PEG水系电解液用于高性能锌碘双离子电池  

PEG-Wate r Electrolyte for High-Performance Zinc Iodine Dual-Ion Batte ries

作　　者：屈小峰 唐宇婷 何鑫程 周佳晟 唐子恒 冯文华 刘军[1] Xiao-Feng Qu;Yu-Ting Tang;Xin-Cheng He;Jia-Sheng Zhou;Zi-Heng Tang;Wen-Hua Feng;Jun Liu(Guangdong University of Technology,Guangzhou 510006,China;Nie Rong County Science and Technology Bureau,Naqu,853500,China)

机构地区：[1]广东工业大学,广东广州510006 [2]聂荣县科技局,西藏那曲853500

出　　处：《电化学（中英文）》2023年第11期28-36,共9页Journal of Electrochemistry

基　　金：国家自然科学基金面上项目(No.21673051);广东省科技厅国际合作项目(No.2019A050510043)资助。

摘　　要：碘因来源丰富和具有较快的氧化还原反应动力学使其作为电池的正极材料而备受青睐,然而,由于碘单质在电解液中的高溶解性而带来的穿梭效应,使得电池的性能下降。本文在水系锌离子电解液中添加聚乙二醇(PEG400)和碘化钾,PEG400能与碘发生络合,抑制了单质碘和碘离子生成碘三离子(I3–)的反应,进而避免了碘的溶解;最后,该电解液搭配双层碳布集流体、锌片及双层隔膜组装成电池,在1 mA·cm^(–2)电流密度下,首圈容量可达1.62 mAh·cm^(–2),参与氧化还原反应的碘占该电池电解液中碘质量的47.52%,库仑效率为93%左右;而在7 mA·cm^(–2)高电流密度下,库仑效率可达98%左右,循环1200圈后,循环保持率为58.33%。Thanks to abundant resource and rapid redox reaction kinetics,iodine is regarded as promising positive materials in the batteries.However,the shuttling effect due to the high solubility of iodine in the electrolyte makes the performance of battery poor.In this paper,polyethylene glycol(PEG400)and potassium iodide were added into zinc-ion aqueous electrolyte.PEG400 could complex with iodine to reduce the dissolution of iodine,therefore alleviating the formation of soluble triiodide(I_(3)^(–))from iodine and iodide ions.Furthermore,this electrolyte was used in the battery with double carbon cloths as the current collectors,double separators and zinc anode.At the current density of 1 mA·cm^(–2),the first discharge capacity reached 1.62 mAh·cm^(–2),and the coulombic efficiency was around 93%.Iodine involved in the electrochemical redox reaction is calculated to account for 47.52%of the total mass of iodine in this electrolyte.At high current density of 7 mA·cm^(–2),its coulombic efficiency still remained 98%,and the rate of capacity retention was 58.33%after 1,200 cycles.

关 键 词：锌碘电池 聚乙二醇 双离子电池 络合 高电流密度 

分 类 号：TM912[电气工程—电力电子与电力传动]