Improved thermal stability of LiCoO2 by nanoparticle AlPO4 coating with respect to spinel Li1.05Mn1.95O4

The thermal instability of the LiCoO2 cathode material was greatly improved by the nanoparticle AlPO4 coating. The AlPO4 coating appears to minimize the violent exothermic reaction of the cathode with the flammable electrolytes, resulting in excellent thermal stability even at the overcharged state. Moreover, the results of the overcharge and elevated temperature cycling tests show that, when compared with the spinel Li1.05Mn1.95O4, the AlPO4 nanoparticle coating results not only in enhanced thermal stability of the cathodes but also in reduced Co dissolution in the electrolytes. (C) 2003 Published by Elsevier Science B.V.