Synthesis and characterization of LiNi 0.85Co 0.15−2x(TiMg) xO 2 as cathode materials for lithium-ion batteries

Abstract

Samples of LiNi 0.85Co 0.15−2 x (TiMg) x O 2 ( x = 0.0125, 0.025 and 0.05), prepared by solid state reaction at 725 °C for 24 h from LiOH·H 2O, Ni 2O 3, Co 2O 3, TiO 2 and Mg(OH) 2 under oxygen flow, were characterized by TG–DTA, XRD and electrochemical tests. LiNiO 2 simultaneously doped by Co-Ti-Mg has been tried to improve the cathode performance. The results show that co-doping ( x = 0.025) definitely has a large beneficial effect in increasing the capacity (182.7 mA h g −1 of the first discharge capacity for LiNi 0.85Co 0.10(TiMg) 0.025O 2) and cycling behavior (170.6 mA h g −1 after 15 cycles). Differential capacity versus voltage curves indicate the co-doped LiNiO 2 show suppression of the phase transitions as compared with LiNiO 2.