Electrochemical Of Aggregated Porous TiO₂ Prepared In Urea-Choline Chloride

TiO₂ is considered as a promising anode materials for Li-ion batteries because of its small volume change （4%） low cost, environmentally friendly, long cycle life and safety.In this paper, aggregated porous TiO₂ anode material was prepared by atmospheric hydrolysis and Pressurized hydrolysis method using etrabutyl titanate （TBOT） as titanium source in urea-choline （UC） medium. The structure, morphology and electrochemical properties of the prepared samples were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, Brunauer-Emmett-Teller （BET） analysis, cyclic voltammetry （CV）, electrochemical impedance spectra （EIS） and galvanostatic harge-discharge testing.In order to prepare TiO₂ by the atmospheric hydrolysis, the misture of H₂O, UC, TBOT with volume ratio of 3:3:2 is hydrolyzed at 80 ℃ for 4 h to obtan the precursor, and the the precursor is sintered at 450 ℃ calcined 3h. The prepared TiO₂ is an aggregated porous material composed of～20 nm primary particles and 8.8 nm mesoporous channels with a specific surface area of 82.0 m2·g-1. This aggregated porous TiO₂ deliveres a discharge capacity of 255.7 mAh·g-1 with a a capacity retention ratio of approximately 90% after 50 cycles at 0.5 C, and it gives a discharge capacity of 131.8 mAh·g-1 at 10 C, exhibiting good rate capability and reversibility.The hydrolysis temperature is 130℃, and the hydrolysis time is 24h in the pressurized hydrolysis processes. Other conditions were similar with the atmospheric hydrolysis processes. TiO₂ synthesized by the pressurized hydrolysis processes is also a porous materials made up of～20 nm primary particles and 7.6 nm mesoporous channels with a specific surface area of 139.7 m2·g-1. The prepared samples presents a discharge capacity of 289.2 mAh·g-1 with a capacity retention of 86.7% after 50 cycles at 0.5 C.