超声辅助共沉淀法制备富锂锰基正极材料

Preparation of Li-Rich Materials by Ultrasonic-Assisted Co-precipitation Method

采用超声辅助共沉淀法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8 h时,复合材料的放电比容量最好,在0.1 C的初始放电比容量为327.8 mAh·g^-1,高于未超声的复合材料的265.2 mAh·g^-1,1 C下循环50次后放电容量为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。

The effect of different ultrasonic time on the morphology,structure and electrochemical performance of Li-rich materials Li[Li0.144 Ni0.136 Co0.136 Mn0.544]O2 was studied by a ultrasonic assisted co-precipitation method.Results show that ultrasonic assisting can make the materials more uniform,and therefore the structure becomes more reasonable,which is beneficial to the improvement of the electrochemical performance.The sample with 8 h ultrasonic time shows the best capacity,and the initial discharge specific capacity of 0.1 C 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 1 C rate after 50 cycles,with the capacity retention of 84.8%.After the cyclic voltammetry test and the EIS test,it is found that the composite oxide has higher current,lower charge transfer impedance and better rate performance.