All-fluorinated electrolyte for non-flammable batteries with ultra-high specific capacity at 4.7 V  

作　　者：Zhe Wang Zhuo Li Jialong Fu Sheng Zheng Rui Yu Xiaoyan Zhou Guanjie He Xin Guo 

机构地区：[1]State Key Laboratory of Material Processing and Die&Mould Technology,Laboratory of Solid State Ionics,School of Materials Science and Engineering,Huazhong University of Science and Technology,Wuhan,430074,China [2]Electrochemical Innovation Lab,Department of Chemical Engineering,University College London,20 Gordon Street,London WC1E 7JE,UK

出　　处：《Green Energy & Environment》2024年第10期1601-1609,共9页绿色能源与环境（英文版）

基　　金：the National Natural Science Foundation of China and the Israeli Science Foundation for funding this research within the framework of the joint NSFC-ISF grant#51961145302;supported by China Postdoctoral Science Foundation funded project(Grant#2020M682403).

摘　　要：Li metal batteries(LMBs)with LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NMC811)cathodes could release a specific energy of>500 Wh kg^(-1) by increasing the charge voltage.However,high-nickel cathodes working at high voltages accelerate degradations in bulk and at interfaces,thus significantly degrading the cycling lifespan and decreasing the specific capacity.Here,we rationally design an all-fluorinated electrolyte with addictive tri(2,2,2-trifluoroethyl)borate(TFEB),based on 3,3,3-fluoroethylmethylcarbonate(FEMC)and fluoroethylene carbonate(FEC),which enables stable cycling of high nickel cathode(LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2),NMC811)under a cut-off voltage of 4.7 V in Li metal batteries.The electrolyte not only shows the fire-extinguishing properties,but also inhibits the transition metal dissolution,the gas production,side reactions on the cathode side.Therefore,the NMC811||Li cell demonstrates excellent performance by using limited Li and high-loading cathode,delivering a specific capacity>220 mA h g^(-1),an average Coulombic efficiency>99.6%and capacity retention>99.7%over 100 cycles.

关 键 词：Fluorinated electrolyte Li metal batteries Solid electrolyte interphase Cathode electrolyte interphase Coulombic efficiency 

分 类 号：TM912[电气工程—电力电子与电力传动]