磺化聚醚醚酮与氧化石墨烯共混膜的制备以及在全钒液流电池中的应用

Preparation of Sulfonated Poly(ether ether ketone)/Graphene Oxide Blend Membranes and Their Application in Vanadium Redox Flow Battery

以浓硫酸为溶剂和磺化剂制备磺化度(DS)为65%的磺化聚醚醚酮(SPEEK),根据SPEEK和氧化石墨烯(GO)不同质量比制备一系列共混膜(S/GO).对共混膜的含水量、离子交换容量、面电阻、质子电导率、钒离子渗透率、机械强度以及耐氧化性进行研究.采用扫描电子显微镜(SEM)观察S/GO共混膜的形态;通过热重分析(TG)表征共混膜的热稳定性.结果表明随着GO引入量的增加,共混膜的含水量增加,离子交换容量(IEC)降低,质子电导率减小,钒离子渗透率减小,机械性能增强.共混膜能量效率均高于Nafion115,其中S/GO-2(GO含量2 wt%)的电池效率最佳,能量效率达到80%,相比于Nafion115提高近9%.在运行100次循环以后S/GO共混膜电池效率稳定性良好.S/GO共混膜有望在全钒液流电池中得到应用.

A series of sulfonated poly （ether ether ketone） （SPEEK） and graphene oxide （GO） blend membranes were prepared with various mixing mass ratios. The water uptake, ion exchange capacity, proton conductivity, vanadium ion permeability, mechanical properties and chemical stability were measured. The blend membranes were characterized by FTIR, SEM and TG. The blend membranes exhibit higher water uptake and ion exchange capacity and lower vanadium ion permeability than Nafionll5 membranes,the ion exchange capacity decreases with the increase of GO content. The VO2 ~ permeability of the blend membranes decreased, while mechanical properties increased with increasing GO content. Random embedding of GO in the membranes can block the transport of vanadium ions effectively, resulting in vanadium ion permeability of the blend membranes decreased obviously. In VRB single cell test, the biend membranes showed higher energy efficiency （EE） compared with Nafionll5 membrane,the EE of S/GO-2 （GO,2 wt% ） blend membrane was 80% which increased by 9% compared to that with Nafion115. The S/GO blend membranes showed stable performance up to 100 cycles test. The experimental results indicate that the S/GO blend membranes show favorable development prospects for VRB.