Electrochemical properties of Co-doped rod-like Li_4Ti_(4.92)Co_(0.08)O_(12) as anode material for lithium-ion batteries

摘要

In this study, the Li_4Ti_(5-x)Co_xO_(12) anode material was synthesized by hydrothermal method using Ti(OC_4H_9)_4, LiOH·H_2O and CoAc_2 as raw materials. When the doping molar amount of Co is 0.08, the prepared Li_4Ti_(4.92)Co_(0.08)O_(12) anode material has good electrochemical performance. The material sample is a small-sized and rod-like structure (about 100-400 nra), and the rod-like structures of different sizes are sparsely arranged to successfully improve the discharge specific capacity. Doping Co~(2+) makes the 3d orbit of pure phase Li_4Ti_5O_(12) have electrons, which increases the electronic conductivity of the material. In the rate performance test, the discharge specific capacity is as high as 256.9 mAh g~(-1) at a current density of 20 mA g~(-1). In the cycle performance test, the specific capacity of Li_4Ti_(4.92)Co_(0.08)O_(12) anode material was stable at 156.5 mAh g~(-1) at the current density is 1 A g~(-1) after 1000 cycles, and the capacity retention rate was as high as 92.17%.