Effect of particle size on lithium intercalation rates in natural graphite

Citation
K. Zaghib et al., Effect of particle size on lithium intercalation rates in natural graphite, J POWER SOU, 103(1), 2001, pp. 140-146
Citations number
25
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physical Chemistry/Chemical Physics","Environmental Engineering & Energy
Journal title
JOURNAL OF POWER SOURCES
ISSN journal
0378-7753 → ACNP
Volume
103
Issue
1
Year of publication
2001
Pages
140 - 146
Database
ISI
SICI code
0378-7753(200112)103:1<140:EOPSOL>2.0.ZU;2-E
Abstract
The intercalation rate of Li+-ions in flake natural graphite with particle size that ranged from 2 to 40 mum was investigated. The amount of Li+-ions that intercalate at different rates was determined from measurement of the reversible capacity during deintercalation in 1 M LiClO4/1:1 (volume ratio) ethylene carbonate-dimethyl carbonate. The key issues in this study are th e role of particle size and fraction of edge sites on the rate of intercala tion and deintercalation of Li+-ions. At low specific current (15.5 mA/g ca rbon), the composition of lithiated graphite approaches the theoretical val ue, x = 1 in LixC6, except for the natural graphite with the largest partic le size. However, x decreases with an increase in specific current for all particle sizes. This trend suggests that slow solid-state diffusion of Li+- ions limits the intercalation capacity in graphite. The flake natural graph ite with a particle size of 12 mum may provide the optimum combination of r eversible capacity and irreversible capacity loss in the electrolyte and di scharge rates used in this study. (C) 2001 Elsevier Science B.V. All rights reserved.