【摘要】 应用柠檬酸辅助溶胶-凝胶法.合成了Y3+掺杂的尖晶石LiNi0.49Mn1.49Y0.02O4材料.XRD、循环伏安、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3.5～4.9V,1C倍率下,其初始放电比容量为114.9 mAh.g-1,100次循环后放电比容量仍可达113.0 mAh.g-1,容量保持率为98.3%.掺杂Y3+能减小材料界面阻抗.更多还原

【Abstract】 The LiNi0.49 Mn1.49 Y0.02 O4 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 1C 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 and 113.0 mAh·g-1 after 100 cycles with the capacity retention was 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.更多还原