Synthesis of LiCoO2 powders for lithium-ion batteries from precursors derived by rotary evaporation

Lithium cobalt oxide (LiCoO2) has received considerable attention in the last few years and is a well-known cathode material for high voltage (4 V) rechargeable Li-ion batteries. A simple chemical approach based on aqueous solution chemistry has been developed to synthesize molecularly mixed amorphous precursors. The precursors begin to transform to form LiCoO2 upon heat treatment at temperatures as low as 400°C. Strong peaks characteristic of the desired high temperature (HT) phase of LiCoO2 evolve when the precursors are heat treated to 800°C for 2 h. The morphology and particle size of the powders have been examined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Cathodes fabricated from the oxide powders have been analyzed for their electrochemical performance using ‘hockey-puck’ type test cells. The cells exhibit initial discharge specific capacity as high as 165 mAH/g and an average specific capacity of about 161 mAH/g with a reversible range close to 0.6 Li-ions.