Effect of the synthesis temperature on the structure and electrochemical behaviour of the LiNi0.65Co0.25Mn0.1O2 positive electrode material

Three kinds of LiNi0.65Co0.25Mn0.1O2 samples were prepared using a combustion method at different synthetic conditions (C1: 900 degrees C/1 h; C2: 900 degrees C/12 h and C3: 1000 degrees C/12 h). The samples were characterized using X-ray diffraction, scanning electron microscopy and magnetization measurements before their use as positive electrode material in lithium-ion batteries. Sample C1 presents the most ordered structure with less than 3% of nickel ions in the lithium plane. Increasing synthesis temperature and/or time lead to an increase of the Li/Ni disorder. The amount of extra-nickel ions in the lithium plane strongly affects the magnetic behaviour and the electrochemical performances of the prepared material. LiNi0.65Co0.25Mn0.1O2 prepared at 900 degrees C for 1 h presents the best cycling properties. (c) 2007 Elsevier B.V. All rights reserved.