Using Electrospinning-Based Carbon Nanofiber Webs for Methanol Crossover Control in Passive Direct Methanol Fuel Cells.

Wei Yuan,Yong Tang,Zongtao Li,Yonghui Chen,Guoyun Fang

doi:10.3390/ma11010071

Abstract

Methanol crossover (MCO) significantly affects the performance of a direct methanol fuel cell (DMFC). In order to reduce its effect, this study presents in-house carbon nanofiber webs (CNWs) used as a porous methanol barrier for MCO control in a passive DMFC. The CNW is made from polyacrylonitrile (PAN) by using electrospinning and heat treatment. The impacts of PAN concentration and carbonizing temperature on the material properties are considered. The concentration of PAN has a great effect on the micro structures of the CNWs since a higher concentration of PAN leads to a larger nanofiber diameter and lower porosity. A higher carbonizing temperature helps promote the sample conductivity. The use of CNWs has twofold effects on the cell performance. It helps significantly enhance the cell performance, especially at a low methanol concentration due to its balanced effect on reactant and product management. There is an increase in peak power density of up to 53.54% when the CNW is used, in contrast with the conventional DMFC at 2 mol/L. The dynamic and constant-load performances of the fuel cell based on CNWs are also investigated in this work.

Highlights

The rapid development of direct methanol fuel cell (DMFC) technology accelerates the wide application of low-power portable devices due to its advantages such as low-temperature operation, high power density and safe fuel storage [1]
It has been widely known that methanol crossover (MCO) happens unavoidably in the Nafion-based membrane when methanol arrives at the anode [2,3]
The sintering bonds tend to lower the porosity of the carbon nanofiber webs (CNWs) and reduce the permeability of the material to some extent

Summary

Introduction

The rapid development of direct methanol fuel cell (DMFC) technology accelerates the wide application of low-power portable devices due to its advantages such as low-temperature operation, high power density and safe fuel storage [1]. In this field, a special type of DMFC based on the passive methanol/oxygen feeding mode is attracting increasing attention. Different from the active system with pumps, blowers, heat exchangers and so on, a passive DMFC eliminates accessional apparatus, depending on spontaneous mass and heat transfer mechanisms.

Methods

Results

Conclusion