Temperature dependent surface morphology and lithium diffusion kinetics of LiCoO sub(2) cathode

• Published in: Metals and materials international 2012-04, Vol.18 (2), p.249-255
• Main Authors: Lakshmanan, R, Gangulibabu, Gangulibabu, Bhuvaneswari, D, Kalaiselvi, N
• Format: Article
• Language: English
• Subjects: Combustion; Cycles; Diffusion; Lithium; Morphology; Phase (cyclic); Spectra; Surface chemistry
• 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 sub(2), the compound was synthesized at four different temperatures, viz., 600, 700, 800 and 900 degree C using a novel gelatin-assisted combustion method. LiCoO sub(2) synthesized at 800 degree C is found to be a mixture of rhombohedral and cubic LiCoO sub(2) and a temperature of 900 degree C leads to the formation of cubic LiCo sub(2)O sub(4) compound, thus favoring lower temperatures such as 600 and 700 degree C to prepare phase pure rhombohedral LiCoO sub(2). Cyclic voltametry and impedance spectral studies evidence that LiCoO sub(2) synthesized at 600 degree 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 sub(2) with preferred surface morphology and better lithium diffusion kinetics at a relatively lower temperature of 600 degree C, using a gelatin-assisted combustion method.