Synthesis and electrochemical properties of LiNi0.8Co0.15Al0.05O2 prepared from the precursor Ni0.8Co0.15Al0.05OOH

LiNi0.8Co0.15Al0.05O2 cathode material for lithium-ion batteries is synthesized by sintering the precursor Ni0.8Co0.15Al0.05OOH, which is prepared from the corresponding metal sulphates solution by a co-oxidation-controlled crystallization method. The effects of calcination temperature and time on the electrochemical performance of the material are investigated on the basis of TG-DSC analysis. XRD analyses show that the powders obtained by calcination at 700 degrees C for 6 h have the best-ordered hexagonal layer structure. SEM images show that these powders are spherical particles with diameter in the 5-12 mu m range. The XPS measurement and the chemical titration display that Ni ions of these powders are in the form of Ni3+. The charge-discharge tests demonstrate that these powders have the best electrochemical properties, with an initial discharge capacity of 196.8 mAh g(-1) and capacity retention of 96.1% after 50 cycles when cycled at a current density of 0.2C between 2.8 and 4.3V. Besides, these powders have also exhibited excellent rate capability and high-temperature performance. (C) 2011 Elsevier B.V. All rights reserved.