Structural and kinetic characterization of lithium intercalation into carbon anodes for secondary lithium batteries

Journal Article · Wed Feb 01 04:00:00 EST 1995 · Journal of the Electrochemical Society

DOI:https://doi.org/10.1149/1.2044017· OSTI ID:61494

Takami, Norio; Satoh, Asako; Hara, Michikazu; Ohsaki, Takahisa ^[1]

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1. Toshiba Corp., Kawasaki (Japan)

Electrochemical intercalation of lithium into carbons has been studied using mesophase-pitch-based carbon fibers with different heat-treatment temperatures, coke, and graphites as anodes for secondary lithium batteries. The variations in the average layer spacing and the voltage profile for the carbons with intercalating depend on the degree of graphitization. The intercalation into a more disordered carbon fiber heated at 900 C has been characterized as intercalation into the layer structure for 0 < x < 0.5 in Li{sub x}C{sub 6}, but additional lithium insertion into an unorganized carbon loses the layer structure. The polarization resistance (R{sub p}) estimated from the impedance spectrum decreased by increasing degree of graphitization. The variation in R{sub p} with intercalation revealed the intercalation processes in various disordered carbons to be single-phase reactions with different stoichiometries of lithium intercalation. The chemical diffusion coefficient D{sub Li} of lithium ions in carbons decreased by increasing the composition x in Li{sub x}C{sub 6} up to x = 0.5. The chemical diffusion coefficient was considerably affected by the texture and the degree of graphitization of the carbons. The graphitized carbon fiber heated at 3,000 C for 0.1 < x < 0.5 in Li{sub x}C{sub 6} exhibited one order magnitude larger values of D{sub Li} than those of graphites. The rapid diffusion in the graphitized carbon fiber has been attributed to the radial texture in the cross section. It has been found that the activation energy for the diffusion process decreased by increasing the degree of graphitization.

• Sponsoring Organization: USDOE
• OSTI ID: 61494
• Journal Information: Journal of the Electrochemical Society, Journal Name: Journal of the Electrochemical Society Journal Issue: 2 Vol. 142; ISSN 0013-4651; ISSN JESOAN
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
ANODES
CARBON FIBERS
CARBONIZATION
CLATHRATES
COKE
ELECTRIC BATTERIES
EXPERIMENTAL DATA
FABRICATION
GRAPHITE
LITHIUM
LITHIUM CARBIDES
PITCHES