Pre-swelled nanostructured electrode for lithium ion battery: TiO 2-pillared layered MnO2

Abstract

Porous structure of layered manganate pillared with titania nanoparticles has been realized by the exfoliation and reassembling route. First, the layered protonic manganese oxide, H0.13MnO2·0.7H 2O, is exfoliated by the intercalation of tetrabutylammonium (TBA) ions, and then the exfoliated manganate nanosheets are reassembled in the presence of titania nanoparticles, which results in porous nanohybrid materials. X-Ray diffraction (XRD), cross-sectional transmission electron microscopy (TEM), and Mn K-edge X-ray absorption spectroscopy (XAS) analyses clearly show that the titania nanoparticles with a diameter of 1 nm are successfully intercalated into the two dimensional manganate lattice without any deterioration of electronic structure and local symmetry of Mn ion. According to the N2 adsorption-desorption isotherms, the present nanohybrid is determined to be highly porous with a high specific surface area (106 m 2 g-1), which is 10 times larger than that (11 m 2 g-1) of the pristine. Finally, electrochemical experiments demonstrate that the specific capacity of the present pillared material is 288 mA h g-1, which is significantly larger than the theoretical value (193 mA h g-1) from the physical mixture of the pristine potassium birnessite and titania nanoparticles. © 2010 The Royal Society of Chemistry.