采用简单的机械球磨法和高温热解法将热解碳包覆在纳米硅表面,再通过二次球磨制备出碳包硅/石墨复合材料。采用X射线衍射(XRD)、扫描电镜(SEM)对复合材料的微观结构和表面形貌进行表征,并将该复合材料制成扣式电池,对其进行恒流充放电循环性能测试和交流阻抗测试。研究发现,碳包硅/石墨复合材料首次可逆比容量为1026mAh/g,经过50次循环后,比容量仍然保持在875.4mAh/g,容量保持率为82.27%。循环稳定性远高于单一的碳包硅材料,极大地提高了硅基材料作为锂离子电池负极材料的电化学性能。
The carbon-coated silicon material was prepared by simple mechanical ball milling and high-temperature pyrolysis method to coat the pyrolytic carbon on the surface of the nano silicon,and the carbon-coated silicon/graphite composite material was prepared by secondary ball milling.The microstructure and surface morphology of the composite were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).The composite was made into a button battery,and subjected to electrochemical charge and discharge test and AC impedance test.The study found that the first reversible specific capacity of the composite was 1026mAh/g.After 50 cycles,the specific capacity remained at 875.4mAh/g and the capacity retention rate was 82.27%.The cycle stability was much higher than that of single carbon-coated silicon material,which greatly improved the electrochemical performance of silicon-based materials as cathode materials for lithium ion batteries.
[1] 牛津,张苏,牛越,等.硅基锂离子电池负极材料[J].化学进展,2015,27(9):1275-1290.
[2] Boukamp B A,Lesh G C,Huggins R A.All-solid lithium electrodes with mixed-conductor matrix[J].J Electrochem Soc,1981,128(4):725-729.
[3] Tang X F,Wen G W,Song Y.Novel scalable synthesis of porous silicon/carbon composite as anode material for superior lithium-ion batteries[J].J Alloys Compd,2018,739:510-517.
[4] Li X L,Yan P F,Bruce W,et al.A stable nanoporous silicon anode prepared by modified magnesiothermic reactions[J].Nano Energy,2016,20:68-75.
[5] Chen Y L,Hu Y,Shen Z,et al.Hollow core-shell structured silicon@carbon nanoparticles embed in carbon nanofibers as binder-free anodes for lithium-ion batteries[J].J Power Sources,2017,342:467-475.
[6] Li M,Hou X H,Sha Y J,et al.Facile spray-drying/pyrolysis synthesis of core-shell structure graphite/silicon-porous carbon composite as a superior anode for Li-ion batteries[J].J Power Sources,2014,248:721-728.
[7] Tang J L,Dysart A D,Dong H,et al.Fabrication of carbon/silicon composite as lithium-ion anode with enhanced cycling stability[J].Electrochimica Acta,2017,247:626-633.
[8] Holzapfel M,Buqa H,HAardwick L,et al.Nano silicon for lithium-ion batteries[J].Electrochimica Acta,2006,52(3):973-978.
[9] Kostecki R,McLarnon F.Microprobe study of the effect of Li intercalation on the structure of graphite[J].Journal of Power Sources,2003,119:550-554.
[10] Guo P,Song L,Chen X.Electrochemical performance of graphene nanosheets as anode material for lithium-ion batteries[J].Electrochem Commun,2009,11:1320-1324.
[11] Appetecchi G,Croce F,Persi L,et al.Transport and interfacial properties of composite polymer electrolytes[J].Electrochimica Acta,2000,45:1481-1490.
[12] Acevedo-Pena P,Haro M,Rincon M,et al.Facile kinetics of Li-ion intake causes superior rate capability in multiwalled carbon nanotube@TiO2 nanocomposite battery anodes[J].Journal of Power Sources,2014,268:397-403.
基金资助
中央引导地方科技专项(83017078)
PDF
(2363KB)
