Spinel LiNi0.5Mn1.5O4 (LNMO) has become one of the most practical power lithium-ion battery cathode materials due to its advantages of three-dimensional Li+ diffusion channel, higher potential window (3.5–5V), high-energy density (∼660 Wh/kg), and high-power density. In this manuscript, a hollow spherical LNMO material with large size and high crystallinity is prepared by a modified coprecipitation method using ethyl alcohol as a peptizator. Subsequently, the prepared LNMO material is further modified by an Al2O3 coating to improve its cycle stability. Results show that the initial discharge-specific capacity of LNMO material with 1 wt% Al2O3 coating is 133.7 mAh g−1 at 0.2 C rate, and the capacity retention rate is 97.7% after 100 cycles. The effective increase in the cycle life of the battery can be attributed to the uniform and dense Al2O3 coating on the surface of the material.