Journal of Power Sources, Vol.239, 424-432, 2013
Alkali doped polyvinyl alcohol/graphene electrolyte for direct methanol alkaline fuel cells
Despite the intensive effort directed at the synthesis of anion exchange membranes (AEMs) only a few studies show enhanced ionic conductivity with simultaneous suppression of unfavourable mass transport and improved thermal and mechanical properties. Here we report an alkaline nanocomposite membrane based on fully exfoliated graphene nanosheets and poly(vinyl alcohol) (PVA) prepared by a simple blending process. The composite membrane shows improved ionic transport due to the homogeneous distribution of the graphene nanosheets which are able to form continuous, well-connected ionic channels. Significant enhancement of the ionic conductivity for the prepared graphene/PVA composite membranes is observed with a 0.7 wt% graphene loading resulting in a similar to 126% improvement in ionic conductivity and a similar to 55% reduction in methanol permeability. The resulting maximum power density obtained by incorporating the membrane in a cell is increased by similar to 148%. A higher graphene loading (1.4 wt%) enhances the adhesion of the nanofiller matrix, giving a similar to 73% improvement in the tensile strength. This study provides a simple route to designing and fabricating advanced AEMs. (C) 2013 Elsevier B.V. All rights reserved.