Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5457352 | Solid State Communications | 2017 | 6 Pages |
Abstract
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 75Â nm) and thickness from 20 (MLG) to 2Â 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 â590 to â1270mAhgâ1. 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 (<100Â 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.
Related Topics
Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
H. Sun, A. Varzi, V. Pellegrini, D.A. Dinh, R. Raccichini, A.E. Del Rio-Castillo, M. Prato, M. Colombo, R. Cingolani, B. Scrosati, S. Passerini, F. Bonaccorso,