Synthesis Of Nanowire Arrays As Anodes Of Lithium-ion Batteries

New anode materials for lithium-ion batteries with long cycle life and high capacity are greatly pursued to meet the increasing demands of electrical vehicles and portable electronic devices. Compared with traditional anode materials, three-dimensional nanoarray structure electrodes have received great interest, because of their significant advantages in kinetics, electronic conduction and structural stability when used as anode materials of lithium-ion batteries.In this dissertation, we propose two kinds of nanoarray structure of Co-SnO2 and Co3O4@SnO2@Ag on a Ti sheet substrate as anodes of lithium-ion batteries. Owing to the special structure, the above-mentioned nanostructured electrodes exhibit improved electrochemical performance, and our main innovative results are listed as follows:(1) We demonstrated the synthesis of Co3O4@SnO2@Ag three-dimensional nanostructure electrodes via simple hydrothermal and sputtering methods. The as-prepared electrodes show remarkably the improved initial coulombic efficiency of 89.5%, which much higher than that of the pure SnO2 nanotube array (60.3%) at the current density of 200 mA g-1. After 50 cycles, the capacity retention is about 94.9% of the first reversible capacity, which is much higher than that of CO3O4 nanowire arrays (51.7%).(2) Co@SnO2 nanowire (NW) array electrodes have been prepared by using hydrothermal, hydrogen thermal-reduction and sputtering, which exhibit high capacity and good cycling performance. After 100 cycles, the 3D nanostructured electrodes maintains at 674.3 mAhg-1 with the capacity retention of 85.7% when tested at the current density of 0.5C, which is much higher than that SnO2 planar electrodes.