阴极Mg^(2+)污染物对PEMFC电化学性能及电化学阻抗影响  

EFFECTS OF Mg^(2+)CONTAMINANT AT CATHODE ON PEMFC ELECTROCHEMICAL PERFORMANCE AND ELECTROCHEMICAL IMPEDANCE

作　　者：许丽凤 谈金祝[1] 李易惠子 朱京宇 侯琼 韦彦强 Xu Lifeng;Tan Jinzhu;Li Yihuizi;Zhu Jingyu;Hou Qiong;Wei Yanqiang(College of Mechanical and Power Engineering,Nanjing Tech University,Nanjing 211816,China)

机构地区：[1]南京工业大学机械与动力工程学院,南京211816

出　　处：《太阳能学报》2024年第3期269-276,共8页Acta Energiae Solaris Sinica

基　　金：国家自然科学基金(52275152)。

摘　　要：质子交换膜燃料电池经过长期运行后,其部件(弹性垫片、极板等)会发生损伤,并产生金属离子污染物(如Ca^(2+)、Mg^(2+)),这将影响燃料电池长期运行的稳定性和耐久性。通过向燃料电池阴极空气流中添加不同浓度(100、300和500 mg/L)的Mg^(2+)溶液,研究了极化曲线以及电化学阻抗谱,分析了阴极Mg^(2+)污染物对燃料电池电化学性能及电化学阻抗的影响。极化曲线实验结果表明3种浓度梯度的阴极Mg^(2+)污染物均对燃料电池的电化学性能有明显负面影响,污染后的燃料电池的电流密度出现下降,且下降程度与阴极Mg^(2+)污染物浓度和污染时间呈正相关。极化曲线理论分析结果表明:3种浓度梯度的阴极Mg^(2+)污染物均显著影响质子交换膜的渗透性并增大质子交换膜对氢离子的阻抗,且污染时间越长,质子交换膜性能恶化越严重。电化学阻抗谱分析结果表明:3种浓度梯度的阴极Mg^(2+)污染物均会增大质子交换膜对氢离子的阻抗以及阴极法拉第电阻,且质子交换膜对氢离子的阻抗随污染时间增加而增大;阴极双电层结构受这3种浓度梯度的阴极Mg^(2+)污染物影响不明显。During long-term operation,the components(such as bipolar plates and elastomeric gaskets)of proton exchange membrane fuel cell(PEMFC)may degrade and produce the metal ion contaminants(e.g.Ca^(2+),Mg^(2+)).This could affect the long-term stability and durability of the PEMFC for its applications.In this paper,polarization curves and electrochemical impedance spectroscopy(EIS)were investigated experimentally by introducing the various concentration(i.e.100 mg/L,300 mg/L and 500 mg/L)Mg^(2+)solutions into the cathode air stream of the PEMFC,and then the effects of Mg^(2+)contaminant at the cathode on the PEMFC electrochemical performance and electrochemical impedance were analyzed.The polarization curve results show that the cathodic Mg^(2+)contaminant with three levels of concentrations had significantly negative effects on the electrochemical performance of the fuel cell,the current density of the fuel cell contaminated by Mg^(2+)decreased,andthe current density decreased more drastically withtheincrease of Mg^(2+)concentration and contamination time.The theoretical analysis results of polarization curves indicate that the cathodic Mg^(2+)contaminant with three levels of concentrations could affect the permeability of the proton exchange membrane and increase the H+impedance in the proton exchange membrane,and the performance of the proton exchange membrane deteriorated more severely with the increase of contamination time.The EIS results show that the cathodic Mg^(2+)contaminant with three levels of concentrations could increase the H+impedance in the proton exchange membrane and the cathode Faraday resistance,and the H+impedance in the proton exchange membrane and cathode Faraday resistance increase with the increase of contamination time,and the cathode electric double-layers are not significantly affected by the Mg^(2+)contaminant at the cathode in this work.

关 键 词：质子交换膜燃料电池 镁离子 电化学阻抗谱 电化学性能 

分 类 号：TM911[电气工程—电力电子与电力传动]