One atom thick structure of the two dimensional single layer graphene has distinguished itself as a very promising material due to its unique properties. Excellent in-plane electron conductivity and permeability to proton but barrier to other kinds makes it a very tempting and cost effective membrane material for environment friendly alternative energy devices-proton exchange membrane (PEM) fuel cells. Expensive Nafion and Pt are the commonly used membrane and catalyst for fuel cells, covering 50 % of the total amount of the fuel cell cost [1]. To make them commercially viable, the overall cost needs to be reduced or the performance has to be enhanced at the expense of the same cost.

Our work showed that incorporation of monolayer graphene into the membrane electrode assembly with the Nafion enhances the direct methanol fuel cell power density by 45 %, owing to the graphene’s methanol barrier properties [2]. In this work we report inexpensive polybenzimidazole (PBI) membrane as mechanical support for the monolayer graphene substituting Nafion. The composites are tailored with different degrees of graphene coverage. The influence of these ‘defects’ are studied with respect to the fuel cell operation in different conditions. Further functionalization of the composition demonstrated to be a cost effective solution, showing a good prospect as an alternative to Nafion.

References:

1. US Department of Energy Hydrogen and Fuel cells programs record, 2017

2. Stuart M. Holmes, Prabhuraj Balakrishnan, Vasu. S. Kalangi, Xiang Zhang, Marcelo Lozada-Hidalgo, Pulickel M Ajayan, Rahul R. Nair., 2D Crystals Significantly Enhance the Performance of a Working Fuel Cell. Advanced Energy Materials 7 (2017) 1601216.