• 文献标题:   How much does size really matter? Exploring the limits of graphene as Li ion battery anode material
  • 文献类型:   Article
  • 作  者:   SUN H, VARZI A, PELLEGRINI V, DINH DA, RACCICHINI R, DEL RIOCASTILLO AE, PRATO M, COLOMBO M, CINGOLANI R, SCROSATI B, PASSERINI S, BONACCORSO F
  • 作者关键词:   graphene, liquid phase exfoliation, lithium ion battery, electrode
  • 出版物名称:   SOLID STATE COMMUNICATIONS
  • ISSN:   0038-1098 EI 1879-2766
  • 通讯作者地址:   Ist Italiano Tecnol
  • 被引频次:   14
  • DOI:   10.1016/j.ssc.2016.12.016
  • 出版年:   2017

▎ 摘  要

We unravel the role of flake dimensionality on the lithiation/de-lithiation processes and electrochemical performance of anodes based on few-(FLG) and multi-layer graphene (MLG) flakes prepared by liquid phase exfoliation (LPE) of pristine graphite. The flakes are sorted by lateral size (from 380 to 75 nm) and thickness from 20 (MLG) to 2 nm (FLG) exploiting a sedimentation-based separation in centrifugal field and, finally, deposited onto Cu disks for the realization of four binder-free anodes. The electrochemical results show that decreasing lateral size and thickness leads to an increase of the initial specific capacity from approximate to 590 to approximate to 1270mAhg(-1). However, an increasing irreversible capacity is also associated to the reduction of flakes' size. We find, in addition, that the preferential Li ions storage by adsorption rather than intercalation in small lateral size (< 100 nm) FLG flakes has a detrimental effect on the average de-lithiation voltage, resulting on low voltage efficiency of these anodes. We believe that the results reported in this work, provide the guidelines for the practical exploitation of graphene-based electrodes.