Novel Composite Membrane Based On Polyimide and Polyvinyl Alcohol for Direct Methanol Fuel Cells

摘要

@@1.Introduction The direct methanol fuel cells (DMFCs) is attracting much attention as the promising alternative power source due to many advantages such as high power density and low emission[1]. As the key component of DMFCs, proton-exchange-membrane(PEM) such as Nation, a perfluorosulfonic acid polymer show high proton conductivity and chemical stability, but it have some disvantages such as high cost and synthetic difficulties, especially its high methanol permeability which leads to DMFCs' efficiency reduction. Sulfonated aromatic polymers, such as poly(ether ether ketone) [2], poly(ether sulfone)s[3] and polyimide[4] are widely investigated as candicate PEM materials due to their low methanol permeability. But these membranes required addition of more sulfonic acid conductors may increase conductivity, that makes them excessively water-swollen or soluble in water. Therefore, they have failed to meet the requirement of durability under DMFCs operating conditions. To overcome this drawback, preparing of composite membrane is an promising approach due to its ability to combine the attractive features of each composite component[5].