Evaluation of polyaniline-Nafion® composite membranes for direct methanol fuel cells durability tests. (6th July 2015)

• Record Type: Journal Article
• Authors: Escudero-Cid, R.; Montiel, M.; Sotomayor, L.; Loureiro, B.; Fatás, E.; Ocón, P.
• Is Part Of: International journal of hydrogen energy. Volume 40:Number 25(2015)
• Page Start: 8182
• Page End: 8192
• Publication Date: 2015-07-06
• Subjects: Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2015.04.130
• Languages: English
• ISSNs: 0360-3199

Abstract

<abstract xml:lang="en" abstract-type="author" id="abs0010"> <title id="sectitle0010">Abstract</title> <sec> <p id="abspara0010">A Nafion<sup>®</sup> membrane has been both electrochemically and chemically modified in-situ to incorporate polyaniline (PANi) into its structure. The proposed objective was to decrease the methanol (MeOH) permeability and thus improve the durability of a direct methanol fuel cell device. Permeability and conductivity of the modified membranes were measured using the unmodified Nafion<sup>®</sup> 117 as a reference. The permeability was determined from the electrochemical oxidation of permeated methanol, and the conductivity was determined via electrochemical impedance spectroscopy. To evaluate the effect of these modifications, the performance of a MeOH/O<sub>2</sub> single-cell was measured using different MeOH flows and concentrations. The device durability was evaluated under a constant potential and at different operating times. The power density, <italic>p</italic>, at high MeOH flows and concentrations was 7 times higher for the PANi-modified membrane than the unmodified Nafion<sup>®</sup> 117. The durability of the modified membranes containing small amounts of PANi was 2 times higher using low MeOH flows and concentrations, while the power densities were similar. Impedance measurements were performed before and after the long-term durability tests in order to identify the improvements at the different parts of the fuel cell.</p> </sec> </abstract>