ZnO-coated LiNi0.5Mn1.5O4 cathode materials for Li-ion batteries have been synthesized. Samples were characterized by scanning electron microscopy (SEM), X-ray diffractometry (XRD) and charge-discharge tests. The results of XRD and scanning electron microscopy (SEM) showed the ZnO-coating was nano-sized, and the LiNi0.5Mn1.5O4 powder exhibits a typical cubic spinel structure with a space group of Fd3m. Electrochemical tests demonstrate that the ZnO-coated sample obtained possesses high capacity and excellent cycling stability compared with the as-prepared LiNi0.5Mn1.5O4. When being discharged at a rate of 1C after 50 cycles, the ZnO-coated LiNi0.5Mn1.5O4 powders can still deliver a capacity of 115.5 mAh•g-1, with nearly no capacity fading, which shows to be a potential cathode material for high-energy density power batteries.