水系有机液流电池中分子体系研究进展

Advances of redox-active molecules in aqueous organic redox flow batteries

作为一种极具潜力的大规模储能设备,氧化还原液流电池(redox flow batteries,RFBs)近十年来发展迅速。与传统水系无机RFBs(以钒、锌、铁、卤素等无机离子为氧化还原活性分子)相比,水系有机氧化还原液流电池(aqueous organic redox flow batteries,AORFBs)的电化学活性分子种类更多、来源更广,AORFBs已成为RFBs领域中的研究热点。此外,有机分子所具有的结构易修饰、电化学窗口灵活可调的优势,使AORFBs有望突破传统水系RFBs的功率和能量密度。然而,目前有机分子的稳定性差和溶解度低等问题使AORFBs的实际寿命和运行成本仍无法与钒液流电池的相比。为此,研究者们做了大量工作,本文综述了5类常见的AORFBs体系的研究进展,分别为以有机金属配合物、氮氧自由基、醌类化合物、紫精衍生物和有机聚合物作为活性分子构成的AORFBs体系;总结了各类AORFBs分子体系的特点和待解决的科学问题,并对未来AORFBs的发展方向进行了展望。

As a promising large-scale energy storage technology,redox flow batteries(RFBs)have been developed rapidly in recent ten years.Compared with the traditional aqueous inorganic RFBs(which take vanadium,zinc,iron,halogen or other inorganic ions as redox-active molecules),aqueous organic redox flow batteries(AORFBs)have more choices of redox-active molecules from a wide range of sources,which have become a research hotspot in RFBs.Besides,the structure of organic molecules is easy to modify and the electrochemical window is flexible and adjustable,thus AORFBs are expected to break through the power and energy density of traditional aqueous RFBs.However,the poor stability and low solubility of organic molecules make the actual life and operating costs of AORFBs still not comparable to vanadium flow batteries.Therefore,researchers have done a lot of works.This review summarizes the recent advances of five typical AORFBs systems,including organic metal complexes,nitric oxide radicals,quinones,viologen derivatives and organic polymers AORFBs systems.Moreover,the characteristics and scientific problems of AORFBs have been discussed,and future advancement of AORFBs are also prospected.