质子交换膜燃料电池电堆阳极饥饿反极的研究

Study on Reverse Polarization of Proton Exchange Membrane Fuel Cell Stack Caused by Anode Starvation

目前,质子交换膜燃料电池(PEMFC)反极研究主要通过单电池完成,反极过程没有考虑相邻电池的影响,与电堆实际情况并不完全相同.本文通过控制加湿度和过量系数等测试条件分析了5片PEMFC电堆阳极在水淹和缺气情况下的饥饿反极情况.结果表明,在电堆阳极水淹情况下,反极单电池电压表现为缓慢下降到电解水平台然后迅速恢复的循环过程,性能恢复归因于水淹单电池阳极进出口压差上升使其液态水排出而氢气重新进入;在电堆阳极缺气情况下,反极单电池电压表现为迅速降低到碳腐蚀平台然后迅速恢复的循环过程,这是由于缺气单电池的阳极进出口压差下降使电堆内氢气重新分配.缺气反极电池电压会降低到碳腐蚀平台,因此会对电池性能造成不可逆的损害.

At present,the study of proton exchange membrane fuel cell(PEMFC)reversal was mainly completed through a single cell,and the reversal process didn’t consider the influence of adjacent cells,which was not completely the same as the actual situation of the stack.This paper analyzed the anode starvation reverse polarity of PEMFC stack composed of 5 single cells under water flooding and gas shortage conditions by controlling testing conditions such as humidity and excess coefficient.The results show that under anode water flooding conditions,the voltage of the reverse polarity single cell slowly decreases to the electrolysis level table and then quickly recovers.The reason for performance recovery is that the pressure difference between the inlet and outlet of the water flooded single cell anode increases, causing liquid water to be discharged and hydrogen to enter again. Under the condition of gasshortage in the anode of the stack, the voltage of the reverse pole single cell exhibits a cyclic process of rapidlydecreasing to the carbon corrosion platform and then rapidly recovering. The reason for the performance recovery isthat the decrease in pressure difference between the anode inlet and outlet of the gas deficient single cell causes a newdistribution of hydrogen gas in the stack. Due to the lack of gas, the voltage of the reverse polarity battery willdecrease to the carbon corrosion platform, which will cause irreversible damage to the battery performance.