Research On New Polymer Of Intrinsic Microporosity(PIM)based Anion Exchange Membrane

Fuel cells are highly efficient at converting chemical energy from clean fuels into electricity,with the anion exchange membrane fuel cell（AEMFC）offering the advantage of using non-precious metals as catalysts.AEMs are the core component that separates the electrodes on both sides and conducts hydroxide ions,and the ideal AEM should have high ion conductivity,good mechanical strength,low gas permeability,high swelling resistance,and good chemical and thermal stability.A mild two-step modification method based on the microporous material PIM was developed to produce the microporous anion exchange membrane QPIM-1 AEM,whose microporous structure absorbs water and becomes a conduction channel for hydroxide ions,resulting in an ion conductivity of 47 ms cm^-1 at room temperature with high.After assembling the microporous membrane into a single cell,peak power densities of up to 143 m W cm^-2 are measured and the cell had high and stable open circuit voltage values over a period of up to 7 days.Using gas chromatography and linear sweep voltammetry,the structural and performance characteristics of the polymer were investigated to demonstrate the excellent resistance of microporous anion exchange membranes to hydrogen permeation in high humidity environments.The hydrogen permeation flux（5.33 barrer）and the hydrogen crossover current density(0.42 m A cm^-2)of the～32 um microporous anion exchange membrane are measured at 100%relative humidity.Based on the defects of high water absorption and high swelling of microporous anion exchange membrane,the covalently cross-linked microporous anion exchange membrane is prepared by introducing appropriate amount of diazide cross-linker into the membrane by impregnation method and modified by thermal initiation cross-linking.The swelling ratio of c QPIM-1（5.0 wt%）is only 44%of the original membrane.The mechanical strength,thermal stability and alkali stability of the microporous membranes were enhanced by the introduction of cross-linked bonds to enhance the interaction between the original chains.In summary,this study has prepared an with good ionic conductivity,low hydrogen permeability,excellent stability and swelling resistance based on a flexible post-modification modification of the polymer of intrinsic microporosity and the introduction of an external cross-linker to trigger the modification reaction,which has the potential to be used in AEMFC.