The precursor Ni0.25Mn0.75(OH)2 was prepared by co-precipitation controlled crystallization method, and then Al3+-doped LiNi0.5-0.5xMn1.5-0.5xAlxO4 material was prepared by high temperature solid phase method. XRD and SEM results show that Al3+ is uniformly doped into the crystal lattice of the material to replace part of Ni and Mn, which improves the crystallinity and structural stability of the material. Electrochemical test results show that doping with Al3+ can effectively improve the rate performance and cycle performance of the material. The capacity retention rate of LiNi0.475Mn1.475Al0.05O4 is 96.75% after 100 cycles at 0.5 C at room temperature, and 93.24% after 100 cycles at 55 ℃ at 0.5 C, the discharge specific capacity is 101.45 mA·h/g at 10 C at room temperature. Compared with LiNi0.5Mn1.5O4, the material doped with Al3+ has better reversibility and higher lithium ion conductivity.