• 文献标题:   Influence of lithium precursors and calcination atmospheres on graphene sheets-modified nano-Li4Ti5O12 anode material
  • 文献类型:   Article
  • 作  者:   LI WT, YUAN T, ZHANG WM, MA JJ, ZHANG CM, HE YS, LIAO XZ, MA ZF
  • 作者关键词:   nanoli4ti5o12, graphene sheet, lithium precursor, anode material, calcination atmosphere
  • 出版物名称:   JOURNAL OF POWER SOURCES
  • ISSN:   0378-7753 EI 1873-2755
  • 通讯作者地址:   Sinopoly Battery Res Ctr
  • 被引频次:   18
  • DOI:   10.1016/j.jpowsour.2015.02.021
  • 出版年:   2015

▎ 摘  要

The influence of Li precursors and calcination atmospheres on the reaction mechanisms, physical properties and electrochemical performance of graphene sheets (GS)-modified nano-Li4Ti5O12 (LTO/GS) has been systematically investigated. Field emission scanning electron microscopy (FE-SEM) and mass spectrometry (MS) results demonstrate the lithium precursor containing carboxyl anion such as lithium acetate (LiAc) and Li2CO3 interact with oxygen groups of graphene oxide (GO) by strong hydrogen bonds to restrict the morphology and the phase formation of products. We also notice from the thermogravimetry (TG) and MS results that the consumption of GS is proportional to oxygen content of lithium precursor. Cyclic voltammetry (CV) and X-ray photoelectric spectroscopy (XPS) results indicate that the product calcined in reducing atmosphere possess smaller electrochemical polarization due to more reduced Ti3+ on the surface of the product. The LTO/GS sample with LiOH as Li precursor calcined in diluted hydrogen atmosphere show the best electrochemical performance with a capacity of 134.4 mAh g(-1) at 10C discharge rate and very stable cycling life with a 98.6% capacity retention after 800 cycles at 40C rate. This study not only provides an optimization of Li precursor and calcination condition for LTO/GS anode material, but also guides any future one-step syntheses of lithium composite materials with GO participation. (C) 2015 Elsevier B.V. All rights reserved.