Alkaline Anion-exchange Membrane In Fuel Cells

Direct methanol fuel cells (DMFC) have attracted considerable attention as an alternative to the present power sources, since they offer numerous benefits, including high efficiency, high power density, low or zero emissions and easy fuel carriage. DMFC are expected to find wide application as a portable or mobile power, exemplified by battery for cellular phones or engine for electric vehicles. However, at present, two major technology problem is the crossover of methanol through the electrolyte membrane. The other is slow methanol oxidation kinetics on the anode catalyst.Alkaline anion exchange membranes for direct methanol fuel cells(AMDMFC) use an anion exchange membrane as polyelectrolyte and the whole system is basic. The methol oxidative rate is faster in alkaline media than in acid。And there is no reaction intermediate which can make electrode catalyst poisoned. In AMDMFC, the direction of OH-anion motion opposes that of the methanol flux through the membrane leading to an intrinsic reduction in methanol permeability. AMDMFC can overcome the drawback of DMFC.The anion-exchange membrane has the dual function of both the hydroxide ion conduction and the separation of fuel and oxidizer as the key components.This paper aims to use a novel material called poly (vinylbenzyl chloride) (PVBC1) to prepare a piece of anion-exchange membrane and characterize its properties.Poly (vinylbenzyl chloride) (PVBCl) was dissolved in a appropriate kind of solvent to make a macromolecular solution, then select a suitable kind of cross-linking agent and add to the solution to cross-linking them. The casting solution was casted on a flat glass and then the solvent was evaporated at room temperature for enough time (4h) to make sure the solvent was evaporated. A piece of smooth and transparent membrane with good size stability will be prepared successfully through the solution-casting method. The mechanical performance and the properties of the exchange of the PVBCl membrane have been studied. Analyze the impact of the type of solvent, the carrier, the concentration of polymer, the type and the amount of cross-linking agent to the membrane-forming properties. The properties such as the moisture content of membrane and the exchange capacity have been characterized.