Probing microstructure of solid-state synthesized LiCoO_(2)with MAS NMR spectroscopy

查看全文 作　　者：Suyu [1]Gu;Guozhong [1]Lu;Nianrui [1]Guo;Juncheng [1]Xu;Yu [1]Jiang;Ming [1]Shen;Bingwen [1]Hu 机构地区：[1]Shanghai Key Laboratory of Magnetic Resonance,State Key Laboratory of Precision Spectroscopy,School of Physics and Electronic Science,East China Normal University,Shanghai,200241,China 出　　处：《Magnetic Resonance Letters》索引2023年第3卷第4期,共8页 基　　金：supported by grants from the National Natural Science Foundation of China(Nos.22172049,21874045);Shanghai Science and Technology Innovation Action Plan(No.19142202900);Fundamental Research Funds for Central Universities and Open Foundation of ECNU(42125102);ECNU multifunctional platform for innovation(EPR). 摘　　要：LiCoO_(2)is an important category of active cathode materials in lithium-ion batteries due to its high compacted electrode density,good thermal stability,and stable voltage platform.Recent works on LiCoO_(2)have focused on the realization of higher charging voltages to fully utilize its high theoretical capacity.However,an unambiguous atomic-level local probe is essential for the understanding of structure-function correlation.Here we employ highresolution solid-state nuclear magnetic resonance(NMR)spectroscopy to study the local atomic environments in LiCoO_(2)synthesized with three common sintering methods.While one-dimensional 7Li NMR shows distinct linewidth and subtle dependence on lithium over-stoichiometry,both 7Li and 59Co relaxation times are highly dependent on the sintering method.We prove that the two-step sintering method favors the elimination of unreacted Co3O4,thereby enabling the best discharge capacity in all-solid-state lithium batteries assembled with LiCoO_(2)/LGPS/LiIn,which is in accordance with its narrowest 7Li linewidth and the longest 7Li/59Co T1. 关 键 词：LiCoO_(2) Solid-state NMR T1 relaxation Local structure