Search

Nano-Sn/C composites are ideal anode materials for highenergyand power density Li-ion batteries. However, because of the low meltingpoint of Sn and the tendency of grain growth, especially during hightemperature carbonization, it has been a significant challenge tocreate well-dispersed ultrasmall Sn nanoparticles within a carbonmatrix. In this paper, we demonstrate an aerosol spray pyrolysis technique,as a facile and scalable method, to synthesize a nano-Sn/C compositewith uniformly dispersed 10 nm nano-Sn within a spherical carbon matrix.The discharge capacity of nano-Sn/C composite sphere anodes maintainsthe initial capacity of 710 mAh/g after 130 cycles at 0.25 C. Thenano-Sn/C composite sphere anodes can provide ∼600 mAh/g evenat a high rate of 20 C. To the best of our knowledge, such high rateperformance for Sn anodes has not been reported previously. The exceptionalperformance of the nano-Sn/C composite is attributed to the uniquenano-Sn/C structure: (1) carbon matrix offers mechanical support toaccommodate the stress associated with the large volume change ofnano-Sn, thus alleviating pulverization; (2) the carbon matrix preventsSn nanoparticle agglomeration upon prolonged cycling; and (3) carbonnetwork provides continuous path for Li ions and electrons insidethe nano-Sn/C composite spheres. [ABSTRACT FROM AUTHOR]