Influence of particle size on the self-discharge behavior of graphite electrodes in lithium-ion batteries

• We measured self-discharge rates of charged graphite with different particle sizes. • This was done to characterize the self-discharge of high-rate lithium-ion battery. • Higher surface area particle gave higher self-discharge rate. • The reaction mechanism does not change with particle size of gr...

Full description

Saved in:
Bibliographic Details
Published in:Journal of power sources 2011-10, Vol.196 (20), p.8675-8682
Main Authors: Utsunomiya, Takashi, Hatozaki, Osamu, Yoshimoto, Nobuko, Egashira, Minato, Morita, Masayuki
Format: Article
Language:English
Subjects:
Applied sciences
Basal plane
Direct energy conversion and energy accumulation
Electrical engineering. Electrical power engineering
Electrical power engineering
Electrochemical conversion: primary and secondary batteries, fuel cells
Electrodes
Exact sciences and technology
Graphite
Lithium-ion batteries
Lithium-ion battery
Mathematical analysis
Particle size
SEI formation
Self-discharge
Surface chemistry
Temperature dependence
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:• We measured self-discharge rates of charged graphite with different particle sizes. • This was done to characterize the self-discharge of high-rate lithium-ion battery. • Higher surface area particle gave higher self-discharge rate. • The reaction mechanism does not change with particle size of graphite. Self-discharge characteristics of synthetic graphite electrodes with different particle sizes have been investigated by electrochemical and analytical methods. Variations of open-circuit potential (OCP), residual capacity and electrochemical impedance responses were monitored during or after the storage at different temperatures. The rate of self-discharge depended on the particle size, or the specific surface area, of the graphite sample. The temperature dependence of the self-discharge rate revealed that the activation energy for the process does not depend on the particle size of the graphite electrode. The ac impedance responses suggest that the self-discharge processes consist of the loss of the Li species in the graphite and SEI (Solid-Electrolyte-Interphase) formation at the graphite surface. The latter SEI formation process was found to be dependent on the surface site, edge or basal planes, from the results of surface observation and elemental analyses.
ISSN:0378-7753
1873-2755
DOI:10.1016/j.jpowsour.2011.06.070