Cyclic performance of Li-rich layered material Li1.1Ni0.35Mn0.65O2 synthesized through a two-step calcination method

Abstract

Li-rich layered material Li1.1Ni0.35Mn0.65O2 was synthesized by a two-step calcination method, the relationship between the calcination conditions and the cyclic performance was studied. The results show the calcination conditions of the second step exhibiting great influences on the cyclic performance of the material. As the calcination temperature increases from 970°C to 1030°C, the discharge capacity of the prepared material increases firstly and then decreases, so does the discharge voltage fading. The material obtained at the temperature (The second step calcination) of 990°C exhibits the highest discharge capacity and the highest discharge voltage fading. The material with longer second calcination time shows lower stable discharge capacity but smaller discharge voltage fading. The variation of the cyclic performance with the calcination conditions should be ascribed to the structural change, the electrochemical active area change and the electrochemical impedance.