Hydrothermal synthesis of layered Li[Ni1/3Co1/3Mn1/3]O2 as positive electrode material for lithium secondary battery

In attempts to prepare layered Li[Ni1/3Co1/3Mn1/3]O-2, hydrothermal method was employed. The hydrothermal precursor, [Ni1/3Co1/3Mn1/3](OH)(2), was synthesized via a coprecipitation route. The sphere-shaped powder precursor was hydrothermally reacted with LiOH aqueous solution at 170 degrees C for 4 days in autoclave. From X-ray diffraction and scanning electron microscopic studies, it was found that the as-hydrothermally prepared powders were crystallized to layered alpha-NaFeO2 structure and the particles had spherical shape. The as-prepared Li[Ni1/3Co1/3Mn1/3]O-2 delivered an initial discharge of about 110 mA h g(-1) due to lower crystallinity. Heat treatment of the hydrothermal product at 800 degrees C was significantly effective to improve the structural integrity, which consequently affected the increase in the discharge capacity to 157 (4.3 V cut-off) and 182 mAh g(-1) (4.6 V cut-off) at 25 degrees C with good reversibility. (C) 2005 Elsevier Ltd. All rights reserved.