Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published January 2000 | Published
Journal Article Open

A ^(119)Sn Mössbauer Spectrometry Study of Li-SnO Anode Materials for Li-Ion Cells

Abstract

Anodes of SnO were charged reversibly with Li to capacities greater than 600 mAh/g, The anode materials were characterized by 119Sn Mössbauer spectrometry at 11 and 300 K, and by X-ray diffractometry at 300 K. Trends in the valence of Sn were as expected when the Sn oxides are reduced in the presence of Li. At low Li capacities the SnO is reduced to small particles of β-Sn, and with increasing Li capacity an alloy of Li_(22)Sn_5 is formed. Although the Li_(22)Sn_5 develops over a range of Li concentrations in the anode material, the Li_(22)Sn_5 that forms at low Li insertions is not typical of bulk Li_(22)Sn_5 in either its structural or electrochemical properties. The recoil-free fraction of the Sn oxide (and perhaps the metallic Sn) in the anode materials showed an anomalously large temperature dependence. This is indicative of nanoparticles or a severely defective structure. We monitored the changes in the Li-SnO and Li-Sn materials during atmospheric exposure over times up to 2 months. This oxidation process of Sn was very much the reverse of the Sn reduction during the Li insertion, although it occurred over a much longer time scale. We also report the temperature dependencies of recoil-free fractions for standard samples of β-Sn, SnO_2, and the alloy Li_(22)Sn_5.

Additional Information

© 2000 The Electrochemical Society. Manuscript submitted May 3, 1999; revised manuscript received August 3, 1999. We thank Professor B. Malaman (Universite Henri Poincare, Nancy I) for useful discussions. The work at Caltech was supported by DOE through Basic Energy Sciences grant no. DE-FG03-94ER14493. California Institute of Technology assisted in meeting the publication costs of this article.

Attached Files

Published - HIGjes00.pdf

Files

HIGjes00.pdf
Files (410.4 kB)
Name Size Download all
md5:d73c28d37958f61c21e3f334773a3155
410.4 kB Preview Download

Additional details

Created:
August 19, 2023
Modified:
October 24, 2023