High energy high power electrodes and batteries

• US 9,299,966 B2
• Filed: 03/25/2009
• Issued: 03/29/2016
• Est. Priority Date: 03/25/2008
• Status: Active Grant

• Current Assignee: A123 Systems Incorporated
• Original Assignee: A123 Systems Incorporated
• Inventors: Chiang, Yet-Ming, Chu, Andrew C., Jang, Young-Il, Wixom, Michael
• Primary Examiner(s): Dye, Rena L
• Application Number:
  US12/411,380
• Publication Number:
  US 20090246636A1
• Time in Patent Office: 2,561 Days
• Field of Search: 429/231.95, 429/209, 429/210, 296/232, 296/234
• US Class Current: 1/1
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0585 of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
• CPC Class Codes: H01M 4/131 Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/139 Processes of manufacture
• CPC Class Codes: H01M 4/64 Carriers or collectors
• CPC Class Codes: H01M 50/446 Composite material consisting of a mixture of organic and inorganic materials
• CPC Class Codes: H01M 50/46 Separators, membranes or diaphragms characterised by their combination with electrodes
• 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

Abstract

Subassemblies for use in an electrochemical device are provided, as are processes for preparing the subassemblies and electrochemical cells incorporating the subassemblies. In some embodiments, the subassemblies include (a) a first electrode and (b) a separator or a first current collector or both. The first electrode is bonded to the separator or the first current collector or both. In some embodiments, the subassemblies further include a second electrode and a second current collector. In some embodiments, the electrodes or separators are sintered. Bipolar cells are also provided, including a plurality of stacked electrochemical cells that are joined in series. The positive electrode and the negative electrode of each stack include a sintered electrode.

Claims

1. A subassembly for use in an electrochemical device comprising:

(a) a first sintered electrode having a first surface and a second surface opposing the first surface,

(b) a first current collector surrounds a perimeter of the first electrode orthogonal to the first sintered electrode'"'"'s first surface, where a perimeter area of a portion of the first sintered electrode bonded to the first current collector is less than about 50% of a total area of the first sintered electrode, wherein the current collector is an inactive component, and

(c) a separator, wherein the second surface of the first sintered electrode is adjacent to the separator,

wherein the first sintered electrode is bonded to the separator or the first current collector or both, and

wherein the separator, the first current collector, or both are optionally sintered, and

(d) a second electrode, wherein the first and second electrodes are bonded to opposite surfaces of the separator.

2. The subassembly of claim 1, wherein the first current collector is in the shape of a border or frame.

3. The subassembly of claim 1, wherein the first current collector comprises a metallic current collector.

4. The subassembly of claim 1, wherein the separator comprises an organic compound, an inorganic-organic composite or blend, an inorganic compound, a particulate material, or a sintered particulate ceramic.

5. The subassembly of claim 1, wherein the first electrode comprises a layered oxide, a metal fluoride, or a lithium-transition metal phosphate compound, which optionally includes a dopant metal.

6. The subassembly of claim 1, wherein a portion of the first sintered electrode'"'"'s first surface to which the first current collector is confined is less than about 25% of the total area of the first sintered electrode.

7. The subassembly of claim 6, wherein the portion of the first sintered electrode'"'"'s first surface to which the first current collector is confined is less than about 15% of the total area of the first sintered electrode.

8. The subassembly of claim 1, wherein the second electrode comprises a sintered electrode.

9. The subassembly of claim 1, further comprising a second electrode and a second current collector, wherein the second electrode and the first electrode have a thermal bond to opposite surfaces of the separator and wherein the second current collector and the separator are bonded to opposite surfaces of the second electrode.

10. The subassembly of claim 1, wherein a thickness of an active layer of the first sintered electrode in the subassembly is at least about 200 μ

m.

11. The subassembly of claim 1, wherein a density of the subassembly is at least about 65% of theoretical.

12. The subassembly of claim 1, wherein the first electrode does not comprise a conductive additive.

13. The subassembly of claim 1, wherein a thickness of the first electrode is at least about 600 μ

m.

34. A process for preparing a subassembly for use in an electrochemical device according to claim 1 comprising:

(a) combining a first electrode with a separator; and

(b) heating the first electrode and the separator under conditions effective to form a sintered subassembly; and

(c) before or after the heating step, positioning a first current collector around the perimeter of the first electrode,

wherein the process produces a bond between at least the first electrode and the separator.

35. The process of claim 34 wherein the first current collector is bonded to the first electrode.

36. The process of claim 35, wherein bonding comprises forming a metal-metal bond between the first current collector and a metal film deposited at the first electrode perimeter, or thermal bonding or a forming a bond with a conductive adhesive.

37. The process of claim 34, wherein the first current collector comprises a metallic current collector.

38. The process of claim 34, wherein the heating step comprises heating the first electrode, the separator and the first current collector to form a sintered subassembly.

39. The process of claim 34, wherein a second electrode is combined with the first electrode and the separator, wherein the process produces a bond between first and second electrodes and opposite surfaces of the separator.

40. The process of claim 39, wherein the second electrode comprises a sintered electrode.

41. The process of claim 38, wherein the combining step further comprises combining a second electrode and a second current collector with the first electrode, the first current collector and the separator, and wherein the heating step comprises heating the second electrode and the first electrode with the separator, the first current collector, and the second current collector to form a sintered subassembly.

42. The process of claim 34, wherein the sintered separator comprises an organic compound, an inorganic-organic composite or blend, an inorganic compound, a particulate material, or a sintered particulate ceramic.

43. The process of claim 34, wherein the first sintered electrode comprises a layered oxide, a metal fluoride, or a lithium-transition metal phosphate compound, which optionally includes a dopant metal.

44. The process of claim 34, wherein the first electrode does not comprise a conductive additive.

45. The process of claim 34, wherein the thickness of the first electrode is at least about 600 μ

m.

14. A subassembly for use in an electrochemical device comprising

(a) a first sintered electrode having a first surface and a second surface opposing the first surface, and

(b) a first current collector surrounding a perimeter of the first sintered electrode'"'"'s first surface, where a perimeter area of a portion of the first sintered electrode bonded to the first current collector is less than about 50% of a total area of the first sintered electrode and wherein the current collector is an inactive component, and

(c) a separator, wherein the second surface of the first sintered electrode is adjacent to the separator,

wherein the subassembly is produced by

(i) combining the first electrode with the first current collector and the separator and

(ii) heating the first electrode, the first current collector, and the separator under conditions effective to form a sintered subassembly,

wherein the separator, the first current collector, or both are optionally sintered.

15. The subassembly of claim 14, wherein the separator comprises a sintered separator.

16. The subassembly of claim 14, wherein the first current collector comprises a metallic current collector.

17. The subassembly of claim 14, wherein a portion of the first sintered electrode'"'"'s first surface to which the first current collector is confined is less than about 25% of the total area of the first sintered electrode.

18. The subassembly of claim 17, wherein the portion of the first sintered electrode'"'"'s first surface to which the first current collector is confined is less than about 15% of the total area of the first sintered electrode.

19. The subassembly of claim 14, further comprising a second electrode, wherein the first and second electrodes are bonded to opposite surfaces of the separator.

20. The subassembly of claim 19, wherein the second electrode comprises a sintered electrode.

21. The subassembly of claim 19, wherein the second electrode is free of conductive additives.

22. The subassembly of claim 14, further comprising a second electrode and a second current collector, wherein the second electrode and the first electrode are heated with the separator, the first current collector, and the second current collector to form a sintered subassembly.

23. The subassembly of claim 14, wherein the separator comprises an organic compound, an inorganic-organic composite or blend, an inorganic compound, a particulate material, or a sintered particulate ceramic.

24. The subassembly of claim 14, wherein the first electrode comprises a layered oxide, a metal fluoride, or a lithium-transition metal phosphate compound, which optionally includes a dopant metal.

25. The subassembly of claim 14, wherein a thickness of the subassembly is at least about 200 μ

m.

26. The subassembly of claim 14, wherein a density of the subassembly is at least about 65% of theoretical.

27. The subassembly of claim 14, wherein the first electrode does not comprise a conductive additive.

28. The subassembly of claim 14, wherein a thickness of the first electrode is at least about 600 μ

m.

29. An electrochemical device comprising:

(a) a positive electrode in electronic contact with a positive electrode current collector, the positive current collector in electrical connection with an external circuit;

(b) a negative electrode in electronic contact with a negative electrode current collector, the negative current collector in electrical connection with an external circuit;

(c) a separator positioned between the positive electrode and the negative electrode; and

(d) an electrolyte in ionic contact with the positive and negative electrodes;

wherein the positive electrode or the negative electrode and the separator comprise a sintered subassembly,

wherein at least one of the positive and negative electrodes is a sintered electrode having a first surface and a second surface opposing the first surface and the sintered electrode'"'"'s corresponding current collector surrounds a perimeter of the sintered electrode and is less than about 50% of a total area of the sintered electrode, and wherein the current collector is an inactive component.

30. The electrochemical device of claim 29, wherein a mass fraction of inactive materials in the device is less than about 50%.

31. The electrochemical device of claim 29, wherein a specific energy of the device is greater than about 300 Wh/kg at a power density of greater than about 600 W/kg.

32. The electrochemical device of claim 29, wherein the positive electrode does not comprise a conductive additive.

33. The electrochemical device of claim 29, wherein a thickness of the positive electrode is at least about 600 μ

m.

46. A bipolar cell, comprising a plurality of stacked electrochemical cells, wherein the electrochemical cells are joined in series and wherein each of said stacked electrochemical cells comprises:

(a) a positive electrode in electronic contact with a positive electrode current collector, the positive current collector in electrical connection with an external circuit;

(b) a negative electrode in electronic contact with a negative electrode current collector, the negative current collector in electrical connection with an external circuit;

(c) a separator positioned between the positive electrode and the negative electrode; and

(d) an electrolyte in ionic contact with the positive and negative electrodes;

wherein the positive electrode and the negative electrode of each stack comprise a sintered electrode,

wherein at least one of the positive and negative electrodes is a sintered electrode having a first surface and a second surface opposing the first surface and the sintered electrode'"'"'s corresponding current collector surrounds a perimeter of the sintered electrode and is less than about 50% of a total area of the sintered electrode.

47. The bipolar cell of claim 46, wherein the separator comprises a sintered separator.

48. The bipolar cell of claim 46, wherein (a) the separator and (b) the positive electrode or the negative electrode or both are bonded.

49. The bipolar cell of claim 46, wherein (a) the positive electrode and (b) the separator or the positive current collector or both are bonded.

50. The bipolar cell of claim 46, wherein (a) the negative electrode and (b) the separator or the negative current collector or both are bonded.

51. The bipolar cell of claim 46, wherein the positive current collector, the positive electrode, the separator, the negative electrode and the negative current collector are bonded.

52. The bipolar cell of claim 46, wherein (a) the positive electrode and (b) the separator or the positive current collector or both comprise a sintered subassembly.

53. The bipolar cell of claim 46, wherein (a) the negative electrode and (b) the separator or the negative current collector or both comprise a sintered subassembly.

54. The bipolar cell of claim 46, wherein the positive current collector, the positive electrode, the separator, the negative electrode, and the negative current collector comprise a sintered subassembly.

55. The bipolar cell of claim 46, wherein the positive electrode or the negative electrode formed from a sintered ceramic is at least about 200 μ

m in thickness.

56. The bipolar cell of claim 46, wherein a sintered subassembly is at least about 200 μ

m in thickness.

57. The bipolar cell of claim 46, wherein the cell further comprises a redox shuttle.

58. The bipolar cell of claim 46, wherein the electrolyte comprises an electroactive additive.

59. The bipolar cell of claim 46, wherein the separator comprises an electroactive polymer, wherein the electroactive polymer forms a percolating pathway through the separator.

60. The bipolar cell of claim 46, wherein a thickness of the positive electrode or the negative electrode formed from a sintered ceramic varies by less than 25% from a mean thickness.

61. The bipolar cell of claim 46, wherein the positive electrode does not comprise a conductive additive.

62. The bipolar cell of claim 46, wherein a thickness of the positive electrode is at least about 600 μ

m.