Synthesis and Electrochemical Characterizations of Spherical W doped Li4Ti5O12 Anode Material for Lithium Battery

• Main Authors: WU, YI-LIN, 吳依霖
• Other Authors: LIU, MAO-HUANG
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/tz72bx

碩士 === 輔仁大學 === 化學系 === 107 === In this study, the spherical lithium titanium oxide anode material (Li4Ti5O12, LTO) was synthesized via a spray-drying method. In order to improve the electrochemical performances of the LTO material, the tungsten element (W) with a molar ratio of 0.5%, 1% and 3%, respectively, was doped in Li4Ti5O12. The SEM images show the synthesized LTO particles with spherical morphologies and an average particle size of 12~13 μm. All the powders were confirmed to have a well-defined spinel type structure by XRD and the lattice constants of the LTO material did not change significantly with a W-doping. At the discharge rate of 0.1C, the capacities of LTO, 0.5% W-LTO, 1% W-LTO and 3% W-LTO are 165.48, 173.26, 179.39, and 123.13 mAh/g, respectively. The capacity retention of the LTO and 0.5% W-LTO are 50.4 and 46.8 %, respectively, at a 7.0 C-rate, while the 1% W-LTO and 3% W-LTO are 30.9% and 15.2%, respectively. After 50 charge/discharge cycles, the 0.5% W-LTO lost only ~ 1.1% of the initial capacity. The results of EIS test show that the 0.5% W-LTO has the minimum total resistance (Rf+Rct) among the LTO samples. The PITT results indicate that W doping decreases the diffusion of Li+ ions due to increase the primary-particle size of LTO.