全氟质子交换膜在燃料电池中的寿命测试与性能研究

Lifetime test and research of perfluorinated proton exchange membrane in fuel cell

燃料电池的寿命是制约其商业化推广的主要瓶颈之一,其中核心材料质子交换膜的寿命问题是主要的技术难点.为了研究国产质子交换膜在燃料电池中的性能与寿命表现,将国产质子膜和国外商用质子膜2种质子交换膜制备的膜电极采用穿插组装方式,装配成20片单电池组成的电堆,并在模拟车载运行工况条件下进行了6000 h的寿命测试.通过分析不同工作电流条件下的电压、单电池电压分布和极化曲线随时间的变化来考察电池的性能衰减情况,同时对燃料电池寿命测试前后的敏感性、阻抗、电化学活性面积和透氢电流密度等性能进行分析,并采用红外测温和扫描电镜对寿命测试前后的质子交换膜进行表征,进一步阐明电堆性能衰减的机理.结果表明,经过6000 h的寿命循环测试,国产质子膜在额定电流密度点的极化性能衰减率不超过4%,达到了燃料电池商业化的技术要求.

The lifetime is one of the major bottlenecks which limiting the fuel cells commercialization and promotion,and the lifetime of the key material proton exchange membrane is the main technical challenge.To investigate the performance and lifetime of domestic proton exchange membrane in fuel cell,the membrane electrode assembles(MEA)prepared from two types of PEMs were assembled into a stack of 20 single cells using an interpenetration assembly method,and a lifetime test of 6 ooo hours was conducted under simulated vehicle operating conditions.Analyzing the change in the voltage,the cell voltage distribution and polarization curve of the fuel cell with time under different operating conditions,and measuring the performance such as the sensitivity,impedance,electrochemical active surface area(ECSA)and hydrogen crossover current density.Then characterizing the PEM using infrared temperature measurement and scanning electron microscopy(SEM)before and after the life test to further clarify the mechanism of the performance degradation of the fuel cell stack.The results indicate that after 6 o0o hours of life cycle test,the polarization performance degradation rate of domestic proton exchange membrane at the rated current density point does not exceed 4%,which meets the technical requirements for commercialization of fuel cells.