Electrochemical properties of LiNi1-yTiyO2 synthesized by ball milling and solid-state reaction method

LiNi(1-y)TiyO(2) (y = 0.000, 0.012, 0.025, 0.050, 0.100 and 0.150) were synthesized by ball milling and the solid-state reaction method. The optimum conditions to synthesize a cathode material LiNi0.975Ti0.025O2 are milling for 28 h and then preheating at 600 degrees C for 16 h and finally calcining at 750 degrees C for 30 h in an O-2 stream. LiNi(1-y)TiyO(2) (0 <= y <= 0.150) synthesized under these optimum conditions have the alpha-NaFeO2 Structure of the rhombohedral system (space group; R m). The samples with y = 0, 0.012 and 0.025 show splitting of 0 0 6 and 10 2 peaks of 10 8 and 1 10 peaks, indicating the decrease in cation mixing. The voltage versus discharge capacity curves for y = 0.012 and 0.025 exhibit three distinct plateaus corresponding to phase transitions. Among LiNi1-yTiyO2 (0 <= y <= 0.150), LiNi0.975Ti0.025O2 has the largest first discharge capacity, 155 mAh/g and the relatively good cycling performance (77% at n = 10). (c) 2006 Elsevier Ltd. All rights reserved.