Double carbon decorated lithium titanate as anode material with high rate performance for lithium-ion batteries

摘要

Spinel lithium titanate(Li4Ti5O12) has the advantages of structural stability, however it suffers the disadvantages of low lithium-ion diffusion coefficient as well as low conductivity. In order to solve issues,we reported a simple method to prepare carbon-coated Li4Ti5O12/CNTs(C@Li4Ti5O12/CNTs) using stearic acid as surfactant and carbon source to prepare carbon coated nanosized particles. The obtained Li4Ti5O12 particles of 100 nm in size are coated with the carbon layers pyrolyzed from stearic acid and dispersed in CNTs matrix homogeneously. These results show that the synthesized C@Li4Ti5O12/CNTs material used as anode materials for lithium ion batteries, presenting a better high-rate performance(147 m Ahg-1at20 C). The key factors affecting the high-rate properties of the C@Li4Ti5O12/CNTs composite may be related to the synergistic effects of the CNTs matrix and the carbon- coating layers with conductivity enhancement. Additionally, the amorphous carbon coating is an effective route to ameliorate the rate capability of Li4Ti5O12/CNTs.