Lithium ions in the van der Waals gap of Bi sub(2)Se sub(3) single crystals

• Published in: Journal of solid state chemistry Vol. 183; no. 12; pp. 2813 - 2817
• Main Authors: Bludska, J, Jakubec, I, Karamazov, S, Horak, J, Uher, C
• Format: Journal Article
• Language: English
• Published: 01.12.2010
• Subjects: Bands; Charging; Clusters; Crystals; Electric potential; Extraction; Insertion; Lithium ions; Voltage
• ISSN: 0022-4596
• DOI: 10.1016/j.jssc.2010.09.026

Insertion/extraction of lithium ions into/from Bi sub(2)Se sub(3) crystals was investigated by means of cyclic voltammetry. The process of insertion is reflected in the appearance of two bands on voltammograms at [inline image]1.7 and [inline image]1.5 V, corresponding to the insertion of Li super(+) ions into octahedral and tetrahedral sites of the van der Waals gap of these layered crystals. The process of extraction of Li super(+) ions from the gap results in the appearance of four bands on the voltammograms. The bands 1 and 2 at [inline image]2.1 and [inline image]2.3 V correspond to the extraction of a part of Li super(+) guest ions from the octahedral and tetrahedrals sites and this extraction has a character of a reversible intercalation/deintercalation process. A part of Li super(+) ions is bound firmly in the crystal due to the formation of negatively charged clusters of the (LiBiSe sub(2).Bi sub(3)Se sub(4) super(-)) type. A further extraction of Li super(+) ions from the van der Waals gap is associated with the presence of bands 3 and 4 placed at [inline image]2.5 and [inline image]2.7 V on the voltammograms as their extraction needs higher voltage due to the influence of negative charges localized on these clusters.