Preparation and characterization of flake graphite/silicon/carbon spherical composite as anode materials for lithium-ion batteries

• Published in: Journal of alloys and compounds Vol. 530; pp. 30 - 35
• Main Authors: Lai, Jun, Guo, Huajun, Wang, Zhixing, Li, Xinhai, Zhang, Xiaoping, Wu, Feixiang, Yue, Peng
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 25.07.2012; Elsevier
• Subjects: Anode material; Carbon; Chemistry; Composite materials; Electrochemistry; Electrodes: preparations and properties; Exact sciences and technology; Flake graphite/silicon/carbon composite; Flakes; General and physical chemistry; Glucose; Graphite; Li-ion battery; Lithium batteries; Lithium-ion batteries; Nanomaterials; Nanostructure; Silicon; Spherical composite; Spray drying; Anode material; Spray drying; Flake graphite/silicon/carbon composite; Spherical composite; Li-ion battery; Scanning electron microscopy; Pyrolysis; Spherical shape; Anode; Electrode material; Carbon; X ray diffraction; Composite material; Lithium battery; Electrochemical properties; Transmission electron microscopy; Graphite; Silicon; Chemical synthesis
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2012.03.096

▸ Flake graphite/silicon/carbon composite is synthesized via spray drying. ▸ Flake graphite of ∼0.5μm and glucose are used to prepare the composite. ▸ The as-prepared composite shows spherical and porous appearance. ▸ The composite shows nearly the same cycleability as commercial graphite in 20 cycles. ▸ The composite shows a reversible capacity of 552mAh/g at the 20th cycle. Using nano-Si, glucose and flake graphite of ∼0.5μm as raw materials, flake graphite/silicon/carbon composite is successfully synthesized via spray drying and subsequent pyrolysis. The samples are characterized by XRD, SEM, TEM and electrochemical measurements. The composite is composed of flake graphite, nano-Si and amorphous glucose-pyrolyzed carbon and presents good spherical appearance. Some micron pores arising from the decomposition of glucose exist on the surface of the composite particles. The composite has a high reversible capacity of 602.7mAh/g with an initial coulombic efficiency of 69.71%, and shows nearly the same cycleability as the commercial graphite in 20 cycles. Both the glucose-pyrolyzed carbon and the micron pores play important roles in improving the cycleability of the composite. The flake graphite/silicon/carbon composite electrode is a potential alternative to graphite for high energy-density lithium ion batteries.