In the past, the electrochemical properties of spinel LiNi0.5Mn1.5O4, i.e. rate capability at room temperature and cycle performance at elevated temperature, were not satisfactory. In this study, the influence of glycolic acid on the electrochemical properties of spinel LiNi0.5Mn1.5O4 was studied. With some amount of glycolic acid as an additional reactant, spinel LiNi0.5Mn1.5O4 was synthesized, and its electrochemical properties were improved. In addition, the mechanism of capacity decay at elevated temperature was also studied, which presents constructive view to further improve the electrochemical properties of spinel LiNi0.5Mn1.5O4.