摘要
利用固相法合成了一系列化合物Li1+xNi3/4-5/4xTe1/4+1/4xO2(x=0,0.14,0.33,0.46,0.50和0.60).在x=0.33时,发现C2/m晶体结构中存在一种新奇的围绕Ni离子的短程有序P1-like区域,此区域表现出一种松散结合的局域结构以及更快的Li+迁移率,进而保证了优越的结构和电化学可逆性.通过非原位X射线吸收谱(XAS)、X射线衍射(XRD)、X射线光电子能谱(XPS)和电化学表征研究了材料的性能.证明了这种性能与稳定的短程-长程有序结构以及Ni氧化还原电子对有关.该研究提供了发展高性能富锂正极材料的新思路.
Novel layered oxide Li1+x Ni3/4-5/4x Te1/4+1/4x O2 ( x =0,0.14,0.33,0.46,0.50 and 0.60 ) cathodes were synthesized by a solid-state reaction method.A unique P1 -like domain with a short-range order around Ni ions was found in the monoclinic C2/ m crystal with x =0.33,which displays a loosely bonded local structure and increased Li + mobility,enabling superior structural as well as electrochemical reversibility.The enhanced properties investigated by ex situ X-ray absorption spectroscopy (XAS),X-ray diffraction (XRD),X-ray photoelectron spectroscopy (XPS) and electrochemical characterization were corroborated to originate from the stable short- and long-range ordering structure along with the Ni electron redox.This study may open up new avenues for the development of Li-rich cathode materials with sufficiently good performance.
作者
齐家新
王星博
苏晓智
解晖
REHMAN Ziaur
陶石
储旺盛
QI Jiaxin;WANG Xingbo;SU Xiaozhi;XIE Hui;REHMAN Zia ur;TAO Shi;CHU Wangsheng(National Synchrotron Radiation Laboratory,University of Science and Technology of China,Hefei 230029,China;Shanghai Synchrotron Radiation Facility,Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201204,China;Department of Physics and Electronic Engineering,Changshu Institute of Technology,Changshu 215500,China)
基金
Supported by the National Natural Science Foundation of China(11275227,U1632103)
关键词
锂离子电池
正极材料
局域结构
Li-ion battery
cathode material
local structure
