Study on the relaxation time distribution of electrochemical impedance spectroscopy in high temperature polymer electrolyte membrane fuel cells based on reformed hydrogen fuels

doi:10.11949/0438-1157.20241062

Abstract

Abstract:

The competitive adsorption of carbon monoxide (CO) and hydrogen (H₂) on the surface of platinum (Pt) catalyst has been recognized to reduce the available active sites for the hydrogen oxidation reaction (HOR), which is considered as the primary cause of CO poisoning in proton exchange membrane fuel cells (PEMFCs). In high-temperature PEMFCs utilizing with phosphoric acid electrolyte, the distribution of phosphoric acid in the anode catalyst layer may significantly influence the mass transport and charge transfer processes of CO and H₂ at the electrode interface, making the CO poisoning mechanism even more intricate. Therefore, comprehending the process and mechanism of CO poisoning in high-temperature PEMFCs holds crucial importance in optimizing the structure of the membrane-electrode assembly and enhancing the efficiency of the cell operation when supplied with reformate gas. In this paper, we propose a novel approach to regulate the number density of active sites in the anode catalyst layer and introduce the utilization of electrochemical impedance spectroscopy (EIS) to analyze the distribution of relaxation time (DRT). By employing this method, we aim to establish a quantitative description of the anode electrochemical reaction and mass transport processes. This enables us to better elucidate the mechanism of CO poisoning under conditions where the fuel supply consists of reformate gas. The obtained results demonstrate that the primary reason behind the performance degradation caused by the presence of CO in the anode of high-temperature PEMFCs is the mass transport polarization. The increase in Pt active site density can screen CO components in hydrogen-rich reformed gas and reduce the local CO component concentration, ultimately alleviating the H₂ mass transfer limitation caused by active site occupancy.

Key words: high temperature polymer electrolyte membrane fuel cell, membrane electrode, carbon monoxide, distribution of relaxation time, electrochemical impedance spectroscopy, mass transport

摘要：

采用磷酸掺杂电解质膜的高温聚合物电解质膜燃料电池（HT-PEMFC），其阳极催化层中磷酸分布对电极界面处的CO、H₂的电化学过程产生重要影响。通过研究不同阳极催化层活性位点密度的HT-PEMFC电池在重整气进料条件下的性能，并引入电化学阻抗谱弛豫时间分布（DRT）分析手段，建立阳极电化学反应与物质传输过程定量描述方法，阐释重整气进料条件下CO毒化作用机制。结果表明，低阳极活性位点密度单体电池相较高密度样品，在重整气进料条件下传质极化阻力提高了531%。Pt活性位点密度的提升可筛分富氢重整气中的CO组分、降低局域CO组分浓度，缓解活性位点占据导致的H₂传质受限。

关键词: 高温聚合物电解质膜燃料电池, 膜电极, CO, 弛豫时间分布, 电化学阻抗谱, 物质传输

CLC Number:

TK 091

Junyi WANG, Zhangxun XIA, Fenning JING, Suli WANG. Study on the relaxation time distribution of electrochemical impedance spectroscopy in high temperature polymer electrolyte membrane fuel cells based on reformed hydrogen fuels[J]. CIESC Journal, 2025, 76(7): 3509-3520.

王珺仪, 夏章讯, 景粉宁, 王素力. 基于重整气的高温聚合物电解质膜燃料电池电化学阻抗谱弛豫时间分布研究[J]. 化工学报, 2025, 76(7): 3509-3520.

Figures/Tables 12

Table 1 Structural information of anode MEAs

样品名称	Pt载量/(mg·cm^-2)	炭粉/(mg·cm^-2)	PTFE/(mg·cm^-2)
MEA-A0.2	0.2	0.8	0.3
MEA-A0.6	0.6	0.5	0.3
MEA-A1.0	1.0	0.3	0.3
MEA-A1.4	1.4	0	0.3

Table 2 Electrochemical active surface area of anode

测试温度/℃	ECSA/cm²
测试温度/℃	MEA-A0.2	MEA-A0.6	MEA-A1.0	MEA-A1.4
160	12.47	18.55	29.70	46.08
170	14.26	33.31	60.48	61.90
180	17.65	51.61	85.40	60.00

Fig.1 Polarization curves and hydrogen gain of Pt-loaded anodes at different temperatures and gas flow settings

Fig.2 Tafel plots of Pt-loaded anodes across varying temperatures and gas flow regimes

Table 3 Tafel slope of membrane electrodes

Gas	Tafel slop/(mV·dec^-1)
	160℃				180℃
	MEA-A0.2	MEA-A0.6	MEA-A1.0	MEA-A1.4	MEA-A0.2	MEA-A0.6	MEA-A1.0	MEA-A1.4
H₂	-115	-110	-113	-107	-119	-112	-111	-107
RE	-118	-114	-113	-109	-117	-104	-98	-98

Table 4 EIS testing conditions for membrane electrodes

氧气进料计量比	氢气进料计量比		温度/℃	电流密度/(mA·cm^-2)
氧气进料计量比	H₂进料	RE进料	温度/℃	电流密度/(mA·cm^-2)
2.0	18	—	160	200
4.0	18	—	160	200
10.0	1.8，2.0，2.2		160，180	200，400

Fig.3 EIS spectra of MEA-A0.6 under specified conditions

Fig.4 DRT spectra of MEA-A0.6 under specified conditions

Fig.5 EIS testing and DRT fitting comparison of membrane electrodes

Fig.6 Schematic of the equivalent circuit and ECM components

Fig.7 ECM fitting data of EIS for MEA-A0.2 — MEA-A1.4

Fig.8 The electrode process with different active site densities in HT-PEMFC while anode reformate gas feed

References 30

[1]	Li X, Tan H, Ni Z, et al. Select sensitivity parameters for proton exchange membrane fuel cell model: an identification method from analytical Butler-Volmer equation[J]. Journal of Power Sources, 2024, 608: 234330.
[2]	Rasheed R K A, Liao Q, Caizhi Z, et al. A review on modelling of high temperature proton exchange membrane fuel cells (HT-PEMFCs)[J]. International journal of hydrogen energy, 2017, 42(5): 3142-3165.
[3]	Fan L, Zhang G, Jiao K. Characteristics of PEMFC operating at high current density with low external humidification[J]. Energy Conversion and Management, 2017, 150: 763-774.
[4]	Cullen D A, Neyerlin K C, Ahluwalia R K, et al. New roads and challenges for fuel cells in heavy-duty transportation[J]. Nature Energy, 2021, 6: 462-474.
[5]	Fan R X, Li Z Q, Zhang H M, et al. Analysis of a combined heating and power system based on high-temperature proton exchange membrane fuel cell and steam methane reforming: from energy, exergy and economic point of views[J]. Applied Thermal Engineering, 2024, 247: 123075.
[6]	Pei P C, Xu Y M, Wang M K, et al. Effects of carbon monoxide on proton exchange membrane fuel cells and elimination techniques[J]. International Journal of Hydrogen Energy, 2024, 69: 1287-1304.
[7]	Valdés-López V F, Mason T, Shearing P R, et al. Carbon monoxide poisoning and mitigation strategies for polymer electrolyte membrane fuel cells—a review[J]. Progress in Energy and Combustion Science, 2020, 79: 100842.
[8]	Xu J W, Wu Y H, Xiao S Y, et al. Synergic effect investigation of carbon monoxide and other compositions on the high temperature proton exchange membrane fuel cell[J]. Renewable Energy, 2023, 211: 669-680.
[9]	Pei P, Wang M, Chen D, et al. Key technologies for polymer electrolyte membrane fuel cell systems fueled impure hydrogen[J]. Progress in Natural Science: Materials International, 2020, 30(6): 751-763.
[10]	Das S K, Reis A, Berry K J. Experimental evaluation of CO poisoning on the performance of a high temperature proton exchange membrane fuel cell[J]. Journal of Power Sources, 2009, 193(2): 691-698.
[11]	Chen C Y, Lai W H, Chen Y K, et al. Characteristic studies of a PBI/H₃PO₄ high temperature membrane PEMFC under simulated reformate gases[J]. International journal of hydrogen energy, 2014, 39(25): 13757-13762.
[12]	Zhang J, Zhang C Z, Li J, et al. Multi-perspective analysis of CO poisoning in high-temperature proton exchange membrane fuel cell stack via numerical investigation[J]. Renewable Energy, 2021, 180: 313-328.
[13]	Xu J W, Xiao S Y, Xu X R, et al. Numerical study of carbon monoxide poisoning effect on high temperature PEMFCs based on an elementary reaction kinetics coupled electrochemical reaction model[J]. Applied Energy, 2022, 318: 119214.
[14]	Lei G, Zheng H L, Zhang J, et al. Analyzing characteristic and modeling of high-temperature proton exchange membrane fuel cells with CO poisoning effect[J]. Energy, 2023, 282: 128305.
[15]	Jeppesen C, Polverino P, Andreasen S J, et al. Impedance characterization of high temperature proton exchange membrane fuel cell stack under the influence of carbon monoxide and methanol vapor[J]. International Journal of Hydrogen Energy, 2017, 42(34): 21901-21912.
[16]	Zhang Z N, Xia Z X, Huang J C, et al. Water-induced electrode poisoning and the mitigation strategy for high temperature polymer electrolyte membrane fuel cells[J]. Journal of Energy Chemistry, 2022, 69: 569-575.
[17]	Niya S M R, Hoorfar M. Study of proton exchange membrane fuel cells using electrochemical impedance spectroscopy technique—a review[J]. Journal of Power Sources, 2013, 240: 281-293.
[18]	Darowicki K, Gawel L, Mielniczek M, et al. The impedance of hydrogen oxidation reaction in a proton exchange membrane fuel cell in the presence of carbon monoxide in hydrogen stream[J]. Applied Energy, 2020, 279: 115868.
[19]	Tang Z P, Huang Q A, Wang Y J, et al. Recent progress in the use of electrochemical impedance spectroscopy for the measurement, monitoring, diagnosis and optimization of proton exchange membrane fuel cell performance[J]. Journal of Power Sources, 2020, 468: 228361.
[20]	Lu Y, Zhao C Z, Huang J Q, et al. The timescale identification decoupling complicated kinetic processes in lithium batteries[J]. Joule, 2022, 6(6): 1172-1198.
[21]	Xu J W, Zhao Y W, Wu Y H, et al. Experimental investigation on influences of methanol reformate impurities in performances of high temperature proton exchange membrane fuel cells[J]. International Journal of Hydrogen Energy, 2023, 48(45): 17261-17276.
[22]	Bevilacqua N, Schmid M A, Zeis R. Understanding the role of the anode on the polarization losses in high-temperature polymer electrolyte membrane fuel cells using the distribution of relaxation times analysis[J]. Journal of Power Sources, 2020, 471: 228469.
[23]	Schindler S, Weiß A, Galbiati S, et al. Identification of polarization losses in high-temperature PEM fuel cells by distribution of relaxation times analysis[J]. ECS Transactions, 2016, 75(14): 45-53.
[24]	Weiß A, Schindler S, Galbiati S, et al. Distribution of relaxation times analysis of high-temperature PEM fuel cell impedance spectra[J]. Electrochimica Acta, 2017, 230: 391-398.
[25]	Yuan H, Dai H F, Wei X Z, et al. Internal polarization process revelation of electrochemical impedance spectroscopy of proton exchange membrane fuel cell by an impedance dimension model and distribution of relaxation times[J]. Chemical Engineering Journal, 2021, 418: 129358.
[26]	Heinzmann M, Weber A, Ivers-Tiffée E. Advanced impedance study of polymer electrolyte membrane single cells by means of distribution of relaxation times[J]. Journal of Power Sources, 2018, 402: 24-33.
[27]	Heinzmann M, Weber A. Impedance based performance model for polymer electrolyte membrane fuel cells[J]. Journal of Power Sources, 2023, 558: 232540.
[28]	Xiao W, Xia Z X, Li H Q, et al. Electrochemical interface optimization toward low oxygen transport resistance in high-temperature polymer electrolyte fuel cells[J]. Energy Technology, 2020, 8(9): 2000085.
[29]	Schönleber M, Klotz D, Ivers-Tiffée E. A method for improving the robustness of linear Kramers-Kronig validity tests[J]. Electrochimica Acta, 2014, 131: 20-27.
[30]	Wan T H, Saccoccio M, Chen C, et al. Influence of the discretization methods on the distribution of relaxation times deconvolution: implementing radial basis functions with DRT tools[J]. Electrochimica Acta, 2015, 184: 483-499.