Using layer-by-layer assembly of polyaniline fibers in the fast preparation of high performance fuel cell nanostructured membrane electrodes

Abstract

Membrane electrode assemblies (MEA) for fuel cells require optimization of their nanoscale organization to reach performance parameters, which include enhanced power density, increased catalyst utilization and reduced cost. We applied sprayed layer-by-layer assembly to produce a high activity MEA for H(2)/O(2) fuel cells from polyaniline fibers (PANI-F). This technique produces "fast-prepared" membranes with nanoscale structure, which allows to adequately address specific tuning of their porosity, platinum loading, electronic conductivity, and proton conductivity. Pt nanoparticles were attached to the PANI-F in a reaction of selective heterogeneous nucleation. After functionalization, Pt/PANI-F were assembled with Nafion. Microscopic investigation revealed that functionalized polyaniline fibers formed a highly porous yet tight network of interpenetrating conductors connected to the catalytic Pt particles. The Pt/PANI-F LBL ultrathin MEA demonstrated a power densitiy of 63 mW cm(-2) and yielded a Pt utilization of 437.5 W g(-1) Pt which is comparable to the traditional fuel cell using carbon black as Pt support. Moreover, the amount of Pt used in this work is almost 2 times lower than for usual carbon-supported Pt catalysts.

Structured multilayered electrodes of proton/electron conducting polymer for polymer electrolyte membrane fuel cells assembled by spray coating

“…Following the LBL procedure of Michel et al [12], alternating layers of the positively charged Pt/PANI and the negatively charged Pt/SWCNT polyelectrolytes were sprayed. The application of temperatures of 120 • C during spraying is the main difference to the conventional LBL technique, where spraying is done at temperatures up to 40 • C. The elevated temperature results in a higher evaporation rate and avoids a drainage of excess material.…”

“…In recent years another technique gained much attention for fuel cell applications: the layer-by-layer (LBL) assembly [11][12][13]. The LBL assembly was first published by Decher [14].…”

“…The sprayed LBL technique is suitable for the fabrication of PEMFC MEAs assembled of different catalyst materials. A previous study [12] with a sprayed LBL anode of Pt/PANI and Nafion ® and sprayed commercial Pt/CB layer cathode supplied a power density of 63 mW cm −2 at a Pt utilization of 437.5 mW mg −1 . Here, the amount of Pt used was almost two times lower than for standard carbon supported Pt catalyst MEAs.…”

Spray‐Assisted Polyelectrolyte Multilayer Buildup: from Step‐by‐Step to Single‐Step Polyelectrolyte Film Constructions

“…They reached a power density of 63 mW cm −2 and a Pt utilization of 437.5 mW per mg Pt. [92] To further improve fuel cell efficiency they proposed more recently a new architecture: the anode was obtained by alternating the spray deposition of Pt functionalized polyaniline fibers and Pt functionalized carbon nanotubes. The spraying was performed onto a Nafion membrane at 120 °C and between each deposition step, the layer was allowed to dry The cathode was obtained by spraying an ink composed of Nafion and 20% carbon black.…”

Atmospheric Plasma Deposition: A New Pathway in the Design of Conducting Polymer‐Based Anodes for Hydrogen Fuel Cells

“…[3][4][5][6][7][8][9][10] Despite very promising results, this method of preparation can only be done in a batch process.…”