title: Surface Modification of Li1.2Ni0.13Mn0.54Co0.13O2 by Hydrazine Vapor as Cathode Material for Lithium-Ion Batteries.
abstract: An artificial interface is successfully prepared on the surface of the layered lithium-rich cathode material Li1.2Ni0.13Mn0.54Co0.12O2 via treating it with hydrazine vapor, followed by an annealing process. The inductively coupled plasma-atomic emission spectrometry (ICP) results indicate that lithium ions are leached out from the surface of Li1.2Ni0.13Mn0.54Co0.12O2 by the hydrazine vapor. A lithium-deficiency-driven transformation from layered to spinel at the particle surface happens in the annealing process, which is proved by the results of X-ray diffraction (XRD) and high-resolution transmission electron microscope (HRTEM). It is also found that the content of the spinel phase increases at higher annealing temperature, and an internal structural evolution from Li1-xM2O4-type spinel to M3O4-type spinel takes place simultaneously. Compared to the pristine Li1.2Ni0.13Mn0.54Co0.12O2, the surface-modified sample annealed at 300 °C delivers a larger initial discharge capacity of 295.6 mA h g(-1) with a Coulombic efficiency of 89.5% and a better rate performance (191.7 mA h g(-1) at 400 mA g(-1)).
authors.affiliation: Shanghai Electrochemical Energy Devices Research Center, Department of Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Shanghai Electrochemical Energy Devices Research Center, Department of Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Lei
authors.affiliation: Shanghai Electrochemical Energy Devices Research Center, Department of Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
authors.forename: Jiulin
authors.initials: J
authors.lastname: Wang
authors.affiliation: Shanghai Electrochemical Energy Devices Research Center, Department of Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
authors.forename: Yanna
authors.initials: Y
authors.lastname: NuLi
authors.affiliation: Shanghai Electrochemical Energy Devices Research Center, Department of Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
keywords: cathode material; hydrazine vapor; lithium-ion battery; lithium-rich material; surface modification