Preparation and Electrochemical Properties of LiNi2/3Co1/6Mn1/6O2 Cathode Material for Lithium-Ion Batteries.

The cathode material LiNi2/3Co1/6Mn1/6O2 with excellent electrochemical performance was prepared successfully by a rheological phase method. The materials obtained were characterized by X-ray diffraction, scanning electron microscopy, electrochemical impedance spectroscopy and charge-discharge tests. The results showed that both calcination temperatures and atmosphere are very important factors affecting the structure and electrochemical performance of LiNi2/3Co1/6Mn1/6O2 material. The sample calcinated at 800 °C under O2 atmosphere displayed well-crystallized particle morphology, a highly ordered layered structure with low defects, and excellent electrochemical performance. In the voltage range of 2.8-4.3 V, it delivered capacity of 188.9 mAh g-1 at 0.2 C and 130.4 mAh g-1 at 5 C, respectively. The capacity retention also reached 93.9% after 50 cycles at 0.5 C. All the results suggest that LiNi2/3Co1/6Mn1/6O2 is a promising cathode material for lithium-ion batteries.