Improved graphite anode for lithium-ion batteries. Chemically bonded solid electrolyte interface and nanochannel formation

Journal Article · Mon Jan 01 04:00:00 EST 1996 · Journal of the Electrochemical Society

DOI:https://doi.org/10.1149/1.1836372· OSTI ID:201379

Peled, E; Menachem, C; Bar-Tow, D; Melman, A ^[1]

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1. Tel Aviv Univ. (Israel). School of Chemistry

The effects of mild oxidation (burning) of 2 synthetic graphites on the reversible (Q{sub R}) and irreversible (Q{sub IR}) capacities, anode-degradation rate (on cycling) in three different electrolytes and graphite-surface topology have been studied. STM images of both modified graphites show nanochannels having an opening of a few nanometers and up to tens of nanometers. It is believed that these nanochannels are formed at the zigzag and armchair faces between two adjacent crystallites and in the vicinity of defects and impurities. Mild burn-off was found to improve performance in Li/Li{sub x}C cells: Q{sub R} is increased by 10--30%, Q{sub IR} is generally decreased (for less than 6% burn-off) and Li{sub x}C{sub 6} anode degradation rate is much lower. Performance improvement is attributed to the formation of a solid electrolyte interface (SEI) chemically bonded to the surface carboxylic groups at the zigzag and armchair faces, and to accommodation of extra lithium at the zigzag, armchair, and other edge sites and nanovoids.

• Sponsoring Organization: USDOE
• OSTI ID: 201379
• Journal Information: Journal of the Electrochemical Society, Journal Name: Journal of the Electrochemical Society Journal Issue: 1 Vol. 143; ISSN 0013-4651; ISSN JESOAN
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
ANODES
BATTERY CHARGING
CARBONACEOUS MATERIALS
ELECTRIC BATTERIES
INTERFACES
LITHIUM
LITHIUM CARBIDES
MICROSCOPY
OXIDATION
PERFORMANCE
SOLID ELECTROLYTES
SURFACE PROPERTIES
VOLTAGE DROP