Innovative Flow Field Combination Design on Direct Methanol Fuel Cell Performance

Abstract

The flow-field design of Direct Methanol Fuel Cells (DMFCs) is an important subject about the DMFCs performance. Flow-fields play an important role on ability to transport fuel and drive out the products (H2O, CO2). In general, most of fuel cells utilize the same structure of flow-field for both anode and cathode. The popular flow-fields used for DMFCs are parallel and grid designs. Nevertheless, the characteristics of reactants and products are entirely different in anode and cathode of DMFCs. Therefore; the influences of the flow-fields designs on the cell performance were investigated due to the same logic for catalyst used for cathode and anode differently. To get the better and more stable performance of DMFC, three flow-fields (Parallel, Grid and Serpentine) are utilized with different combination were studied in this research. As a consequence, by using parallel flow-field in anode side and serpentine flow -field in cathode, the most and highest power output was obtained.

Mass transport phenomena in direct methanol fuel cells

“…Another advantage of the serpentine flow field is that the pressure difference between two adjacent channels is larger, creating stronger under-rib convection and enhancing the removal of liquid water accumulated in the cathode DL under channel ribs. Therefore, it is generally agreed that the serpentine flow field shows the better liquid water removal ability and more stable performance [53,55,120]. The utilization of under-rib convection to mitigate the cathode flooding has also been embodied in other types of flow field, such as the interdigitated flow field [121] and the modified serpentine flow field [51].…”

“…Particular attention needs to be paid to the design of the flow field such that liquid water accumulated in the cathode DL under the flow channel ribs can be effectively removed [51]. Previous visual studies showed that in both the parallel and the spot flow field, the accumulated liquid water could clog part of the flow channels, reducing the total reactive area and lowering the cell performance [53,55,120]. On the contrary, it was found that the serpentine flow field could more effectively transport liquid water out of the cell.…”

“…The function of the cathode flow field is to supply and distribute oxygen to the electrode as well as to transport liquid water out of the cell [31,50,51,[53][54][55]100,120]. Particular attention needs to be paid to the design of the flow field such that liquid water accumulated in the cathode DL under the flow channel ribs can be effectively removed [51].…”

“…Since the two-phase flow behavior in the flow field affects not only the mass transport of methanol to the anode CL, but also the removal of gas CO 2 from the cell, it is directly related to cell performance [2,. To gain better understanding of the mass transport of methanol and gas CO 2 on the DMFC anode, twophase flow behaviors in different anode flow fields have been extensively studied [2,10,14,[31][32][33][34][35][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54]. The commonly used flow fields are sketched in Fig.…”