磺化聚砜/POSS杂化质子传导膜的制备及钒电池性能

Preparation of sulfonated polysulfone/POSS hybrid proton exchange conductive membranes for vanadium redox flow battery

将磺化度为62%的磺化聚砜(SPSf)与笼型倍半硅氧烷(POSS-NH2)进行共混,得到系列SPSf/POSS-NH2杂化质子传导膜,研究了POSS-NH2含量对SPSf/POSS-NH2膜的吸水率、面电阻、质子电导率、钒离子渗透率、机械强度、耐氧化性能及相应钒电池性能的影响.研究表明,添加POSS-NH2后,热分解温度提高,质子电导率可达10.55 mS/cm,POSS-NH2质量分数为5%的S-P-5%杂化膜钒离子渗透率降低至5.47×10^(-9) cm^(2)/min,质子选择性提高(1.930×10^(6) S·min/cm^(3)),远优于Nafion115膜(1.23×10^(5) S·min/cm^(3))和纯SPSf膜(S-P-0%膜)(5.41×10^(5) S·min/cm^(3)).与S-P-0%膜相比,S-P-5%膜为电池效率最佳,库伦效率可稳定维持在99.4%左右,高于Nafion115膜(92.38%)和S-P-0%膜(91.72%),电压效率和能量效率也得到明显提升,300次循环仍然具有较稳定的电池效率,自放电时间达117 h,是Nafion115膜的10倍,POSS的引入为SPSf质子传导膜性能的提升提供了新思路.

A series of SPSf/POSS-NH2 hybrid proton exchange conductive membranes were prepared by blending sulfonated polysulfone(SPSf)with the degree of sulfonation of 62%and aminopropyllsobutyl polyhedral oligomeric silsesquioxane(POSS-NH2).The effects of content of the POSS-NH2 on the water uptake,area resistance,ptoton proton conductivity,vanadium permeability,mechanical strength,oxidation resistance and the performance of vanadium redox flow battery were investigated in detailed.The results showed that the addition of POSS-NH2 increases the thermal decomposition temperature and proton conductivity to a value of 10.55 mS/cm.When the mass fraction of POSS-NH2 was 5%,the S-P-5%hybrid membrane exhibited lower vanadium permeability of 5.47×10^(-9) cm^(2)/min,and higher proton selectivity(1.930×10^(6) S·min/cm^(3)),which were better than that of Nafion115 membrane(1.23×10^(5) S·min/cm^(3))and S-P-0%membrane(5.41×10^(5) S·min/cm^(3)).Compared with S-P-0%membrane,S-P-5%membrane showed higher battery efficiency.Its coulombic efficiency could be maintained at about 99.4%,which was higher than that of Nafion 115 membrane(92.38%)and S-P-0%membrane(91.72%).Meanwhile,the voltage efficiency and energy efficiency were also significantly improved.The battery efficiency was still stable after 300 cycles,and the self-discharge time was 117 h,which was 10 times than that of Nafion 115 membrane.The introduction of POSS provided a new idea for the improvement of SPSf proton exchange conductive membrane performance.