synthesis narrated the principle as well as the existing design good and bad points which the flow field design should pay attention, proposed one kind of new flow field design. After the experiment and the simulation analysis, to removes in the flow field the liquid water to have the unique effect.(3) the gas insufficient directs the rebellion extremely is the fuel cell researcher needs to avoid occurring vigorously, because in time fuel or oxidant insufficiency, will cause the damage to the electricity catalyst which permanent might not be restored, by SEM, TEM,XRD,XPS as well as the circulation volt-ampere and so on the test analysis method may know that, 30 seconds gas insufficient direct rebellion after the granules of catalyst particle size to be able to increase about extremely 50%, the catalyzed effective catalytic activity area loses about 18%, moreover has part of CO and the CO2 production.(4) through the alternating-current impedance simulation analysis, may join the electrochemical potential low activeness high matter protection platinum carbon catalyst, when fuel or oxidant insufficiency has the electrochemistry response is these new matter first, but the platinum carbon receives the injury reduces greatly…
Key words: proton exchange membrane fuel cell; cell reversal; flooding; gas starvation; degradation

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