Preparation And Electrochemical Performance Of One Dimensional Micro/Nanostructured Cobalt-Based Electrode Materials For Lithium Ion Batteries

Lithium-ion battery has played an more and more important role in consumers’ lives for the consideration of air pollution and fuel crisis. However, conventional power batteries consisted of LiFePO4 or LiMn2O4 cathode versus graphite anode couldn’t meet the demands for the next generation of power batteries due to energy densities and power densities. Thus, it is important to explore novel cathodes with large specific capacity or modify the electrode materials. The main points are summarized as follows:1、A facile stepwise co-precipitation method was employed to prepare layered li-rich Li1.2Ni0.13Co0.13Mn0.54O2, ni-rich LiNi0.8Co0.15Al0.05O2 cathodes, and spinel CoMn2O4 anode. The Li1.2Ni0.13Co0.13Mn0.54O2 microrod exhibits excellent electrochemical performance, delivering a discharge capacity of 300 mAh g-1 at 0.1 C with an initial columbic efficiency of 86%, and a capacity retention of 90% after 100 cycles at 2 C. Even at high rate of 10 C, it can still maintain a capacity of 127.7 mAh·g-1. Meanwhile, the LiNio.8Coo.15Al0.05O2 cathode also exhibits excellent electrochemical performance, which can shorten the diffusion distance of electrons and lithium ions, provide the appropriate contact area between the active materials and electrolytes and the high strain accommodation ability.in the process of charge and discharge. To solve the low initial columbic efficiency of Li1.2Ni0.13Co0.13Mn0.54O2, the as-prepared Li1.2Ni0.13Co0.13Mn0.54O2 microrod was mixed with NH4VO3 in hot water, followed by post heat, to obtain Li1.2Ni0.13Co0.13Mn0.54O2-V2O5 material. The initial columbic efficiency was obviously improved from 86% to 111%, and the discharge capacity was also improved with modified. The issue of initial low coulombic efficiency was solved effectively. The reason could be associated to the electrochemical activity of V2O5 to generate LixVO3 with li-ion come from Li metal.2、 A new Li1.2Ni0.13Co0.13Mn0.54O2||Fe3O4/Cu full cell has been successfully assembled based on Fe3O4/Cu nanorod array anode and 1D microrod Li1.2Ni0.13Co0.13Mn0.54O2 cathode. We prepared the full cell by adjusting the positive/negative capacity ratio of 1.1:1 and directly assembled without prelithiation of the Fe3O4/Cu anode with lithium foils as counter electrode. Benefit to the good electrochemical performance of the mircorod Li1.2Ni0.13Co0.13Mn0.54O2 cathode and nanorod Fe3O4/Cu anode, Li1.2Ni0.13Co0.13Mn0.54O2||Fe3O4/Cu full-cell can deliver a high discharge specific energy of 230 Wh kg-1 at 0.1 C and 196 Wh kg-1 at 0.5 C after 50 cycles.