RESUMEN
With the increasing applications of Lithium-ion batteries in heavy equipment and engineering machinery, the requirements of rate capability are continuously growing. The high-rate performance of Li4Ti5O12(LTO) needs to be further improved. In this paper, we synthesized LTO microsphere-TiO2(B) nanosheets (LTO-TOB) composite by using a solvothermal method and subsequent calcination. LTO-TOB composite combines the merits of TiO2(B) and LTO, resulting in excellent high-rate capability (144.8, 139.3 and 124.4 mAh g-1at 20 C, 30 C and 50 C) and superior cycling stability (98.9% capability retention after 500 cycles at 5 C). Its excellent electrochemical properties root in the large surface area, high grain-boundary density and pseudocapacitive effect of LTO-TOB. This work reveals that LTO-TOB composite can be a potential anode for high power and energy density lithium-ion batteries.
RESUMEN
Titanium niobium oxides (TNOs), benefitting from their large specific capacity and Wadsley-Roth shear structure, are competitive anode materials for high-energy density and high-rate lithium-ion batteries. Herein, carbon and oxygen vacancy co-modified TiNb6O17 (A-TNO) was synthesized through a facile sol-gel reaction with subsequent heat treatment and ball-milling. Characterizations indicated that A-TNO is composed of nanosized primary particles, and the carbon content is about 0.7 wt%. The nanoparticles increase the contact area of the electrode and electrolyte and shorten the lithium-ion diffusion distance. The carbon and oxygen vacancies decrease the charge transfer resistance and enhance the Li-ion diffusion coefficient of the obtained anode material. As a result of these advantages, A-TNO exhibits excellent rate performance (208 and 177 mA h g-1 at 10C and 20C, respectively). This work reveals that A-TNO possesses good electrochemical performance and has a facile preparation process, thus A-TNO is believed to be a potential anode material for large-scale applications.