超声辅助对共沉淀法制备富锂锰基正极材料Li[Li_0.144Ni_0.136Co_0.136Mn_0.544]O₂性能影响的研究

Effect of ultrasonic-assisted co-precipitation method for preparing Li-rich materials Li[Li_0.144Ni_0.136Co_0.136Mn_0.544]O₂

摘要:

通过超声辅助共沉淀法成功制备了富锂锰基正极电极材料,研究了不同的超声时间对材料形貌、结构和电化学性能的影响。研究发现,超声辅助能够使材料颗粒更加均匀,结构更合理,有利于材料电化学性能的提升。当合成前躯体材料超声时间为8h时,复合材料的放电比容量最好,在0.1C的初始放电比容量为327.8 mAh g_-1,均高于未超声的复合材料的265.2 mAh g_-1,1C下循环50圈后放电容量为181.6 mAh g_-1,保持率为84.8%。通过循环伏安法测试和电化学交流阻抗测试,发现超声后的复合材料还原氧化峰电流更大,电荷转移阻抗更小,具有较好的倍率性能。

Abstract:

_: _{The effect of different ultrasonic time on the morphology, structure and electrochemical}_{performance of}_{Li-rich materials}_Li[Li_0.144_Ni_0.136_Co_0.136_Mn_0.544_]O₂_was_{studied by ultrasonic assisted co-precipitation method.}_Our_{study found that}_ultrasonic_{can make the materials more uniform, and therefore the structure became more reasonable, which is beneficial to improve the electrochemical performance. The}_sample_{with 8h ultrasonic}_time_{shows the best capacity, and the initial discharge specific capacity of 0.1C rate is 327.8 mAh g}_-1_{(higher than 265.2 mAh g}_-1_{of the sample without}_ultrasonic_{). The discharge capacity is 181.6 mAh g}_-1_{at 1C rate after 50 cycles, with the capacity retention of 84.8%. After the cyclic voltammetry test and the EIS test, it was found that the composite oxide had higher current and reduced charge transfer impedance, and better rate performance.}