Ghosh, Paromita and Mahanty, Sourindra and Basu, Rajendra Nath (2009) Lanthanum-doped LiCoO(2) cathode with high rate capability. Electrochimita Acta, 54 (5). pp. 1654-1661. ISSN 0013-4686

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Abstract

Lanthanum-doped LiCoO(2) composite cathode materials, containing 0.1-10 mol% of La were synthesized by citric acid aided combustion technique. Thermal analyses showed that the sharp decomposition reaction for pristine LiCoO(2) became sluggish upon addition of lanthanum. X-ray diffraction analyses of the composites revealed existence of minute quantities of lanthanum-rich perovskite phases-rhombohedral LaCoO(3) (R (3) over bar) and tetragonal La(2)Li(0.5)Co(0.5)O(4) (14/mmm), along with rhombohedral LiCoO(2) (R (3) over barm). Electron microscopy showed a distinct grain growth with increasing La content. An increase of about two orders of magnitude in the electrical conductivity (1.09 x 10(-3) Scm(-1)) was observed for 1.0 mol% La-doped LiCoO(2). An excellent cycling performance with capacity retention by a factor of similar to 10 in comparison to the pristine LiCoO(2) was observed for the composite cathode containing 5.0 mol% La, when 2032 type coin cells were cycled at 5C rate. This has been ascribed to the structural stability induced by La doping and presence of the ion-conducting phase La(2)Li(0.5)Co(0.5)O(4) which acts as a solid electrolyte for Li(+) ions. A negligible growth of impedance upon repeated cycling has been observed. Cyclic voltammetry showed a remarkable improvement in reversibility and stability of the La-doped electrodes. These composite cathodes might be very useful for high rate power applications. (c) 2008 Elsevier Ltd. All rights reserved.

Item Type:	Article
Uncontrolled Keywords:	Lithium-ion battery; Lithium cobalt oxide; Cyclic voltammetry; Charge-discharge cycle; Impedance spectroscopy
Subjects:	Electronics
Divisions:	Fuel Cell and Battery
Depositing User:	Bidhan Chaudhuri
Date Deposited:	27 Feb 2012 08:12
Last Modified:	01 Apr 2016 06:20
URI:	http://cgcri.csircentral.net/id/eprint/1024

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