Enhanced Proton Selectivity in Ionomer Nanocomposites Containing Hydrophobically Functionalized Silica Nanoparticles
Enhanced Proton Selectivity in Ionomer Nanocomposites Containing Hydrophobically Functionalized Silica Nanoparticles
复制标题
含有疏水功能化二氧化硅纳米粒子的离聚物纳米复合材料中质子选择性增强
DOI：
10.1021/acs.macromol.0c01696
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发表时间：
2021
期刊：
影响因子：
5.5
通讯作者：
Davis, Eric M.
中科院分区：
文献类型：
--
作者：
Domhoff, Allison;Martin, Tyler B.;Silva, Mayura S.;Saberi, Mansour;Creager, Stephen;Davis, Eric M.
全氟磺酸 (PFSA) 离聚物作为钒氧化还原液流电池 (VRFB) 中的质子交换膜 (PEM) 普遍存在，因为它们具有高质子电导率和强大的化学稳定性。然而，传统的 PFSA 离聚物存在高钒离子交叉，即离子选择性低，从而降低了电池的效率和寿命。本文提出了一种制备含有氟碳装饰二氧化硅纳米粒子的 PFSA 纳米复合材料的新方法。与目前的基准商业离聚物相比，这些复合离聚物表现出钒离子渗透性大大降低，质子选择性几乎提高了两个数量级。小角度中子散射数据表明，这些纳米复合材料的纳米结构与其原始对应物有很大不同，其中疏水域的周期性间距显着减小，而离子结构的变化被认为是最小的。这项工作表明，含有可改变离聚物疏水性、非离子导电相的第二相的复合质子交换膜可能被证明是一种富有成效的制造途径，可生产具有增强性能的用于 VRFB 的离聚物膜。
Perfluorosulfonic acid (PFSA) ionomers are ubiquitous as proton-exchange membranes (PEMs) in vanadium redox flow batteries (VRFBs), as they provide high proton conductivity and robust chemical stability. However, traditional PFSA ionomers suffer from high vanadium ion crossover, i.e., low ion selectivity, which reduces the efficiency and lifetime of the battery. Herein, a novel method to fabricate PFSA nanocomposites containing fluorocarbon-decorated silica nanoparticles is presented. These composite ionomers exhibit drastically reduced vanadium ion permeability and an almost two orders of magnitude increase in proton selectivity when compared to the current benchmark commercial ionomer. Small-angle neutron scattering data suggest that the nanostructures of these nanocomposites are drastically different from their pristine counterpart, where the periodic spacing of the hydrophobic domains is significantly reduced, while changes to the ionic structure were seen to be minimal. This work suggests that composite PEMs containing a secondary phase that alters the hydrophobic, nonion-conducting phase of the ionomer may prove to be a fruitful fabrication route to produce ionomer membranes with enhanced performance for use in VRFBs.