Li-ion battery material under high pressure:amorphization and enhanced conductivity of Li_4Ti_5O_(12)  

作　　者：Yanwei Huang Yu He Howard Sheng Xia Lu Haini Dong Sudeshna Samanta Hongliang Dong Xifeng Li Duck Young Kim Ho-kwang Mao Yuzi Liu Heping Li Hong Li Lin Wang 

机构地区：[1]Center for High Pressure Science and Technology Advanced Research [2]College of Materials and Environmental Engineering, Hangzhou Dianzi University [3]Key Laboratory of High-temperature and High-pressure Study of the Earth's Interior,Institute of Geochemistry, Chinese Academy of Sciences [4]Department of Physics and Astronomy, George Mason University [5]State Key Laboratory of Organic-Inorganic Composites, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Energy, Beijing University of Chemical Engineering [6]School of Mechatronic Engineering and Automation, Shanghai University [7]Geophysical Laboratory,Carnegie Institution [8]Center for Nanoscale Materials,Argonne National Laboratory [9]Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences

出　　处：《National Science Review》2019年第2期239-246,共8页国家科学评论（英文版）

基　　金：mainly supported by the National Natural Science Foundation of China(11874076);National Science Associated Funding(U1530402)and the Science Challenging Program(JCKY2016212A501);the support of the National Natural Science Foundation of China(61504034 and 51302259);the China Postdoctoral Science Foundation(2016M592701);the Youth Innovation Promotion Association of CAS;the Key Laboratory of Inorganic Coating Materials,Chinese Academy of Sciences;the State Key Laboratory of Organic-Inorganic Composites(oic-201701011);the Fundamental Research Funds for the Central Universities(ZY1720);the Beijing Advanced Innovation Center for Soft Matter Science and Engineering for their funding support

摘　　要：Lithium titanium oxide(Li_4Ti_5O_(12),LTO),a‘zero-strain’anode material for lithium-ion batteries,exhibits excellent cycling performance.However,its poor conductivity highly limits its applications.Here,the structural stability and conductivity of LTO were studied using in situ high-pressure measurements and first-principles calculations.LTO underwent a pressure-induced amorphization(PIA)at 26.9 GPa.The impedance spectroscopy revealed that the conductivity of LTO improved significantly after amorphization and that the conductivity of decompressed amorphous LTO increased by an order of magnitude compared with its starting phase.Furthermore,our calculations demonstrated that the different compressibility of the Li O_6 and Ti O_6 octahedra in the structure was crucial for the PIA.The amorphous phase promotes Li^+ diffusion and enhances its ionic conductivity by providing defects for ion migration.Our results not only provide an insight into the pressure depended structural properties of a spinel-like material,but also facilitate exploration of the interplay between PIA and conductivity.Lithium titanium oxide(Li_4Ti_5O_(12),LTO),a‘zero-strain’anode material for lithium-ion batteries,exhibits excellent cycling performance.However,its poor conductivity highly limits its applications.Here,the structural stability and conductivity of LTO were studied using in situ high-pressure measurements and first-principles calculations.LTO underwent a pressure-induced amorphization(PIA)at 26.9 GPa.The impedance spectroscopy revealed that the conductivity of LTO improved significantly after amorphization and that the conductivity of decompressed amorphous LTO increased by an order of magnitude compared with its starting phase.Furthermore,our calculations demonstrated that the different compressibility of the Li O_6 and Ti O_6 octahedra in the structure was crucial for the PIA.The amorphous phase promotes Li^+ diffusion and enhances its ionic conductivity by providing defects for ion migration.Our results not only provide an insight into the pressure depended structural properties of a spinel-like material,but also facilitate exploration of the interplay between PIA and conductivity.

关 键 词：high pressure PRESSURE-INDUCED amorphization LITHIUM-ION battery materials IONIC CONDUCTIVITY 

分 类 号：N[自然科学总论]