Challenges facing high-voltage/high-capacity cathodes,in addition to the longstanding problems pertinent to lithium(Li)-metal anodes,should be addressed to develop high-energy-density Li-metal batteries.This issue mos...Challenges facing high-voltage/high-capacity cathodes,in addition to the longstanding problems pertinent to lithium(Li)-metal anodes,should be addressed to develop high-energy-density Li-metal batteries.This issue mostly stems from interfacial instability between electrodes and electrolytes.Conventional carbonate-or ether-based liquid electrolytes suffer from not only volatility and flammability but also limited electrochemical stability window.Here,we report a nitrile electrolyte strategy based on concentrated nitrile electrolytes(CNEs)with co-additives.The CNE consists of high-concentration lithium bis(fluorosulfonyl)imide(LiFSI)in a solvent mixture of succinonitrile(SN)/acetonitrile(AN).The SN/AN solvent mixture is designed to ensure high oxidation stability along with thermal stability,which are prerequisites for high-voltage Li-metal cells.The CNE exhibits interfacial stability with Li metals due to the coordinated solvation structure.Lithium nitrate(LiNO_(3))and indium fluoride(InF_(3))are incorporated in the CNE as synergistic co-additives to further stabilize solid-electrolyte interphase(SEI)on Li metals.The resulting electrolyte(CNE+LiNO_(3)/InF_(3))enables stable cycling performance in Li||LiNi_(0.8)Co_(0.1)Mn_(0.1)and 4.9 V-class Li||LiNi_(0.5)Mn_(1.5)O_(4)cells.Notably,the Li||LiNi_(0.5)Mn_(1.5)O_(4)cell maintains its electrochemical activity at high temperature(100℃)and even in flame without fire or explosion.展开更多
基金supported by the U.S.Army Research Office(ARO)(W911NF-18-1-0016)supported by the Basic Science Research Program(2021R1A2B5B03001615,2021M3H4A1A02099355)through the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT and Future Planning,the Technology Innovation Program(20010960,20012216)funded by the Ministry of Trade,Industry&Energy(MOTIE)the R&D program for Forest Science Technology(FTIS 2021354D10-2123-AC03)provided by Korea Forest Service(Korea Forestry Promotion Institute).
文摘Challenges facing high-voltage/high-capacity cathodes,in addition to the longstanding problems pertinent to lithium(Li)-metal anodes,should be addressed to develop high-energy-density Li-metal batteries.This issue mostly stems from interfacial instability between electrodes and electrolytes.Conventional carbonate-or ether-based liquid electrolytes suffer from not only volatility and flammability but also limited electrochemical stability window.Here,we report a nitrile electrolyte strategy based on concentrated nitrile electrolytes(CNEs)with co-additives.The CNE consists of high-concentration lithium bis(fluorosulfonyl)imide(LiFSI)in a solvent mixture of succinonitrile(SN)/acetonitrile(AN).The SN/AN solvent mixture is designed to ensure high oxidation stability along with thermal stability,which are prerequisites for high-voltage Li-metal cells.The CNE exhibits interfacial stability with Li metals due to the coordinated solvation structure.Lithium nitrate(LiNO_(3))and indium fluoride(InF_(3))are incorporated in the CNE as synergistic co-additives to further stabilize solid-electrolyte interphase(SEI)on Li metals.The resulting electrolyte(CNE+LiNO_(3)/InF_(3))enables stable cycling performance in Li||LiNi_(0.8)Co_(0.1)Mn_(0.1)and 4.9 V-class Li||LiNi_(0.5)Mn_(1.5)O_(4)cells.Notably,the Li||LiNi_(0.5)Mn_(1.5)O_(4)cell maintains its electrochemical activity at high temperature(100℃)and even in flame without fire or explosion.
