Graphite/Carbon Nanofiber Composite Anode Modified with Nano Size Metal Particles for Lithium Ion Battery

Abstract

Carbon nanofibers and nano-size metal particles were incorporated into the surface of graphite particles. The carbon nanofibers prepared from the decomposition of ethylene over nickelcopper catalyst and the micro-size silicon particles were directly introduced into the graphite particles by mixing. Nano-size tin particles were also incorporated into the graphite particles by impregnation. The three different graphite composites were tested as anode base materials for lithium ion secondary battery. The incorporation of a certain amount of carbon nanofibers into the graphite electrode improved the cyclic performance as well as the initial charge/discharge capacity. With the introduction of silicon, the initial charge/discharge capacity increased but exhibited the bad cyclic characteristics. With the modification with tin, an improved electrochemical performance was observed in both initial charge/discharge capacity and cyclic characteristics.

Carbon Materials in Lithium-Ion Batteries

“…673 Other groups suggest simple mixing or impregnation processes to incorporate into carbon nanosized silicon particles which are produced by laser or chemical vapor decomposition. 505,674,675 Silicon-coated carbon materials have been prepared by chemical vapor deposition, laser-induced vapor deposition, thermal vapor decomposition, a gas suspension spray method, and spray pyrolysis. 246,[676][677][678][679][680][681][682][683][684] To decrease the irreversible capacity of these materials, they could be coated by a layer of hard carbon at the particle surface.…”