The development of high-performance solid polymer electrolytes is crucial for producing all-solid-state lithium metal batteries with high safety and high energy density.However,the low ionic conductivity of solid poly...The development of high-performance solid polymer electrolytes is crucial for producing all-solid-state lithium metal batteries with high safety and high energy density.However,the low ionic conductivity of solid polymer electrolytes and their unstable electrolyte/electrode interfaces have hindered their widespread utilization.To address these critical challenges,a strong Lewis acid(aluminum fluoride(AIF_(3)))with dual functionality is introduced into poly(ethylene oxide)(PEO)-based polymer electrolyte.The AlF;facilitates the dissociation of lithium salt,increasing the iontransfer efficiency due to the Lewis acid-base interaction;further the in-situ formation of lithium fluoride-rich interfacial layer is promoted,which suppresses the uneven lithium deposition and continuous undesired reactions between the Li metal and PEO matrix.Benefiting from our rational design,the symmetric Li/Li battery with the modified electrolyte exhibits much longer cycling stability(over 3600 h)than that of the pure PEO/lithium bis(trifluoromethanesulfonyl)imide(LiTFSI)electrolyte(550 h).Furthermore,the all-solid-state LiFeP04 full cell with the composite electrolyte displays a much higher Coulombic efficiency(98.4%after 150 cycles)than that of the electrolyte without the AlF;additive(63.3%after 150 cycles)at a large voltage window of 2.4-4.2 V,demonstrating the improved interface and cycling stability of solid polymer lithium metal batteries.展开更多
基金supported by the research fund of Shenzhen Science and Technology Innovation Committee(SGDX20201103093600003)the University of Macao,Macao SAR(MYRG2018-00079-IAPME and MYRG2019-00115-IAPME)+2 种基金the Science and Technology Development Fund,Macao SAR(0092/2019/A2,0059/2018/A2,and 009/2017/AMJ)the National Thousand Young Talent planthe National Natural Science Foundation of China(21875040&21905051)。
文摘The development of high-performance solid polymer electrolytes is crucial for producing all-solid-state lithium metal batteries with high safety and high energy density.However,the low ionic conductivity of solid polymer electrolytes and their unstable electrolyte/electrode interfaces have hindered their widespread utilization.To address these critical challenges,a strong Lewis acid(aluminum fluoride(AIF_(3)))with dual functionality is introduced into poly(ethylene oxide)(PEO)-based polymer electrolyte.The AlF;facilitates the dissociation of lithium salt,increasing the iontransfer efficiency due to the Lewis acid-base interaction;further the in-situ formation of lithium fluoride-rich interfacial layer is promoted,which suppresses the uneven lithium deposition and continuous undesired reactions between the Li metal and PEO matrix.Benefiting from our rational design,the symmetric Li/Li battery with the modified electrolyte exhibits much longer cycling stability(over 3600 h)than that of the pure PEO/lithium bis(trifluoromethanesulfonyl)imide(LiTFSI)electrolyte(550 h).Furthermore,the all-solid-state LiFeP04 full cell with the composite electrolyte displays a much higher Coulombic efficiency(98.4%after 150 cycles)than that of the electrolyte without the AlF;additive(63.3%after 150 cycles)at a large voltage window of 2.4-4.2 V,demonstrating the improved interface and cycling stability of solid polymer lithium metal batteries.
