NOVELTY - The method of depositing silicon onto a carbon material to form an alloy as an anode useful in rechargeable lithium ion batteries, comprises heating the carbon material having vapor grown carbon nanofibers at 700 degrees C, flowing a silicon-containing precursor gas in contact with the carbon material for a time sufficient for the gas to decompose and to form a coating on the surface of the carbon material, and forming the anode by adding a binder to the silicon-coated carbon material. The carbon material has a length of 1-500 mm, and is in the form of a low density composite or preform.    USE - The method is useful for depositing silicon onto a carbon material to form an alloy as an anode useful in rechargeable lithium ion batteries, which is useful in the development of consumer electronics and electric-based vehicles.    ADVANTAGE - The method is capable of effectively depositing the silicon onto the carbon material in less time-consuming manner thus resulting silicon-carbon alloy having high energy capacity, high power capability and high thermal conductivity, which enhances heat removal from the batteries thus reducing the risk of overheating during rapid charge/discharge cycles.    DETAILED DESCRIPTION - The method of depositing silicon onto a carbon material to form an alloy as an anode useful in rechargeable lithium ion batteries, comprises heating the carbon material having vapor grown carbon nanofibers at 700 degrees C, flowing a silicon-containing precursor gas in contact with the carbon material for a time sufficient for the gas to decompose and to form a coating on the surface of the carbon material, and forming the anode by adding a binder to the silicon-coated carbon material. The carbon material has a length of 1-500 mm, is in the form of a low density composite or preform, and includes a carbide material, a carbon or graphite additive having single-walled carbon nanotubes, multi-walled carbon nanotubes, exfoliated graphite flakes, graphite platelets, graphene particles, carbon black and mesocarbon microbeads, and a conductive additive having macroscopic vapor grown carbon nanofibers with a diameter of 500 nm to 10 mm. The silicon is coated onto the carbon material at a thickness of 2-100 nm. The silicon-coated carbon material has a graded interface. INDEPENDENT CLAIMS are included for:    (1) an anode formed by depositing silicon onto a carbon material useful in lithium ion batteries; and    (2) a lithiated carbon-silicon alloy formed by providing a carbon material.    DESCRIPTION OF DRAWING(S) - The diagram shows an electron microscope image of carbon nanofibers including a silicon coating.