自支撑碳纳米纤维的宏量制备及其储钠性能

Mass-preparation and sodium storage performance of self-supporting carbon nanofibers

为大批量制备高储钠性能的电极材料,以乙炔为碳源气体,采用连续化学气相沉积(CVD)法原位催化生长碳纳米纤维材料,制备出自支撑式电极材料。通过扫描电子显微镜(SEM)和拉曼测试(Raman)表征分析样品的微观结构、形貌及结晶性,并对其钠离子存储电化学性能进行测试分析。结果表明:通过多温区连续大批量原位催化生长,制备出多尺寸三维结构碳纳米纤维(3D CNFs),结构的变化导致碳纳米纤维暴露出丰富的空位缺陷,这为钠离子提供了大量的吸附活性位点;三维立体的结构不仅使得电解液可以快速浸润活性材料,而且有效地增强了结构的稳定性;3D CNFs作为钠离子电池负极材料,在电流密度为0.1 A/g的条件下比容量高达150 mA·h/g,且在循环50圈之后没有明显的容量衰减,表现出优异的储钠性能和循环稳定性。

In order to mass prepare electrode materials with high sodium storage performance, carbon nanofiber materials were in-situ catalytic growth by continuous chemical vapor deposition(CVD) method with acetylene as a carbon source gas, a self-supporting electrode material was prepared. The microstructure, morphology, and crystallinity of the samples were characterized and analyzed by scanning electron microscopy(SEM) and Raman testing(Raman), and the electrochemical performance of sodium ion storage was tested and analyzed. The results show that the multi-size three-dimensional structure carbon nanofibers(3D CNFs) are prepared by continuous and largescale in-situ catalytic growth in multiple temperature zones. The structural change leads to a large number of vacancy defects in the carbon nanofibers, which will provide abundant adsorption active sites for sodium ions. The 3D structure can promote the rapid infiltration of electrolytes into active materials. Meanwhile, this characteristic effectively enhances the structure stability. 3D CNFs as the anode material of the sodium-ion battery display a high specific capacity of 150 mA·h/g at a high current density of 0.1 A/g and no obvious capacity decay after 50 cycles, which shows excellent sodium storage performance and cycling stability.