Poly(arylene ether ketone) proton exchange membranes grafted with long aliphatic pendant sulfonated groups for vanadium redox flow batteries
Poly(arylene ether ketone) proton exchange membranes grafted with long aliphatic pendant sulfonated groups for vanadium redox flow batteries
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DOI：
10.1039/c6ta07456a
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发表时间：
2017-01
影响因子：
--
通讯作者：
Sun Yang;Yeonho Ahn;Dukjoon Kim
中科院分区：
文献类型：
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作者：
Sun Yang;Yeonho Ahn;Dukjoon Kim
全钒液流电池作为一种储能系统，以其寿命长、设计灵活、维护成本低、储能容量大等优点而备受关注。质子交换膜是VRFBs的核心组件之一，由具有长侧基磺烷基的聚（亚芳基醚酮）（PAEK）制备。通过1H-NMR和FT-IR对PAEK的化学结构进行了表征，并对所合成的膜进行了质子传导性、离子交换容量、钒离子渗透性沿着热稳定性、机械稳定性和化学稳定性等性能测试，并与商用Nafion 117®膜进行了比较。由于质子传导率随着磺化度（DS）而增加，具有40%的DS的磺化PAEK膜（S-PAEK-40）显示出比Nafion 117®膜更高的质子传导率。所有的S-PAEK膜在高达200 °C下是热稳定的，并且在本实验中在电解质溶液中没有观察到化学降解。长的脂肪族侧链阻止钒离子接近（攻击）聚合物骨架（苯环），因此其导致比Nafion 117更低的VO 2+渗透性。虽然S-PAEK膜的离子簇尺寸大于Nafion 117®膜的离子簇尺寸，但S-PAEK膜显示出比Nafion 117®膜更高的库仑效率。此外，S-PAEK膜在100个循环的循环测试期间显示出优异的稳定性。
As an energy storage system (ESS), all-vanadium redox flow batteries (VRFBs) have drawn much attention for their long life time, flexible design, low maintenance cost, and high energy capacity. The proton exchange membrane, one of the core components of VRFBs, is prepared from poly(arylene ether ketone) (PAEK) with long pendant sulfoalkyl groups. The chemical structure of PAEK is identified by using 1H-NMR and FT-IR. The essential properties as a membrane for VRFB application such as proton conductivity, ion exchange capacity, and vanadium ion permeability along with the thermal, mechanical and chemical stability are tested for all membranes synthesized, and are compared with those of a commercial Nafion 117® membrane. As the proton conductivity increases with the degree of sulfonation (DS), the sulfonated PAEK membrane with a DS of 40% (S-PAEK-40) shows even higher proton conductivity than the Nafion 117® membrane. All of the S-PAEK membranes are thermally stable up to 200 °C and no chemical degradation is observed in electrolyte solution in the present experiment. The long aliphatic side chains prohibit the approach (attack) of vanadium ions to the polymer backbone (phenyl rings) and thus it results in lower VO2+ permeability than Nafion 117. While the ion cluster dimensions of S-PAEK membranes are larger than that of the Nafion 117® membrane, S-PAEK membranes display higher coulombic efficiency than the Nafion 117® membrane. In addition, S-PAEK membranes show excellent stability during the cycling test with 100 cycles.