碳包覆CaSnO3纳米纤维作为高性能锂离子电池负极材料

采用静电纺丝技术制备出CaSnO3纳米纤维(CaSnO3 NFs)并作为模板,再经表面原位聚合酚醛树脂和碳化处理制得碳包覆CaSnO3纳米纤维(CaSnO3@C NFs)。使用X射线衍射、扫描电子显微镜、透射电子显微镜和X射线光电子能谱对材料的物相组成、形貌和微观结构进行了表征,通过循环伏安、恒电流充放电和交流阻抗谱研究了碳包覆及碳化温度对CaSnO3 NFs负极材料电化学性能的影响。结果显示,碳包覆改性使CaSnO3 NFs的电化学性能得到较大程度的提高,而且随着碳化温度的升高,CaSnO3@C NFs复合电极的比容量先增加后下降,600℃碳化获得的CaSnO3@C NFs?600复合材料具有最好的电化学性能。在0.1 A·g^-1的电流密度下,CaSnO3@C NFs?600电极的首圈放电比容量达到1102.2 mAh·g^-1,充放电循环100圈后比容量为548.8 mAh·g^-1,当电流密度提高到2 A·g^-1时,其比容量仍保持在333.5 mAh·g^-1。

Carbon-Coated CaSnO3 Nanofibers as High Performance Anode Materials for Lithium Ion Batteries

Carbon coated CaSnO3 nanofibers(denoted as CaSnO3@C NFs)were prepared via the electrospinning technique combined with in?situ polymerization and carbonization processes.The phase compositions,surface morphology and microstructures of the samples were characterized by means of X?ray diffraction,scanning electron microscope,transmitting electron microscope and X?ray photoelectron spectroscopy.The influences of carbon coating and carbonization temperature on the electrochemical properties of CaSnO3 NFs?based anode materials were investigated using cyclic voltammetry,galvanostatic charge/discharge and AC impedance spectroscopy.The test results show that the electrochemical performance of CaSnO3 NFs was greatly improved after carbon coating,and meanwhile the specific capacity of CaSnO3@C NFs composites first increased and then decreased with increasing carbonization temperature,in which the CaSnO3@C NFs?600 composite obtained by carbonization at 600℃exhibited an optimal electrochemical performance.The CaSnO3@C NFs?600 electrode had a high initial discharge specific capacity of 1102.2 mAh·g^-1 at a current density of 100 mA·g^-1,and delivered a reversible specific capacity of 548.8 mAh·g^-1 after 100 charge/discharge cycles.Moreover,it also showed a superior rate performance and retained a specific capacity of 333.5 mAh·g^-1 even at 2 A·g^-1.