SECONDARY BATTERY, AND ELECTRODE SHEET CUTTING APPARATUS

• US 20130309566A1
• Filed: 01/28/2011
• Published: 11/21/2013
• Est. Priority Date: 01/28/2011
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Umehara, Masakazu
• Granted Patent: US 9,548,483 B2
• Time in Patent Office: Days
• US Class Current: 429/211
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 4/04 Processes of manufacture in general
• CPC Class Codes: H01M 4/0404 by coating on electrode collectors
• CPC Class Codes: H01M 4/0471 involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
• CPC Class Codes: H01M 4/0483 by methods including the handling of a melt H01M4/0438, take precedence
• 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 4/139 Processes of manufacture
• CPC Class Codes: H01M 4/366 as layered products
• CPC Class Codes: H01M 4/622 being polymers
• CPC Class Codes: H01M 50/46 Separators, membranes or diaphragms characterised by their combination with electrodes
• CPC Class Codes: H01M 50/461 with adhesive layers between electrodes and separators
• 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: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y10T 29/49108 Electric battery cell making
• CPC Class Codes: Y10T 29/53139 including deforming means

Abstract

A secondary battery 100 comprises a positive electrode current collector 221 and a positive electrode active material layer 223 applied on the positive electrode current collector 221 and containing at least a positive electrode active material. The lithium-ion secondary battery 100 further comprises a negative electrode current collector 241 provided so as to oppose the positive electrode current collector 221 and a negative electrode active material layer 243 applied on the negative electrode current collector 241 and containing at least a negative electrode active material. The lithium-ion secondary battery 100 is also formed with a porous insulating layer 245 which contains stacked resin particles having insulating properties and is formed so as to cover at least one of the positive electrode active material layer 223 and the negative electrode active material layer 243 (in this case, negative electrode active material layer 243). The lithium-ion secondary battery 100 further comprises, on the edge of the insulating layer 245, a molten part 246 where the resin particles are melted.

Claims

1. A secondary battery comprising:

a positive electrode current collector;

a positive electrode active material layer retained on the positive electrode current collector and containing at least a positive electrode active material;

a negative electrode current collector provided so as to oppose the positive electrode current collector;

a negative electrode active material layer retained on the negative electrode current collector and containing at least a negative electrode active material;

a porous insulating layer, including resin particles of insulation stacked with voids on a surface of at least one of the positive electrode active material layer and the negative electrode active material layer so as to cover at least one of the positive electrode active material layer and the negative electrode active material layer; and

a molten part formed on an edge of the insulating layer by melting the resin particles with disappearing the voids.

2. The secondary battery according to claim 1, wherein the insulating layer contains an inorganic filler of insulation.

3. The secondary battery according to claim 1, wherein the insulating layer contains rubber particles having insulating properties.

5. The secondary battery according to claim 1, wherein the insulating layer is stacked on the negative electrode active material layer.

6. The secondary battery according to claim 1, wherein the negative electrode active material layer has a broader width than the positive electrode active material layer and is provided so as to oppose the positive electrode active material layer, and the insulating layer is stacked on the negative electrode active material layer on the side opposing the positive electrode active material layer.

4. (canceled)

7. A method for producing a secondary battery comprising:

preparing an electrode sheet including a current collector, an active material layer formed on the surface of the current collector and containing an electrode active material, and a porous insulating layer, containing stacked resin particles of insulation, formed so as to cover the active material layer;

melting the resin particles in the insulating layer of the electrode sheet prepared in the step of preparing the electrode sheet, along a predetermined line; and

cutting the electrode sheet along the line where the insulating layer is melted, upon the resin particles, melted in the step of melting, being solidified.

8. The method for producing a secondary battery according to claim 7, wherein in the step of melting, the resin particles in the insulating layer are melted by irradiating a laser onto the insulating layer.

9. The method for producing a secondary battery according to claim 8, wherein the laser is a CO₂ laser.

10. The method for producing a secondary battery according to claim 7, further comprising a step of cooling the electrode sheet between the step of melting and the step of cutting.

11. The method for producing a secondary battery according to claim 7, wherein the electrode sheet prepared in the step of preparing the electrode sheet contains, in the insulating layer, an inorganic filler having insulating properties.

12. The method for producing a secondary battery according to claim 7, wherein the electrode sheet prepared in the step of preparing the electrode sheet contains, in the insulating layer, rubber particles having insulating properties.

13. An apparatus for cutting an electrode sheet being conveyed along a conveyance route, the electrode sheet including a current collector, an active material layer formed on the surface of the current collector and containing an electrode active material, and a porous insulating layer containing stacked resin particles of insulation formed so as to cover the active material layer,

the apparatus comprising:

a heater provided along a predetermined line so as to heat the electrode sheet along a predetermined line for melting the resin particles in the insulating layer to form a molten part; and

a cutter provided downstream from the heater, in a conveyance direction, for cutting the electrode sheet along the line after the molten resin particles are solidified.

14. The electrode sheet cutting apparatus according to claim 13, wherein the heater is a laser device for irradiating a laser onto the electrode sheet.

15. The electrode sheet cutting apparatus according to claim 14, wherein the laser device is a device for irradiating a CO₂ laser.

16. The electrode sheet cutting apparatus according to claim 14,

further comprising a conveying device for conveying the electrode sheet along a predetermined conveyance route,

the heater and the cutter being fixed along the conveyance route, and

the electrode sheet cutting apparatus further comprising a position adjustment mechanism for adjusting a position of the electrode sheet relative to the heater and the cutter.

17. The electrode sheet cutting apparatus according to claim 16, wherein the electrode sheet is a strip-shaped sheet, and the conveying device continuously conveys the electrode sheet along the conveyance route.

18. The electrode sheet cutting apparatus according to claim 17, wherein

the conveyance device includes a plurality of guide rolls that support and convey the electrode sheet, and

the heater is provided so that the electrode sheet is heated at a position downstream, in a conveyance direction, of a position where the guide rolls support the electrode sheet.

20. The electrode sheet cutting apparatus according to claim 13, further comprising a cooling device for cooling the electrode sheet after heating by the heater and before cutting by the cutter.

21. The electrode sheet cutting apparatus according to claim 20, wherein the cooling device is a fan that blows air towards the electrode sheet.

22. The electrode sheet cutting apparatus according to claim 20, wherein the cooling device includes a metal roll to be pressed to the electrode sheet and a cooling member for cooling the metal roll.

19. (canceled)