Li_4Ti_5O_(12)溶胶-凝胶法合成及其机理研究

Study on Synthesis and Mechanism of Li_4Ti_5O_(12) by Sol-Gel Method

0 引言目前商用锂离子电池负极材料大多采用各种嵌锂碳/石墨材料.但是,这种电池在高功率脉冲充电时固有的安全性也令人存在一些担心[1].同时,锂离子在反复地插入和脱嵌过程中,使碳材料结构受到破坏,从而导致容量的衰减[2].

The precursors of Li4Ti5O12 were prepared from tetrabutyl titanate and lithium acetate by sol-gel process. The Li4Ti5O12 samples were synthesized by calcining the gel precursors at 400similar to900 degreesC in air for 6similar to20 h. Its reaction mechanism was investigated by infrared spectroscopy (IR), thermogravimetry(TG) and X-ray diffraction (XRD). The effects of sinter-temperature, calcination-time and thermal-treatment for the products were discussed. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). The results showed that the single-phase products were obtained by calcining the gel precursors at 800 degreesC in air for 20 h, the sinter-temperature was lower than that of solid-state method, the particles were narrowly distributed, well crystallized with a size range from 0.3 mum to 0.5 mum.