LiNO_3-TiO_2-尿素体系燃烧合成锂离子电池负极材料Li_4Ti_5O_(12)及电化学性能

Combustion Synthesis and Electrochemical Properties of Li_4Ti_5O_(12) Cathode Material in LiNO_3–TiO_2–Urea System

以纳米TiO2和LiNO3为原料,尿素为燃料,燃烧法合成了锂离子电池负极材料Li4Ti5O12.利用XRD、SEM和恒电流充放电、循环伏安和交流阻抗对其进行表征.结果表明,预设炉温850℃,尿素与锂摩尔比1,焙烧8 h,制备得到平均粒径小于500 nm、粒度分布均匀的纯相尖晶石型结构Li4Ti5O12,并具有良好的电化学性能,具有1.5 V充放电平台,在0.1 C倍率下(1 C=170 mA·h/g),其首次充放电容量达到168 mA·h/g,经过100次循环后放电比容量仍有162 mA·h/g,容量保持率96.4%.

Li4Ti5012 was prepared by a combustion method using nano-TiO2 and LiNO3 as raw materials, and characterized by XRD, SEM, constant current charge-discharge, cyclic voltammetry and electrochemical impedance spectroscopy. The results show that when the molar ratio of urea to lithium is 1：1, the preset temperature for muffle furnace 850℃ and calcination time 8 h, the obtained pure phase spinel Li4Ti5012 with the average particle size of 500 um has better electrochemical performance. The initial discharge specific capacity of the material is as high as 168 mA·h/g at the current density of 0.1 C （1 C=170 mA·h/g） with a single voltage plateaus at around 1.5 V. The capacity remains 162 mA·h/g after 100 cycles and the retention rate of charged capacity is 96.4%.