Synthesis and electrochemical performance of the high voltage cathode material Li[Li0.2MnO0.56Ni0.16Co0.08]O2 with improved rate capability

Li J, Klöpsch R, Stan MC, Nowak S, Kunze M, Passerini S, Winter M

Abstract

The high voltage layered Li[Li0.2Mn0.56Ni0.16Co0.08]O2 cathode material, which is a solid solution between Li2MnO3 and LiMn0.4Ni0.4Co0.2O2, has been synthesized by co-precipitation method followed by high temperature annealing at 900°C. XRD and SEM characterizations proved that the as prepared powder is constituted of small and homogenous particles (100-300nm), which are seen to enhance the material rate capability. After the initial decay, no obvious capacity fading was observed when cycling the material at different rates. Steady-state reversible capacities of 220mAhg-1 at 0.2C, 190mAhg-1 at 1C, 155mAhg-1 at 5C and 110mAhg-1 at 20C were achieved in long-term cycle tests within the voltage cutoff limits of 2.5 and 4.8V at 20°C.