Abstract
In the society that several alternative energy sources are developing, lithium ion batteries have being designed to meet the raising requirement of electric vehicle (EV) and back-up storage systems. Li4Ti5O12 is a promising anode material for both high-power and high-safety lithium-ion batteries (LIBs). Li4Ti5O12 possesses the advantages of high safety and long cycle life, due to robust spinel structure and no solid electrolyte interface (SEI) formation. However, Li4Ti5O12 is electron insulated. Hence, this study aims to improve the electron conductivity through atmosphere control and carbon-assistance to promote its high-rate performance. Initially, the study probes into the effect of reductive atmosphere. Beyond the enhancement of electron conductivity, it is found that the lithium diffusion is also facilitated due to disorder structure. Furthermore, in view of that both lithium diffusivity and electron conductivity should be promoted for high rate capability, polymer-assisted solid-state method incorporated with reductive atmosphere is proposed. Porous structure, carbon network and disorder structure are synthesized under one-step synthesis, resulting in the outstanding electrochemical performance. The high-rate capacity of 5C reaches 155 mAh/g, 89% of theoretical value, and retained the initial value after 200 discharging/charging cycles.