Lithium cobalt (III) oxide
Crystal structure | ||||||||||||||||
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__ Li + __ Co 3+ __ O 2− | ||||||||||||||||
General | ||||||||||||||||
Surname | Lithium cobalt (III) oxide | |||||||||||||||
other names |
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Ratio formula | LiCoO 2 | |||||||||||||||
Brief description |
blue powder |
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properties | ||||||||||||||||
Molar mass | 97.88 g mol −1 | |||||||||||||||
Physical state |
firmly |
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . |
Lithium cobalt (III) oxide (LiCoO 2 ), LCO for short , is a chemical compound of lithium , cobalt and oxygen and is used as a material for the positive electrode in lithium cobalt dioxide batteries . Its usefulness as an electrode material was discovered in 1980 by a research group led by John B. Goodenough at the University of Oxford .
LiCoO 2 is a solid , in the crystal structure of which the lithium atoms lie between cobalt oxide layers . Cobalt is coordinated octahedrally by oxygen atoms or bound to them, creating a honeycomb-like link. The symmetry of the connection, expressed in the Hermann-Mauguin symbolism , is the rhombohedral space group R 3 m (space group no. 166) .
Due to the layered structure, the lithium ions are quite mobile and can diffuse relatively quickly within their layer . This is used in accumulators : when discharging, lithium is expanded and released into the electrolyte , Li x CoO 2 is formed with 0 < x <1. The structure of the cobalt oxide remains stable, so that lithium is built in again when a voltage is applied and the accumulator can be recharged.
Lithium cobalt dioxide is not soluble in water. During production, there may be contact with substances that, among other things, lead to diseases of the heart muscle .
Batteries based on lithium-cobalt-dioxide tend to run away thermally when overloaded . At temperatures above 180 ° C, lithium cobalt dioxide releases oxygen . This released oxygen reacts exothermically with the organic electrolyte materials used in the accumulator and leads to the self-increasing fire that can no longer be stopped from the outside, which completely destroys the lithium-cobalt dioxide accumulator.
Individual evidence
- ↑ a b Datasheet Lithium cobalt (III) oxide, 99.8% trace metals basis from Sigma-Aldrich , accessed on February 16, 2012 ( PDF ).
- ↑ Data sheet lithium cobalt (III) oxide from AlfaAesar, accessed on February 15, 2012 ( PDF )(JavaScript required) . .
- ↑ a b Entry on lithium cobalt dioxide in the GESTIS substance database of the IFA , accessed on January 8, 2020(JavaScript required) .
- ↑ K. Mizushima, PC Jones, PJ Wiseman, JB Goodenough: Li x CoO 2 (0 <x <l): A new cathode material for batteries of high energy density . In: Materials Research Bulletin . 15, 1980, pp. 783-789.
- ↑ Yang Shao-Horn, Laurence Croguennec, Claude Delmas, E. Chris Nelson, Michael A. O'Keefe: Atomic resolution of lithium ions in LiCoO 2 . In: Nature Materials . 2, No. 7, July 2003, pp. 464-467. doi : 10.1038 / nmat922 . PMID 12806387 .
- ↑ HJ Orman and PJ Wiseman: Cobalt (III) lithium oxide, CoLiO 2 : structure refinement by powder neutron diffraction . In: Acta Crystallographica Section C . 40, No. 1, January 1984, pp. 12-14. doi : 10.1107 / S0108270184002833 .
- ↑ Ondřej Jankovský, Jan Kovařík, Jindřich Leitner, Květoslav Růžička, David Sedmidubský (2016) "Thermodynamic properties of stoichiometric lithium cobaltite LiCoO2". Thermochimica Acta , volume 634, pages 26-30. doi : 10.1016 / j.tca.2016.04.018
- ↑ Donald G. Barceloux, Donald Barceloux: Cobalt . In: Journal of Toxicology Clinical Toxicology . 37, No. 2, 1999, pp. 201-216. doi : 10.1081 / CLT-100102420 .
- ↑ Vehicle Battery Safety Roadmap Guidance. National Renewable Energy Laboratory, US Department of Energy, p. 108 , accessed October 10, 2017 .