Si/C及Si/C-石墨复合材料的电化学性能  

Electrochemical performance of Si/C and Si/C-graphite composites

作　　者：谷书华 李玮珂 高可政 王力臻 GU Shu-hua;LI Wei-ke;GAO Ke-zheng;WANG Li-zhen(College of Material and Chemical Engineering,Zhengzhou University of Light Industry,Zhengzhou,Henan 450000,China)

机构地区：[1]郑州轻工业大学材料与化学工程学院,河南郑州450000

出　　处：《电池》2022年第5期507-511,共5页Battery Bimonthly

基　　金：河南省高等学校重点科研项目计划基础研究专项(20zx008)。

摘　　要：为改善石墨负极的性能,采用葡萄糖水热辅助高能球磨法制备碳包覆硅(Si/C)-石墨复合材料。利用XRD、SEM、透射电镜(TEM)及电化学性能测试,研究产物的结构、形貌及电化学性能。制备的Si/C材料为核壳结构;掺杂改性对天然石墨的结构、形貌没有影响。Si/C材料以400 mA/g的电流在0.001~1.500 V循环100次,脱锂比容量为604.1 mAh/g,容量保持率为82.8%;与天然石墨相比,Si/C-石墨复合材料的倍率及循环性能更好:Si/C质量分数为7.5%时,以400 mA/g的电流循环100次,脱锂比容量仍可达380.7 mAh/g,容量保持率为84.8%,Si/C-石墨材料的实际放电容量较预计值提高了17.6%,说明石墨与Si/C混合负极在嵌脱锂过程中发生了协同效应。The carbon-coated silicon(Si/C)-graphite composites were prepared by glucose hydrothermal-assisted high-energy ball milling method in order to improve the performance of graphite anode.The structure,morphology and electrochemical performance of products were studied by XRD,SEM,transmission electron microscope(TEM)and electrochemical performance tests.The prepared Si/C material had a core-shell structure.Doping modification had no effect on the structure and morphology of natural graphite.The specific delithiation capacity of the Si/C material was 604.1 mAh/g in 0.001-1.500 V at a current of 400 mA/g after 100 cycles,the capacity retention rate was 82.8%.Compared with natural graphite,Si/C-graphite composites had better rate capability and cycle performance.When the mass fraction of Si/C was 7.5%,the specific delithiation capacity of the Si/C-graphite composites was 380.7 mAh/g at a current of 400 mA/g after 100 cycles,the capacity retention rate was 84.8%.Compared with the assumed value,the actual discharge capacity of the Si/C-graphite composites was increased by 17.6%,indicated that the synergistic effect between graphite and Si/C composite anode occurred during the intercalation and delithiation process.

关 键 词：锂离子电池 碳包覆硅(Si/C) 水热法 石墨 协同效应 

分 类 号：TM912.9[电气工程—电力电子与电力传动]