Microemulsion preparation and electrochemical characteristics of LiNi1/3Co1/3Mn1/3O2 powders

LiNi1/3Co1/3Mn1/3O2 Layer-structured was Successfully synthesized via a reverse microemulsion (R mu E) route. Well-crystallized nanosized (around 45 nm) powders were obtained with calcination at 800 degrees C. The Rietveld refinement data revealed low degree of cationic displacement in the obtained powders. Within the voltage range of 2.5-4.5 V, the microemulsion-derived LiNi1/3Co1/3Mn1/3O2 delivered 187.2 and 195.5 mAh g(-1) at room temperature and 55 degrees C, respectively. The prepared powders were found to exhibit low irreversible capacity and good capacity retention. Microemulsion-derived LiNi1/3Co1/3Mn1/3O2 demonstrated better rate capability than the solid-state derived samples, owing to the reduced particle size and increased surface area. Once the upper cut-off voltage reached 4.6 V, the capacity faded more rapidly than in other operation potential ranges. In this study, the microemulsion process effectively improved the electrochemical characteristics of LiNi1/3Co1/3Mn1/3O2. This soft chemical route possesses a great potential for synthesizing other types of cathode materials with multiple cations. (C) 2009 Published by Elsevier B.V.