Toward using porous metal-fiber sintered plate as anodic methanol barrier in a passive direct methanol fuel cell

A porous metal-fiber sintered plate (PMFSP) based on multi-tooth cutting and high-temperature solid-phase sintering is used as the methanol barrier at the anode of a passive DMFC in order to reduce the effect of methanol crossover. Its roles in controlling the mass transfer mechanisms related to reactant supply and product removal are also considered in this study. Results show that the cell performance can be significantly improved by using such a macroporous material, especially at a higher methanol concentration. The porosity of the PMFSP has great effects on the cell performance in the form of interacting with the current collector setup. When the combination of anodic circular-hole-array with an open ratio of 28.3% and cathodic parallel fence with 58% is used, it is favorable to use a lower porosity of 70%. When the above current collectors are reversed, a higher porosity of 80% is recommended. Results also demonstrate that the PMFSP with a medium thickness of 2 mm achieves a higher cell performance. Moreover, the PMFSP assembled in an outside manner is proved to be more able to enhance the cell performance than that based on inside-type. The mechanisms related to the roles of the PMFSP in mass transfer process are provided in detail.

► A porous metal-fiber sintered plate (PMFSP) is used as the methanol barrier.
► The effects of PMFSP porosity, thickness and assembly pattern are discussed.
► The use of a PMFSP improves the cell performance especially at a higher concentration.
► The roles of the PMFSP in mass transfer management are explained in detail.