Particle size control of LiCoO2 powders by powder engineering methods

The directed influence on the micromorphology of precursors during preparation of lithium cobaltate powders by chemical synthesis methods allows to control the size of LiCoO2 crystallites from 4-6 mum to 60-100 nm. Localization of melting during thermolysis by mixing acetate precursors with foaming agents promotes the reduction of grain size from 4-6 down to 1-1.5 mum. More efficient prevention of grain coalescence can be performed by introducing a thermally stable inert encapsulation agent (K2SO4) removed by dissolution after thermal processing. The combination of this method with intense deagglomeration of precursor mixtures by planetary milling results in keeping the grain size at the level of primary LiCoO2 particles (60-80 nm) even at T=800 degreesC. Intense mechanical processing of as-formed LiCoO2 powders is undesirable due to negative influence on the crystallographic ordering processes. (C) 2003 Elsevier Science Ltd. All rights reserved.