Manufacturing apparatus and method for making silicon nanowires on carbon based powders for use in batteries

Abstract

Manufacturing apparatus, systems and method of making silicon (Si) nanowires on carbon based powders, such as graphite, that may be used as anodes in lithium ion batteries are provided. In some embodiments, an inventive tumbler reactor and chemical vapor deposition (CVD) system and method for growing silicon nanowires on carbon based powders in scaled up quantities to provide production scale anodes for the battery industry are described.

We claim: 
     
         1 . A manufacturing apparatus for growing silicon nanowires on carbon based powders, comprising:
 a CVD chamber;   a process tube positioned within the CVD chamber; and   a tumbler reactor configured to receive the carbon based powder, the tumbler reactor removably positioned within the process tube, the tumbler reactor having a gas distribution manifold positioned therein, and the tumbler reactor configured to rotate within the process tube,   wherein the tumbler reactor further comprises one or more fins mounted on one or more inner walls of the tumbler reactor, and wherein the one or more fins comprise an elongated lip that projects from the surface of the one or more inner walls.   
     
     
         2 . The manufacturing apparatus of  claim 1 , wherein the gas distribution manifold comprises one or more gas injection members. 
     
     
         3 . The manufacturing apparatus of  claim 2 , wherein the one or more gas injection members comprise a plurality of gas injection ports formed therein for injecting process gas into the tumbler reactor. 
     
     
         4 . The manufacturing apparatus of  claim 1 , wherein the gas distribution manifold comprises a U-shaped gas injection member. 
     
     
         5 . The manufacturing apparatus of  claim 4 , wherein the U-shaped injection member comprises a plurality of gas injection ports formed therein for injecting process gas into the tumbler reactor. 
     
     
         6 . The manufacturing apparatus of  claim 3 , wherein the injection ports are substantially equally distributed along the gas injection member to provide substantially uniform distribution of the process gas within the tumbler reactor. 
     
     
         7 . The manufacturing apparatus of  claim 5 , wherein the injection ports are substantially equally distributed along the gas injection member to provide substantially uniform distribution of the process gas within the tumbler reactor. 
     
     
         8 . The manufacturing apparatus of  claim 1 , further comprising one or more scrapers configured to scrape at least a portion of the inner walls of the tumbler reactor. 
     
     
         9 . The manufacturing apparatus of  claim 8 , wherein the one or more scrapers is positioned at one or more of the ends of the tumbler reactor and scraps powder from the periphery of the tumbler reactor. 
     
     
         10 . The manufacturing apparatus of  claim 8 , wherein the one or more scrapers comprises an elongated blade that extends at least a portion of the length of the tumbler reactor. 
     
     
         11 . The manufacturing apparatus of  claim 10 , wherein a brush-like member is positioned along at least a portion of the outer side of the elongated blade. 
     
     
         12 . The manufacturing apparatus of  claim 8 , wherein the one or more scrapers is integrated with a gas distribution manifold. 
     
     
         13 . The manufacturing apparatus of  claim 1 , wherein the process tube comprises metal. 
     
     
         14 . The manufacturing apparatus of  claim 1 , wherein the one or more fins are configured to provide at least one of control and distribution of powder motion in the tumbler reactor. 
     
     
         15 . The manufacturing apparatus of  claim 1 , wherein the one or more fins are configured to prevent the carbon based powders from slipping along or clinging to the one or more inner walls during rotation of the tumbler reactor. 
     
     
         16 . The manufacturing apparatus of  claim 1 , further comprising a carriage rail with wheels configured to support the tumbler reactor and to move the tumbler reactor in and out of the process tube. 
     
     
         17 . The manufacturing apparatus of  claim 1 , further comprising a carriage rail with wheels configured to move the CVD chamber away from the process tube and tumbler reactor. 
     
     
         18 . The manufacturing apparatus of  claim 1 , further comprising two or more tumbler reactors positioned within the process tube. 
     
     
         19 . The manufacturing apparatus of  claim 18 , wherein the two or more tumbler reactors are processed in the process tube in a semi-continuous manner. 
     
     
         20 . The manufacturing apparatus of  claim 1 , wherein the tumbler reactor further comprises: a mesh end cap positioned on each end of the tumbler reactor, the mesh end cap comprising a mesh having a plurality of apertures sized to allow flow of gases between the tumbler reactor and the process tube, while containing the carbon based powders inside the tumbler reactor and prohibiting the flow of the carbon based powders into the process tube. 
     
     
         21 . The manufacturing apparatus of  claim 1 , wherein the carbon based powders comprise graphite. 
     
     
         22 . The manufacturing apparatus of  claim 1 , wherein the manufacturing apparatus produces at least 1 kg of silicon nanowires on carbon based powders per batch. 
     
     
         23 . The manufacturing apparatus of  claim 1 , wherein the manufacturing apparatus produces at least 10 kg of silicon nanowires on carbon based powders per batch. 
     
     
         24 . The manufacturing apparatus of  claim 1 , wherein the manufacturing apparatus produces at least 100 kg of silicon nanowires on carbon based powders per batch.