A low-cost SPEEK-K type membrane for neutral aqueous zinc-iron redox flow battery

• Published in: Surface & coatings technology 2019-01, Vol.358, p.190-194
• Main Authors: Chang, Shunli, Ye, Jiaye, Zhou, Wei, Wu, Chun, Ding, Mei, Long, Yong, Cheng, Yuanhang, Jia, Chuankun
• Format: Article
• Language: English
• Subjects: Energy density; Energy storage; Flux density; High efficiency; Ion exchange membrane; Iron; Low cost; Power efficiency; Rechargeable batteries; SPEEK membrane; Zinc; Zinc‑iron redox flow battery
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2018.11.028

The ions exchange membrane is the key component in the redox flow battery (RFB), which determines the cycle life and the cost of RFB. Herein, we successfully prepared a low-cost K+ formed sulfonated poly(ether ether ketone) (SPEEK-K) membrane for the neutral Zn-Fe redox flow battery (ZFB) by solution casting method. The ZFB based on our SPEEK-K membrane shows outstanding performance with the coulombic efficiency and energy efficiency over 95% and 78%, respectively, at a high current density of 40 mA cm−2. The cost of SPEEK-K membrane for ZFB is also investigated, compared with commercial Nafion 117 membrane. The comprehensive performance of the SPEEK-K membrane for high energy density ZFB makes this membrane as one of the promising candidates for next generation large-scale energy storage system. •A low-coat and high-performance SPEEK-K membrane has been developed for Zn-Fe flow battery.•The stability and conductivity of the SPEEK-K is higher than that of the pristine SPEEK and commercial Nafion 117 membrane.•The Zn-Fe flow battery based on the SPEEK-K membrane exhibits high coulombic efficiency and energy efficiency.