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以Mn2+和NH4HCO3为原料,通过控制结晶法合成球形MnCO3前驱体模板。以LiNO3和MnCO3为原料,按照一定的摩尔比机械混合,在700°C下煅烧8h,合成高倍率性能和长循环性能的球形尖晶石LiMn2O4材料。分别考查原料的摩尔比、反应时间以及反应温度对前驱体MnCO3形貌和产率的影响。采用X射线粉末衍射和扫描电镜对合成的MnCO3和LiMn2O4进行表征,对LiMn2O4样品进行室温条件下的充放电性能测试。电化学测试结果表明:尖晶石锰酸锂微球在10C的放电倍率下的首次放电容量达90mA·h/g(1C放电容量为148mA/g),800次循环后容量保持率达到75%。该方法合成的LiMn2O4微球作为高功率型锂离子电池的正极材料有着较好的应用前景。
Taking Mn2 + and NH4HCO3 as raw materials, a spherical MnCO3 precursor template was synthesized by controlled crystallization. LiNO3 and MnCO3 as raw materials, according to a certain molar ratio of mechanical mixing, calcined at 700 ° C for 8h, synthesis of high rate performance and long cycle performance of spinel spinel LiMn2O4 material. The effects of molar ratio of raw materials, reaction time and reaction temperature on morphology and yield of precursor MnCO3 were investigated. The synthesized MnCO3 and LiMn2O4 were characterized by X-ray powder diffraction and scanning electron microscopy. The charge-discharge performance of LiMn2O4 samples was tested at room temperature. The results of electrochemical tests showed that the first discharge capacity of spinel lithium manganate microspheres was 90mA · h / g at 1C discharge rate (148mA / g at 1C), and the capacity retention rate reached 75% after 800 cycles . The synthesized LiMn2O4 microspheres has a good application prospect as a cathode material of a high-power lithium ion battery.