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Preparation of Brookite-Type TiO2/Carbon nanocomposite Electrodes for the Application to Li-Ion Batteries
|Du-Hee Lee 1,2, Jae-Gwan Park 1, Kyung-Jin Choi 1, Heon-Jin Choi 2, Dong-Wan Kim 1|
1. Korea Institute of Science and Technology, Nano-Materials Research Center, Seoul 136-791, Korea, South
The increasing demand for portable power has generated significant research interest in nanostructured electrode materials, essentially due to their large interfacial contact area with the electrolyte and short path lengths for Li-ion transport. To date, TiO2 has been widely investigated as an electroactive Li-insertion host. However, lithium reactivity of brookite-type TiO2 has rarely been addressed compared to the common polymorphs, anatase and rutile, due to the difficulties encountering in obtaining phase-pure brookite structure. Herein, we report the simple synthesis of monodispersed nanocrystalline brookite-type TiO2 using titanium trichloride (TiCl3) and urea ((NH2)2CO). The average size of the particles precipitated at 100oC is ~ 10 nm. The brookite structure was stable up to 400oC and was completely transformed to rutile structure at 1000oC in O2 atmosphere. We evaluated the electrochemical properties of each TiO2 powder heat-treated at preset temperatures. The hybrid carbon/TiO2 nanocomposites with high conductivity were also fabricated using stable suspension of 40 nm sized carbon black or multi-walled carbon nanotubes in aqueous suspension with an appropriate surfactant and subsequent precipitation of TiO2. Incorporation of carbon clearly provides better capacity retention of TiO2 upon cycling.
Presentation: Poster at E-MRS Fall Meeting 2007, Symposium A, by Dong-Wan Kim
See On-line Journal of E-MRS Fall Meeting 2007
Submitted: 2007-05-12 17:23 Revised: 2009-06-07 00:44