新型含硼添加剂在锂金属二次电池中的应用  

A New Boron Containing Lithium Salt as an Additive Boosting Lithium Metal Batteries

作　　者：陈官胜 周新红[1] Chen Guansheng;Zhou Xinhong(College of Chemistry and Molecular Engineering,Qingdao University of Science and Technology,Qingdao 266042,China)

机构地区：[1]青岛科技大学化学与分子工程学院,山东青岛266042

出　　处：《山东化工》2024年第15期1-3,7,共4页Shandong Chemical Industry

基　　金：国家自然科学基金(52072195)。

摘　　要：在锂电池中,六氟磷酸锂(LiPF_(6))因其最佳综合性能成为应用最广泛的锂盐,然而,LiPF_(6)在高温下易分解以及界面不稳定等因素限制了其进一步发展。为此,本文通过简单的一步反应合成了一种新型添加剂:全氟频哪醇硼酸锂(LiFPB)。该添加剂的阴离子可以优先吸附并在锂负极表面分解,形成导电且坚韧的固体电解质界面(SEI)层。在1 mol/L LiPF_(6)-EC/DMC电解液中加入微量的LiFPB添加剂(0.03 mol/L),可以有效地抑制锂枝晶的生长,Li/Cu和Li/Li电池在循环过程中表现出良好的沉积/剥离稳定性(Li/Cu电池140圈平均库伦效率为97.1%)。在LiCoO_(2)/Li锂金属电池中表现出了优越的循环稳定性(500圈循环容量保持为86%),实现了高温下LiPF_(6)类电解液的实际应用。本研究揭示了设计新型添加剂的重要性。At present,lithium hexafluorophosphate(LiPF_(6))has become a commercial lithium salt because of its best comprehensive performance.However,the decomposition of LiPF_(6) under high temperature and inferior interfacial stability limits its further development.Hence,we synthesize a new type of lithium salt,lithium perfluoropinacolatoborate(LiFPB)as an additive through a simple one-step reaction.The anion of LiFPB can be preferentially adsorbed and decomposed on the surface of Li anode,forming a conductive and robust solid electrolyte interface(SEI)layer.The addition of trace amounts of LiFPB additive(0.03 mol/L)to 1 mol/L LiPF_(6)-EC/DMC can effectively inhibit the growth of lithium dendrite.Li/Cu(average Coulombic efficiency of 97.1%)and Li/Li cells exhibit good lithium plating/stripping stability during cycling.It also shows excellent cycling stability in LCO/Li metal batteries(86%capacity retention after 500 cycles)and realizes the practical application of LiPF_(6) based electrolytes at high temperatures.This study reveals the importance of designing novel additives.

关 键 词：锂金属电池 添加剂 高温 固态电解质界面 

分 类 号：TQ152[化学工程—电化学工业] TM912[电气工程—电力电子与电力传动]