Temperature dependent surface morphology and lithium diffusion kinetics of LiCoO2 cathode

• Published in: Metals and materials international 2012, 18(2), , pp.249-255
• Main Authors: Lakshmanan, R., Gangulibabu, Bhuvaneswari, D., Kalaiselvi, N.
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Engineering Thermodynamics; Heat and Mass Transfer; Machines; Magnetic Materials; Magnetism; Manufacturing; Materials Science; Metallic Materials; Processes; Solid Mechanics; 재료공학
• ISSN: 1598-9623; 2005-4149
• DOI: 10.1007/s12540-012-2008-4

In an attempt to understand the effect of synthesis temperature upon surface morphology and lithium diffusion kinetics of LiCoO 2 , the compound was synthesized at four different temperatures, viz., 600, 700, 800 and 900 °C using a novel gelatin-assisted combustion method. LiCoO 2 synthesized at 800 °C is found to be a mixture of rhombohedral and cubic LiCoO 2 and a temperature of 900 °C leads to the formation of cubic LiCo 2 O 4 compound, thus favoring lower temperatures such as 600 and 700 °C to prepare phase pure rhombohedral LiCoO 2 . Cyclic voltametry and impedance spectral studies evidence that LiCoO 2 synthesized at 600 °C exhibits better electrochemical cycling behavior and considerably reduced internal resistance upon cycling, which are substantiated further from the higher lithium diffusion coefficient value. The study demonstrates the possibility and superiority of synthesizing electrochemically active LiCoO 2 with preferred surface morphology and better lithium diffusion kinetics at a relatively lower temperature of 600 °C, using a gelatin-assisted combustion method.