Lithium Ion Prismatic Cells

• US 20090068548A1
• Filed: 09/06/2007
• Published: 03/12/2009
• Est. Priority Date: 09/06/2007
• Status: Abandoned Application

• Current Assignee: Gillette Company (The Procter & Gamble Company)
• Original Assignee: Gillette Company (The Procter & Gamble Company)
• Inventors: Kaplan, Alexander
• Application Number:
  US11/850,971
• Publication Number:
  US 20090068548A1
• Time in Patent Office: Days
• US Class Current: 429/56
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0587 of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
• CPC Class Codes: H01M 4/0404 by coating on electrode collectors
• CPC Class Codes: H01M 4/5825 Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
• CPC Class Codes: H01M 4/661 Metal or alloys, e.g. alloy coatings H01M4/669 take precedence
• CPC Class Codes: H01M 50/103 prismatic or rectangular H01M50/109, H01M50/11 take precedence
• CPC Class Codes: H01M 50/3425 in the form of rupturable membranes or weakened parts, e.g. pierced with the aid of a sharp member
• CPC Class Codes: H01M 50/555 Window-shaped terminals
• 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

Abstract

The disclosure relates to prismatic lithium ion secondary cells. Some cells include venting features and/or multiple connecting tabs. In some cells the cathode includes LiFePO₄.

Claims

1. A secondary battery comprising

a prismatic-shaped housing;

and

an anode, a cathode including LiFePO₄, and a separator between the anode and the cathode disposed within the housing.

2. A lithium ion prismatic cell comprising

cell components, including an anode, a cathode comprising lithium, and a separator between the anode and cathode, and

a housing in which the cell components are disposed, the housing including two or more vents, at least two of the vents configured to burst when the internal pressure of the prismatic cell reaches different predetermined levels of internal pressure.

3. The cell of claim 2 wherein one of the vents is on a side surface of the housing.

4. The cell of claim 2 wherein at least one of the vents comprises a coined feature.

5. The cell of claim 2 wherein at least one of the vents comprises an elongated groove having a triangular or trapezoidal cross-section.

6. The cell of claim 2 wherein one of the vents comprises an elongated groove having a length that is about 50 to 80% of the width of the housing, a depth such that the wall thickness in the groove is about 20 to 30% of the wall thickness of the housing, and a width that is about 50 to 60% of the wall thickness of the housing.

7. The cell of claim 5 wherein the elongated groove extends parallel to a top surface of the cell, on a side wall of the housing, at a distance of about 20 to 40% of the total height of the cell from the top edge of the housing.

8. The cell of claim 3 wherein the cell further comprises a cover, sealingly joined to the housing, and the other vent is in the cover.

9. The cell of claim 8 wherein the wall thickness of the vent in the cover is about 6-10% of the wall thickness of the cover.

10. The cell of claim 8 wherein the vent in the cover has a shape that includes at least two intersecting lines.

11. The cell of claim 2 wherein said cathode comprises LiFePO₄.

12. A secondary lithium ion battery comprising:

a housing having at least one substantially flat side along the length of the housing, with the housing supporting a negative contact and a positive contact,

an anode, and a cathode comprising lithium, disposed within the housing, with at least the cathode comprising a sheet having a predetermined length, and

a plurality of connection tabs disposed at spaced locations along the length of the cathode to connect the cathode to the positive contact.

13. The battery of claim 12 wherein the cathode comprises a sheet form metal substrate, and a coating of active material disposed on the substrate.

14. The battery of claim 13 wherein the sheet form metal substrate comprises a copper foil.

15. The battery of claim 12 wherein the connection tabs are evenly spaced along the length of the cathode.

16. The battery of claim 12 wherein the connection tabs are formed of aluminum.

17. The battery of claim 12 wherein said cathode comprises LiFePO₄.

18. The battery of claim 12 wherein said anode and said cathode each include a foil layer and a coating of active material disposed on a surface of the foil layer.

19. The battery of claim 12 wherein said anode and cathode are each in the form of sheets, the sheets are spirally wound together, and the battery further comprises a separator interposed between the spirally wound sheets.

20. The battery of claim 12 wherein said housing has a thickness of between about 2 mm and 15 mm, a width between about 10 mm and 50 mm, and a length between about 20 mm and 60 mm.