Fabrication and Performance of Membrane Electrode Assembly Prepared by a Catalyst-Coated Membrane Method: Effect of Solvents Used in a Catalyst Ink Mixture

Abstract

The effect of solvent types used to prepare catalyst-coated membrane (CCM) electrodes on the coating ink, applied coating process, interaction of catalyst ink and Nafion membrane and, thus, on the performance and power density of the proton exchange membrane fuel cells (PEM fuel cells) was investigated. Among seven types of solvents studied, the catalyst ink prepared using the isopropanol solvent showed the highest cell performance, followed in descending order by ethanol, acetone, water-ethylene glycol, ethylene glycol dimethyl ether (EGDME), and ethylene glycol diethyl ether (EGDEE). The superior performance was due to the good attachment of catalyst layer to membrane and the good surface coverage revealed by the results from the scanning electron microscope (SEM) of the CCMs, optical transmittance of the CCMs, and solvent absorption capacity of membrane. In electrode preparation by the CCM method, the solventionomer mixture in solution form was more favorable than that in colloid form, as it gave higher cell performance. Finally, the catalyst-coated membrane on the H þ form Nafion demonstrated better power density than the CCM on the Na þ form Nafion.

Optimisation of electrophoretic deposition parameters for gas diffusion electrodes in high temperature polymer electrolyte membrane fuel cells

“…http://repository.uwc.ac.za 5 Morphology of the GDEs was characterised by Scanning Electron Microscopy (SEM) using the Carl Zeiss Auriga HRFEGSEM working at 20 kV. Porosity of GDEs was characterised by mercury intrusion porosimetry using the Autopore IV 9510 (Micromeritics, USA) mercury porosimeter applying pressures between 0.0145 and 4136.85 bar.…”

“…Each method is aimed at improving MEA performance and reducing the catalyst loading and thereby the overall cost. The CL can be deposited either onto the GDL known as Catalyst Coated Substrate (CCS) or directly onto the membrane known as Catalyst Coated Membrane (CCM) [5]. Catalyst deposition methods include spraying, hand brushing, direct printing, screen printing, decal transfer, electrodeposition, DC magnetic sputtering, EPD and even combinations of these methods [6].…”

Rationalizing Catalyst Inks for PEMFC Electrodes Based on Colloidal Interactions

“…Equation [5] considers a collision efficiency of unity i.e. all collisions lead to aggregate formation.…”

Inherent Acidity of Perfluorosulfonic Acid Ionomer Dispersions and Implications for Ink Aggregation

“…[8][9][23][24][25][26][27][28][29][30][31][32] Unfortunately, none of these results are directly comparable to each other due to different components studied. While this solvent effect on cast properties has been 4 established, there is currently a lack of understanding of the interactions between the catalyst, solvent, and PFSA present in the ink.…”