Silicon/carbon composite microspheres with hierarchical core–shell structure as anode for lithium ion batteries

• Published in: Electrochemistry communications Vol. 49; pp. 98 - 102
• Main Authors: Li, Shuo, Qin, Xianying, Zhang, Haoran, Wu, Junxiong, He, Yan-Bing, Li, Baohua, Kang, Feiyu
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.12.2014; Amsterdam Elsevier; New York, NY
• Subjects: Applied sciences; Core–shell structure; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Electrochemical properties; Exact sciences and technology; Lithium ion battery; Si/C anode; Spray drying; Spray drying; Lithium ion battery; Si/C anode; Electrochemical properties; Core–shell structure; Lithium ion batteries; Anode; Surface coating; Electrode material; Composite material; Surface structure; Characterization; Silicon; Core-shell structure; Manufacturing; Electrical characteristic; Scanning electron microscopy; Cycling; Microsphere; Thermogravimetry; Secondary cell; Core-shell particle; Carbon; Polyvinylalcohol; Morphology; Thermal analysis
• ISSN: 1388-2481; 1873-1902
• DOI: 10.1016/j.elecom.2014.10.013

Silicon/carbon composite microspheres with hierarchical core–shell structure were prepared by spray drying polyvinyl alcohol (PVA) solution containing silicon (Si) nanoparticles, followed by surface coating with polyacrylonitrile (PAN) and heat treatment. For the hierarchical structure, the core section (Si/po-C) was composed of PVA-based porous carbon framework and the embedded Si nanoparticles, and the desired Si/po-C@C microspheres were formed by encapsulating the Si/po-C core with PAN-based carbon shell. The Si/po-C@C anode gave rise to stable cycling performances with high capacity and excellent rate capability attributed to the hierarchical structure. The compact PAN-based carbon shell was able to block electrolyte to contact with Si effectively, promoting the formation of stable solid-electrolyte interphase. The porous carbon framework could accommodate the volume change of embedded Si nanoparticles and enhance the internal conductivity. [Display omitted] •Spray drying was used to make Si/C composite with hierarchical structure.•Si/po-C@C electrode displayed excellent electrochemical performances.•Carbon shell blocked the electrolyte from contacting with silicon.•Structural integrity of anode was maintained by porous carbon framework.