Synthesis and Electrochemical Properties of LiCo[sub 2]O[sub 4] Spinel Cathodes

This is the authors' abstract. We don't add key points for this paper.

The formation of spinel oxide has been investigated by chemically extracting lithium with the oxidizing agent from three samples of that were synthesized at 400, 600, and 800°C to obtain followed by heat-treatment at 200°C. The samples have been characterized by X-ray diffraction, atomic absorption spectroscopy, and a redox titration to determine the oxygen content. While the sample obtained from the crystallizes in the normal cubic spinel structure with a cation distribution of that obtained from the maintains the layer structure even after heating at moderate temperatures. The voltage profile of the spinel has been investigated experimentally. While the extraction of lithium from the 8a sites occurs at around 3.8-4 V, the insertion of lithium into the 16c sites occurs at around 3.5-3.6 V. The experimentally observed voltage difference of 0.3 V between the two processes is much smaller than that predicted from theoretical calculations (1.3 V) in the literature and observed for the system (1 V).