静电纺丝法制备自支撑二氧化锡/碳复合柔性电极及其在锂离子电池中的应用

Electro-Spun Free-Standing Flexible SnO2/Carbon Composite Electrode for Lithium-Ion Battery Application

以聚乙烯吡咯烷酮(PVP)为碳前驱体及聚合物模板,二水合氯化亚锡(SnCl2·2H2O)为锡源,采用静电纺丝法并控制热解工艺制备了二氧化锡/碳复合纳米纤维(SCF)柔性负极材料。通过X射线衍射、扫描电镜、透射电镜和电化学测试对样品结构、形貌和电化学性能进行表征,测试结果显示,与直接添加SnO2纳米粒子相比,采用原位生成方法制备的纤维粗细均一,直径约300nm,SnO2纳米粒子均匀地分布在由PVP热解生成的无定形碳纤维上;将其作为锂离子电池负极材料,表现出优异的循环稳定性,在100mA/g的电流密度下经过100次循环后,其可逆比容量保持在598mA·h/g,远高于纯SnO2的86mA·h/g,并且该材料柔性极佳,可直接作为锂离子电池负极使用。

A flexible SnO2/carbon composite lithium-ion battery (LIB) anode was prepared by electro-spinning followed by controlled heat treatment with the use of polyvinylpyrrolidone (PVP) as carbon source as well as a polymer template and the use of tin (Ⅱ) chloride dihydrate (SnCl2·2H2O) as tin source. After characterization by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electronic microscopy (TEM), and electrochemical measurements, it is found that compared to the control protocol wherein SnO2 particles are added directly, the in situ method leads to more uniformly shaped carbon fibers resulted from the PVP carbonization with diameters of ca. 300 nm in which SnO2 nanoparticles could be homogeneously dispersed. When applied as an anode for lithium-ionbattery, it delivers an outstanding cycling stability with a reversible specific capacity of 598 mA·h/g maintained after 100 cycles at a current density of 100 mA/g, which significantly prevails over that of pristine SnO2 electrode with only 86 mA·h/g remaining after 50 cycles. Moreover, the as prepared electrode possesses excellent flexibility and self-supporting capability that allows it to be directly applied as LIB anode.