Chemical and electrochemical insertion of Li into the spinel structure of CuCr2Se4: ex situ and in situ observations by X-ray diffraction and scanning electron microscopy.

Bensch, Wolfgang, Ophey, Jannes, Hain, Holger, Gesswein, Holger, Chen, Di, Mönig, Reiner, Gruber, Patric A. and Indris, Sylvio (2012) Chemical and electrochemical insertion of Li into the spinel structure of CuCr2Se4: ex situ and in situ observations by X-ray diffraction and scanning electron microscopy. Physical Chemistry Chemical Physics, 14 (20). p. 7509. DOI 10.1039/c2cp00064d.

Full text not available from this repository.

Supplementary data:

Abstract

The chemical and electrochemical insertion of lithium into the spinel structure of CuCr2Se4 was studied and the chemical reaction pathway was followed by ex situ X-ray diffraction on samples with different Li contents. The electrochemical reaction was investigated by in situ X-ray diffraction and in situ scanning electron microscopy. In the early steps of chemical intercalation, two phases with a different Li content coexist and Cu is extruded from the host material. After 4 days of Li intercalation, a conversion reaction is observed. The overall Li uptake is 8 Li ions per formula unit. The structural behaviour of the two intercalated phases at the early stages of intercalation is totally different. For one phase a strong expansion of the a-axis is observed while for the other phase it is only slightly affected by Li uptake. A three-step mechanism was found consisting of reduction of Se− followed by a Cu–Li exchange and finally a complete reduction of Cr3+ to the metallic state accompanied by the formation of Li2Se. The discharge capacity of the first cycle amounts to 530 mAh g−1 and drops to about 380 mAh g−1 in the fifth cycle. In in situ SEM images the occurrence of Cu whiskers that partially grow out of the crystallites can be observed.

Document Type: Article
Research affiliation: Kiel University > Kiel Marine Science
OceanRep > The Future Ocean - Cluster of Excellence
Kiel University
Refereed: Yes
Open Access Journal?: No
DOI etc.: 10.1039/c2cp00064d
ISSN: 1463-9076
Projects: Future Ocean
Date Deposited: 12 Jun 2018 10:24
Last Modified: 04 Apr 2019 08:55
URI: http://oceanrep.geomar.de/id/eprint/43332

Actions (login required)

View Item View Item