Influence of LiF additions on Li[NixCo1-2xMnx]O2 materials -: Sintering, structure, and lithium insertion properties

Li[NixCo1-2xMnx]O-2 materials prepared at 900degreesC show good electrochemical cell performance and appear to be much less reactive with electrolyte at high temperatures than LiCoO2 when charged to high potential. However, the tap density and resulting electrode density of samples reported previously may be lower than required for many industrial applications in Li-ion batteries. A way to increase the density while preserving the low heating temperature at 900degreesC is to use a sintering agent. Attempts were made on the addition of a few weight percent of LiF during the synthesis of Li[NixCo1-2xMnx]O-2 materials (x=0.1 and x=0.25). The preparation, structure, morphology, density, and electrochemical behavior of such materials for the two compositions x=0.25 and 0.1 are presented as a function of LiF addition. Dense Li[NixCo1-2xMnx]O-2 could be obtained (electrode density around 3.5 g/cm(3)) using LiF as a sintering agent with almost no disturbance of the cell performance. (C) 2004 The Electrochemical Society.