通过聚甲基丙烯酸甲酯(PMMA)胶晶模板法制备尖晶石型LiMn204材料,并探讨焙烧温度对材料性能的影响。运用热重分析(TG)、X线衍射(xRD)、扫描电镜(SEM)、充放电测试和循环伏安测试等方法对LiMn204样品的结构、形貌以及电化学性能进行表征和测试。研究结果表明:在不同温度下制备的LiMn204样品均具有较好的尖晶石型结构,且粒径分布均匀;在700℃时制备的LiMn204样品(S-700)具有最佳的电化学性能,在3.0-4.4V时,O.2C倍率首次放电比容量为130.9mA·h/g;0.5C倍率首次放电比容量为126.4mA·h/g,50次循环之后容量仍有102.7mA·h/2,具有良好的循环稳定性。
Spinel LiMn204 was successfully prepared by using polymethyl methacrylate (PMMA) colloidal crystal as templates. Effect of calcining temperature on the properties of the LiMn204 samples was studied. The structure, morphology and electrochemical performance of the LiMn204 samples synthesized at different temperatures were investigated using thermogravimetry (TG), X-ray diffraction (XRD), scanning electron microscope (SEM), charge-discharge tests and cyclic voltammetry (CV), respectively. The results show that all of the synthesized materials are of spinel structure and exhibits uniform particle size distribution. The sample synthesized at 700 ℃(S-700) has the best electrochemical properties compared with other samples. The initial discharge capacities of the sample S-700 are as high as 130.9 mA·h/g at 0.2C rate and 126.4 mA.h/g at 0,5C rate with the potential range between 3.0 and 4.4 V versus Li/Li^+, respectively. The specific capacity of the sample remains 102.7 mA.b./g after 50 cycles at 0.5C rate. Besides, the sample S-700 possesses high capacity and excellent cycle performance,