离子型添加剂四丁基胺-双(氟磺酰)亚胺对锂电池性能的影响

Influences of Ionic Additive Tetrabutylammonium-bis(fluorosulfonyl) imide on Performance of Lithium Metal Batteries

将离子型添加剂四丁基胺-双(氟磺酰)亚胺(TBA-FSI)应用于Li|Cu和Li|FePO_4二次锂电池,测试了含有TBA-FSI添加剂的1 mol/L LiTFSI 1,3-二氧戊烷/乙二醇二甲醚(DOL/DME,体积比1∶1)电解液与金属负极的界面匹配性.研究发现,与1 mol/L LiTFSI DOL/DME相比,含有TBA-FSI添加剂的锂电池表现出更小的极化电压、稳定的界面阻抗和较长的循环寿命.这主要归功于TBA-FSI在金属锂表面还原生成富含LiF和Li3N等无机物的稳定固态电解质界面(SEI)膜.

An ionic compound,tetrabutylammonium-bis(fluorosulfonyl)imide(TBA-FSI)was employed as an additive to lithium metal batteries.The 1 mol/L lithium bis(trifluoromethanesulfonyl)imide(LiTFSI)-based 1,3-dioxolane(DOL)/dimethoxyethane(DME)electrolyte showed high compatibility toward lithium metal anode when 5%(mass fraction)TBA-FSI was added owing to the formation of a LiF-,Li3N-riched solid electrolyte interpase(SEI)film on lithium metal anode.As a result,the lithium dendrite growth was significantly restricted and coulombic efficiency of Li|Cu cells was markedly enhanced.