The effects of Zn substitution for Ni on the crystal structure and electrochemical properties of LiZn x Ni0.5-x Mn1.5O4 (x =0−0.5) are investigated. The LiZn x Ni0.5-x Mn1.5O4 samples, which were synthesized by a sol-gel method, were analyzed by X-ray diffraction (XRD), Raman spectroscopy, field-emission scanning electron microscopy (FE-SEM), battery cycling test, cyclic voltammetry (CV), and X-ray photoelectron spectroscopy (XPS). Of the compositions investigated, the LiZn0.08Ni0.42Mn1.5O4 delivered improved cycle-life and C-rate performance even at elevated temperature compared with those of Zn-free LiNi0.5Mn1.5O4. XRD and XPS results show that a thick positive electrode/electrolyte interphase film is formed on the surface of the x =0.08 electrode, which may prevent the continuous electrolyte oxidation during cycling.