LINI1-XCOXO2 PREPARED AT LOW-TEMPERATURE USING BETA-NI1-XCOXOOH AND EITHER LINO3 OR LIOH

Li1-yCoyO2 has been prepared at 400 degrees C by using beta-Ni1-yCoyOO H and either LiNO3 or LiOH. The mechanism of these reactions was clari fied by differential thermal and thermogravimetric analyses. The mater ial prepared with LiNO3 is well crystallized because LiNO3 melts and t hen reacts with the oxyhydroxide in a viscous state. However, when LiO H is used, a solid-solid diffusion reaction takes place and leads to a material with broad X-ray diffraction peaks. The electrochemical char acteristics of these materials were evaluated and compared with those prepared by the usual processes at high temperature. (C) 1997 Elsevier Science S.A.