Synthesis and electrochemical properties of cation-disordered Li-Ni-Ti-O compounds as cathode material for lithium ion batteries

Li-excess disordered rock-salt cathode material, Li1+z/3Ni1/2-z/2Ti1/2+z/6O2 (Z = 0, 0.1, 0.2, 0.3, 0.4, 0.5) compounds have been synthesized via a facile sol-gel method. The X-ray diffraction (XRD) indicates that the obtained phase of the Li-excess materials is rock-salt. Morphology and microstructure observation shows that the particles size of this material is well distributed within the range of 100 nm. Cells are examined at room temperature with the voltage range of 2.5-4.5 V and the sample Li1.1Ni0.35Ti0.55O2 delivers the highest capacity of about 116.5 mAh g−1 at 20 mA g−1. The exploration of the lithium mobility in this system indicates that 0-transition metal diffusion channels do form when increasing the amount of Li. Furthermore, combining XRD after cycle, their structure evolution in these cation-disordered Li-excess materials was investigated.