Carbon-Coated Silicon Particle Powder as the Anode Material for Lithium Ion Batteries and Method of Making the Same

Abstract

A process for the production of coated silicon/carbon particles comprising: providing a carbon residue forming material; providing silicon particles; coating said silicon particles with said carbon residue forming material to form coated silicon particles; providing particles of a carbonaceous material; coating said particles of carbonaceous material with said carbon residue forming material to form coated carbonaceous particles; embedding said coated silicon particles onto said coated carbonaceous particles to form silicon/carbon composite particles; coating said silicon/carbon composite particles with said carbon residue forming material to form coated silicon/carbon composite particles; and stabilizing the coated composite particles by subjecting said coated composite particles to an oxidation reaction. The coated composite particles will have a substantially smooth coating. The particles may be coated with multiple layers of carbon residue forming material/

1 - 36 . (canceled) 
   
   
       37 . Coated silicon/carbon composite particles comprising a core of silicon and carbonaceous particles wherein each of the silicon particles and carbonaceous particles are each coated with a carbon residue forming material, combined together and further coated with a layer of carbon residue forming material. 
   
   
       38 . The coated composite particles according to  claim 37 , wherein the composite particles comprise a pulvurent carbonaceous material selected from the group consisting of petroleum pitches, calcined petroleum cokes, uncalcined petroleum cokes, highly crystalline cokes, coal tar cokes, synthetic graphites, natural graphites, soft carbons derived from organic polymers, and soft carbons derived from natural polymers. 
   
   
       39 . The coated carbonaceous particles according to  claim 37 , wherein the composite particles are a pulvurent carbonaceous material selected from the group consisting of calcined petroleum cokes, uncalcined petroleum cokes, highly crystalline cokes, synthetic graphites, and natural graphites. 
   
   
       40 . The coated carbonaceous particles of  claim 37  wherein the coating layer is graphitic. 
   
   
       41 . A method for the production of a Li-ion battery wherein the coated carbonaceous particles of  claim 37  are used as the anode material, and wherein such Li-ion battery exhibits a first cycle charge efficiency greater than 90% at the cut-off potential of 1 volt versus Li when tested with electrolyte containing no propylene carbonate solvent. 
   
   
       42 . An electrical storage cell comprising the coated carbonaceous particles of  claim 37 . 
   
   
       43 . An electrical storage cell according to  claim 42 , wherein the electrical storage cell is a rechargeable electrical storage cell. 
   
   
       44 . A method for the manufacture of an electrical storage cell which comprises incorporating the coated composite particles of  claim 37  into an anode of the electrical storage cell. 
   
   
       45 - 52 . (canceled) 
   
   
       53 . A method for the manufacture of an electrical storage cell, wherein the method comprises incorporating into an anode of the electrical storage cell coated, silicon/carbon composite materials comprising coated silicon particles and coated carbonaceous particles having a coating layer formed of an oxidized, carbon residue forming material. 
   
   
       54 - 64 . (canceled)