The electrochemical properties of AlPO4-coated LiCoO2 cathodes prepared in a water or ethanol solvent were characterized with the view of stabilizing LiCoO2 at charge-cutoff voltages of 4.6 and 4.8V. Under the influence of the AlPO4 crystallinity, the coated LiCoO2 prepared in ethanol had better capacity retention than those prepared in water. This enhancement also correlated with the improved suppression of Li-diffusivity decay in the coated cathode from the ethanol compared to that from water. In addition, the differential scanning calorimetry (DSC) results of the AlPO4 nanoparticle-coated LiCoO2 with ethanol showed an enhanced thermal stability.