Synthesis and electrochemical performance of the high voltage cathode material Li[Li0.2Mn0.56Ni0.16Co0.08]O2 with improved rate capability

The high voltage layered Li[Li0.2Mn0.56Ni0.16Co0.08]O-2 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 degrees C. XRD and SEM characterizations proved that the as prepared powder is constituted of small and homogenous particles (100-300 nm), 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 220 mAh g(-1) at 0.2C, 190 mAh g(-1) at 1C, 155 mAh g(-1) at 5C and 110 mAh g(-1) at 20C were achieved in long-term cycle tests within the voltage cutoff limits of 2.5 and 4.8 V at 20 degrees C. 2011 Elsevier B.V. All rights reserved.