Synthesis and Electrochemical Characterizations of Spherical Mg, Sr doped Li4Ti5O12 Anode Material for Lithium Battery

• Main Authors: HSIAO,TZU-CHIEN, 蕭子倩
• Other Authors: LIU,MAO-HUANG
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/77739209457943965558

碩士 === 輔仁大學 === 化學系 === 104 === The spinel Li4Ti5O12 is a promising electrode material for high power density lithium-ion batteries, but has the drawback of poor electronic conductivity. In order to enhance the conductivity of Li4Ti5O12 in rechargeable batteries for electric vehicles. In this study, Spherical M doped Li4Ti5O12 (M=Mg, Sr) had been synthesized by spray-dry method. Under the scanning electron microscope observations, the synthesized M doped Li4Ti5O12 (M=Mg, Sr) is shown the perfectly spherical particle and particle size about 8~10μm. The XRD results confirmed the effect of the Mg dopants on the powder properties of the spinel Li4Ti5O12, which exhibited a pure spinel structure without any secondary phase; but Sr doping introduced a small amount of SrLi2Ti6O14 to the composites, which will supply the channels for lithium-ion intercalation and deintercalation, and thus improve the rate performance of Li4Ti5O12. Electrochemical testing results showed that discharge capacity of 3% Mg-LTO are 163.95 and 59.06 mAh/g at discharge rates of 0.1 and 15C, respectively. The corresponding values for 1% Sr-LTO are 165.39 and 88.29 mAh/g. During the cycle-life test of 3% Mg-LTO and 1% Sr-LTO, there are no obvious decay in capacity even after 50 cycles at 0.5C. After analyzing the EIS and PITT experimental datas, the results prove that Mg and Sr dopants can significantly enhance the electronic conductivity and ionic conductivity of Li4Ti5O12.