应用柠檬酸辅助溶胶凝胶方法，合成了Y3+取代的尖晶石LiNi0.49Mn1.49Y0.02O4材料. XRD、循环伏安法、恒流充放电和交流阻抗测试结果表明，Y3+的掺杂能提高LiNi0.5Mn1.5O4的倍率和循环性能，在电压区间3.5 ~ 4.9 V，1C倍率下，其初始容量为114.9 mAh?g-1，100次循环后放电比容量仍可达到113 mAh?g-1，容量保持率98.3%，掺杂Y3+能减小材料界面阻抗.

The LiNi0.49Mn1.49Y0.02O4 cathode material was synthesized using the citric acid-assisted sol-gel method by partial substitutions of Ni and Mn with Y in the LiNi0.5Mn1.5O4 material. The influences of Y doping on the structure and electrochemical properties were investigated by means of X-ray diffraction, cyclic voltammetry, galvanostatic charge/discharge tests and AC impedance spectroscopy. The results showed that the introduction of Y into the LiNi0.5Mn1.5O4 greatly improved the cycle performance and rate capability. When the charge and discharge current was 1 C in the potential range from 3.5 to 4.9 V, the LiNi0.49Mn1.49Y0.02O4 electrode delivered the initial discharge capacity of 114.9 mAh?g-1 and 113mAh?g-1 after 100 cycles with the capacity retention of 98.3%. AC impedance data indicated that the LiNi0.49Mn1.49Y0.02O4 electrode had the lower impedance value during cycling, and Y doping effectively stabilized the crystal structure.