Unique double-layer solid electrolyte interphase formed with fluorinated ether-based electrolytes for high-voltage lithium metal batteries  

作　　者：Ruo Wang Jiawei Li Bing Han Qingrong Wang Ruohong Ke Tong Zhang Xiaohu Ao Guangzhao Zhang Zhongbo Liu Yunxian Qian Fangfang Pan Iseult Lynch Jun Wang Yonghong Deng 

机构地区：[1]Department of Materials Science&Engineering,School of Innovation and Entrepreneurship,Southern University of Science and Technology,Shenzhen 518055,Guangdong,China [2]School of Geography,Earth and Environmental Sciences,University of Birmingham,Edgbaston,Birmingham B152TT,UK [3]Key Laboratory of Marine Environmental Corrosion and Bio-Fouling,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,Shandong,China [4]Shenzhen CAPCHEM Technology Co.,Ltd.,Shenzhen 518118,Guangdong,China [5]CALB Group Co.,Ltd.,Changzhou 213200,Jiangsu,China

出　　处：《Journal of Energy Chemistry》2024年第1期532-542,I0012,共12页能源化学（英文版）

基　　金：the financial supports from the KeyArea Research and Development Program of Guangdong Province (2020B090919001);the National Natural Science Foundation of China (22078144);the Guangdong Natural Science Foundation for Basic and Applied Basic Research (2021A1515010138 and 2023A1515010686)。

摘　　要：Li metal batteries using high-voltage layered oxides cathodes are of particular interest due to their high energy density.However,they suffer from short lifespan and extreme safety concerns,which are attributed to the degradation of layered oxides and the decomposition of electrolyte at high voltage,as well as the high reactivity of metallic Li.The key is the development of stable electrolytes against both highvoltage cathodes and Li with the formation of robust interphase films on the surfaces.Herein,we report a highly fluorinated ether,1,1,1-trifluoro-2-[(2,2,2-trifluoroethoxy)methoxy]ethane(TTME),as a cosolvent,which not only functions as a diluent forming a localized high concentration electrolyte(LHCE),but also participates in the construction of the inner solvation structure.The TTME-based electrolyte is stable itself at high voltage and induces the formation of a unique double-layer solid electrolyte interphase(SEI)film,which is embodied as one layer rich in crystalline structural components for enhanced mechanical strength and another amorphous layer with a higher concentration of organic components for enhanced flexibility.The Li||Cu cells display a noticeably high Coulombic efficiency of 99.28%after 300 cycles and Li symmetric cells maintain stable cycling more than 3200 h at 0.5 mA/cm^(2) and 1.0m Ah/cm^(2).In addition,lithium metal cells using LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) and Li CoO_(2) cathodes(both loadings~3.0 m Ah/cm^(2))realize capacity retentions of>85%over 240 cycles with a charge cut-off voltage of 4.4 V and 90%for 170 cycles with a charge cut-off voltage of 4.5 V,respectively.This study offers a bifunctional ether-based electrolyte solvent beneficial for high-voltage Li metal batteries.

关 键 词：Lithium metal batteries High-voltage layered oxides Fluorinated ether-based electrolytes Solid electrolyte interphase Cathode electrolyte interphase 

分 类 号：TM912[电气工程—电力电子与电力传动] O646.1[理学—物理化学]