Abstract Blend membranes of quaternized polysulfone/polyvinylidene fluoride (Q/P) for all vanadium redox flow battery (VRFB) are prepared by one-step solution casting method to reduce the vanadium permeation and improve the mechanical properties of pure quaternized polysulfone membrane. The physicochemical properties and electrochemical performances of the Q/P membranes are characterized in detail. In comparison with the Nafion 115 membrane, Q/P blend membranes exhibit higher water uptake, ion exchange capacity (IEC) and swelling ratio, lower ionic conductivity and ultra-lower vanadium permeability, better stability and superior VRFB cycle performances. Owing to the ultra-low vanadium permeability, the VRFB with Q/P-20% blend membrane has shown the highest coulombic efficiency of 99.29% at 80 mA cm−2 and the Q/P-15% membrane has shown the highest EE of 91.12% at 40 mA cm−2, which is 4.89% and 3.33% higher than that of Nafion 115 at the same current density, respectively. The mechanical properties of the Q/P blend membranes increase with the increasing of the PVDF mass ratio. It reveals that the introduction of PVDF is of great significance to improve the performances of the Q/P blend membranes.

中文翻译：

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一种用于全钒氧化还原液流电池的具有超低钒渗透率的新型氯甲基化/季铵化聚（砜）/聚（偏二氟乙烯）阴离子交换膜

摘要 采用一步溶液浇注法制备全钒液流电池用季铵化聚砜/聚偏氟乙烯（Q/P）共混膜，以减少钒渗透，提高纯季铵化聚砜膜的力学性能。详细表征了 Q/P 膜的物理化学性质和电化学性能。与 Nafion 115 膜相比，Q/P 混合膜表现出更高的吸水率、离子交换容量 (IEC) 和溶胀比，更低的离子电导率和超低的钒渗透率，更好的稳定性和卓越的 VRFB 循环性能。由于超低的钒渗透率，具有 Q/P-20% 混合膜的 VRFB 显示出最高的库仑效率 99。在 80 mA cm−2 下为 29%，Q/P-15% 膜在 40 mA cm−2 下显示出最高 91.12% 的 EE，在相同的电流密度下比 Nafion 115 高 4.89% 和 3.33% ， 分别。Q/P 共混膜的机械性能随着 PVDF 质量比的增加而增加。说明PVDF的引入对提高Q/P共混膜的性能具有重要意义。