High-concentration operation of a passive air-breathing direct methanol fuel cell integrated with a porous methanol barrier

To realize high-concentration operation of a passive air-breathing direct methanol fuel cell (PAB-DMFC) is a critical issue that should be addressed before it is used for practical applications. This work reports the feasibility of using a porous metal fiber sintered felt (PMFSF) as the anodic methanol barrier to control methanol crossover (MCO) in order to feed the fuel cell with a higher concentration of methanol fuel. The effectiveness of this method is successfully validated. The optimization criterion of using this material is to maintain a balance between reactant and product management. Results demonstrate that a medium value of PMFSF thickness, i.e. 2 mm yields a higher performance. The PMFSF porosity has twofold effect on the cell performance, which interacts with the current collector setup including the opening pattern and ratio. The related mechanisms concerning such effects on mass transfer process are explained in detail. In addition, the dynamic characteristics of this PMFSF-based PAB-DMFC are also evaluated in this study. (C) 2012 Elsevier Ltd. All rights reserved.