Ex-situ solid electrolyte interface modification using chalcogenides for lithium metal anode
Implementations described herein generally relate to metal electrodes, more specifically lithium-containing anodes, high performance electrochemical devices, such as secondary batteries, including the aforementioned lithium-containing electrodes, and methods for fabricating the same. In one implementation, an anode electrode structure is provided. The anode electrode structure comprises a current collector comprising copper. The anode electrode structure further comprises a lithium metal film formed on the current collector. The anode electrode structure further comprises a solid electrolyte interface (SEI) film stack formed on the lithium metal film. The SEI film stack comprises a chalcogenide film formed on the lithium metal film. In one implementation, the SEI film stack further comprises a lithium oxide film formed on the chalcogenide film. In one implementation, the SEI film stack further comprises a lithium carbonate film formed on the lithium oxide film.
1. A method, comprising:
forming a lithium metal film on an anode film, wherein the anode film is formed on a current collector comprising a copper film; and
forming a solid electrolyte interface (SEI) film stack on the lithium metal film, comprising:
forming a chalcogenide film on the lithium metal film, wherein the chalcogenide film is selected from the group of bismuth chalcogenide, a copper chalcogenide, or combinations thereof.
2. The method of claim 1 , wherein the anode film comprises graphite.
3. The method of claim 1 , wherein forming the lithium metal film comprises an evaporation process, a sputtering process, a gravure printing system, a slot-die process, or a three-dimensional lithium printing process.
4. The method of claim 1 , wherein the SEI film stack further comprises at least one of a lithium fluoride (LiF) film, a lithium carbonate (Li 2 CO 3 ) film, a lithium oxide film, a lithium nitride (Li 3 N) film, or combinations thereof.
5. The method of claim 4 , wherein the current collector has a thickness between about 2 micrometers and about 8 micrometers.
6. The method of claim 1 , wherein the current collector comprises:
a first nickel or chromium containing film;
the copper film formed on the first nickel or chromium containing film and having a thickness between about 50 nanometers and about 500 nanometers; and
a second nickel or chromium containing film formed on the copper film and having a thickness between about 20 nanometers and about 50 nanometers.
7. The method of claim 1 , wherein the current collector comprises:
a polyethylene terephthalate (PET) polymer substrate; and
the copper film formed on the PET polymer substrate, wherein the copper film is deposited via a physical vapor deposition process.
8. The method of claim 1 , wherein the current collector comprising the copper film is exposed to a plasma treatment or corona discharge process to remove organic materials from exposed surfaces of the current collector.
9. The method of claim 1 , wherein the SEI film stack further comprises lithium fluoride formed on the chalcogenide film.
10. The method of claim 1 , wherein the chalcogenide film is selected from the group of CuS, Cu 2 Se, Cu 2 S, Cu 2 Te, CuTe, Bi 2 Te 3 , Bi 2 Se 3 , or combinations thereof.
11. The method of claim 1 , wherein the SEI film stack further comprises a lithium oxide film formed on the chalcogenide film.
12. The method of claim 11 , wherein the SEI film stack further comprises a lithium carbonate film formed on the lithium oxide film.
13. The method of claim 1 , wherein the chalcogenide film is deposited using a physical vapor deposition (PVD) process having an RF power source or a DC power source coupled to a target composed of the materials of the chalcogenide film.
14. The method of claim 13 , further comprising:
forming a lithium oxide film on the chalcogenide film by depositing an additional lithium metal film via a PVD process performed in an oxygen-containing atmosphere.
15. An anode electrode structure, comprising:
a current collector comprising a copper film;
an anode film formed on the current collector;
a lithium metal film formed on the anode film; and
a solid electrolyte interface (SEI) film stack formed on the lithium metal film, comprising:
a lithium oxide film;
a lithium carbonate film formed on the lithium oxide film; and
a chalcogenide film formed on the lithium carbonate film, wherein the chalcogenide film is selected from the group of a bismuth chalcogenide, a copper chalcogenide, or combinations thereof.
16. The anode electrode structure of claim 15 , wherein the SEI film stack further comprises a lithium nitride film formed between the lithium metal film and the lithium oxide film.
17. The anode electrode structure of claim 15 , wherein the chalcogenide film is selected from the group of CuS, Cu 2 Se, Cu 2 S, Cu 2 Te, CuTe, Bi 2 Te 3 , Bi 2 Se 3 , or combinations thereof.
18. The anode electrode structure of claim 17 , wherein the chalcogenide film has a thickness between about 1 nanometer to about 400 nanometers.
19. The anode electrode structure of claim 18 , wherein the lithium metal film has a thickness between about 1 micrometers and about 20 micrometers.
20. The anode electrode structure of claim 15 , wherein the chalcogenide film is Bi 2 Te 3 .