Method for preparing proton exchange membrane for direct methanol fuel cell

Abstract

The invention relates to a method for preparing a proton exchange membrane for a direct methanol fuel cell. The method comprises the following steps of: dissolving tungsten powder into hydrogen peroxide solution, adding isopropanol into the solution, standing the solution, and decomposing the excessive hydrogen peroxide to obtain tungsten-containing solution; mixing the tungsten-containing solution and perfluorinated sulfonic acid solution, and regulating the mixed solution by using an organic solvent so that the solid content of the mixed solution is in a certain ratio; stirring and ultrasonically treating the mixed solution, and pouring the mixed solution into a horizontal die; heating the mixed solution by programs, and controlling the heating conditions so that the tungsten-containingcompound generates a trioxide by inter-molecular dehydration in a membrane forming process; and drying the solvent, and releasing a product from the die to obtain the proton exchange membrane with a thickness of 50 to 250 microns. The method has the characteristics of high methanol rejecting property, high proton conductivity and simple and convenient process, reduces the cost of the proton exchange membrane compared with a membrane, and is easy for scale production.

Description

technical field [0001] The invention relates to a proton exchange membrane for a fuel cell, in particular to a preparation method for a proton exchange membrane for a direct methanol fuel cell. Background technique [0002] Direct methanol fuel cell may be the first to achieve industrialization [Fuel Cells, 2005, 5: 186-200], it can not only be widely used in fuel cell electric vehicles [J Power Sources, 1998, 71: 150-155], but also more The energy density of the battery is 5 to 10 times higher, and it works at 20 to 50°C, and can be replenished with fuel at any time and conveniently. [0003] Patent CN101188301 discloses a cross-linked sulfonated polyether ether ketone proton exchange membrane and its preparation process. Compared with perfluorosulfonic acid membrane, although it has better alcohol resistance ability, it has complex preparation process and material price More expensive and other defects. Jiang et al [Adv Mater, 2006, 18:1068-1072] utilize Membrane-SO 3...

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Problems solved by technology

for business After the membrane is modified, the proton conductivity of the membrane itself is reduced, which has a negative impact on the overall performance of the battery; in addition, there are problems of complicated operation and high cost

The solution casting method is usually used to prepare inorganic / organic composite membranes. After inorganic or organic substances are introduced into the perfluorosulfonic acid membrane as fillers, they play a role in preventing the penetration of methanol in the membrane, such as Jiang et al. [J.Membr.Sci.2006, 272:116-124] Preparation of Nafion / SiO with alcohol-inhibiting effect by sol-gel method 2 Composite films, but usually SiO 2 Introduced into the membrane, it is easy to cause the composite membrane to become brittle and reduce the mechanical strength of the composite membrane

Methods for synthesizing non-fluorine or partially fluorine-containing polymer electrolyte membranes, such as polyetheretherketone membranes [Electrochem Solid State Lett, 2003, 6: A229-A231], polysulfone membranes [JPower Sources, 2006, 157: 222-225 ] and sulfonated polyaryletherketone membranes [Electrochimica Acta, (in press)], etc. These non-fluorine or partially fluorine-containing polymer electrolyte membranes usually have good alcohol resistance properties, which can reduce the cost of proton exchange membranes, but they The proton conductivity, mechanical strength and stability are far inferior to perfluorosulfonic acid membranes

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