LiNi0.88Co0.09Al0.03O2 cathode material was modified with NH4F and carbon nanotubes through high temperature solid phase reaction and a superficial deposit process. The results of X-ray diffraction demonstrate that the interslab distances was enlarged after fluorine doping, which is more conductive to the internal diffusion of lithium ions. The X-ray photoelectron spectroscopy confirms the changes of valence states of the metallic elements after F- doping. The Scanning electron microscope and the transmission electron microscopy results demonstrate that the carbon nanotubes coating layer was successfully loaded on the surface of the material. The rate capability and the cycle stability of the composite materials were improved remarkably. Eventually, the modified cathode material exhibits a reversible capacity up to 194.3mAhg(-1) at 0.1C, corresponding to 88% capacity retention after 150 cycles at 2C between 2.8 and 4.3V.