14 research outputs found

    Unraveling TM Migration Mechanisms in LiNi<sub>1/3</sub>Mn<sub>1/3</sub>Co<sub>1/3</sub>O<sub>2</sub> by Modeling and Experimental Studies

    No full text
    Electrochemical cycling induces transition-metal (TM) ion migration and oxygen vacancy formation in layered transition-metal oxides, thus causing performance decay. Here, a combination of ab initio calculations and atomic level imaging is used to explore the TM migration mechanisms in LiNi1/3Mn1/3Co1/3O2 (NMC333). For the bulk model, TM/Li exchange is an favorable energy pathway for TM migration. For the surface region with the presence of oxygen vacancies, TM condensation via substitution of Li vacancies (TMsub) deciphers the frequently observed TM segregation phenomena in the surface region. Ni migrates much more easily in both the bulk and surface regions, highlighting the critical role of Ni in stabilizing layered cathodes. Moreover, once TM ions migrate to the Li layer, it is easier for TM ions to diffuse and form a TM-enriched surface layer. The present study provides vital insights into the potential paths to tailor layered cathodes with a high structural stability and superior performance

    Additional file 1 of The relationship between sleep status and activity of daily living: based on China Hainan centenarians cohort study

    No full text
    Additional file 1: Table S1. The relationship between sleep status and ADL disability in male and female centenarians. Table S2. The relationship between sleep status and ADL moderate and severe disability in male and female centenarians. Table S3. The distribution of the 7 components of PSQI and different ADL function groups. Table S4. The relationship between the 7 components of PSQI and ADL disability/ADL moderate and severe disability
    corecore