Blend Concepts for Fuel Cell Membranes

1Introduction Direct methanol fuel cells (DMFC) are an alternative to lithium ion batteries as energy supply for mobile applications such as laptops, PDA's and cellphones. It would be advantageous if pure or highly concentrated methanol could be used as the fuel in these DMFC, due to the high energy density of meOH. However, most of the ionomer membranes used up to now as proton conductor in DMFC can not withstand pure or highly concentrated methanol due to extreme swelling or even dissolution under these conditions. Therefore it is required to prepare H+ -conducting membranes which remain dimensionally stable in pure or highly concentrated methanol. One way to approach this goal is to cross-link the ionomer membranes so that the swelling under the desired methanol-rich conditions is limited.