Surface design with spinel LiMn1.5Ni0.5O4 for improving electrochemical properties of LiNi0.5Co0.2Mn0.3O2 at high cut-off voltage

• Published in: Materials letters Vol. 184; pp. 29 - 33
• Main Authors: Cao, Jingchao, Xiao, Kesong, Jiang, Feng, Xi, Xiaoming, Liao, Daqian, He, Du
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2016
• Subjects: Coating; Cut-off; Electric potential; Electrochemical analysis; Electrochemical impedance spectroscopy; Electrodes; Lithium-ion batteries; Sol-gel preparation; Spinel; Spinel LiMn1.5Ni0.5O4; Surface design; Thermal properties; Voltage; Sol-gel preparation; Thermal properties; Lithium-ion batteries; Surface design; Spinel LiMn1.5Ni0.5O4
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2016.08.011

Spinel LiNi0.5Mn1.5O4 is successfully coated on the surface of LiNi0.5Co0.2Mn0.3O2 cathode material by sol-gel method. The results show that the spinel LiNi0.5Mn1.5O4 has been successfully coated on the surface of LiNi0.5Co0.2Mn0.3O2 and exhibits a good electrochemical performance at high cut-off voltage (4.6V), showing initial discharge capacity of 192.1mAhg−1 and retains 92.4%after 100 cycles. The rate capability results show that the reversible capacity retention of LiNi0.5Co0.2Mn0.3O2 increases from 84.1% to 90.6% after being coated with LiNi0.5Mn1.5O4. Electrochemical impedance spectroscopy (EIS) reveals that the coating layer can protect LiNi0.5Co0.2Mn0.3O2 from HF attack, reduce the charge transfer resistance and favor the lithium diffusion of the electrode. •LiMn1.5Ni0.5O4-coated LiNi0.5Co0.2Mn0.3O2 sample has been successfully prepared by sol-gel method.•The spinel coating with a 3D network for Li+ diffusion improves the cycle and rate performance.•The spinel coating suppresses the impurities on the surface and reduces the resistance.