Structural Modifications and Electrochemical Behavior of Lithium-Inserted In16Fe8S32

✍ Scribed by C. Pérez Vicente; C. Bousquet; A. Krämer; J.L. Tirado; J. Olivier-Fourcade; J.C. Jumas

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 310 KB
• Volume: 138
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1998.7771

✦ Synopsis

We have studied the structural modifications that occur during electrochemical insertion of lithium into the spinel compound In 16 Fe 8 S 32 . Studies by X-ray diffraction (Rietveld analysis) and Mo¨ssbauer spectroscopy of the lithiated products indicate that some cation migration takes place during the insertion process. The Mo¨ssbauer spectra show that no reduction of Fe 2؉ takes place during the insertion. The variation of the isomer shift indicates an increase in the covalency of the network. The results of the X-ray absorption experiments show the absence of a clear reduction of In 3؉ and the incorporation of incoming electrons into the delocalized band structure. Analysis of the discharge curve shows the presence of two different domains. For the first one there is a small interaction between inserted ions. The second one shows a repulsive interaction and a decrease in the diffusion coefficient.