Fundamental Linkage Between Structure, Electrochemical Properties, and Chemical Compositions of LiNi1–x–yMnxCoyO2 Cathode Materials

• DOI: 10.1021/acsami.0c18942
• Publication Date: 2021-01-10T08:56:54Z
• Authors: Jiangtao Hu; Qinchao Wang; Bingbin Wu; Sha Tan; Zulipiya Shadike; Yujing Bi; M. Stanley Whitti...; Jie Xiao; Xiao-Qing Yang; Enyuan Hu
• Keywords: X-ray absorption spectroscopy

LiNi1–x–yMnxCoyO2 (NMC) is an important class of high-energy-density cathode materials. The possibility changing both x and y in the chemical formula provides numerous materials with diverse electrochemical structural properties. It highly desirable to have guidance on correlating NMC properties their composition for material designing screening. Here, using synchrotron-based X-ray diffraction, absorption spectroscopy, characterization, literature survey, content difference between Mn Co (denoted as x–y NMC) identified effective indicator estimate Li/transition metal (Li/TM) cation mixing ratio first-cycle Coulombic efficiency (CE). In addition, a linear relationship oxygen position "z" size Li+ TM (normalized by c-axis length) found, such linearity can be used accurately predict considering average length. also concluded that shortest O–O distance bulk could not shorter than 2.5 Å even at charged state. Therefore, release likely take place from if structure maintains R3 ̅m symmetry.