Electrochemical properties of LiNi1−yTiyO2 and LiNi0.975M0.025O2 (M=Zn, Al, and Ti) synthesized by the solid-state reaction method

Abstract LiNi 1− y Ti y O 2 ( y = 0.000, 0.012, 0.025, 0.050, 0.100, and 0.150) and LiNi 0.975 M 0.025 O 2 (M = Zn, Al, and Ti) were synthesized by the solid-state reaction method. The voltage vs. discharge capacity curves for y = 0.012 and y = 0.025 exhibit four distinct plateaus corresponding to phase transitions. Among LiNi 1− y Ti y O 2 , LiNi 0.975 Ti 0.025 O 2 has the largest first discharge capacity, 154.8 mAh/g, at a rate of 0.1 C, and a relatively good cycling performance (77% at n = 10). Among LiNi 0.975 M 0.025 O 2 (M = Zn, Al, and Ti) samples, the LiNi 0.975 Ti 0.025 O 2 sample had the largest first discharge capacity. The LiNi 0.975 Ti 0.025 O 2 sample has sharper peaks for the −d x /|d V | vs. V curves than the LiNi 0.975 M 0.025 O 2 (M = Zn and Al). The LiNi 0.975 Al 0.025 O 2 sample, with the first discharge capacity of 128.5 mAh/g at a rate of 0.1 C, has the best cycling performance (98% at n = 10).