Synthesis and Electrochemical Properties of Ru/PC/SiO₂/Carbon Nanofiber Composites as Anode Materials in Lithium Secondary Batteries.

Carbon nanofibers (CNFs) were grown by chemical vapor deposition method on -fiber textiles that Ni and Cu catalysts were pre-deposited via electrophoretic deposition. Carbon nanofibers were oxidized by nitric acid to create hydroxyl group and then coated with silica layer via hydrolysis of TEOS (Tetraethyl orthosilicate). Pyrolytic carbon was coated on the SiO₂/CNFs composite by flowing ethylene gas at 900 °C, and then Ru was dip-coated to prepare Ru/PC/SiO₂/CNFs composite. The morphologies, compositions, and crystal qualities of CNFs and the various carbon nanofiber composites were characterized by SEM, TEM, XPS, and Raman spectroscopy. The electrochemical properties and the capacitance of the carbon nanofibers and its composites as anode materials of Li secondary batteries were investigated by galvanostatic charge-discharge and cyclic voltammetry. The galvanostatic charge/discharge results of the CNFs, SiO₂/CNFs composite, (PC)SiO₂/CNFs composite, and Ru/(PC)SiO₂/CNFs composite exhibited maximum capacities of 809 mAh/g, 1,289 mAh/g, 2,469 mAh/g, and 2,451 mAh/g, respectively.