摘要
电解质是决定超级电容器安全性、能量密度和循环性能的最重要因素之一。盐包水电解质由于其不易燃性和宽工作电压范围,已被广泛用于高性能储能装置中。但是,盐包水电解质的低电导率和高粘度通常制约着超级电容器的高倍率性能。本文将1,3-二氧戊烷(DIOX)引入盐包水电解质体系中,形成“LiTFSI-DIOX/H_(2)O”混合电解质。与盐包水电解质相比,该电解质在保证宽的工作电位窗口的情况下,具有低粘度、高电导率和低成本的特点。利用5 m LiTFSI-DIOX/H_(2)O电解质构成的超级电容器在电流密度为1 A g^(-1)的条件下循环5000次后容量保持率为98.5%,库仑效率接近100%。即使在-30℃的低温下,也能保持室温容量的76.1%,这表明超级电容器具有良好的低温倍率性能。
Electrolyte is one of the most important factors determining the safety,energy density and cycle performance of supercapacitors.Water-in-salt electrolyte has been widely used in high-performance energy storage devices due to its non-flammability and wide operating voltage range.However,the low conductivity and high viscosity of water-in-salt electrolyte usually restrict the rate performance of supercapacitors.In this work,1,3-dioxopentane(DIOX)was introduced into the water-in-salt electrolyte system to form a“LiTFSI-DIOX/H_(2)O”hybrid electrolyte.Compared with the water-in-salt electrolyte,the electrolyte has the characteristics of low viscosity,high conductivity and low cost while ensuring a wide working potential window.The supercapacitor composed of 5 m LiTFSI-DIOX/H_(2)O electrolyte has a capacity retention rate of 98.5%and a coulombic efficiency of nearly 100%after 5000 cycles at a current density of 1 Ag^(-1).Even at a low temperature of-30℃,it can maintain 76.1%of the room temperature capacity,which indicates that the supercapacitor has good low temperature rate performance.
作者
张唱唱
王茜
曹晓婷
袁宁一
ZHANG Chang-chang;WANG Xi;CAO Xiao-ting;YUAN Ning-yi(School of materials science and engineering,Changzhou University,Changzhou 213164,China)
出处
《功能材料与器件学报》
CAS
2023年第2期124-133,共10页
Journal of Functional Materials and Devices
关键词
超级电容器
盐包水电解质
低温
宽电压窗口
Supercapacitor
Water-in-salt electrolyte
Low temperature
Wide voltage window
作者简介
张唱唱(1997-),女,硕士,主要研究方向为超级电容器、水系电解液(E-mail:2937524170@qq.com);通信作者:袁宁一(1966-),女,博士,教授,主要研究方向为低维材料微纳器件、新能源材料与器件(E-mail:nyyuan660211@163.com).
