The reasons for the high power density of fuel cells fabricated with directly deposited membranes

Vierrath, Severin; Breitwieser, Matthias; Klingele, Matthias; Britton, Benjamin; Holdcroft, Steven; Zengerle, Roland; Thiele, Simon

doi:10.1016/j.jpowsour.2016.06.132

Cited by 59 publications

(47 citation statements)

References 25 publications

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“…In Figure a, the fresh MEA was imaged prior to any fuel cell operation in the beginning of test (BOT) state. The total membrane thickness was determined to be similar: We measured 11.3 ± 0.2 µm (beginning of test) and 11.7 ± 0.2 µm (end of test) for the MEA cross‐sections shown in Figure , similar to DMD‐type membranes measured . A thin pure ionomer layer in the middle of the membrane was observed, likely a result of Nafion remaining on top of the fully infiltrated pore space of the decorated nanofiber network after the printing process.…”

Section: Resultssupporting

confidence: 55%

“…The total membrane thickness was determined to be similar: We measured 11.3 ± 0.2 µm (beginning of test) and 11.7 ± 0. [33] A thin pure ionomer layer in the middle of the membrane was observed, likely a result of Nafion remaining on top of the fully infiltrated pore space of the decorated nanofiber network after the printing process. [33] A thin pure ionomer layer in the middle of the membrane was observed, likely a result of Nafion remaining on top of the fully infiltrated pore space of the decorated nanofiber network after the printing process.…”

Section: Membrane Morphology and Cerium Migrationmentioning

confidence: 99%

“…This is also in agreement with previous work, where significantly reduced values of R LF-HF were found for DMD fuel cells with a pure Nafion membrane, [31,44] in particular at high current densities. [33,46] Comparable improvements were reported for patterned membranes enhancing the catalyst layer/PEM interaction. [33,46] Comparable improvements were reported for patterned membranes enhancing the catalyst layer/PEM interaction.…”

Section: Beginning Of Test/ End Of Test -Analysismentioning

confidence: 99%

“…[43,47] In previous work, this low R LF-HF was related to strong water Adv. [33,48] The low R LF-HF values are highly relevant to the process development of DMD fuel cells. 2017, 7, 1602100 www.advenergymat.de www.advancedsciencenews.com back-diffusion from the cathode to the anode side, resulting in an improved oxygen supply to the cathode catalyst layer.…”

Section: Beginning Of Test/ End Of Test -Analysismentioning

confidence: 99%

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Cerium Oxide Decorated Polymer Nanofibers as Effective Membrane Reinforcement for Durable, High‐Performance Fuel Cells

Breitwieser

Klose

Hartmann

et al. 2016

Advanced Energy Materials

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High‐power, durable composite fuel cell membranes are fabricated here by direct membrane deposition (DMD). Poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDF‐HFP) nanofibers, decorated with CeO2 nanoparticles are directly electrospun onto gas diffusion electrodes. The nanofiber mesh is impregnated by inkjet‐printed Nafion ionomer dispersion. This results in 12 µm thin multicomponent composite membranes. The nanofibers provide membrane reinforcement, whereas the attached CeO2 nanoparticles promote improved chemical membrane durability due to their radical scavenging properties. In a 100 h accelerated stress test under hot and dry conditions, the reinforced DMD fuel cell shows a more than three times lower voltage decay rate (0.39 mV h−1) compared to a comparably thin Gore membrane (1.36 mV h−1). The maximum power density of the DMD fuel cell drops by 9%, compared to 54% measured for the reference. Impedance spectroscopy reveals that ionic and mass transport resistance of the DMD fuel cell are unaffected by the accelerated stress test. This is in contrast to the reference, where a 90% increase of the mass transport resistance is measured. Energy dispersive X‐ray spectroscopy reveals that no significant migration of cerium into the catalyst layers occurs during degradation. This proves that the PVDF‐HFP backbone provides strong anchoring of CeO2 in the membrane.

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Section: Resultssupporting

confidence: 55%

Section: Membrane Morphology and Cerium Migrationmentioning

confidence: 99%

Section: Beginning Of Test/ End Of Test -Analysismentioning

confidence: 99%

Section: Beginning Of Test/ End Of Test -Analysismentioning

confidence: 99%

See 2 more Smart Citations

Cerium Oxide Decorated Polymer Nanofibers as Effective Membrane Reinforcement for Durable, High‐Performance Fuel Cells

Breitwieser

Klose

Hartmann

et al. 2016

Advanced Energy Materials

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“…Polymer electrolyte fuel cells (PEMFCs) and polymer electrolyte water electrolyzers (PEMWEs) serve as models for CO 2 electrolyzers, having achieved current densities in excess of amperes per square centimeter using GDE‐based electrodes. [ 11–14 ] We suggest that if we wish to emulate the high current densities found in PEWMEs or PEMFCs, we need to understand the structure of CO 2 RR GDEs to subsequently improve it. Especially, we need to understand how the structure–property relations are similar and different from those found in PEMFCs and PEMWEs.…”

Section: Introductionmentioning

confidence: 99%

Tomographic Reconstruction and Analysis of a Silver CO₂ Reduction Cathode

McLaughlin

Bierling

Moroni

et al. 2020

Advanced Energy Materials

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electrochemical CO 2 RR enables direct power-to-X technology, that is the integration of electricity from (intermittent) renewable sources into the formation process of various valuable products. Technoeconomic analyses of CO 2 electrolyzers have identified current density and energy efficiency as the key benchmarks of this technology. [1][2][3][4][5] They further estimate that for adoption of this technology high current densities (hundreds of mA cm − ² or more) are required. The current density of the batch cells, which are ubiquitous in CO 2 RR catalyst research, is intrinsically limited. This points to flow cells with gas diffusion electrodes (GDEs) as a more promising solution. Endrődi et al. [6] and Weekes et al. [7] provide reviews of publications on flow cells using GDEs. Both highlight how flow cells and GDEs enable the aforementioned increase in current density and energy efficiency. Further recent publications demonstrate high current densities using GDEs. [8][9][10] The morphology of these electrodes is likely instrumental to their outstanding properties.Polymer electrolyte fuel cells (PEMFCs) and polymer electrolyte water electrolyzers (PEMWEs) serve as models for CO 2 electrolyzers, having achieved current densities in excess of amperes per square centimeter using GDE-based electrodes. [11][12][13][14] We suggest that if we wish to emulate the high current densities found in PEWMEs or PEMFCs, we need to understand the structure of CO 2 RR GDEs to subsequently improve it. Especially, we need to understand how the structure-property relations are similar and different from those found in PEMFCs and PEMWEs. This understanding in turn would enable rational design of catalyst layers (CLs), thus guiding the optimization of the manufacturing processes.To give an example: A point of discussion in some recent publications and perspectives has been the nature of the CO 2 delivery to the catalyst. Following the successful demonstration of GDEs application for CO 2 reduction, Cook et al. proposed a three-phase boundary mechanism according to which CO 2 reacts directly from the gas phase. [15] This model has been called into question. Burdyny and Smith [16] posit that the CL is fully flooded during operation; Weng et al. [17] propose that a thin layer of electrolyte covers the catalyst surface, in analogy to ionomer coverages often found in fuel cell models. This again points to the need for an improved understanding of electrode structure, especially its wetting behavior.Tomographic reconstruction has been well established as a valuable tool in the analysis of polymer electrolyte fuel cell (PEMFC) electrodes. While forays have been made into applying it to polymer electrolyte water electrolyzer (PEMWE) electrodes, CO 2 electrolyzer electrodes are still new ground. Here a tomographic analysis of an electrochemical CO 2 reduction gas diffusion electrode by means of focused ion beam scanning electron microscope tomography is presented. The reconstruction shows a porosity of 68%. While most of the porosity is on th...

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Advances in Noble Metal Electrocatalysts for Acidic Oxygen Evolution Reaction: Construction of Under‐Coordinated Active Sites

Wang,

Yan,

Cheng

et al. 2024

Advanced Science

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Renewable energy‐driven proton exchange membrane water electrolyzer (PEMWE) attracts widespread attention as a zero‐emission and sustainable technology. Oxygen evolution reaction (OER) catalysts with sluggish OER kinetics and rapid deactivation are major obstacles to the widespread commercialization of PEMWE. To date, although various advanced electrocatalysts have been reported to enhance acidic OER performance, Ru/Ir‐based nanomaterials remain the most promising catalysts for PEMWE applications. Therefore, there is an urgent need to develop efficient, stable, and cost‐effective Ru/Ir catalysts. Since the structure‐performance relationship is one of the most important tools for studying the reaction mechanism and constructing the optimal catalytic system. In this review, the recent research progress from the construction of unsaturated sites to gain a deeper understanding of the reaction and deactivation mechanism of catalysts is summarized. First, a general understanding of OER reaction mechanism, catalyst dissolution mechanism, and active site structure is provided. Then, advances in the design and synthesis of advanced acidic OER catalysts are reviewed in terms of the classification of unsaturated active site design, i.e., alloy, core‐shell, single‐atom, and framework structures. Finally, challenges and perspectives are presented for the future development of OER catalysts and renewable energy technologies for hydrogen production.

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The reasons for the high power density of fuel cells fabricated with directly deposited membranes

Cited by 59 publications

References 25 publications

Cerium Oxide Decorated Polymer Nanofibers as Effective Membrane Reinforcement for Durable, High‐Performance Fuel Cells

Cerium Oxide Decorated Polymer Nanofibers as Effective Membrane Reinforcement for Durable, High‐Performance Fuel Cells

Tomographic Reconstruction and Analysis of a Silver CO₂ Reduction Cathode

Advances in Noble Metal Electrocatalysts for Acidic Oxygen Evolution Reaction: Construction of Under‐Coordinated Active Sites

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The reasons for the high power density of fuel cells fabricated with directly deposited membranes

Cited by 59 publications

References 25 publications

Cerium Oxide Decorated Polymer Nanofibers as Effective Membrane Reinforcement for Durable, High‐Performance Fuel Cells

Cerium Oxide Decorated Polymer Nanofibers as Effective Membrane Reinforcement for Durable, High‐Performance Fuel Cells

Tomographic Reconstruction and Analysis of a Silver CO2 Reduction Cathode

Advances in Noble Metal Electrocatalysts for Acidic Oxygen Evolution Reaction: Construction of Under‐Coordinated Active Sites

Contact Info

Product

Resources

About

Tomographic Reconstruction and Analysis of a Silver CO₂ Reduction Cathode