A General, One-Step and Template-Free Route to Rattle-Type Hollow Carbon Spheres and Their Application in Lithium Battery Anodes

• Published in: Journal of physical chemistry. C 2009-07, Vol.113 (30), p.13065-13069
• Main Authors: Zheng, Rongbo, Meng, Xianwei, Tang, Fangqiong, Zhang, Lin, Ren, Jun
• Format: Article
• Language: English
• Subjects: C: Nanops and Nanostructures
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp901474w

A general, rapid, template-free, one-step, and continuous approach have been designed to rattle-type hollow carbon spheres (M@carbon, M = multiple Sn, Pt, Ag, or Fe-FeO nanoparticles) via ultrasonic spray pyrolysis of aqueous solutions containing sodium citrate and corresponding inorganic metal salts. The route involves the following three procedures: (1) initial generation of metal nanoparticles via the reduction of corresponding metal salts with sodium citrate in the hot liquid droplets and subsequent formation of a sodium citrate outer shell due to the tendency of free sodium citrate molecules to move to the periphery of the hot liquid droplets; (2) the formation of carbon outer shell via carbonization of the sodium citrate outer shell; and (3) the production of M@carbon via removing water-soluble byproduct. The content of encapsulated nanoparticles in M@carbon can be controlled via tuning the concentration of metal salts. Due to its novel structures, Sn@carbon exhibits high capacity and good cycle performance when they were used as anode materials for lithium batteries.