Accession Number : ADA263728

Title :   Characterization of Lithium Electrode Surface in Lithium Secondary Batteries by In Situ Raman Spectroscopic Methods.

Descriptive Note : Final rept. 1 Sep 89-31 Dec 92,

Corporate Author : JACKSON STATE UNIV MS DEPT OF CHEMISTRY

Personal Author(s) : Tachikawa, Hiroyasu

Report Date : 24 MAR 1993

Pagination or Media Count : 23

Abstract : Surface layers on lithium electrodes formed in several solvents including dimethyl carbonate (DMC), diethyl carbonate (DEC), polyethylene glycol 400 dimethyl ether (PEG400DME), and propylene carbonate (PC) have been studied by Raman spectroscopy. Both DMC and DEC were used singly, and also mixed with either methyl acetate or methyl formate. The Raman spectra showed that passive films formed on the Li surface in different solvents may have different chemical structures, which changed during the charging and discharging processes. A solid film of fullerene C60, which could be used as a cathode in Li rechargeable batteries, was examined in the PEG400DME solution by both electrochemical and Raman spectroscopy. Cyclic voltammograms (CVs) showed five redox peaks which suggested the formation of C60(-), C60(2-), C60(3-), C60(4-), and C60(5-). Raman spectra obtained from thin C60 film indicated that the thin fulleride film dissolved in the PEG400DME/LiC10(4) solution at negative potentials.... Lithium electrode, Fullerenes, Electrochemistry, Raman spectroscopy.

Descriptors :   *ELECTRODES, *LITHIUM, *RAMAN SPECTROSCOPY, *SURFACES, *LITHIUM BATTERIES, ACETATES, CARBONATES, CATHODES, CHEMICALS, ELECTROCHEMISTRY, ETHERS, FILMS, FORMATES, FULLERENES, GLYCOLS, LAYERS, POLYETHYLENE, PROPENES, RAMAN SPECTRA, SOLIDS, SOLVENTS, SPECTROSCOPY, STRUCTURES, MOLECULAR STRUCTURE, OXIDATION REDUCTION REACTIONS, DEPOSITION, LITHIUM PERCHLORATE.

Subject Categories : Physical Chemistry
      Atomic and Molecular Physics and Spectroscopy
      Electrochemical Energy Storage

Distribution Statement : APPROVED FOR PUBLIC RELEASE