title: Lithium-Excess Research of Cathode Material Li₂MnTiO₄ for Lithium-Ion Batteries.
abstract: Lithium-excess and nano-sized Li2+xMn₁-x/2TiO₄ (x= 0, 0.2, 0.4) cathode materials were synthesized via a sol-gel method. The X-ray diffraction (XRD) experiments indicate that the obtained main phases of Li2.0MnTiO₄ and the lithium-excess materials are monoclinic and cubic, respectively. The scanning electron microscope (SEM) images show that the as-prepared particles are well distributed and the primary particles have an average size of about 20-30 nm. The further electrochemical tests reveal that the charge-discharge performance of the material improves remarkably with the lithium content increasing. Particularly, the first discharging capacity at the current of 30 mA g-1increases from 112.2 mAh g-1of Li2.0MnTiO₄ to 187.5 mAh g-1of Li2.4Mn0.8TiO₄. In addition, theex situXRD experiments indicate that the monoclinic Li₂MnTiO₄ tends to transform to an amorphous state with the extraction of lithium ions, while the cubic Li₂MnTiO₄ phase shows better structural reversibility and stability.
authors.affiliation: College of Engineering, Peking University, Beijing 100087, China. zhxy235@pku.edu.cn.
authors.forename: Xinyi
authors.initials: X
authors.lastname: Zhang
authors.affiliation: College of Engineering, Peking University, Beijing 100087, China. leyang@pku.edu.cn.
authors.forename: Le
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Earth and Environmental Engineering, Columbia University, New York, NY 10027, USA. fh2314@columbia.edu.
authors.forename: Feng
authors.initials: F
authors.lastname: Hao
authors.affiliation: Institute of Advanced Structure Technology, Beijing Institute of Technology, Beijing 100081, China. chenhs09@mails.tsinghua.edu.cn.
authors.forename: Haosen
authors.initials: H
authors.lastname: Chen
authors.affiliation: College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009, China. yangmengyy@njtech.edu.cn.
authors.forename: Meng
authors.initials: M
authors.lastname: Yang
authors.affiliation: College of Engineering, Peking University, Beijing 100087, China. fangdn@pku.edu.cn.|Institute of Advanced Structure Technology, Beijing Institute of Technology, Beijing 100081, China. fangdn@pku.edu.cn.
authors.forename: Daining
authors.initials: D
authors.lastname: Fang
keywords: cathode; lithium excess; lithium-ion batteries; nanoscale particle; phase transition; titanate material