Electrochemical Properties of Al3+/Cl- Doped-0.2Li(2)MnO(3)center dot 0.8LiNiO(2) Cathode Materials for Lithium-Ion Batteries
Journal
Journal of Nanoscience and Nanotechnology
Journal Volume
18
Journal Issue
1
Pages
68-74
Date Issued
2018
Author(s)
Abstract
Li-rich layered cathode materials, Li1.2Ni0.4-xAlxMn0.6O2.2-y Cly (0 ≤ x ≤ 0.03 and 0 ≤ y ≤ 0.03), were successfully synthesized through coprecipitation, and the effects of Al3+-Cl- co-substitution on their surface morphology, crystal structure, surface chemistry, and electrochemical performance were characterized through XRD, SEM, XPS, TEM, and electrochemical and charge-discharge cycling. Doping the cathodes with Al3+ and Cl- ions enhanced electrochemical performance at room temperature and at a high working temperature of 55 °C. The as-synthesized optimal composition was Li1.2Ni0.37Al0.03Mn0.6O2.17Cl0.03. The discharge capacity demonstrated high cycle retention at 55 °C. XPS analyses revealed that Al3+-Cl- co-substitution enhanced the structural stability of the cathode materials by forming strong Mn-O and Ni-O bonds. Moreover, compared with un-doped cathode materials, the impedance of Al3+-Cl--codoped cathode materials was drastically reduced by 52.2%. The results indicated that Al3+-Cl--codoped Li-excess cathodes deliver a high cycle performance at high temperatures.
Type
journal article