中文摘要：

随着人们对高比能量锂离子电池需求的逐步增加,Sn基合金成为目前高比容量负极材料的研究热点.以低成本的金属氧化物、活性炭为原料经碳热还原法首先合成出中间产物CoSn2,再将Co、石墨引入,经高能球磨制备了Sn30Co30C40三元合金负极材料.材料呈现微米级颗粒形貌,其内部是由均匀分散于无定形碳中10 nm左右CoSn晶粒所组成.材料的比容量为550 mAh/g左右,首次效率为80%左右,循环稳定性好、倍率性能优越,是一种非常有发展前景的高比容量锂离子电池负极材料.

英文摘要：

With the development of advanced lithium ion batteries,electrode materials with higher capacity are urgently in demand.With respect to the anode materials,Sn-based alloy materials with high theoretical capacity（990 mAh/g） have the potential to replace the traditional,low capacity carbon-based materials.However,the practical application of Sn-based an-ode materials is severely retarded due to the poor cycling stability of electrode,which is believed to be caused by the pul-verization of active particles resulting from the large volume of Sn during lithiation/delithiation process.The Sn-Co-C ternary alloy with amorphous or nano microstructure can overcome this problem and therefore display attractive electrochemical performance,including high capacity and good cycle stability.In the present work,amorphous Sn30Co30C40 alloy material was synthesized through a simple and scalable two-step method（carbothermal reduction-high energy ball milling method）.Sn30Co30C40 material with much smaller CoSn grain dispersed in carbon matrix and thus critical to the better electrochemical performance.XRD,SEM,TEM,HR-TEM,S-TEM and electrochemical tests were used to evaluate the structure and electro-CoSn2 alloy was firstly prepared by the carbothermal reduction route from low cost metal oxide and activated carbon.Then the prepared CoSn2 were mixed with metal cobalt and graphite in a molar ratio of 3∶3∶8 via a high energy ball milling process to synthesize the final Sn30Co30C40 material.The preferential synthesis of CoSn2 alloy was important to get chemical performance of the CoSn2 and Sn30Co30C40 materials.The synthesized Sn30Co30C40 material displayed micro-sized particle morphology,which in fact was composed of 10 nm CoSn grains distributed well in amorphous carbon matrix.The Sn30Co30C40 material showed high specific capacity of 550 mAh/g with an initial coulombic efficiency of 80%,good cycling stability and excellent rate-capability.The specific capacity of 430,380,280 mAh/g could be achieved at the rate of 1 C,2 C and 5