Journal Article

FZJ-2018-07245

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Layer Formation from Polymer Carbon-Black Dispersions

Scheepers, F. (Corresponding author)FZJ* ; Stähler, A.FZJ* ; Stähler, M.FZJ* ; Carmo, M.FZJ* ; Lehnert, W.FZJ* ; Stolten, D.FZJ*RWTH*

2018
MDPI Basel

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Please use a persistent id in citations: http://hdl.handle.net/2128/20405  doi:10.3390/coatings8120450

Abstract: It has been well-established that effects such as cracking are observable when wet layers are dried. In particular, the layer thickness, as well as the surface tension of the liquid, is responsible for this behavior. The layer formation of polymer electrolyte fuel cells and electrolyzer electrodes, however, has not yet been analyzed in relation to these issues, even though the effect of cracks on cell performance and durability has been frequently discussed. In this paper, water propanol polymer-containing carbon-black dispersions are analyzed in situ with regard to their composition during drying. We demonstrate that crack behavior can be steered by slight variations in the initial dispersion when the solvent mixture is near the dynamic azeotropic point. This minor adjustment may strongly affect the drying behavior, leading to either propanol or water-enriched liquid phases at the end of the drying process. If the evaporation of the solvent results in propanol enrichment, the critical layer thickness at which cracks occur will be increased by about 30% due to a decrease in the capillary pressure. Microscopic images indicate that the crack area ratio and width depend on the wet layer thickness and initial liquid phase composition. These results are of much value for future electrode fabrication, as cracks affect electrode properties.

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Contributing Institute(s):

1. Elektrochemische Verfahrenstechnik (IEK-3)

Research Program(s):

1. 135 - Fuel Cells (POF3-135) (POF3-135)

Appears in the scientific report 2018

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Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Engineering, Computing and Technology ; DOAJ Seal ; IF < 5 ; JCR ; Science Citation Index Expanded ; Web of Science Core Collection

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