摘要
采用机械球磨法制备BaFeSi/C复合物,并考察了其作为锂离子电池负极材料的电化学性能.结果表明,这种复合材料具有较高的初始放电容量、合适的充放电平台和良好的循环可逆性.XRD和XPS研究证明:BaFeSi/C复合物循环性能的提高主要源于惰性导电组分FeSi2、BaSi2和外层石墨骨架的协同作用,它们的存在不仅有效地缓冲了活性组分硅的体积变化,同时在很大程度上增强了复合材料的电子导电性和离子导电性.
A novel BaFeSi/C composite was prepared by mechanical ball milling, and lithium insertion reactions on the composite electrode were investigated by cyclic voltammetry ,charge-discharge measurements, XRD and XPS spectroscopy. It is demonstrated that the capacity retention with indiscernible capacity decas during charge-discharge cycling. The improved cycling ability of the composite is suggested from a cooperative action by inactive FeSi_(2 )and BaSi_2 matrix and outer graphite shell, which both buffer the volumetric changes of the active Si phase and provide a good connection for electronic and ionic conduction during lithium insertion and extraction processes.
出处
《电化学》
CAS
CSCD
2004年第4期391-396,共6页
Journal of Electrochemistry
基金
国家"973"计划项目 (2 0 0 2CB2 1 1 80 0 )资助