摘要
采用高能球磨法制备了纳米硅/石墨烯(Si@G)复合锂离子电池负极材料,并研究了高能球磨时间对Si@G复合材料成分和电化学性能的影响。X射线衍射分析结果表明:球磨40 min后,产物中出现少量电化学惰性的碳化硅。球磨20 min的Si@G复合材料具有最高的首次放电比容量(3 418 mA?h/g)和首次Coulomb效率(89%),但其充放电循环稳定性较差,放电比容量在33次充放电后即衰减为首次的80%。而球磨40 min的Si@G复合材料,充放电84次后,其容量保持率仍为80%。表明没有储锂容量的杂质相SiC虽然导致Si@G负极材料的首次充放电比容量下降,但有利于提高充放电循环稳定性。
Silicon/graphene composites(Si@G)anode materials for lithium-ion battery were prepared via high-energy ball milling.The effect of milling time on the composition and electrochemical performance of Si@G composites was investigated.Based on the analysis by X-ray diffraction,a small amount of electrochemically inert silicon carbide(SiC)is formed at milling time of 40 min.The Si@G composite produced by miling for 20 min has the optimum initial specific discharge capacity(i.e.,3 418 m A?h/g)and the first coulombic efficiency(i.e.,89%),with 80%of the initial specific discharge capacity retained after 33 charge–discharge cycles.The Si@G composite produced by milling for 40 min is charged and discharged for 84 times,and its capacity retention rate is still 80%.This indicates that SiC shows no lithium storage capacity,resulting in a decrease in the first specific charge–discharge capacity.However,SiC can improve the cycling stability of Si@G composite anode materials.
作者
肖思
谢旭佳
谢雍基
刘斌
刘丹
施志聪
XIAO Si;XIE Xujia;XIE Yongji;LIU Bin;LIU Dan;SHI Zhicong(Guangdong University of Technology,School of Materials and Energy,Guangzhou510000,China;Guangdong Engineering Technology Research Center for New Energy Materials and Devices,Guangzhou510000,China;Dynavolt Tech,Shantou515000,Guangdong,China)
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2019年第9期1327-1334,共8页
Journal of The Chinese Ceramic Society
基金
国家自然科学基金重点项目(21673051)
广东省科技厅产学研重大专项(2017B010119003)
关键词
锂离子电池
负极材料
硅–石墨烯复合材料
高能球磨
lithium ion battery
anode material
silicon–graphene composite
high energy ball mill