LiFSI-LiPF_(6)电解液在高镍/硅碳锂电池中的应用  

Application of LiFSI-LiPF_(6)Electrolyte in High-grade Nickel/Silicon Carbon Lithium Batteries

作　　者：刘驰 喻鹏[1] 张纯 张薇[1] 王志国 黄卫[1] 刘辉[1] LIU Chi;YU Peng;ZHANG Chun;ZHANG Wei;WANG Zhiguo;HUANG Wei;LIU Hui(School of Chemistry and Materials Science of Hunan Agricultural University,Changsha,Hunan 410128,China)

机构地区：[1]湖南农业大学化学与材料科学学院,湖南长沙410128

出　　处：《有色冶金设计与研究》2024年第1期9-13,53,共6页Nonferrous Metals Engineering & Research

基　　金：长沙市自然科学基金(项目编号:kq2208079);广东省先进储能材料重点实验室开放课题(项目编号:AESM202103)。

摘　　要：高镍/硅碳体系是最具潜力的下一代高能量密度锂离子电池体系,但由于电池循环稳定性差,目前规模化应用受限。研究认为,构建稳定的SEI是提升高镍/硅碳电池容量保持率的关键方法之一。传统电解液中六氟磷酸锂(LiPF_(6))会产生酸腐蚀性产物,不利于SEI的稳定;双氟磺酰亚胺锂(LiFSI)作为一种新秀锂盐被证明有优异的热稳定和成膜性能,会腐蚀正极集流体。研究了LiFSI-LiPF_(6)双盐电解液在高镍/硅碳软包电池中的应用,通过化成、循环和储存测试,评测其电化学性能。结果表明,LiFSI-LiPF_(6)电解液可以降低电池化成产气量和内阻,提升电极稳定性,0.6mol/dm^(3)LiFSI+0.6mol/dm^(3)LiPF_(6)电池循环1000圈后的容量保持率最高,达75.66%,其储存电压降比LiFSI单盐电池少37.64%。The high-grade nickel/silicon carbon system is the most promising next-generation high-energy density lithium-ion battery system.However,owing to weak cycling stability of the battery,its large-scale application is currently limited.It believes in the study that building a stable SEI is one of the key methods to improve the capacity retention rate of high-grade nickel/silicon carbon batteries.LiPF in traditional electrolytes produces acidic corrosive products,which are not conducive to the stability of SEI.LiFSI has been proven to have excellent thermal stability and film-forming properties as a novel lithium salt,but it can corrode the positive current collector.The paper makes a study of the application of LiFSI-LiPFe double-salt electrolyte in high-grade nickel/silicon carbon pouch batteries,and analyzes its electrochemical performance by formation,cycling,and storage tests.The results show that LiFSI-LiPF_(6)electrolyte can reduce the gas production and internal resistance of battery formation,and enhance electrode stability.The 0.6 mol/dm^(3)LiFSI+0.6 mol/dm^(3)LiPFbattery has the highest capacity retention rate of 75.66%after 1000 cycles,and its storage voltage drop is 37.64%less than that of the LiFSI single-salt battery.

关 键 词：六氟磷酸锂 双氟磺酰亚胺锂 双盐电解液 高镍/硅碳软包电池 

分 类 号：O646[理学—物理化学] TM912[理学—化学]