Coordination structure regulation in non-flammable electrolyte enabling high voltage lithium electrochemistry  

作　　者：Zhiwen Deng Ye Jia Yan Deng Changhaoyue Xu Xuemei Zhang Qiujie He Jianan Peng Hao Wu Wenlong Cai 

机构地区：[1]College of Materials Science and Engineering,Sichuan University,Chengdu 610064,Sichuan,China [2]Engineering Research Center of Alternative Energy Materials and Devices,Sichuan University,Chengdu 610064,Sichuan,China

出　　处：《Journal of Energy Chemistry》2024年第9期282-290,共9页能源化学（英文版）

基　　金：supported by the National Science Foundation of Sichuan Province(2023NSFSC1124);Fundamental Research Funds for the Central Universities(YJ2021141);the Science and Technology Cooperation Special Fund of Sichuan University and Zigong City(2022CDZG-9).

摘　　要：High-voltage battery systems bring significant increases in energy density but are also accompanied by fast degradation of electrochemical performance and serious safety issues.Herein,Li^(+)coordination structure regulation was conducted to formulate a non-flammable electrolyte,which consists of 1.5 M lithium bis(fluor sulfonyl)imide(LiFSI)in triethyl phosphate and methyl 2,2,2-trifluoromethyl carbonate(FEMC).The renamed TEP-FEMC-FEC(TFF)electrolyte exhibits an FSI^(−)-dominated solvation structure contributed by the weakly-solvating ability of FEMC.The generated inorganic-rich interfacial layers are conducive to stabilizing the phase transition of high-voltage cathodes while suppressing the dendritic growth on lithium metal or co-intercalation behavior in graphite anode.This TFF electrolyte enables LiCoO_(2)||Li batteries to achieve capacity maintenance over 79%after 400 cycles with high-rate of 5 C at an ultra-high voltage of 4.6 V,and an outstanding capacity exceeding 100 mA h g^(−1)even at a super-high current density of 20 C.Additionally,the Ah-level LiCoO_(2)||graphite pouch cells also exhibit high capacity retention and satisfactory safety performance even under fast charging.This work provides a novel research direction for the pursuit of high energy density non-flammable electrolytes.

关 键 词：NON-FLAMMABLE Solvation structure HIGH-VOLTAGE Lithium batteries 

分 类 号：TM91[电气工程—电力电子与电力传动] TQ131.11[化学工程—无机化工]