中国科学技术大学学报 ›› 2019, Vol. 49 ›› Issue (4): 259-267.DOI: 10.3969/j.issn.0253-2778.2019.04.001

• 论著 •    下一篇

局域结构优化Li-Ni-Te-O正极的电化学可逆性

齐家新,王星博,苏晓智,解晖,REHMANZiaur,陶石,储旺盛   

  1. 1.中国科学技术大学国家同步辐射实验室,安徽合肥 230026;2.中国科学院上海应用物理研究所上海光源,上海 201204; 3.常熟理工学院物理与电子工程学院,江苏常熟 215500
  • 收稿日期:2018-03-01 修回日期:2018-05-22 接受日期:2018-05-22 出版日期:2019-04-30 发布日期:2018-05-22

Improved electrochemical reversibility of Li-Ni-Te-O cathode by local domain structure optimization

  1. QI Jiaxin, WANG Xingbo, SU Xiaozhi2, XIE Hui, REHMAN Zia ur, TAO Shi3, CHU Wangsheng
  • Received:2018-03-01 Revised:2018-05-22 Accepted:2018-05-22 Online:2019-04-30 Published:2018-05-22
  • Contact: CHU Wangsheng
  • About author:QI Jiaxin, male, born in 1991, master. Research field: energy storage and conversion material. E-mail: qjiaxin@mail.ustc.edu.cn
  • Supported by:
    Supported by the National Natural Science Foundation of China (11275227, U1632103).

摘要: 利用固相法合成了一系列化合物Li1+xNi3/4-5/4xTe1/4+1/4xO2 (x=0, 0.14, 0.33, 0.46, 0.50和 0.60).在x=0.33时,发现C2/m晶体结构中存在一种新奇的围绕Ni离子的短程有序P1-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.

关键词: 锂离子电池, 正极材料, 局域结构

Abstract: Novel layered oxide Li1+xNi3/4-5/4xTe1/4+1/4xO2 (x=0, 0.14, 0.33, 0.46, 0.50 and 0.60) cathodes were synthesized by a solid-state reaction method. A unique P1-like domain with a short-range order around Ni ions was found in the monoclinic C2/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.

Key words: Li-ion battery, cathode material, local structure

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