Radiation curable frame for stacked cell construction and for edge sealing of electrolytic cells to retard dendritic short-circuits

• US 5,770,331 A
• Filed: 09/20/1996
• Issued: 06/23/1998
• Est. Priority Date: 04/20/1994
• Status: Expired due to Fees

• Current Assignee: Valence Technology Incorporated (Lithium Werks B.V.)
• Original Assignee: Valence Technology Incorporated (Lithium Werks B.V.)
• Inventors: Buckley, James, Olsen, Ib I., Golovin, Neal, Payne, Douglas J., Moulton, Russell D., Chaloner-Gill, Benjamin
• Primary Examiner(s): Maples, John S.
• Application Number:
  US08/727,176
• Time in Patent Office: 641 Days
• Field of Search: 429/162, 429/153, 429/159, 429/254, 429/185, 429/192
• US Class Current: 429/162
• CPC Class Codes: H01M 10/044 with bipolar electrodes
• CPC Class Codes: H01M 10/05 Accumulators with non-aqueous electrolyte H01M10/39 takes precedence
• CPC Class Codes: H01M 50/121 Organic material
• CPC Class Codes: H01M 50/186 characterised by the disposition of the sealing members
• CPC Class Codes: H01M 50/193 Organic material
• CPC Class Codes: H01M 6/181 with polymeric electrolytes
• 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

A new technique for securing into place a plurality of layers which make a battery body, and for preventing electrical short-circuits within the battery by retarding the formation of dendritic growths is disclosed. A radiation curable layer of material is coated onto a portion of at least one outwardly exposed face of a battery body, whereupon the layer of material is then cured. The cured layer of material is positioned relative to the body such that the cured layer provides support to the body in a manner to secure in place a plurality of layers which make up the battery body, thereby ensuring proper electrical contact between the plurality of layers. In addition, the cured layer of material is also positioned such that the cured layer inhibits formation of short circuiting electrical paths between the anode and cathode layers of the battery, the paths being caused by formation of dendritic growths extending out from the anode layer towards the cathode layer.

Claims

1. A flat cell battery comprising:

a body comprising a plurality of layers including;

at least one anode layer, said at least one anode layer including lithium or materials incorporating lithium.

at least one cathode layer,

at least one electrolyte layer of solid material, said at least one electrolyte layer including a lithium salt, and

a continuous radiation cured layer of material in contact with a portion of at least one outwardly exposed face of said body, said cured layer of material being positioned relative to said body such that the cured layer inhibits formation of short circuiting electrical paths between said anode and cathode layers, said paths being caused by formation of dendritic growths extending out from said anode layer towards said cathode layer;

said cured layer of material further being positioned relative to said body such that the cured layer forms a unitary frame which provides support to said body in a manner to secure in place relative positions of said plurality of layers.

2. The battery of claim 1 wherein said cured layer of material includes a mixture comprising either a radiation cured plastic or a thermoset plastic.

3. The battery of claim 1 wherein said cured layer includes a plurality of extensions which penetrate in between at least a portion of said plurality of layers.

4. The battery of claim 1 wherein said cured layer is flexible.

5. The battery of claim 1 wherein said cured layer is non-flexible.

6. The battery of claim 1 wherein said cured layer is in physical contact with a portion of at least one outwardly exposed face of said at least one anode layer.

7. The battery of claim 1 wherein said battery is devoid of a Mylar masking material, and wherein said cured layer penetrates in between at least a portion of said plurality of layers to form a gradual boundary between each of said layers, thereby establishing a transition zone for limited ionic activity.

8. The battery of claim 2 wherein said mixture is selected from the group having chemically active bonds consisting of:

material comprising carbon-carbon double bonds,

material comprising epoxide,

material comprising thiol, and

material comprising thiolene.

9. The battery of claim 2 wherein said mixture is selected from the group consisting of monomers and oligomers.

10. The battery of claim 1 further comprising physical bonds which secure said cured layer to said body.

11. The battery of claim 1 wherein said unitary frame is sufficiently strong such that when pressure is applied on said frame, the edges of said plurality of layers will not be deformed.

12. The battery of claim 1 wherein said unitary frame has a thickness of 0.1-10 millimeters.

13. A flat cell battery comprising:

a body comprising a plurality of layers including;

at least one anode layer, said at least one anode layer including lithium or materials incorporating lithium,

at least one cathode layer,

at least one electrolyte layer or solid material, said at least one electrolyte layer including a lithium salt, and

a unitary, cured frame, made from a mixture comprised of either a radiation cured plastic or a thermoset plastic, encasing a portion of said body such that said frame provides support to said body in a manner to secure in place relative positions of said plurality of layers;

said unitary frame including a plurality of extensions which penetrate in between at least a portion of said plurality of layers for inhibiting formation of dendritic growths between anode and cathode layers of said battery;

said unitary frame formed from a material that substantially inhibits formation of short circuiting dendritic growth between said anode and cathode layers.

14. The battery of claim 13 further comprising physical bonds which secure said cured frame to said body.

15. The battery of claim 13 wherein said unitary frame is sufficiently strong such that when pressure is applied on said frame, the edges of said plurality of layers will not be deformed.

16. The battery of claim 13 wherein said unitary frame has a thickness of 0.1-10 millimeters.

17. A rechargeable battery comprising:

a body comprising a plurality of layers including;

at least one anode layer, said at least one anode layer including lithium or materials incorporating lithium,

at least one cathode layer, and

at least one electrolyte layer of a solid material, said at least one electrolyte layer including a lithium salt, and

a continuous barrier in contact with at least a portion of an outwardly exposed face of said body, said barrier layer being positioned so as to inhibit short circuiting electrical paths between said anode and cathode layers, said paths being caused by formation of dendritic growths extending out from said anode layer towards said cathode layer;

said barrier further being positioned relative to said body such that the barrier forms a unitary frame which provides support to said body in a manner to secure in place relative positions of said plurality of layers.

18. The battery of claim 17 wherein said barrier is made from a mixture comprised of either a synthetic rubber or a natural rubber.

19. The battery of claim 18 wherein said mixture comprises EPDM rubber.

20. The battery of claim 17 wherein said barrier is made from a radiation curable material.

21. The battery of claim 17 wherein said barrier is made from a material which is non-electrically conductive, and which is chemically inert to all materials which form said plurality of layers.

22. The battery of claim 17 wherein said barrier material is selected from the group consisting of:

synthetic rubbers,

natural rubbers,

buta diene diacrylate, and

ethylene vinyl acetate.

23. The battery of claim 17 wherein said barrier comprises a plurality of extensions which penetrate in between at least a portion of said plurality of layers.

24. The battery of claim 17 wherein said barrier is in physical contact with a portion of at least one outwardly exposed face of said at least one anode layer.

25. The battery of claim 17 wherein said barrier is flexible.

26. The battery of claim 17 wherein said battery is devoid of a Mylar masking material, and wherein said barrier penetrates in between at least a portion of said plurality of layers to form a gradual boundary between each of said layers, thereby establishing a transition zone for limited ionic activity.

27. The battery of claim 17 wherein said unitary frame is sufficiently strong such that when pressure is applied on said frame, the edges of said plurality of layers will not be deformed.

28. The battery of claim 17 wherein said unitary frame has a thickness of 0.1-10 millimeters.