Improvement of the cycle life of LiCoO2 powder by Sr doping

Strontium doped LiCoO2 cathode material for rechargeable lithium ion batteries were synthesized by starch assisted combustion route method. The structural characterization was carried out by X-ray powder diffraction and laser Raman spectroscopy. The sample exhibited a well-defined rhombohedral structure and the lattice parameters varied with the increasing strontium (Sr) content. Surface morphology of the synthesized materials was determined by Scanning electron microscope. The cathode materials consisted of highly ordered single crystalline particles with spherical shape. An increase of about two orders of magnitude in the electrical conductivity (5.9 x 10(-3) S cm(-1)) was observed for 10 mol%. Decrease of the electrode impedance was observed with increase in Sr content in system. Electrochemical properties were characterized by the assembled test cells using galvanostatic discharge studies that were carried out at a current rate of 0.1 C. Galvanostatic discharge profiles of coin cells fabricated with the synthesized powders show a significant enhancement in the discharge capacity during 5 mol% Sr doping LiCoO2. (C) 2010 Elsevier B.V. All rights reserved.