Li3PO4 coated Li1.18Co0.15Ni0.15Mn0.52O2 cathode materials were prepared by the precipitation method. The Li3PO4 coating process cleans the Li2CO3 impurity on the surface of the material. In addition, a continuous stacking faults region forms in the near-surface region of the material. Electrochemical studies show that Li3PO4 coating improves the activation of Mn4+ ions, prohibits the growth of solid electrolyte interface film and facilitates the charge transfer reactions at the electrode/electrolyte interface. As a result, the Li3PO4 coated materials show larger discharge capacities, longer cycle life and better rate capability than the un-coated one. With the coating content as small as 1.0wt%, the material shows a high discharge capacity of 272.5mAhg−1 at the 0.4C rate and 121.1mAh g−1 at the 10C rate. The capacity fading rate at 0.4C is only 0.08 % per cycle. Differential scanning calorimetry shows that the exothermic temperature of the fully charged electrode increases from 203.0°C to 289.7°C after Li3PO4 coating. And the thermal release reduces from 832.4Jg−1 to 305.5Jg−1 highlighting the improved thermal stability of the Li3PO4 coated material.