Enhanced electrochemical performance of LiNi0.6Co0.2Mn0.2O2 cathode materials by ultrasonic-assisted co-precipitation method

Homogenous nanoscale LiNi0.6Co0.2Mn0.2O2 (NCM) cathode material powder was successfully synthesized by the ultrasonic-assisted co-precipitation (UC) method. Compared with traditional co-precipitation (TC) method, the obtained NCM by UC method has better layered structure and lower level of cation mixing, which is confirmed by the XRD and Rietveld refinement results. First-principles calculations also verify that NCM material with better structure stability can be obtained by UC method as the ultrasonic catalysis reduces the formation energy of NCM. The electrochemical test shows that NCM materials synthesized by UC method exhibit enhanced cycling capability (improved from 72.1% to 84.3% after 100 cycles at 1 C) and rate performance (deliver 119.5 mA h g(-1) at 5 C). Moreover, the CV and EIS results demonstrated that UC method is beneficial to improve the transfer kinetic behavior of Li ions of NCM material. (C) 2015 Elsevier B.V. All rights reserved.