:LiNi0.5Mn1.5O4 of a 5 V cathode material was prepared by a sol-gel method, and subsequently coated with ZnF2 as a buffering layer. XRD test showed that ZnF2 coating treatment have no effect on the crystal structure of LiNi0.5Mn1.5O4. EDS,SEM,TEM test indicated that 2wt% ZnF2 formed uniform layer on the surface of LiNi0.5Mn1.5O4 with a thickness of 7 nm.The electrochemical performance of the pristine LiNi0.5Mn1.5O4 and LiNi0.5Mn1.5O4 with various coating levels of 1wt%, 2wt%, 3wt% ZnF2 were tested and compared in half-cells. The ZnF2 coating layer decreased the interaction between the electrolyte and the cathode material, greatly stabilized the electrode surface,thus improving the electrochemical performances. LiNi0.5Mn1.5O4 with an optimized coating level of 2wt% ZnF2 exhibited the best performances, delivering a discharge capacity of 109 mAh·g-1 and maintaining 79.7% capacity retention at 0.2 C after 200 cycles. After cycled 500 cycles at a high current of 5 C, it still showed a high 85.6% capacity retention of 85.6% with a discharge capacity of 94.2 mAh·g-1.