锡碳负极材料的结构与电化学性能研究

Study on Structure and Electrochemical Properties of Tin-Carbon Anode Materials

本论文将SnCl4溶解于蔗糖溶液中,然后通过液相法包覆到人造石墨的表面,最后经高温还原法在人造石墨基体表面包覆了均匀分散有Sn纳米颗粒的硬碳材料,制备得到了一种新型Sn/C复合材料。利用扫描电子显微镜(SEM)、X射线衍射(XRD)、拉曼光谱(Raman)对Sn/C复合材料的结构进行了表征,并通过恒流充放电、循环伏安(CV)、循环、倍率等方法对其电化学性能进行了研究。结果表明:蔗糖加入量分别为1mmol、5mmol、15mmol时,材料的结构和电化学性能均产生较大变化,其中蔗糖加入量为1mmol时,Sn/C复合材料的电化学性能优异,在100mA·g^(-1)的电流密度下,首次放电容量达897.2mAh·g^(-1),首次库伦效率为62.85%,在50次循环后,材料的可逆比容量依旧保持在459.2mAh·g^(-1),并且倍率性能良好。本实验制备工艺简单,对于在实际生产中的应用具有重大意义。

In this thesis,SnCl4 was dissolved in sucrose solution,and then coated on the surface of arti?cial graphite by liquid phase method.Finally,the surface of artificial graphite substrate was coated with hard carbon material uniformly dispersed with Sn nanoparticles by high temperature reduction method.A new type of Sn/C composite was obtained.The structure of Sn/C composites was characterized by scanning electron microscopy(SEM),X-ray diffraction(XRD)and Raman spectroscopy(Raman),and was subjected to constant current charge and discharge,cyclic voltammetry(CV),cycle,and magnification.The electrochemical properties of the method were studied.The results showed that when the sucrose addition amount was 1 mmol,5 mmol and 15 mmol,the structure and electrochemical properties of the materials changed greatly.When the sucrose addition amount was 1 mmol,the electrochemical performance of the Sn/C composite was excellent.At the current density of 100 mA·g-1,the initial discharge capacity reached 897.2 mAh·g-1,and the?rst coulombic ef?ciency was 62.85%.After 50 cycles,the reversible speci?c capacity of the material remained at 459.2 mAh·g-1,and the rate performance is good.The preparation process of the experiment is simple,and has great signi?cance for the application in actual production.