Abstract
The Nb-doped Li[Li0.2Mn0.54-x/3Ni0.13-x/3Co0.13-x/3Nbx]O2 (x = 0, 0.01, 0.02, 0.03) materials are synthesized and characterized by X-ray diffractometry (XRD), transmission electron microscope (TEM), scanning electron microscopy (SEM), charge–discharge measurements, AC impedance spectroscopy as well as cyclic voltammetry. XRD results indicate that Nb-doped Li1.2Ni0.13Co0.13Mn0.54O2 materials exhibit similar XRD patterns to the pristine sample. The results of EDS mapping confirm the homogenous distribution of Nb element in the materials. The Nb substituted for transition metal ions with x = 0.02 is found to be the most effective in improving the cycling properties and in lowering the voltage fade. Particularly, it exhibits remarkably improved cycling performance with the capacity retention ratio of 83% compared with 54% for pristine one after 100 cycles at 1C. Besides, it shows much lower discharge midpoint voltage decay (0.1913 V) than that of pristine sample (0.6951 V) after 100 cycles. The improved electrochemical performance can be attributed to the better structure stability and decreased charge transfer resistance caused by dopant of Nb. These results reveal that Nb-doping can be a promising method for improving the performance of Li-rich material.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
