Efficient Composite Process And Properties Of Sulfonated Poly(p-phenylene-co-aryl Ether Ketone)proton Exchange Membrane

In recent years,the problems of energy shortage and environmental pollution arebecoming more and more serious.Direct methanol fuel cell(DMFC)with methanol asfuel has broad application prospects in mobile and portable power supply due to its simple structure design,convenient refueling and low pollution.Proton exchange membrane(PEM)is a key component of DMFCs,which can isolate fuel and conduct protons in fuel cells.However,due to the low methanol oxidation kinetics of anode catalyst and high methanol permeability of proton exchange membrane,the large-scale commercial application of DMFCs is seriously hindered.As a potential proton exchange membrane(PEM)material that can replace perfluorosulfonic acid membrane,polyphenylene materials have been widely concerned because of their excellent thermochemical stability and good mechanical properties.In order to reduce methanol permeation,sulfonated poly(phenylene oxide ketone)polymer was synthesized,and a series of novel poly(phenylene oxide ketone)proton exchange membrane materials were obtained by efficient composite of Sulfonated Poly(phenylene oxide ketone)polymer with Nafion and SCTF,respectively.The specific research includes the following aspects1.The monomer was synthesized and coupled with the sulfonated2,5-dichlorobenzophenone monomer by Ni(0)catalyst.Then,a series of novel cross-linked bimetallic PEMs were synthesized by self crosslinking of cyano group with non-volatile perfluorosulfonic acid(Nafion)as catalyst.This kind of crosslinked proton exchange membrane shows good mechanical properties,excellent oxidation stability and dimensional stability,and high proton conductivity.It can effectively improve the alcohol resistance of the original sulfonated polyphenylene oxide ketone material,and has good battery performance.2.Sulfonated covalent triazine framework(SCTF)nanosheets were prepared by micro interface method and post sulfonation method.The SCTF nanosheets had good dispersion in water and DMAC.Then,a series of composite proton exchange membranes were prepared by blending SCTF nanosheets with sulfonated polyphenylene ether ketones(SPP Co paeks)resin(SCTF-x@SPP3).The results show that due to the good interfacial compatibility between SCTF and polymer matrix,the series of membrane materials have good proton/methanol selectivity,and the proper addition of SCTF can significantly improve the proton conductivity,thermodynamic performance and fuel cell performance of the membrane.3.Proton conductivity and methanol permeability are the comprehensive factors to evaluate the performance of passive DMFC single cell.A series of proton exchange membranes,such as sulfonated polyphenylene oxide ketone Nafion cross-linked membrane and SCTF composite membrane,were tested for methanol fuel cell under the conditions of air cathode and 4m methanol solution anode.The results show that the maximum power density of nafion-30%@spp-3 is 29.8 m A cm^-2,which is 10%higher than that of spp-3(27.1 m A cm^-2).SCTF-7.5@SPP-3 The maximum power density of the composite film is 33.3 m A cm^-2,which is 23%higher than that of spp-3(27.1 m A cm^-2).It can be seen that the efficient composite of sulfonated polyphenylene oxide ketone can significantly reduce the methanol permeability of the original material,improve the proton conductivity,and then effectively improve the performance of passive DMFC single cell.