Journal of Power Sources, Vol.159, No.1, 263-267, 2006
Synthesis by molten salt and cathodic properties of Li(Ni1/3CO1/3Mn1/3)O-2
The mixed oxide, Li(Ni1/3Co1/3Mn1/3)O-2, with the layer structure has been prepared by a one-pot method using the molten-salt mixture, LiNO3-LiCl at temperatures 750, 850 and 950 degrees C in air. The compounds were characterized by a variety of techniques. As per Rietveld data, only 4.0 and 2.5% of 'cation-mixing' was observed in the compounds prepared at 850 and 950 degrees C, respectively. Cyclic voltammetry with Li metal as counter electrode showed a clear indication of Ni2+/4+ redox couple at similar to 3.6-3.9V in all compounds. Charge-discharge cycling was carried out in the range 2.5-4.3, 2.5-4.4 and 2.5-4.5V versus Li at a current rate of 20 or 30 mA g(-1). The fifth cycle discharge capacities varied from 125 to 145 (+/- 5) mA h g(-1) for the compounds prepared at 850 and 950 degrees C. They exhibited excellent capacity-retention without noticeable capacity-fade till 50 cycles irrespective of the voltage cut-off. (c) 2006 Elsevier B.V. All rights reserved.