Performance Degradation of Proton Exchange Membrane Fuel Cell Caused by an Accelerated Stress Test

Zhang, X.; Yang, Yupeng; Guo, Liejin; Liu, Hongtan

doi:10.1002/fuce.201800152

Cited by 22 publications

(7 citation statements)

References 40 publications

(53 reference statements)

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“…First, a preliminary test was executed by keeping the fuel cell at constant current density: 0.5 A cm −2 was selected as a representative value for real applications [28] and kept fixed for 1000 h at 60 • C and RH 80-60%. Moreover, an ex situ mechanical acceler-ated stress test (AST) was also designed on the same samples in order to have a faster assessment of the durability of the prepared components in terms of mechanical resistance without performing continuous tests for thousands of hours, which is a common practice also for electrochemical ASTs evaluating degradation of different fuel cell components, such as electrodes or membrane [34,35]. Indeed, it has been demonstrated that the most detrimental degradation mechanism for GDMs is the mechanical one, which is due to both the continuous flow of the gaseous streams and the presence of water causing the detachment of the MPL surface carbon [28].…”

Section: Methodsmentioning

confidence: 99%

“…ment of the durability of the prepared components in terms of mechanica out performing continuous tests for thousands of hours, which is a com for electrochemical ASTs evaluating degradation of different fuel cell c as electrodes or membrane [34,35]. Indeed, it has been demonstrated th mental degradation mechanism for GDMs is the mechanical one, which continuous flow of the gaseous streams and the presence of water causin of the MPL surface carbon [28].…”

Section: Morphologymentioning

confidence: 99%

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Non-Conventional Hybrid Microporous Layers for Enhanced Performance and Durability of PEM Fuel Cells

et al. 2023

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In this work, novel microporous layers (MPLs) were developed based on fluorinated ethylene propylene (FEP), as a hydrophobic agent, and carboxymethylcellulose (CMC), as a wettability modulator and rheology controller for the inks, which were deposited onto pre-hydrophobized macroporous gas diffusion layers (GDLs). Higher CMC amounts led to higher dynamic viscosities of the inks, which induced the formation of a more compact and less cracked MPL surface. Different concentrations of CMC were tested and the experimental measurements showed a threshold limit pointing out an optimal composition that positively affected the electrochemical performances at medium-low relative humidity (RH), which is important to mitigate the need of saturating inlet gases. Durability of the best performing samples was assessed by means of an ad hoc developed accelerated stress test (AST) and compared to one of the conventional FEP-based GDMs. It was found that a lower decrement of both the output power density and the overall cell efficiency can be obtained upon the ASTs with the novel samples.

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Section: Methodsmentioning

confidence: 99%

Section: Morphologymentioning

confidence: 99%

Non-Conventional Hybrid Microporous Layers for Enhanced Performance and Durability of PEM Fuel Cells

et al. 2023

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“…The aging test protocol is used because the consequences of carbon corrosion in PEMFC are in diverse aspects, including kinetic and non-kinetic, in CL and also MPL/GDL. The experimental method has been commonly used in previous studies [18][19][20]30 and proven to achieve comprehensive accelerated stress testing for PEMFCs. The cell performance decay rate is significantly accelerated in AST compared to that in normal operations.…”

Section: Electrochemical Characterization and Aging Testmentioning

confidence: 99%

Durability improvement mechanism of proton exchange membrane fuel cell by microporous layer

Zuo

Jian

Yang

2022

Intl J of Energy Research

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Summary Microporous layer (MPL) has been proven to significantly improve water management in proton exchange membrane fuel cells (PEMFC). However, its effects on fuel cell durability have not been fully revealed. In this contribution, the effects of MPL on the degradation of PEM fuel cells are investigated. Two single fuel cells, with and without MPL at the cathode, are assembled. The aging test is conducted and the cell performance is periodically characterized under various operating conditions. The experimental results show that the presence of MPL can effectively mitigate the degradation of PEMFC. The electrochemical impedance analysis at low current (150 mA cm−2) shows the fuel cell with MPL has a smaller increase in charge transfer resistance during aging test, indicating MPL can mitigate kinetic degradation. The scanning electron microscope (SEM) images show less thickness reduction in aged catalyst layer of the fuel cell with MPL, indicating MPL can protect the catalyst layer from carbon corrosion and micro‐structure damage. Besides, the effect of MPL on mass transport loss is analysed, and the results show that MPL can alleviate the increase in mass transport loss during aging test. Under either wet (air relative humidity of 75% and 100%) or very low air flow rate conditions, the presence of MPL unambiguously improves the water transport for the fresh cell. Most importantly, the superior water management capability of MPL is sustained after the harsh aging test, reducing mass transfer resistance.

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“…The collapse of porous structure and reduction in thickness caused by carbon loss in CCLs, , as well as the increased hydrophilicity of carbon surface due to oxygen-containing functional groups with the concentration of liquid water, would impede molecular and Knudsen oxygen transport process in the CCLs, thereby affecting r bulk . Regarding the governing role of TPBs in the oxygen transport process, the carbon support corrosion in CCLs plays a critical role in determining the interface between carbon/Pt and the ionomer, thus affecting R local .…”

Section: Introductionmentioning

confidence: 99%

Unraveling the Effects of Carbon Corrosion on Oxygen Transport Resistance in Low Pt Loading Proton Exchange Membrane Fuel Cells

Li,

You,

Cheng

et al. 2023

ACS Appl. Mater. Interfaces

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Cost and durability have become crucial hurdles for the commercialization of proton exchange membrane fuel cells (PEMFCs). Although a continuous reduction of Pt loading within the cathode catalyst layers (CCLs) can lead to cost savings, it also increases the oxygen transport resistance, which is further compounded by key material degradation. Hence, a further understanding of the mechanism of significant performance loss due to oxygen transport limitations at the triple phase boundaries (TPBs) during the degradation process is critical to the development of low Pt loading PEMFCs. The present study systematically investigates the impact of carbon corrosion in CCLs on the performance and oxygen transport process of low Pt loading PEMFCs through accelerated stress tests (ASTs) that simulate start-up/shutdown cycling. A decline in peak power density from 484.3 to 251.6 mW cm −2 after 1500 AST cycles demonstrates an apparent performance loss, especially at high current densities. The bulk and local oxygen transport resistances (r bulk and R local ) of the pristine cell and after 200, 600, 1000, and 1500 AST cycles are quantified by combining the limiting current method with a dual-layer CCL design. The results show that r bulk increased from 1527 to 1679 s cm −2 , R local increased from 0.38 to 0.99 s cm −1 , and the local oxygen transport resistance with the normalized Pt surface area (r local ) exhibited an increase from 18.5 to 32.0 s cm −1 , indicating a crucial impact on the structure collapse and changes in the chemical properties of the carbon supports in the CCLs. Further, the interaction between the ionomer and carbon supports during the carbon corrosion process is deeply studied via electrochemical quartz crystal microbalance and molecular dynamics simulations. It is concluded that the oxygen-containing functional groups on the carbon surface could impede the adsorption of ionomers on carbon supports by creating an excessively water-rich layer, which in turn aggravates the formation of ionomer agglomerations within the CCLs. This process ultimately leads to the destruction of the TPBs and hinders the transport of oxygen through the ionomer.

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Performance Degradation of Proton Exchange Membrane Fuel Cell Caused by an Accelerated Stress Test

Cited by 22 publications

References 40 publications

Non-Conventional Hybrid Microporous Layers for Enhanced Performance and Durability of PEM Fuel Cells

Non-Conventional Hybrid Microporous Layers for Enhanced Performance and Durability of PEM Fuel Cells

Durability improvement mechanism of proton exchange membrane fuel cell by microporous layer

Unraveling the Effects of Carbon Corrosion on Oxygen Transport Resistance in Low Pt Loading Proton Exchange Membrane Fuel Cells

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