Buried anode lithium thin film battery and process for forming the same

• US 20030162094A1
• Filed: 03/17/2003
• Published: 08/28/2003
• Est. Priority Date: 11/13/2001
• Status: Active Grant

• Current Assignee: Alliance For Sustainable Energy LLC
• Original Assignee: Midwest Research Institute
• Inventors: Lee, Se-Hee, Liu, Ping, Tracy, C. Edwin
• Granted Patent: US 6,805,999 B2
• Time in Patent Office: Days
• US Class Current: 429/231.95
• CPC Class Codes: H01M 10/0436 Small-sized flat cells or batteries for portable equipment
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0562 Solid materials
• CPC Class Codes: H01M 10/058 Construction or manufacture
• CPC Class Codes: H01M 4/0421 involving vapour deposition
• CPC Class Codes: H01M 4/0426 Sputtering
• CPC Class Codes: H01M 4/0438 by electrochemical processing electroless electrochemical plating C23C18/54
• CPC Class Codes: H01M 4/0445 Forming after manufacture of the electrode, e.g. first charge, cycling
• CPC Class Codes: H01M 4/1391 of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/1395 of electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/382 Lithium H01M4/405 takes precedence
• CPC Class Codes: H01M 4/485 of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy H01M4/505, H01M4/525 take precedence
• CPC Class Codes: H01M 4/505 of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 29/49108 Electric battery cell making
• CPC Class Codes: Y10T 29/49115 including coating or impregnating

Abstract

A reverse configuration, lithium thin film battery (300) having a buried lithium anode layer (305) and process for making the same. The present invention is formed from a precursor composite structure (200) made by depositing electrolyte layer (204) onto substrate (201), followed by sequential depositions of cathode layer (203) and current collector (202) on the electrolyte layer. The precursor is subjected to an activation step, wherein a buried lithium anode layer (305) is formed via electroplating a lithium anode layer at the interface of substrate (201) and electrolyte film (204). The electroplating is accomplished by applying a current between anode current collector (201) and cathode current collector (202).

Claims

1. The process of producing a secondary, lithium based, thin film battery, the process comprising the steps of:

a) depositing a film comprising a solid state electrolyte material onto an exposed, conductive face of a substrate, wherein the solid state electrolyte material is a conductor of lithium ions;

b) depositing a film of a transition metal oxide upon an exposed face of said film of solid state electrolyte material;

c) lithiating said transition metal oxide film until it contains a supra-stoichiometric amount of lithium, thus forming a cathode film layer;

d) depositing a current collector film upon an exposed face of said cathode film layer, said current collector comprising an electron conducting material;

e) orming a buried anode layer comprising lithium metal between said conductive face of said substrate and said solid state electrolyte material by flowing a current between said substrate conductive face and said cathode current collector, whereby said cathode film layer is oxidized, causing lithium ions to migrate into and through said solid state electrolyte material, thence being reduced to lithium metal and forming said buried anode layer; and

f) maintaining said current flow until said buried anode layer contains a desired amount of lithium metal.

2. The process of claim 1, wherein techniques used to deposit said films are selected from vacuum evaporation and reactive sputtering.

3. The process of claim 1, wherein said solid state electrolyte film comprises Sub-stoichiometric lithium phosphorous oxynitride.

4. The process of claim 3, wherein said cathode film is selected from lithium vanadate, lithium manganate, lithium nickelate, and lithium cobaltate.

5. The process of claim 1, wherein said substrate is selected from stainless steel, plastic bearing a conductive coating on at least one face, and glass bearing a conductive coating on at least one face.

6. The process of claim 1, wherein said cathode current collector is selected from aluminum, gold, and refractory metals.

35. The process of claim 3, wherein said cathode film is lithium vanadate.

36. The process of claim 3, wherein said cathode film is lithium manganate.

37. The process of claim 3, wherein said cathode film is lithium nickelate.

38. The process of claim 3, wherein said cathode film is lithium cobaltate.

7. The process of producing a secondary, lithium based, thin film battery, the process comprising the steps of:

a) depositing a film comprising a solid state electrolyte material onto an exposed, conductive face of a substrate, wherein the solid state electrolyte material is a conductor of lithium ions;

b) depositing a cathode film comprising a lithiated transition metal oxide upon an exposed face of said film of solid state electrolyte material;

c) depositing a current collector film upon an exposed face of said cathode film layer, said current collector comprising an electron conducting material;

d) forming a buried anode layer comprising lithium metal between said conductive face of said substrate and said solid state electrolyte material by flowing a current between said substrate conductive face and said cathode current collector, whereby said cathode film layer is oxidized, causing lithium ions to migrate into and through said solid state electrolyte material, thence being reduced to lithium metal and forming said buried anode layer; and

e) maintaining said current flow until said buried anode layer contains a desired amount of lithium metal.

8. The process of claim 7, wherein techniques used to deposit said films are selected from vacuum evaporation and reactive sputtering.

9. The process of claim 7, wherein said solid state electrolyte film comprises Sub-stoichiometric lithium phosphorous oxynitride.

10. The process of claim 9, wherein said cathode film is selected from lithium vanadate, lithium manganate, lithium nickelate, and lithium cobaltate.

11. The process of claim 7, wherein said substrate is selected from stainless steel, plastic beating a conductive coating on at least one face, and glass beating a conductive coating on at least one face.

12. The process of claim 7, wherein said cathode current collector is selected from aluminum, gold, and refractory metals.

13. The process of producing a secondary, lithium based, thin film battery, the process comprising the steps of:

a) depositing a film comprising lithium phosphorous oxynitride on an exposed face of type 430 stainless steel substrate by reactive ion sputtering from a target of Li₃PO₄ in nitrogen, thereby forming a lithium phosphorous oxynitride electrolyte film bonded to one face of said stainless steel substrate;

b) forming a cathode film comprising lithium vanadate bonded to an exposed face of said lithium phosphorous oxynitride;

c) depositing a film comprising copper metal upon an exposed face of said cathode film, thereby forming a cathode current collector bonded to said lithium vanadate cathode film;

d) depositing a film comprising copper metal upon an exposed face of said lithium vanadate cathode film, thereby forming a cathode current collector bonded to said lithium vanadate cathode film;

e) forming a buried anode layer comprising lithium metal between said stainless steel substrate and said lithium phosphorous oxynitride electrolyte film by flowing a current between said stainless steel substrate and said cathode current collector, whereby said cathode film layer is oxidized, causing lithium ions to migrate into and through said solid state electrolyte material, thence being reduced to lithium metal and forming said buried anode layer; and

f) maintaining said current flow until said buried anode layer contains a desired amount of lithium metal.

14. The process of producing a secondary, lithium based, thin film battery, the process comprising the steps of:

a) depositing a film comprising lithium phosphorous oxynitride on the exposed face of a type 304 stainless steel substrate by reactive ion sputtering from an LiPO₄ target in nitrogen, thereby forming a lithium phosphorous oxynitride electrolyte film bonded to said stainless steel substrate face;

b) depositing a film comprising vanadium oxide upon an exposed face of said lithium phosphorous oxynitride film by thermal evaporation from vanadium oxide powder, thereby forming a vanadium oxide film bonded to said phosphorous oxynitride film;

c) exposing said vanadium oxide film to lithium metal vapor, thereby forming a lithium vanadate cathode film;

d) depositing a film comprising copper metal upon an exposed face of said lithium vanadate cathode film, thereby forming a cathode current collector bonded to said lithium vanadate cathode film;

e) forming a buried lithium anode layer between said stainless steel substrate and said lithium phosphorous oxynitride electrolyte film by flowing a current between said substrate and said cathode current collector, whereby said lithium vanadate cathode film is oxidized, causing lithium ions to migrate into and through said lithium phosphorous oxynitride electrolyte film, thence being reduced to lithium metal and forming said buried anode layer; and

f) maintaining said current flow until said buried anode layer contains a desired amount of lithium metal.

15. The process of claim 14, wherein said vanadium oxide film is exposed to sufficient lithium vapor to form a film having the formula LixV₂O₅ where x is about 3 or greater.

16. A lithium battery composite precursor having:

a) an anode current collector layer that has at least one conductive face and is characterized by its ability to support layers deposited onto it;

b) an electrolyte layer, one face of which is in communication with a conductive face of said anode current collector layer, wherein said electrolyte layer is a conductor of lithium ions;

c) a cathode layer that is in communication with a face of said electrolyte layer that is not in communication with said anode current collector layer; and

d) a cathode current collector layer that is in communication with a face of the cathode layer that is not in communication with the electrolyte layer, the composite precursor being characterized by its ability to form a buried lithium anode layer at the interface between said anode current collector and said electrolyte when a current is maintained between the anode current collector and the cathode current collector, and its ability to be chemically stable when exposed to an ambient environment.

17. The composite structure of claim 16 having an anode current collector comprising a stainless steel, an electrolyte comprising Sub-stoichiometric lithium phosphorous oxynitride, and a cathode layer comprising a material of the formula Li_xV₂O₅, where X is about 3 or greater.

18. A lithium thin film battery having:

a) an anode current collector layer that has at least one conductive face and is characterized by its ability to support layers deposited onto it;

b) a buried anode layer comprising lithium metal in communication with a conductive face of said anode current collector;

c) an electrolyte layer, one face of which is in communication with said anode layer;

d) a cathode layer that is in communication with a face of said electrolyte layer that is not in communication with said anode layer; and

e) a cathode current collector layer that is in communication with a face of the cathode layer that is not in communication with the electrolyte layer, the battery being characterized by an increase in the amount of metallic lithium contained in its buried anode layer upon charging and a reduction in the amount of lithium metal in its buried anode layer upon discharging, and its chemical stability when exposed to an ambient environment in any state of charge.

19. The battery of claim 18 having an anode current collector comprising a stainless steel, an electrolyte comprising Sub-stoichiometric lithium phosphorous oxynitride, and a cathode layer comprising a material of the formula Li_xV₂O₅, where in the uncharged state, x is about 3 or greater.

20. The process of producing a lithium based, thin film battery precursor composite structure, the process comprising the steps of:

a) depositing a film comprising a solid state electrolyte material onto an exposed, conductive face of a substrate, wherein the solid state electrolyte material is a conductor of lithium ions;

b) depositing a film comprising a transition metal oxide upon an exposed face of said film of solid state electrolyte material;

c) lithiating said transition metal oxide film until it contains a supra-stoichiometric amount of lithium, thus forming a cathode film layer; and

d) depositing a current collector film upon an exposed face of said cathode film layer, said current collector comprising an electron conducting material.

21. The process of claim 20, wherein techniques used to deposit said films are selected from vacuum evaporation and reactive sputtering.

22. The process of claim 20, wherein said solid state electrolyte film is Sub-stoichiometric lithium phosphorous oxynitride.

23. The process of claim 22, wherein said cathode film layer is selected from lithium vanadate, lithium manganate, lithium nickelate, and lithium cobaltate.

24. The process of claim 20, wherein said substrate is selected from stainless steel, plastic bearing a conductive coating on at least one face, and glass beating a conductive coating on at least one face.

25. The process of claim 20, wherein said cathode current collector is selected from aluminum, gold, and refractory metals.

26. The process of producing a lithium based, thin film battery precursor composite structure, the process comprising the steps of:

a) depositing a film comprising a solid state electrolyte material onto an exposed, conductive face of a substrate, wherein the solid state electrolyte material is a conductor of lithium ions;

b) depositing a cathode film comprising lithiated transition metal oxide upon an exposed face of said film of solid state electrolyte material; and

c) depositing a current collector film upon an exposed face of said cathode film layer, said current collector comprising an electron conducting material.

27. The process of claim 26, wherein techniques used to deposit said films are selected from vacuum evaporation and reactive sputtering.

28. The process of claim 26, wherein said solid state electrolyte film is Sub-stoichiometric lithium phosphorous oxynitride.

29. The process of claim 28, wherein said cathode layer is selected from lithium vanadate, lithium manganate, lithium nickelate, and lithium cobaltate.

30. The process of claim 26, wherein said substrate is selected from a stainless steel, a plastic bearing a conductive coating on at least one face, and a glass bearing a conductive coating on at least one face.

31. The process of claim 26, wherein said cathode current collector is selected from aluminum, gold, and refractory metals.

32. The process of producing a lithium based, thin film battery precursor composite structure, the process comprising the steps of:

a) depositing a film comprising lithium phosphorous oxynitride on an exposed face of a type 430 stainless steel substrate by reactive ion sputtering from a target of Li₃PO₄ in nitrogen, thereby forming a lithium phosphorous oxynitride electrolyte film bonded to one face of said stainless steel substrate;

b) forming a cathode film comprising lithium vanadate bonded to an exposed face of said lithium phosphorous oxynitride; and

c) depositing a film comprising copper metal upon an exposed face of said cathode film, thereby forming a cathode current collector bonded to said lithium vanadate cathode film.

33. The process of producing a lithium based, thin film battery precursor composite structure, the process comprising the steps of:

a) depositing a film comprising lithium phosphorous oxynitride on the exposed face of a type 430 stainless steel substrate by reactive ion sputtering from an LiPO₄ target in nitrogen, thereby forming a lithium phosphorous oxynitride electrolyte film bonded to said stainless steel substrate face;

b) depositing a film comprising vanadium oxide upon an exposed face of said lithium phosphorous oxynitride film by thermal evaporation from vanadium oxide powder, thereby forming a vanadium oxide film bonded to said phosphorous oxynitride film;

c) exposing said vanadium oxide film to lithium metal vapor, thereby forming a lithium vanadate cathode film; and

d) depositing a film comprising copper metal upon an exposed face of said lithium vanadate cathode film, thereby forming a cathode current collector bonded to said lithium vanadate cathode film.

34. The process of claim 33, wherein said vanadium oxide film is exposed to sufficient lithium vapor to form a film having a composition Li_xV₂O₅, where x is about 3 or greater.

39. A lithium based, thin film battery precursor composite structure produced by the process comprising the steps of:

a) depositing a film comprising a solid state electrolyte material onto an exposed, conductive face of a substrate, wherein the solid state electrolyte material is a conductor of lithium ions;

b) depositing a film comprising a transition metal oxide upon an exposed face of said film of solid state electrolyte material;

c) lithiating said transition metal oxide film until it contains a supra-stoichiometric amount of lithium, thus forming a cathode film layer; and

d) depositing a current collector film upon an exposed face of said cathode film layer, said current collector comprising an electron conducting material.

40. A secondary, lithium based, thin film battery produced by the process comprising the steps of:

a) depositing a film comprising a solid state electrolyte material onto an exposed, conductive face of a substrate, wherein the solid state electrolyte material is a conductor of;

lithium ions;

b) depositing a film of a transition metal oxide upon an exposed face of said film of solid state electrolyte material;

c) lithiating said transition metal oxide film until it contains a supra-stoichiometric amount of lithium, thus forming a cathode film layer;

d) depositing a current collector film upon an exposed face of said cathode film layer, said current collector comprising an electron conducting material;

e) forming a buried anode layer comprising lithium metal between said conductive face of said substrate and said solid state electrolyte material by flowing a current between said substrate conductive face and said cathode current collector, whereby said cathode film layer is oxidized, causing lithium ions to migrate into and through said solid state electrolyte material, thence being reduced to lithium metal and forming said buried anode layer; and

f) maintaining said current flow until said buried anode layer contains a desired amount of lithium metal.