Fey, G.T.K. and Weng, Z.X. and Chen, J.G. and Lu, C.Z. and Premkumar, T. and Naik, S.P. and Chiang, A.S.T. and Lee, D.C. and Lin, J.R. (2004) Preformed boehmite nanoparticles as coating materials for long-cycling LiCoO2. Journal of Applied Electrochemistry, 34 (7). pp. 715-722. ISSN 0021-891X

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Abstract

A simple mechano-thermal coating procedure for the production of long-cycling LiCoO2 is described. Preformed nanoparticulate boehmite was used as the coating material. The coating procedure resulted in the cathode particles covered in a 20–30 nm thick kernel of boehmite, as revealed by TEM examination. XRD studies showed that the lattice parameter c diminished upon coating, indicating that a substitutional compound of the composition LixAlyCo1yO2 may have formed upon calcination. SEM images, R-factor values from XRD studies and galvanostatic charge–discharge studies showed that a coating level of 1.0 wt % gave an optimal performance in capacity and cyclability. SEM images showed that above the 1.0 wt %coating level, the excess boehmite adhered to the coated cathode particles as sperules. ESCA depth profile analysis showed partial diffusion of aluminum from the surface to the interior. Galvanostatic cycling studies showed that at a coating level of 1.0 wt %, cyclability improved three- and twelve-fold for the two commercial LiCoO2 samples tested. Cyclic voltammetry revealed that the hexagonal- monoclinic-hexagonal phase transformations during cycling were suppressed in the coated cathode materials.

Item Type:	Article
Uncontrolled Keywords:	coated cathode; cyclability; LiCoO2; lithium batteries; nanoparticulate coating
Subjects:	Lithium batteries Electrochemical Power Sources
Divisions:	UNSPECIFIED
Depositing User:	ttbdu cecri
Date Deposited:	06 Apr 2012 14:10
Last Modified:	06 Apr 2012 14:10
URI:	http://cecri.csircentral.net/id/eprint/946

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