【摘要】 以商业Fe-Si、沥青作为原料,石墨烯作为导电剂,采用机械球磨和高温热解制得具有石墨烯和无定形碳包覆结构的Fe-Si@C/石墨烯复合负极材料。将以同样方法制备添加碳纳米管(CNTs)的Fe-Si@C/CNTs、不添加导电剂的Fe-Si@C及原料Fe-Si作为对比,分析比较各负极材料的电化学性能。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线能谱仪(EDS)和恒流充放电测试仪对复合材料的物相、颗粒形貌及电化学性能进行表征。结果表明,采用Fe-Si@C/石墨烯制备的电池的可逆容量得到了有效提升,同时表现出优异的循环稳定性和倍率性能,其首次放电比容量为916.3 mAh/g,库仑效率为82.4%,200 mA/g的电流密度下循环100周后放电容量稳定在600 mAh/g左右。更多还原

【Abstract】 Graphene and amorphous carbon coated Fe-Si@C/graphene anode composite was prepared by mechanical milling and high temperaturepyrolysis,using commercial Fe-Si and asphalt as raw materials,adding graphene as conductive agent. In contrast,Fe-Si @ C/CNTs,Fe-Si@C and Fe-Si were prepared in the same way in order to analyze the electrochemical property differences of each composite. The phase composition,morphology and electrochemical performance of the composites were detected by X-ray diffractometer( XRD),scanning electron microscope( SEM),transmission electron microscope( TEM),energy disperse spectroscopy( EDS) and constant current charge-discharge test. The results reveal that the reversible capacity of Fe-Si@C/graphene has been effectively improved and it exhibits superior cyclability and rate performance. It’s initial discharge specific capacity is 916. 3 m Ah/g and the initial Coulombic efficiency is 82. 4%. What’s more,it’s specific capacity remains above 600 m Ah/g after 100 cycles at a current density of 200 m A/g.更多还原