Performance of air-breathing direct methanol fuel cell with anion-exchange membrane

Abstract

This report details development of an air-breathing direct methanol alkaline fuel cell with an anion-exchange membrane. The commercially available anion-exchange membrane used in the fuel cell was first electrochemically characterized by measuring its ionic conductivity, and showed a promising result of 1.0 x 10(-1) S cm(-1) in a 5 M KOH solution. A laboratory-scale direct methanol fuel cell using the alkaline membrane was then assembled to demonstrate the feasibility of the system. A high open-circuit voltage of 700 mV was obtained for the air-breathing alkaline membrane direct methanol fuel cell (AMDMFC), a result about loo mV higher than that obtained for the air-breathing DMFC using a proton exchange membrane. Polarization measurement revealed that the power densities for the AMDMFC are strongly dependent on the methanol concentration and reach a maximum value of 12.8 MW cm(-2) at 0.3 V with a 7 M methanol concentration. A durability test for the air-breathing AMDMFC was performed in chronoamperometry mode (0.3 V), and the decay rate was approximately 0.056 mA cm(-2) h(-1) over 160 h of operation. The cell area resistance for the air-breathing AMDMFC was around 1.3 Omega cm(2) in the open-circuit voltage (OCV) mode and then is stably supported around 0.8 Omega cm(2) in constant voltage (0.3 V) mode. (C) 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.