Catholyte engineering to release the capacity of iodide for high-energy-density iodine-based redox flow batteries  

作　　者：Bo Lu Minghui Yang Mei Ding Su Yan Weizhe Xiang Yuanhang Cheng Hu Fu Zhizhao Xu Chuankun Jia 

机构地区：[1]Institute of Energy Storage Technology,Changsha University of Science&Technology,Changsha,China [2]School of New Energy,Nanjing University of Science and Technology,Jiangyin,Jiangsu,China

出　　处：《SusMat》2023年第4期522-532,共11页可持续发展材料（英文）

基　　金：National Key Research and Development Program of China,Grant/Award Number:2022YFB2405100;National Natural Science Foundation of China,Grant/Award Number:22209015;Scientific Research Foundation of Hunan Provincial Education Department,Grant/Award Number:21A0195;100 Talented Team of Hunan Province,Grant/Award Number:[2016]91。

摘　　要：Due to the high solubility,high reversibility,and low cost of iodide,iodine-based redox flow batteries(RFBs)are considered to have great potential for upscaling energy storage.However,their further development has been limited by the low capacity of I−as one-third of the I−is used to form I3−(I2I−)during the charging process.Herein,we have demonstrated that the pseudohalide ion,thiocyanate(SCN−),is a promising complexing agent for catholyte of iodinebased RFBs to free up the I−by forming iodine-thiocyanate ions([I2SCN]−)instead of I3−,unlocking the capacity of iodide.Applying this strategy,we have demonstrated iodine-based RFBs with full utilization of iodide to achieve high capacity and high energy density.Both the zinc/iodine RFB and polysulfide/iodine RFB with SCN−complex agent achieve their theoretical capacity of around 160 A h Lposolyte^(−1)(6.0MI−in catholyte).Therefore,the zinc/iodine RFB delivers a high energy density of 221.34Wh Lposolyte^(−1),and the polysulfide/iodine RFB achieves a highenergy density of 165.62Wh Lposolyte^(−1).It is believed that this effective catholyte engineering can be further generalized to other iodine-based RFBs,offering new opportunities to unlock the capacity of iodide and achieve high energy density for energy storage.

关 键 词：energy storage high energy density iodine-based redox flow batteries unlock iodide capacity 

分 类 号：TM912[电气工程—电力电子与电力传动]