溶胶—凝胶法制备锰酸锂作为锂离子电池正极材料的研究

LiMn_2O_4 as Anode Materials for Lithium Ion Batteries by Polymerization

文章以硝酸锂和醋酸锰为原料,以水和丙烯酸为分散介质,采用溶胶—凝胶法在空气气氛下进行分段烧结,控制烧结温度和时间,成功制备了尖晶石结构Li Mn2O4粉体材料。通过XRD、SEM、恒电流充放电测试等手段研究了其形态、结构及电化学性能。结果表明:制备出来的粉体为尖晶石型锰酸锂,结晶度高,无杂质相。其中700℃烧结的样品晶粒大小约在58.9 nm,颗粒大小约为200 nm左右。在1 C的电流密度下,首次放电比容量为112 m Ah/g,经过30次循环放电比容量为104.3 m Ah/g,容量保持率在93.2%,充放电库仑效率接近100%。样品表现出良好的电化学性能。

In the experiment, LiMn2O4 cathode material was synthesized in air atmosphere with nitric acid lithium and acetic acid manganese as raw materials and distilledwater as dispersant when various conditions such as the calcination temperature and time were controlled strictly. The products were characterized by X-ray diffraction （XRD）. scanning electronic microscopy （SEM） and galvanostatic cycle. The results showed that the prepared materialwas spinel phase lithium manganite with characters of high crystallinity, no impurity phase. The 700℃calcined powder with crystal size is about 58.9 nm and particle size about 200 nm, The first discharge specific capacities of the LiMn2O4 was 112 mAh/g and discharge capacity is still more than 104.3 mAh/g After 30 times cycles, the specific capacity retention was 93.2 % at the current density of 1 C. Coulomb charge-discharge efficiency was about 100 %. The good electrochemical properties of the prepared material are obtained.