锂离子电池负极用网络结构SnO2-C复合涂层的微观结构及其性能

摘要

通过简单的刮涂工艺,将含有氯化亚锡、聚丙烯腈(PAN)和聚甲基丙烯酸甲酯(PM-MA)的二甲基甲酰胺(DMF)溶液涂覆在铜箔表面,然后在真空下煅烧,制备出具有三维网络结构的SnO2-C复合涂层,对其微观结构进行了表征,并对该网络结构SnO2-C复合涂层一体化负极材料的性能进行了测试.结果表明:该复合涂层具有由宽度为0.1～1 m的碳基枝条相互连接而形成的连续三维网络结构,该碳基枝条由无定型结构的碳基体、尺寸为10～150 nm的SnO2纳米粒子和尺寸为1～5 nm的微孔组成;当该复合涂层直接用作锂离子电池的负极时,在50 mA.g 1电流密度下经过100次循环后其比容量为642 mAh·g-1,在此循环过程中未出现比容量衰减的现象,在10 A·g-1电流密度下其比容量仍为50 mA.g-1电流密度下比容量的43％,该复合涂层表现出良好的电化学性能.%The dimethylformamide (DMF) solution containing SnCl2,polyacrylonitrile (PAN) and poly (methyl methacrylate) (PMMA) was coated on the surface of Cu foils by simple knife coating,and then calcined in vacuum.The SnO2-C composite coating with three dimensional network structure was fabricated successfully.The micro-structure of the composite coating was characterized and the performance of network structure SnO2-C composite coating as lithium ion batteries anode was tested.The results show that the coating presented the continuous network structure formed by interconnected carbon based branches with width of 0.1-1 μm which consisted of amorphous carbon matrix,SnO2 nano-particles with size of 10-150 nm and micro-pores with size of 1-5 nm.When the composite coating was employed as anodes of lithium ion batteries,after 100 times cycling under current density of 50 mA·g-1,the composite coating electrodes exhibited specific capacity of 642 mAh· g-1 without capacity fading during the cycling.The specific capacity of the electrodes under current density of 10 A·g-1 was 43％ of the specific capacity under current density of 50 mA · g-1.The composite coating had the good electrochemical performance.