Carbon Nanohorns Carried Iron Fluoride Nanocomposite with ultrahigh rate lithium ion storage properties

Novel hierarchical carbon nanohorns (CNHs) carried iron fluoride nanocomposites have been constructed by direct growth of FeF3 center dot 0.33H(2)O nanoparticles on CNHs. In the FeF3 center dot 0.33H(2)O@CNHs nanocomposite, the mesopore CNHs play the role as conductive matrix and robust carrier to support the FeF3 center dot 0.33H(2)O nanoparticles. The intimate conductive contact between the two components can build up an express way of electron transfer for rapid Li+ insertion/extraction. The CNHs can not only suppress the growth and agglomeration of FeF3 center dot 0.33H(2)O during the crystallization process, but also sever as an "elastic confinement" to support FeF3 center dot 0.33H(2)O. As was to be expected, the hierarchical FeF3 center dot 0.33H(2)O@CNHs nanocomposite exhibits impressive rate capability and excellent cycle performance. Markedly, the nanocomposite proves stable, ultrahigh rate lithium ion storage properties of 81 mAh g(-1) at charge/discharge rate of 50C (a discharge/charge process only takes 72 s). The integration of high electron conductivity, confined nano sized FeF3 center dot 0.33H(2)O (similar to 5 nm), hierarchical mesopores CNHs and the "elastic confinement" support, the FeF3 center dot 0.33H(2)O@CNHs nanocomposite demonstrates excellent ultrahigh rate capability and good cycling properties.