Study of node flow fields of micro direct methanol fuel cells

Abstract

To improve the low mass transfer efficiency and poor performance of micro direct methanol fuel cells (μDMFCs), a detailed study on the micro direct methanol fuel cell flow field structure is developed in this paper. Since the flow field structure plays an important role in increasing the performance of cells. Silicon-based self-breathing μDMFCs with the gird, parallel, single serpentine, double serpentine and tapered single serpentine anode flow fields are fabricated using MEMS technology. First of all, compared to the grid and parallel and double serpentine structures, single serpentine has been proved to perform a best result. However, Owing to the mass transport shadow region of an under-rib diffusion layer from the channel to the electrode, it results in the fall of methanol transport efficiency. A new tapered single serpentine has been fabricated and tested to prove its superiority. The results show that the cell performance with tapered single serpentine flow field is better than conventional single serpentine. And the maximum output power density is 15.41mW/cm2 with the increment of 35%, which contributed to further development of portable micro power sources systems.