摘要
为了抑制锂硫电池的穿梭效应,改善锂硫电池的电化学性能,尝试以二硫苏糖醇(DTT)为剪切剂,对高阶多硫化物进行剪切以阻止其溶解。将二硫苏糖醇(DTT)掺入多壁碳纳米管(MWCNTs)纸中,制得DTT夹层,将该DTT夹层置于锂硫扣式半电池正极片和隔膜之间,正极片的载硫面密度约为2 mg/cm2。SEM观察结果证实DTT均匀分散在MWCNTs纸的表面和空隙中。电化学测试结果表明引入DTT夹层结构的锂硫电池在0.05C倍率首次放电比容量达到1 288 mAh/g,首次库伦效率接近100%,在0.5C、2C、4C倍率下充放电时的比容量分别达到650mAh/g、600mAh/g、410mAh/g。DTT夹层结构的引入可有效剪切高阶多硫化物并阻止其迁移到锂负极,从而抑制穿梭效应,改善锂硫电池的循环稳定性和库伦效率。
The present work aimed to restrain shuttle effect of lithium-sulfur(Li-S)batteries and improve the cycle perfor-mance,and made an attempt to utilize dithiothreitol(DTT)as scission reagent to prevent dissolution of lithium polysulfur(LiPS).The prefabricated MWCNTs paper was immersed in the DTT solution and dried to obtain a DTT interlayer,which was subsequently located between the cathode disk(with a sulfur areal loading of 2 mg/cm 2)and the separator of a Li-S coin half-cell.The morphological and structural observation over the DTT interlayer by scanning electron microscopy(SEM)validated the uniform dispersion of DTT in the MWCNTs paper.The electrochemical test showed that the Li-S half-cell with the DTT interlayer possesses an initial discharge capacity of 1 288 mAh/g and a Coulombic efficiency approaching 100%,and moreover,maintains specific capacities of 650 mAh/g,600 mAh/g and 410 mAh/g under the current rates of 0.5C,2C and 4C respectively.Our experiment indicated DTT can effectively slice high-order LiPS and hinder its migration to the anode,and in consequence,significantly improve the cycle stability and Coulombic efficiency of Li-S battery.
作者
王杰
孙晓刚
陈珑
邱治文
蔡满园
李旭
陈玮
WANG Jie;SUN Xiaogang;CHEN Long;QIU Zhiwen;CAI Manyuan;LI Xu;CHEN Wei(College of Mechantronics Engineering,Nanchang University,Nanchang 330031)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2018年第7期1079-1083,共5页
Materials Reports
基金
江西省教育厅科研项目(20142BBE50071)
关键词
锂硫电池
碳纳米管
夹层
二硫苏糖醇
剪切剂
穿梭效应
lithium-sulfur battery
carbon nanotube
interlayer
dithiothreitol
scission reagent
shuttle effect
作者简介
王杰:男,1992年生,硕士研究生,研究方向为锂硫电池 E-mail:464425175@qq.com;孙晓刚:通信作者,男,1957年生,教授,硕士研究生导师,研究方向为碳纳米管和锂离子电池 E-mail:xiaogangsun@163.com
