Abstract: The effect of Ti-doping on different morphologic LiCoO2 was characterized by scanning electron microscope(SEM) along with energy dispersive spectroscopy(EDS), X-ray diffraction(XRD), electrochemical impedance spectroscopy(EIS), and galvanostatic charge-discharge tests. The result indicated that Ti-doping did not affect the structure of different morphologic LiCoO2 but considerably improved its electrochemical performance, especially the behavior of large current discharge (1 C). In the case of being discharged at a 1 C discharge rate, 3.8 V voltage plateau(the ratio of capacity above 3.8 V to total capacity) of secondary particles doped with TiO2 could retain 60% after 20 cycles, which was better than primary particles doped with TiO2 (40%). EIS result showed that Ti-doping could evidently suppress the increase of the electrochemical reaction resistant at large current discharge rate for secondary particles.

Key words: LiCoO2, Morphology, Doping, Titanium oxide, Lithium ion batteries