基于DRT分析的SOFC极化性能与反应机理研究  

Study of SOFC polarization performance and reaction mechanism based on DRT analysis

作　　者：王涛 张涛 孙元娜 王俊勃 李青山 WANG Tao;ZHANG Tao;SUN Yuanna;WANG Junbo;LI Qingshan(College of Materials Engineering,Xi’an Polytechnic University,Xi’an Shaanxi 710001,China)

机构地区：[1]西安工程大学材料工程学院,陕西西安710001

出　　处：《电源技术》2024年第5期908-915,共8页Chinese Journal of Power Sources

基　　金：国家自然科学基金项目(22109124);陕西省高校科协青年人才托举计划(20210421);中国纺织工业联合会科技指导性计划项目(2021038,2021042);西安工程大学博士科研启动金(BS1609,BS1610);陕西省自然科学基础研究计划(2021JQ-673);陕西省教育厅自然科学专项项目(21JK0644);陕西省大学生创新创业训练计划项目(202110709056,202110709032);陕西省人力资源和社会保障厅留学人员科技活动择优资助项目(2019年度第16项);西安市纺织复合材料重点实验室(xafzfc-zd05)。

摘　　要：固体氧化物燃料电池(SOFC)是一个不透明的实体,有时被称为“黑盒子”,动力学过程在其运行中发挥着关键作用。对电池内部的动力学过程进行深入研究,可以促进电池的精确诊断,并推动电池机理研究的进步。弛豫时间分布(DRT)技术是近年来备受瞩目的一种方法,可以有效地评估SOFC系统中的电化学特性。然而,传统的DRT分析技术中,由于正则化参数选择的问题,会使DRT结果出现伪峰和表示不对称现象,这干扰了时域分析中时间常数识别的稳定性和准确性。基于最佳参数自动确定的DRT技术,通过不同物理参数(SOFC阴极厚度、反应温度、进气流量)条件下动力学过程的特性差异对电化学阻抗的时域信息进行了分析,将DRT得出的四个高峰分别总结为:P1的欧姆极化、P2的活化极化、P3的浓差极化、P4的物理吸附和气体扩散。通过判断各个峰所代表的物理意义进一步发现:阴极厚度的增加会导致电催化层厚度的相应增加,如果电催化层厚度超过17μm的临界厚度,就会导致迁移电阻的活化极化显著降低。Solid Oxide Fuel Cell(SOFC)are opaque entities,sometimes referred to as"black boxes",in which kinetic processes play a crucial role in their operation.An in-depth investigation of the kinetic processes within the cell can promote accurate diagnosis of batteries and advance the study of cell mechanisms.Distribution of relaxation time(DRT)is a technique that has acquired significant popularity in recent years and can effectively evaluate the electrochemical properties of SOFC systems.However,in the conventional DRT analysis method,the problem of regularization parameter selection results in pseudo-peaks and representation asymmetry in the DRT results,compromising the stability and accuracy of the time constant identification in the time-domain analysis.In this paper,the time-domain information of electrochemical impedance is analyzed by the characteristic differences of kinetic processes under different physical parameters(SOFC cathode thickness,reaction temperature,and inlet gas flow rate),and the four peaks derived from the DRT are summarized as the ohmic polarization of P1,the activation polarization of P2,the concentration polarization of P3,and the concentration polarization of P4.By determining the physical significance of each peak,it was discovered that an increase in the cathode thickness results in a corresponding increase in the electrocatalytic layer thickness,and if the electrocatalytic layer thickness exceeds the critical thickness of 17μm,it results in a significant decrease in the activation polarization of the migration resistance.

关 键 词：固体氧化物燃料电池 阻抗谱 DRT 极化性能 

分 类 号：TM911[电气工程—电力电子与电力传动]