磷酸锆/磺化聚苯并咪唑填孔型质子交换复合膜的制备与性能研究

Preparation and Characterization of Proton Exchange Composite Membranes Pore-Filled with ZrP/Sulfonated Polybenzimidazole

利用填充法将SPBI-ZrP电解质填充于ePTFE多孔基底中,制备SPBI-ZrP/ePTFE质子交换复合膜。分别采用FESEM、FT-IR、干湿称重法、拉伸测试和交流阻抗法对膜的微观结构和性能表征。实验结果表明,SPBI-ZrP电解质已成功填充于ePTFE基底中,膜表面光滑。SPBI-ZrP-2.5膜在厚度方向的溶胀度是SPBI-ZrP-2.5/ePTFE膜的7.3倍,归因于ePTFE基底能够有效地抑制膜溶胀,提高膜尺寸稳定性;由于ePTFE基底的增强效应,SPBI-ZrP-2.5/ePTFE膜的拉伸强度比SPBI-ZrP-2.5膜提高19.86%;SPBI-ZrP-2.5/ePTFE膜的质子电导率在160和80℃、相对湿度100%下分别达到0.222和0.071 S×cm^(-1),而Nafion膜(EW=1100)在80℃的质子电导率为0.077 S×cm^(-1),在温度(29)100℃时质子电导率急剧下降,说明SPBI-ZrP-2.5/ePTFE膜在高温下具有良好的质子传导性能,能应用于高温质子交换膜燃料电池中。

SPBI-ZrP/ePTFE proton exchange composite membranes were prepared by pore-filling techniquesusing ePTFE porous substrate(supporting material)filled with SPBI-ZrP polymer electrolytes.Themicrostructure and performance of the membranes were characterized by FESEM,FT-IR,dry-wet weightingmethod,tensile test and AC impedance.The results indicate that SPBI-ZrP is successfully filled into the ePTFEsubstrate and the membrane surface is smooth.The swelling degree of the SPBI-ZrP-2.5membrane in thicknessdirection is about7.3times of that of the SPBI-ZrP-2.5/ePTFE membrane,because ePTFE can effectivelysuppress membrane swelling and improve membrane dimensional stability.Simultaneously,because of thereinforced effect of ePTFE,the mechanical strength of the SPBI-ZrP-2.5/ePTFE membrane is19.86%higherthan that of SPBI-ZrP-2.5.The SPBI-ZrP-2.5/ePTFE membrane shows a high proton conductivity of0.222and0.071S.cm-1at160℃and80℃under100%relative humidity,respectively.The proton conductivity of Nafionmembrane(EW=1100)is0.077S.cm-1at80℃and decreases sharply when temperature exceeds100℃.Theseresults indicate that SPBI-ZrP/ePTFE membranes have good proton conductivity at higher temperature,whichcan be applied in fuel cells with high temperature proton exchange membranes.