Formation of lithium-metal-carbon protecting layer and removal of lithium carbonate on lithium metal
A process for forming a lithium-metal-carbon film on a lithium metal structure. A metal-ligand complex is exposed to the metal ligand, such as for 5-30 seconds in a chemical vapor transfer reactor at a temperature of 100-180° C.
1. A method, comprising:
placing a lithium metal structure in a reactor, the lithium metal structure having an exposed coating of lithium carbonate;
flowing a metal-ligand precursor vapor in a carrier gas, the metal-ligand precursor vapor comprising a metal selected from Al, In, Ga, and Zn and an alkyl ligand through the reactor at a temperature of 100-180° C. for a flow time of 5-30 seconds; and
reacting the metal-ligand precursor vapor with the exposed coating of lithium carbonate of the lithium metal structure, removing the lithium carbonate from the lithium metal structure;
reacting the metal-ligand precursor vapor with lithium metal of the lithium metal structure, forming a lithium-metal-carbon film on the lithium metal structure.
2. The method of claim 1 , wherein the temperature is 130-160° C.
3. The method of claim 2 , wherein the carrier gas has a flow velocity of 0.1-20 m/s.
4. The method of claim 2 , wherein reacting the metal-ligand complex with lithium metal is under a high vacuum condition of 10 −6 -10 −10 Torr.
5. The method of claim 1 , wherein the metal of the metal-ligand precursor vapor is aluminum.
6. The method of claim 4 , wherein the lithium-metal-carbon film is a lithium-aluminum-carbon film.
7. The method of claim 1 , wherein the lithium-metal-carbon film is a composite comprising up to 90% Li—Al—C and up to 10% oxygen.
8. A method, comprising:
placing a lithium metal structure in a reactor, the lithium metal structure having an exposed coating of lithium carbonate;
flowing a metal-ligand complex precursor vapor in a carrier gas, the metal-ligand complex precursor vapor comprising a metal selected from Al, In, Ga, and Zn and an alkyl ligand, through the reactor at a temperature of 100-150° C. for a flow time of 5-30 seconds; and
reacting the metal-ligand complex precursor vapor with the exposed coating of lithium carbonate of the lithium metal structure, removing a portion of the lithium carbonate from the lithium metal structure.
9. The method of claim 8 , further comprising forming a lithium-metal-carbon film on the lithium metal structure.
10. The method of claim 9 , wherein the metal of the metal-ligand complex precursor vapor is aluminum.
11. The method of claim 10 , wherein the lithium-metal-carbon film is a lithium-aluminum-carbon film.
12. The method of claim 11 , wherein the lithium-metal-carbon film is a composite comprising up to 90% Li—Al—C and up to 10% oxygen.
13. The method of claim 12 , wherein the metal-ligand complex precursor vapor is trimethylaluminum.
14. The method of claim 8 , wherein the temperature is 130-160° C.
15. The method of claim 14 wherein the carrier gas has a flow velocity of 0.1-20 m/s.
16. The method of claim 14 , wherein reacting the metal-ligand complex with lithium metal is under a high vacuum condition of 10 −6 -10 −10 Torr.
17. The method of claim 8 , wherein alkyl ligand of the metal-ligand complex precursor vapor is a methyl, ethyl, or propyl ligand.
18. The method of claim 8 , wherein the metal-ligand vapor has a partial pressure of 0.001-10 Torr.