Production of metal nanowires directly from metal particles

1. A process for producing metal nanowires having a diameter or thickness from 2 nm to 100 nm, said process comprising:

(A) preparing a source metal material in a solid particulate form having a size from 50 nm to 500 μm, wherein said source metal material is selected from a transition metal, Al, Be, Mg, Ca, an alloy thereof, a compound thereof, or a combination thereof;

(B) depositing a catalytic metal, in the form of nanoparticles having a size from 1 nm to 100 nm or a coating having a thickness from 1 nm to 100 nm, onto a surface of said source metal particulate to form a catalyst metal-coated metal material, wherein said catalytic metal is different than said source metal material, wherein said catalytic metal is selected from Co, Mn, Fe, Ti, Pb, Bi, Sb, Zn, Cd, Ga, In, Zr, Te, P, Sn, Ge, Si, As, Te, Se, or a combination thereof; and

(C) exposing said catalyst metal-coated metal material to a high temperature environment, from 100° C. to 2,500° C., for a period of time sufficient to enable a catalytic metal-assisted growth of multiple metal nanowires from said source metal particulate.

2. The process of claim 1 , wherein said solid metal material particulate has a diameter from 100 nm to 10 μm.

3. The process of claim 1 , wherein said transition metal is selected from Cu, Ni, Co, Mn, Fe, Ti, Ag, Au, Pt, Pd, Zn, Cd, Mo, Nb, Zr, an alloy thereof, or a combination thereof.

4. The process of claim 1 , wherein said step of depositing a catalytic metal includes (a) dissolving or dispersing a catalytic metal precursor in a liquid to form a precursor solution, (b) bringing said precursor solution in contact with a surface of said source metal particulate material, (c) removing said liquid; and (d) chemically or thermally converting said catalytic metal precursor to said catalytic metal coating or nanoparticles.

5. The process of claim 4 , wherein said step (d) of chemically or thermally converting said catalytic metal precursor is conducted concurrently with the procedure (C) of exposing said catalyst metal-coated mixture mass to a high temperature environment.

6. The process of claim 1 , wherein said step of depositing a catalytic metal is conducted by a procedure of physical vapor deposition, chemical vapor deposition, sputtering, plasma deposition, laser ablation, plasma spraying, ultrasonic spraying, printing, electrochemical deposition, electrode plating, electrodeless plating, chemical plating, ball milling, or a combination thereof.

7. The process of claim 1 , wherein said procedure of exposing said catalyst metal-coated metal material to a high temperature environment is conducted in a protective atmosphere of an inert gas, nitrogen gas, hydrogen gas, a mixture thereof, or in a vacuum.

8. The process of claim 1 , wherein said source metal material and said catalytic metal form an eutectic point and said procedure of exposing said catalyst metal-coated metal material to a high temperature environment includes exposing said catalyst metal-coated material to an initial temperature Ti equal to or higher than said eutectic point for a desired period of time and then bringing said catalyst metal-coated material to a temperature Tc, wherein Tc is above or below said eutectic point.

9. The process of claim 8 , wherein said initial exposure temperature Ti is higher than said eutectic temperature by 0.5 to 500 degrees on the Celsius scale.

10. The process of claim 1 , further comprising a procedure of removing said catalytic metal from said metal nanowires.

11. The process of claim 1 , further comprising a procedure of mixing metal nanowires with a carbonaceous or graphitic material as a conductive additive and an optional binder material to form an electrode layer, wherein said carbonaceous or graphitic material is selected from a chemical vapor deposition carbon, physical vapor deposition carbon, amorphous carbon, chemical vapor infiltration carbon, polymeric carbon or carbonized resin, pitch-derived carbon, natural graphite, artificial graphite, mesophase carbon, mesophase pitch, mesocarbon microbead, soft carbon, hard carbon, coke, carbon fiber, carbon nanofiber, carbon nanotube, carbon black, or a combination thereof.

12. A process for producing metal nanowires having a diameter or thickness from 2 nm to 100 nm, said process comprising:

a) preparing a source metal material in a particulate solid form having a size from 50 nm to 100 μm, wherein said source metal material is selected from a transition metal, Al, Be, Mg, Ca, an alloy thereof, a compound thereof, or a combination thereof;

b) depositing a catalyst metal precursor onto a surface of said source metal particulate to form a catalyst metal precursor-coated metal material; and

c) exposing said catalyst metal precursor-coated metal material to a high temperature environment, from 100° C. to 2,500° C., for a period of time sufficient to convert said catalyst metal precursor to a catalyst metal in the form of nanoparticles having a size from 1 nm to 100 nm or a coating having a thickness from 1 nm to 100 nm in physical contact with a surface of said source metal particulate, and enable a catalyst metal-assisted growth of multiple metal nanowires from said source metal particulate, wherein said catalyst metal is selected from Co, Mn, Fe, Ti, Pb, Bi, Sb, Zn, Cd, Ga, In, Zr, Te, P, Sn, Ge, Si, As, Te, Se, or a combination thereof.

13. The process of claim 12 , wherein said source metal material and said catalyst metal form an eutectic point and said step (c) of exposing said catalyst metal precursor-coated metal material to said high temperature environment includes exposing said catalyst metal precursor-coated metal material to an exposure temperature equal to or higher than said eutectic point for a desired period of time and then bringing said catalyst metal precursor-coated metal material to a temperature below said exposure temperature for a desired period of time or at a desired temperature decreasing rate.