Dispersing Agents Impact Performance of Protonated Phosphonic Acid High-Temperature Polymer Electrolyte Membrane Fuel Cells

Jung, Jiyoon; Lim, Kang-Won; Maurya, Sandip; Manriquez, Luis Delfin; Atanasov, Vladimir; Ahn, Cheol‐Hee; Hwang, Seung Sang; Lee, Albert S.; Kim, Yu Seung

doi:10.1021/acsenergylett.2c00359

Cited by 15 publications

(16 citation statements)

References 31 publications

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“…The dried electrodes were assembled with the PA-doped HTMA-DAPP membrane and PTFE gaskets. The detailed MEA fabrication process was described in a previous report …”

Section: Methodsmentioning

confidence: 99%

“…The detailed MEA fabrication process was described in a previous report. 39 HT-PEMFC performance was tested using the two MEAs. The MEAs were preconditioned under a stepwise change of voltage from 0.7 to 0.4 V overnight, followed by running the cell with H 2 /O 2 flow under a water vapor pressure of 46.7 kPa for 3 h at a constant current density of 0.2 A cm 2 .…”

Section: H Nmr Figures S5−s8)mentioning

confidence: 99%

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Quaternized Polynorbornene Random Copolymers for Fuel Cell Devices

Lehmann

Leonard

Zheng

et al. 2023

ACS Appl. Energy Mater.

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Quaternized polymers are critical components for various energy devices. Vinyl-addition polynorbornenes provide high mechanical strength, high ion conductivity, and chemical stability in a wide range of pH environments due to the all-C–C bond backbone. Herein, we present the synthesis of a series of quaternized polynorbornene random copolymers via vinyl addition polymerization and elucidate the impact of polymer composition on their properties. The quaternary ammonium alkyl tether length and the ratio of n-hexylnorbornene to unsubstituted norbornene are systemically tailored. A copolymer of 5-(3-bromopropyl)-2-norbornene and norbornene with pendant trimethylammonium groups achieved hydroxide conductivity of 109 mS/cm at 80 °C with a modest water uptake of 72%. The addition of n-hexylnorbornene to the copolymer, to make a terpolymer, allows for the polymer composition to be tailored for properties, including a decrease in water uptake and higher processability, despite a slightly decreased hydroxide conductivity. Moreover, the developed membranes are chemically robust and highly mechanically stable, enabling thin membranes to be easily fabricated. This study provides insight into important design parameters for quaternized polynorbornenes for a variety of energy storage and conversion devices, especially fuel cells.

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“…The dried electrodes were assembled with the PA-doped HTMA-DAPP membrane and PTFE gaskets. The detailed MEA fabrication process was described in a previous report …”

Section: Methodsmentioning

confidence: 99%

Section: H Nmr Figures S5−s8)mentioning

confidence: 99%

Quaternized Polynorbornene Random Copolymers for Fuel Cell Devices

Lehmann

Leonard

Zheng

et al. 2023

ACS Appl. Energy Mater.

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“…In particular, phosphonated poly(pentafluorostyrene) exhibited stable proton conductivity even at 200 °C. However, ameliorating gas diffusion through binders, especially oxygen accessibility, is still a major challenge in HT-PEMFCs . Recently, great efforts have been devoted to promoting gas permeation in ionomers.…”

Section: Introductionmentioning

confidence: 99%

“…Modestino et al reported that the amorphous domain with a high fractional free volume (FFV) in PFSA ionomers reduced the resistance for gas permeation significantly. Kim and co-workers , investigated the dispersing-agent-induced phase separation to fabricate the porous structure in phosphonated poly(pentafluorostyrene) ionomers. Wang et al presented a composite ionomer by introducing a sulfonated covalent organic framework (COF) into Nafion to promote oxygen permeation.…”

Section: Introductionmentioning

confidence: 99%

“…However, ameliorating gas diffusion through binders, especially oxygen accessibility, is still a major challenge in HT-PEMFCs. 31 Recently, great efforts have been devoted to promoting gas permeation in ionomers. Modestino et al 22 reported that the amorphous domain with a high fractional free volume (FFV) in PFSA ionomers reduced the resistance for gas permeation significantly.…”

Section: ■ Introductionmentioning

confidence: 99%

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Phosphonated Ionomers of Intrinsic Microporosity with Partially Ordered Structure for High-Temperature Proton Exchange Membrane Fuel Cells

Guan

Wang

et al. 2023

ACS Cent. Sci.

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High mass transport resistance within the catalyst layer is one of the major factors restricting the performance and low Pt loadings of proton exchange membrane fuel cells (PEMFCs). To resolve the issue, a novel partially ordered phosphonated ionomer (PIM-P) with both an intrinsic microporous structure and proton-conductive functionality was designed as the catalyst binder to improve the mass transport of electrodes. The rigid and contorted structure of PIM-P limits the free movement of the conformation and the efficient packing of polymer chains, resulting in the formation of a robust gas transmission channel. The phosphonated groups provide sites for stable proton conduction. In particular, by incorporating fluorinated and phosphonated groups strategically on the local side chains, an orderly stacking of molecular chains based on group assembly contributes to the construction of efficient mass transport pathways. The peak power density of the membrane electrode assembly with the PIM-P ionomer is 18−379% greater than that of those with commercial or porous catalyst binders at 160 °C under an H 2 /O 2 condition. This study emphasizes the crucial role of ordered structure in the rapid conduction of polymers with intrinsic microporosity and provides a new idea for increasing mass transport at electrodes from the perspective of structural design instead of complex processes.

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Improved Performance of High‐Temperature Proton Exchange Membrane Fuel Cells by Purified CNT Nanoporous Sheets

Kwon,

Yang,

Kang

et al. 2023

Adv Funct Materials

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Given environmental friendliness, high‐temperature proton exchange membrane fuel cells (HT‐PEMFCs) can be the alternative power source for clean power generation. However, neither developments nor strategies of diffusion media are actively conducted yet to achieve high‐performance HT‐PEMFCs. Herein, a nanoporous carbon nanotube (CNT) sheet, a new anode diffusion layer between the gas diffusion layer|bipolar plate interface that improves fuel cell performance and durability by CNT purification for facilitating fuel accessibility with uniform interfacial contact for reducing acid loss, is reported. Configuration of the optimal CNT‐inserted fuel cell is examined and proposed under the operating temperature of 140–200 °C. The underlying mechanism of this new diffusion layer with multiphysics simulation elucidates that the nanoporous nature induces gas‐wall collision, enabling uniform dispersion within adjacent diffusion media. These fuel cells outperform performance over two times higher and have a voltage decay rate nearly two times lower than conventional HT‐PEMFC.

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Dispersing Agents Impact Performance of Protonated Phosphonic Acid High-Temperature Polymer Electrolyte Membrane Fuel Cells

Cited by 15 publications

References 31 publications

Quaternized Polynorbornene Random Copolymers for Fuel Cell Devices

Quaternized Polynorbornene Random Copolymers for Fuel Cell Devices

Phosphonated Ionomers of Intrinsic Microporosity with Partially Ordered Structure for High-Temperature Proton Exchange Membrane Fuel Cells

Improved Performance of High‐Temperature Proton Exchange Membrane Fuel Cells by Purified CNT Nanoporous Sheets

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