Rechargeable positive electrodes

• US 5,789,108 A
• Filed: 03/11/1997
• Issued: 08/04/1998
• Est. Priority Date: 11/23/1994
• Status: Expired due to Term

• Current Assignee: PolyPlus Battery Company
• Original Assignee: PolyPlus Battery Company
• Inventors: Chu, May-Ying
• Primary Examiner(s): Bell, Bruce F.
• Application Number:
  US08/814,927
• Time in Patent Office: 511 Days
• Field of Search: 429/102, 429/103, 429/104, 429/105, 429/212, 429/218, 429/233, 429/190, 429/192, 429/194, 429/213, 136/238, 136/263
• US Class Current: 429/213
• CPC Class Codes: C07C 227/32 by stereospecific synthesis
• CPC Class Codes: H01M 10/05 Accumulators with non-aqueous electrolyte H01M10/39 takes precedence
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0565 Polymeric materials, e.g. gel-type or solid-type
• CPC Class Codes: H01M 10/0569 characterised by the solvents
• CPC Class Codes: H01M 10/36 Accumulators not provided for in groups H01M10/05-H01M10/34
• CPC Class Codes: H01M 10/39 working at high temperature
• CPC Class Codes: H01M 10/3909 Sodium-sulfur cells
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 2004/028 Positive electrodes
• CPC Class Codes: H01M 2300/0065 Solid electrolytes
• CPC Class Codes: H01M 2300/0085 Immobilising or gelification of electrolyte
• CPC Class Codes: H01M 4/02 Electrodes composed of, or comprising, active material
• CPC Class Codes: H01M 4/04 Processes of manufacture in general
• CPC Class Codes: H01M 4/0402 Methods of deposition of the material
• CPC Class Codes: H01M 4/0404 by coating on electrode collectors
• CPC Class Codes: H01M 4/0409 by a doctor blade method, slip-casting or roller coating
• CPC Class Codes: H01M 4/0411 by extrusion
• CPC Class Codes: H01M 4/0416 involving impregnation with a solution, dispersion, paste or dry powder H01M4/0438 takes precedence
• CPC Class Codes: H01M 4/043 involving compressing or compaction
• CPC Class Codes: H01M 4/0435 : Rolling or calendering
• CPC Class Codes: H01M 4/0438 : by electrochemical processing electroless electrochemical plating C23C18/54
• CPC Class Codes: H01M 4/045 : Electrochemical coating; Electrochemical impregnation
• CPC Class Codes: H01M 4/13 : Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
• CPC Class Codes: H01M 4/38 : of elements or alloys
• CPC Class Codes: H01M 4/382 : Lithium H01M4/405 takes precedence
• CPC Class Codes: H01M 4/581 : Chalcogenides or intercalation compounds thereof
• CPC Class Codes: H01M 4/5815 : Sulfides
• CPC Class Codes: H01M 4/60 : of organic compounds
• CPC Class Codes: H01M 4/62 : Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
• CPC Class Codes: H01M 4/621 : Binders
• CPC Class Codes: H01M 4/624 : Electric conductive fillers
• CPC Class Codes: H01M 4/625 : Carbon or graphite
• CPC Class Codes: H01M 4/626 : Metals
• CPC Class Codes: H01M 50/46 : Separators, membranes or diaphragms characterised by their combination with electrodes
• CPC Class Codes: H01M 6/164 : by the solvent
• CPC Class Codes: H01M 6/168 : by additives
• CPC Class Codes: H01M 6/18 : with solid electrolyte
• CPC Class Codes: H01M 6/181 : with polymeric electrolytes
• CPC Class Codes: H01M 6/188 : Processes of manufacture
• CPC Class Codes: H01M 6/40 : Printed batteries , e.g. thin film batteries
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries

Abstract

Disclosed are positive electrodes containing active-sulfur-based composite electrodes. The cells include active-sulfur, an electronic conductor, and an ionic conductor. These materials are provided in a manner allowing at least about 10% of the active-sulfur to be available for electrochemical reaction. Also disclosed are methods for fabricating active-sulfur-based composite electrodes. The method begins with a step of combining the electrode components in a slurry. Next, the slurry is homogenized such that the electrode components are well mixed and free of agglomerates. Thereafter, before the electrode components have settled or separated to any significant degree, the slurry is coated on a substrate to form a thin film. Finally, the coated film is dried to form the electrode in such a manner that the electrode components do not significantly redistribute.

Claims

1. A positive electrode comprising:

a) an electrochemically active material selected from the group consisting of elemental sulfur, a metal sulfide, a metal polysulfide, and combinations thereof, wherein said metal is selected from the group consisting of alkali metals, alkaline earth metals, and mixtures of alkali and alkaline earth metals;

b) an electronically conductive material mixed with the electrochemically active material so that electrons move between the electrochemically active material and the electronically conductive material; and

c) an ionically conductive material mixed with the electrochemically active material so that ions move between the ionically conductive material and the electrochemically active material, wherein at least about 10% of the electrochemically active material is accessible to electrons and ionic charge carriers, and wherein the ionically conductive material is a solid or gel state material and is not a sulfide or polysulfide.

2. The positive electrode of claim 1, wherein the electrochemically active material is non-molten.

3. The positive electrode of claim 1, wherein the positive electrode contains between about 20% by weight to about 80% by weight electrochemically active material.

4. The positive electrode of claim 3, wherein the positive electrode contains, between about 40% by weight to about 60% by weight, electrochemically active material.

5. The positive electrode of claim 1, wherein the electronically conductive material is selected from the group consisting of carbon black, compounds with conjugated carbon-carbon or carbon-nitrogen double bonds, electronically conductive polymers, polyaniline compounds, polythiophene compounds, polyacteylene compounds, polypyrrole compounds, and combinations thereof.

6. The positive electrode of claim 1, wherein the positive electrode contains, between about 5% by weight to about 40% by weight, electronically conductive material.

7. The positive electrode of claim 1, wherein the positive electrode contains, between about 8% by weight to about 24% by weight, electronically conductive material.

8. The positive electrode of claim 1, wherein the ionically conductive material of the positive electrode is provided in a solid-state form.

9. The positive electrode of claim 8, wherein the ionically conductive material is selected from the group consisting of polymeric electrolytes, ceramic electrolytes, glass electrolytes, beta alumina compounds, and combinations thereof.

10. The positive electrode of claim 8, wherein the solid-state ionic conductor comprises an electrolyte salt that form a complex with compounds selected from the group consisting of polyether compounds, polyimine compounds, polythioether compounds, polyphosphazene compounds, polyalkylene oxide compounds, polyethylene oxide compounds, amorphous polyethylene oxide compounds, and combinations thereof.

11. The positive electrode of claim 10, wherein the solid-state ionic conductor additionally comprises between about 0.1% and about 20% aprotic organic liquid.

12. The positive electrode of claim 1, wherein the positive electrode contains an ionically conductive material in a gel-state.

13. The positive electrode of claim 12, wherein the ionically conductive material comprises:

a) between about 20% and about 80% of an aprotic organic liquid;

b) a gelling agent; and

c) an electrolyte salt.

14. The positive electrode of claim 13, wherein the aprotic organic liquid is selected from the group consisting of sulfolane compounds, dimethyl sulfone compounds, tetrahydrofuran compounds, propylene carbonate compounds, dialkyl carbonate compounds, ethylene carbonate compounds, dimethyl carbonate compounds, butyrolactone compounds, N-methyulpyrrolidinone compounds, tetramethylurea compounds, dioxoalane compounds, glyme and multiglyme compounds, ether compounds, crown ether compounds, dimethoxyethane compounds, and combinations thereof.

15. The positive electrode of claim 13, wherein the gelling agent is selected from the group consisting of polyvinylidine fluoride compounds, hexafluoropropylene-vinylidene fluoride copolymers, polyacrylonitrile compounds, cross-linked polyether compounds, polyalkylene oxide compounds, polyethylene oxide compounds, and combinations thereof.

16. The positive electrode of claim 1, wherein the positive electrode further comprises at least one of the following:

binders, electrocatalysts, surfactants, dispersants, and protective layer forming additives.

17. A positive electrode comprising:

a) an electrochemically active material selected from the group consisting of elemental sulfur, a metal sulfide, a metal polysulfide, and combinations thereof, wherein said metal is selected from the group consisting of alkali metals, alkaline earth metals, and mixtures of alkali and alkaline earth metals;

b) an electronically conductive material mixed with the electrochemically active material so that electrons move between the electrochemically active material and the electronically conductive material; and

c) an ionically conductive material mixed with the electrochemically active material so that ions move between the ionically conductive material and the electrochemically active material, wherein at least about 20% of the electrochemically active material is accessible to electrons and ionic charge carriers, and wherein the ionically conductive material is a solid or gel state material and is not a sulfide or polysulfide.

18. The positive electrode of claim 17, wherein at least about 50% of the electrochemically active material is accessible to electrons and ionic charge carriers.

19. The positive electrode of claim 17, wherein at least about 90% of the electrochemically active material is accessible to electrons and ionic charge carriers.

20. The positive electrode of claim 17, wherein the electrochemically active material is non-molten.

21. The positive electrode of claim 17, wherein the positive electrode contains between about 20% by weight to about 80% by weight electrochemically active material.

22. The positive electrode of claim 17, wherein the positive electrode contains between about 5% by weight to about 40% by weight electronically conductive material selected from the group consisting of carbon black, compounds with conjugated carbon-carbon or carbon-nitrogen double bonds, electronically conductive polymers, polyaniline compounds, polythiophene compounds, polyacteylene compounds, polypyrrole compounds, and combinations thereof.

23. The positive electrode of claim 17, wherein the ionically conductive material of the positive electrode is provided in a solid-state form and includes up to about 20% aprotic organic liquid, and wherein the ionically conductive material is selected from the group consisting of polymeric electrolytes, ceramic electrolytes, glass electrolytes, beta alumina compounds, and combinations thereof.

24. The positive electrode of claim 17, wherein the ionically conductive material is provide in a gel-state and comprises:

a) between about 20% and about 80% of an aprotic organic liquid selected from the group consisting of sulfolane compounds, dimethyl sulfone compounds, tetrahydrofuran compounds, propylene carbonate compounds, dialkyl carbonate compounds, ethylene carbonate compounds, dimethyl carbonate compounds, butyrolactone compounds, N-methyulpyrrolidinone compounds, tetramethylurea compounds, dioxoalane compounds, glyme and multiglyme compounds, ether compounds, crown ether compounds, dimethoxyethane compounds, and combinations thereof;

b) a gelling agent selected from the group consisting of polyvinylidine fluoride compounds, hexafluoropropylene-vinylidene fluoride copolymers, polyacrylonitrile compounds, cross-linked polyether compounds, polyalkylene oxide compounds, polyethylene oxide compounds, and combinations thereof; and

c) an electrolyte salt.

25. A battery cell comprising:

a) a positive electrode comprising a mixture of

i) an electrochemically active material,

ii) a gel-state or solid-state ionically conductive material, and

iii) an electronically conductive material,

the mixture having between about 10% and about 100% of the electrochemically active material accessible to electrons and ionic charge carriers;

b) a current collector electrically connected to the positive electrode;

c) a negative electrode including a metal or metal ion; and

d) an electrolyte separator;

wherein electrochemically active material is selected from the group consisting of elemental sulfur, sulfides of the metal, polysulfides of the metal, and combinations thereof.

26. The battery cell of claim 25, wherein the electrochemically active material is present in the mixture in a weight percentage of between about 20% to about 80%.

27. The battery cell of claim 25, wherein the ionically conductive material is present in the mixture in a weight percentage of between about 15% to 75%.

28. The battery cell of claim 25, wherein the electronically conductive material is present in the mixture in a weight percentage of between about 5% and about 40%.

29. The battery cell of claim 25, wherein said negative electrode is selected from the group consisting of alkali metals, alkaline earth metals, transition metals, mixtures of alkali, alkaline earth and transition metals, lithium or sodium insertion materials, and mixtures of carbon with lithium or sodium.

30. The battery cell of claim 25, wherein said negative electrode is selected from the group consisting of lithium, sodium, Na₄ Pb, lithium-silicon and lithium-aluminum alloys.

31. The battery cell of claim 25, wherein said electrolyte separator is a gel-state electrolyte separator comprising at least 20% by weight of an aprotic organic liquid immobilized by the presence of a gelling agent.

32. The battery cell of claim 25, wherein said electrolyte separator is a solid-state electrolyte separator selected from the group consisting of ceramic electrolytes, polymeric electrolytes, glass electrolytes, beta alumina compounds, porous membranes and combinations thereof.

33. The battery cell of claim 25, wherein the electrolyte separator is a liquid electrolyte separator.

34. The battery cell of claim 25, wherein the ionically conductive material comprises a compound selected from the group consisting of polyether compounds, polyimine compounds, polythioether compounds, polyphosphazene compounds, polyalkylene oxide compounds, polyethylene oxide compounds, and amorphous polyethylene oxide compounds, combinations thereof.

35. The battery cell of claim 25, wherein the ionically conductive material is in a gel state and includes

an aprotic organic liquid selected from the group consisting of sulfolane compounds, dimethyl sulfone compounds, tetrahydrofuran compounds, propylene carbonate compounds, dialkyl carbonate compounds, ethylene carbonate compounds, dimethyl carbonate compounds, butyrolactone compounds, N-methylpyrrolidinone compounds, tetramethylurea compounds, dioxolane compounds, glyme and multiglyme compounds, ether compounds, crown ether compounds, dimethoxyethane compounds, and combinations thereof;

and

a gelling agent selected from the group consisting of polyvinylidine fluoride compounds, hexafluropropylene-vinylidene fluoride copolymers, polyacrylonitrile compounds, cross-linked polyether compounds, polyalkylene oxide compounds, polyethylene oxide compounds, and combinations thereof.

36. The battery cell of claim 25, wherein the positive electrode comprises a) the electrochemically active material in a percentage by weight from 40% to 60%;

b) the ionically conductive material is either amorphous or conventional polyethylene oxide and is in a percentage by weight from 25% to 45; and

c) the electronically conductive material is selected from the group consisting of carbon black, electronically conductive compounds having conjugated carbon-carbon, or both, carbon-nitrogen double bonds, electronically conductive polymers, polyaniline compounds, polythiophene compounds, polyacetylene compounds, polypyrrole compounds, combinations of carbon black and such electronically conductive compound or compounds, and combinations of such electronically conductive compounds; and

wherein said electronically conductive material is in a percentage by weight from 15% to 25%.

37. The battery cell of claim 25, wherein positive electrode further comprises one or more of the following:

binders, electrocatalysts, surfactants, dispersants, and protective layer forming additives.

38. The battery cell of claim 25, wherein the electrochemically active material is non-molten.

39. A battery cell comprising:

a) a positive electrode comprising a mixture of

i) an electrochemically active material,

ii) a gel-state or solid-state ionically conductive material, and

iii) an electronically conductive material,

the mixture having between about 20% and about 100% of the electrochemically active material accessible to electrons and ionic charge carriers;

b) a current collector electrically connected to the positive electrode;

c) a negative electrode including a metal or metal ion; and

d) an electrolyte separator;

wherein electrochemically active material is selected from the group consisting of elemental sulfur, sulfides of the metal, polysulfides of the metal, and combinations thereof.

40. The battery cell of claim 39, wherein at least about 50% of the electrochemically active material is accessible to electrons and ionic charge carriers.

41. The battery cell of claim 39, wherein at least about 90% of the electrochemically active material is accessible to electrons and ionic charge carriers.

42. The battery cell of claim 39, wherein the positive electrode is electrically connected to a current collector.

43. The battery cell of claim 39, wherein the electrochemically active material is non-molten.

44. The battery cell of claim 39, wherein the positive electrode contains between about 20% by weight to about 80% by weight electrochemically active material.

45. The battery cell of claim 39, wherein the positive electrode contains between about 5% by weight to about 40% by weight electronically conductive material selected from the group consisting of carbon black, compounds with conjugated carbon-carbon or carbon-nitrogen double bonds, electronically conductive polymers, polyaniline compounds, polythiophene compounds, polyacteylene compounds, polypyrrole compounds, and combinations thereof.

46. The battery cell of claim 39, wherein the ionically conductive material of the positive electrode is provided in a solid-state form and includes up to about 20% aprotic organic liquid, and wherein the ionically conductive material is selected from the group consisting of polymeric electrolytes, ceramic electrolytes, glass electrolytes, beta alumina compounds, and combinations thereof.

47. The battery cell of claim 39, wherein the ionically conductive material is provide in a gel-state and comprises:

a) between about 20% and about 80% of an aprotic organic liquid selected from the group consisting of sulfolane compounds, dimethyl sulfone compounds, tetrahydrofuran compounds, propylene carbonate compounds, dialkyl carbonate compounds, ethylene carbonate compounds, dimethyl carbonate compounds, butyrolactone compounds, N-methyulpyrrolidinone compounds, tetramethylurea compounds, dioxoalane compounds, glyme and multiglyme compounds, ether compounds, crown ether compounds, dimethoxyethane compounds, and combinations thereof;

b) a gelling agent selected from the group consisting of polyvinylidine fluoride compounds, hexafluoropropylene-vinylidene fluoride copolymers, polyacrylonitrile compounds, cross-linked polyether compounds, polyalkylene oxide compounds, polyethylene oxide compounds, and combinations thereof; and

c) an electrolyte salt.

48. The battery cell of claim 39, wherein said negative electrode is selected from the group consisting of alkali metals, alkaline earth metals, transition metals, mixtures of alkali, alkaline earth and transition metals, lithium or sodium insertion materials, and mixtures of carbon with lithium or sodium.

49. The battery cell of claim 39, wherein said negative electrode is selected from the group consisting of lithium, sodium, Na₄ Pb, lithium-silicon and lithium-aluminum alloys.