Li mass transfer through a metallic copper film on a carbon fiber during the electrochemical insertion/extraction reaction

Citation
J. Suzuki et al., Li mass transfer through a metallic copper film on a carbon fiber during the electrochemical insertion/extraction reaction, EL SOLID ST, 4(1), 2001, pp. A1-A4
Citations number
9
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
ELECTROCHEMICAL AND SOLID STATE LETTERS
ISSN journal
1099-0062 → ACNP
Volume
4
Issue
1
Year of publication
2001
Pages
A1 - A4
Database
ISI
SICI code
1099-0062(200101)4:1<A1:LMTTAM>2.0.ZU;2-4
Abstract
Copper is known to form no alloys with Li, implying that a free mass transf er of Li in copper film is improbable at an ambient temperature. To examine the movement of Li in copper, a copper film was vacuum-deposited over the entire surface of a graphitized carbon fiber and cyclic voltammograms (CV) were measured in a 1:1 (v/v) mixed electrolyte solution of ethylene carbona te and dimethyl carbonate containing 1 M LiClO4. A strong sharp peak due to the intercalation of Li into carbon appeared at about 0.15 V vs. Li/Li+. A strong peak due to the deintercalation of Li from the carbon sample was al so revealed on the anodic branch of the CV as in the case of bare carbon fi ber. This is indicative of insertion of Li into carbon through the copper f ilm. When the film thickness was thin enough, i.e., 100 Angstrom, the peak height was enhanced as compared with that in the absence of the film, altho ugh the peak height was somewhat unstable. The peak height decreased with a n increase in the film thickness, but a fiber with a 1000 Angstrom thick fi lm still revealed a sufficiently observable peak. By the use of a bipolar c ell constructed with a 30 mum thick copper foil which separates an electrol yte containing 1 M LiClO4 in one compartment from that containing 1 M NaClO 4 in the counter compartment, Li+ concentration increase was confirmed in t he NaClO4 compartment during polarization. This experimental evidence suppo rts the postulate that Li moves freely in the film of copper deposited on t he surface of carbon. (C) 2000 The Electrochemical Society. S1099-0062(00)0 5-063-X. All rights reserved.