论文部分内容阅读
以硝酸锰和醋酸锰,采用蔗糖燃烧法制备锂离子电池正极材料LiNi0.5Mn1.5O4通过XRD、SEM、粒径分布测试、循环伏安、恒流充放电测试以及交流阻抗等方法,研究了醋酸锰和硝酸锰对产物的结构、形貌、粒径及电化学性能的影响。XRD测试结果表明样品的结构都为立方尖晶石型,属于Fd3m空间群。不同的锰源对材料的粒径及粒径分布有很大的影响。以醋酸锰为原料制得的材料的粒径较小并且分布更均匀,有利于锂离子的脱出和嵌入从而提高电化学性能。以醋酸锰为锰源制得的LiNi0.5Mn1.5O4在3.6~5.2 V的充放电电压范围内的电化学性能更好,1C(1C=140.0 mA.g-1)倍率的首次放电容量为144.5 mAh.g-1,循环100周后容量保持率为96%,在3C,5C,10C以及20C的放电容量分别为136.3,132.0,124.7以及96.6 mAh.g-1。
LiNi0.5Mn1.5O4 was prepared from lithium manganese nitrate and manganese acetate using sucrose combustion method. The effects of acetic acid (acetic acid) and acetic acid concentration on the electrochemical performance of LiNi0.5Mn1.5O4 were studied by XRD, SEM, particle size distribution, cyclic voltammetry, Effect of Manganese and Manganese Nitrate on Structure, Morphology, Particle Size and Electrochemical Properties of Products. XRD results show that the structure of the sample is cubic spinel, belongs to the Fd3m space group. Different sources of manganese have a large effect on the particle size and particle size distribution of the material. Materials prepared from manganese acetate are smaller in size and more evenly distributed, which facilitates the release and insertion of lithium ions to improve the electrochemical performance. The electrochemical performance of LiNi0.5Mn1.5O4 prepared from manganese acetate as manganese source is better at the charge-discharge voltage range of 3.6-5.2 V and the first discharge capacity at 1C (1C = 140.0 mA.g-1) is 144.5 mAh.g-1, the capacity retention was 96% after 100 cycles and the discharge capacities were 136.3, 132.0, 124.7 and 96.6 mAh.g-1 at 3C, 5C, 10C and 20C, respectively.