以无水乙醇为碳源、二茂铁为催化剂前驱体、噻吩作为碳纳米管生长促进剂，通过改变催化剂前驱体的添加量，采用低压预混火焰燃烧法制备了3种不同组分比例的无定形碳（Amorphous Carbon，AC）/单壁碳纳米管（Single-Walled Carbon Nanotubes，SWCNTs）薄膜，随后将其作为自支撑负极材料组装钠离子电池。采用X射线衍射仪、透射电子显微镜、拉曼光谱和热重分析等表征手段对材料的晶体结构、微观形貌和组成进行分析，并通过充放电性能测试分析材料的电化学性能。研究发现，随着催化剂含量的增加，碳材料的层间距逐渐增大，材料的晶化程度降低，无定形碳成分增多，为Na+的可逆储存提供了空间。利用TG分析材料组成，发现当催化剂含量为0.018 g时，样品（AC/SWCNTs-3）具有最大的无定形碳含量，为67.01%。此时，样品的碳层间距最大，实现了Na+的高效嵌入/脱出，而相互交联的SWCNTs网络结构为电子的传输提供通道，作为附着无定形碳的载体延缓了容量的衰退，表现出最佳的电化学性能。经过60圈倍率性能测试，AC/SWCNTs-3表现出良好的可逆性，可逆比容量达到220.7 mAh/g，在50 mA/g电流密度下循环150圈，电极仍可维持146.7 mAh/g 的比容量。此外，样品AC/SWCNTs-3的反应过程是扩散控制占主导的储钠机制。在扫速0.1 mV/s下，电容贡献率为19.3%。综上，在AC/SWCNTs复合材料中，无定形碳提供了丰富的活性位点，中空管状结构的SWCNTs可作为电子快速传输的通道，保证了Na+在电池工作过程中的快速扩散和可逆存储，使AC/SWCNTs复合材料在钠离子电池中表现出更好的电化学性能。

Three kinds of AC(Amorphous Carbon，AC)/SWCNTs(Single-Walled Carbon Nanotubes，SWCNTs）thin films with different component ratios were prepared by low-pressure premixed flame combustion method with anhydrous ethanol as carbon source，ferrocene as catalyst precursor and thiophene as the growth promoter of carbon nanotube，which was used as a self-supporting negative electrode material to assemble sodium ion battery. The crystal structure，micro morphology and composition of the materials were characterized by X-ray diffraction，transmission electron microscopy，Raman spectroscopy and thermogravimetric analysis，and the electrochemical performances of the anode materials for sodium ion batteries were analyzed by charge-discharge performance tests. The results show that with the increase of catalyst content，the layer spacing of carbon materials gradually increases，the crystallization degree of materials decreases，and the amorphous carbon composition increases，which provides space for the reversible storage of Na+. The composition of the material was analyzed by TG. It is found that when the catalyst content is 0.018 g，the sample(AC/SWCNTs-3）has the largest amorphous carbon content，which is 67.01%. At this time，the carbon layer spacing of the sample is the largest，Na+ is embedded/stripped，and the cross-linked SWCNTs network structure provides channels for electron transmission. As a carrier attached to amorphous carbon，the decline of capacity is delayed and there is the best electrochemical performance. After 60 cycles of rate performance test，AC/SWCNTs-3 shows good reversibility，and the reversible specific capacity reaches 220.7 mAh/g  after 150 cycles at 50 mA/g current density，the electrode can still maintain the specific capacity of 146.7 mAh/g. In addition，the reaction process of sample AC/SWCNTs-3 is a sodium storage mechanism，which is dominated by diffusion control mechanism. At sweep speed of 0.1 mV/s，the capacitive contribution rate is 19.3%. In conclusion，amorphous carbon provides rich active sites in AC/SWCNTs composites，and hollow tubular SWCNTs can be used as channels for rapid electron transmission，ensuring the rapid diffusion and reversible storage of Na+ in the working process of the battery，so that AC/SWCNTs composites show better electrochemical performance in sodium ion batteries.

0 引言

1 试验材料和方法

   1.1 材料

   1.2 低压火焰法燃烧装置

   1.3 分析测试仪器

   1.4 以AC/SWCNTs为负极的钠离子电池制备

   1.5 AC/SWCNTs钠离子电池电化学性能试验

2 结果与讨论

   2.1 AC/SWCNTs电极材料的性质分析

   2.2 AC/SWCNTs电极材料的电化学性能测试

3 结论