Zhang Bengui, Zhang Xueting, Liu Qian, Fu Yanshi, Yang Zhirong, Zhang Enlei, Wang Kangjun, Wang Guosheng, Zhang Zhigang, Zhang Shouhai
College of Chemical Engineering, Shenyang University of Chemical Technology, Shenyang 110142, China.
State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China.
Polymers (Basel). 2022 Apr 11;14(8):1552. doi: 10.3390/polym14081552.
Membranes with high conductivity, high selectivity, and high stability are urgently needed for high-power-density vanadium flow batteries (VFBs). Enhancing membrane conductivity presents many challenges, often resulting in sacrificing membrane selectivity and mechanical strength. To overcome this, new robust adamantane-based membranes with enhanced conductivity are constructed for VFB. Low-content basic piperazine (IEC = 0.78 mmol g) and hydrophilic hydroxyl groups are introduced into highly rigid, hydrophobic adamantane containing poly(aryl ether ketone) backbone (PAPEK) and then selectively swelled to induce microphase separation and form ion transport pathways. The highly rigid and hydrophobic PAPEK exhibits high swelling resistance and provides the membranes with slight swelling, high selectivity, and high mechanical strength. The selective swelling temperature has a significant influence on the areal resistance of the resulting membrane, e.g., the PAPEK-130 membrane, when selectively swelled at 130 °C, has low areal resistance (0.22 Ω∙cm), which is approximately two-fifths that of the PAEKK-60 membrane (treated at 60 °C, 0.57 Ω∙cm). Consequently, the resulting PAPEK membranes exhibit low swelling, high selectivity, and low areal resistance, with the VFB constructed with a PAPEK-90 membrane exhibiting excellent energy efficiency (91.7%, at 80 mA∙cm, and 80.0% at 240 mA∙cm) and stable cycling performance for 2000 cycles.
高功率密度钒液流电池（VFBs）迫切需要具有高导电性、高选择性和高稳定性的膜。提高膜的导电性面临许多挑战，往往会导致膜的选择性和机械强度下降。为了克服这一问题，我们构建了新型的具有增强导电性的坚固金刚烷基膜用于钒液流电池。将低含量的碱性哌嗪（IEC = 0.78 mmol g）和亲水性羟基引入到含有高度刚性、疏水性金刚烷的聚芳醚酮主链（PAPEK）中，然后进行选择性溶胀以诱导微相分离并形成离子传输通道。高度刚性和疏水性的PAPEK表现出高抗溶胀性，并为膜提供了轻微的溶胀、高选择性和高机械强度。选择性溶胀温度对所得膜的面电阻有显著影响，例如，PAPEK - 130膜在130°C下选择性溶胀时具有低面电阻（0.22 Ω∙cm），约为PAEKK - 60膜（在60°C处理，0.57 Ω∙cm）的五分之二。因此，所得的PAPEK膜表现出低溶胀、高选择性和低面电阻，用PAPEK - 90膜构建的钒液流电池在80 mA∙cm时表现出优异的能量效率（91.7%），在240 mA∙cm时为80.0%，并具有2000次循环的稳定循环性能。
