Graphene coating of Nafion\(^{(R)}\) membranes for enhanced fuel cell performance

Electrochemically exfoliated graphene (e-G) thin films on Nafion\(^{(R)}\) membranes exhibit a selective barrier effect against undesirable fuel crossover. The approach combines the high proton conductivity of state-of-the-art Nafion\(^{(R)}\) and the ability of e-G layers to effectively block the t...

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Bibliographic Details
Published in:arXiv.org 2022-04
Main Authors: Ruhkopf, Jasper, Plachetka, Ulrich, Moeller, Michael, Pasdag, Oliver, Radev, Ivan, Peinecke, Volker, Hepp, Marco, Wiktor, Christian, Lohe, Martin R, Feng, Xinliang, Butz, Benjamin, Lemme, Max C
Format: Article
Language:English
Subjects:
Diffusion barriers
Electron energy
Electron energy loss spectroscopy
Fuel cells
Graphene
Maximum power density
Membranes
Methanol
Scanning transmission electron microscopy
Thin films
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Summary:Electrochemically exfoliated graphene (e-G) thin films on Nafion\(^{(R)}\) membranes exhibit a selective barrier effect against undesirable fuel crossover. The approach combines the high proton conductivity of state-of-the-art Nafion\(^{(R)}\) and the ability of e-G layers to effectively block the transport of methanol and hydrogen. Nafion\(^{(R)}\) membranes are coated with aqueous dispersions of e-G on the anode side, making use of a facile and scalable spray process. Scanning transmission electron microscopy (STEM) and electron energy-loss spectroscopy (EELS) confirm the formation of a dense percolated graphene flake network which acts as diffusion barrier. The maximum power density in direct methanol fuel cell (DMFC) operation with e-G coated Nafion\(^{(R)}\) N115 is 3.9 times higher than the Nafion\(^{(R)}\) N115 reference (39 vs. 10 mW cm\(^{-2}\) @ 0.3 V) at 5M methanol feed concentration. This suggests the application of e-G coated Nafion\(^{(R)}\) membranes for portable DMFCs, where the use of highly concentrated methanol is desirable.
ISSN:2331-8422
DOI:10.48550/arxiv.2204.04509