摘要
电化学阻抗谱能被用来表征燃料电池内部状态和电化学行为信息,通过构建合适的等效电路模型拟合电化学阻抗谱,可辨识和量化燃料电池内部不同的极化过程及状态。针对质子交换膜燃料电池,系统研究电流密度、工作温度、压力、阴/阳极进气过量系数和阴/阳极进气湿度7种外部工作条件对燃料电池电化学阻抗谱的影响。基于等效电路法,对阻抗谱各频段阻抗的变化及其对工作条件的敏感性进行分析和讨论。研究表明,燃料电池损耗在低、中、高电流密度下分别由活化损耗、欧姆损耗和传质损耗主导;在固定电流密度下,电池温度、压力、阴极进气过量系数和阴极进气湿度对阻抗谱影响较大;欧姆阻抗是对阴阳极进气湿度变化最敏感;阳极活化阻抗仅对阳极进气过量系数和阳极进气湿度较为敏感;阴极活化阻抗是对阴极过量系数最敏感,其次是温度和压力;传质阻抗对阴极过量系数敏感程度最大,压力和温度次之;为燃料电池工作条件优化和内部状态的监测与诊断研究提供指导。
Electrochemical impedance spectroscopy(EIS) can be utilized to characterize the internal state and electrochemical behaviour of fuel cell. The different polarization processes and states in the fuel cell can be identified and quantified by constructing an appropriate equivalent circuit model for impedance fitting. The effects of current density, operating temperature, pressure, cathode/anode stoichiometry, and cathode/anode relative humidity on the proton exchange membrane fuel cell’s electrochemical impedance are systematically studied. Based on the equivalent circuit method, the variation of each frequency band’s equivalent resistance and its sensitivity to operating conditions are analysed and discussed. The results demonstrate that fuel cell loss is dominated by activation loss, ohmic loss, and mass transfer loss at low, medium, and high current densities, respectively. Under the fixed current density, the cell temperature, pressure, cathode stoichiometry, and cathode relative humidity significantly influence the impedance spectrum. Ohmic impedance is mostly sensitive to the humidity change of anode and cathode. The anode activation impedance is mainly liable to the anode stoichiometry and anode relative humidity. The cathode activation impedance is mostly sensitive to the cathode stoichiometry, followed by temperature and pressure. Mass transfer impedance is mainly susceptible to cathode excess coefficient, followed by pressure and temperature. The experimental results provide guidance for the working condition optimization and internal state monitoring and diagnosis of fuel cell.
作者
张少哲
戴海峰
袁浩
明平文
魏学哲
ZHANG Shaozhe;DAI Haifeng;YUAN Hao;MING Pingwen;WEI Xuezhe(School of Automotive Studies,Tongji University,Shanghai 201804;National Fuel Cell Vehicle&Powertrain System Research&Engineering Center,Tongji University,Shanghai 201804)
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2021年第14期40-51,共12页
Journal of Mechanical Engineering
基金
国家重点研发计划资助项目(2019YFB1504605,2018YFB0106502)。
关键词
质子交换膜燃料电池
电化学阻抗谱
等效电路模型
工作条件
敏感性分析
proton exchange membrane fuel cell
electrochemical impedance spectroscopy
equivalent circuit model
external operating conditions
sensitivity analysis
