ELECTRODE ASSEMBLY AND SECONDARY BATTERY USING THE SAME

• US 20110274960A1
• Filed: 12/20/2010
• Published: 11/10/2011
• Est. Priority Date: 05/04/2010
• Status: Active Grant

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: Ahn, Chang-Bum
• Granted Patent: US 8,808,922 B2
• Time in Patent Office: Days
• US Class Current: 429/136
• CPC Class Codes: H01M 10/0459 Cells or batteries with folded separator between plate-like electrodes
• CPC Class Codes: H01M 10/0583 of accumulators with folded construction elements except wound ones, i.e. folded positive or negative electrodes or separators, e.g. with "Z"-shaped electrodes or separators
• CPC Class Codes: H01M 50/124 having a layered structure
• CPC Class Codes: H01M 50/403 Manufacturing processes of separators, membranes or diaphragms
• CPC Class Codes: H01M 50/417 Polyolefins
• CPC Class Codes: H01M 50/426 Fluorocarbon polymers
• CPC Class Codes: H01M 50/466 U-shaped, bag-shaped or folded
• CPC Class Codes: H01M 50/55 on the same side of the cell
• CPC Class Codes: H01M 50/553 Terminals adapted for prismatic, pouch or rectangular cells
• 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
• CPC Class Codes: Y10T 29/4911 including sealing

Abstract

An electrode assembly and a secondary battery using the same. In an embodiment, the electrode assembly includes one or more first electrodes each having a first tab provided to one surface thereof, and one or more second electrodes each having a second tab provided to one surface thereof. The second electrodes are alternately stacked with the first electrodes. A separator is interposed between the first and second electrodes and folded a plurality of times so that the same surfaces of the separator face each other. The separator has one or more tab through-holes through which the first and second tabs protrude at folded portions of the separator.

Claims

1. An electrode assembly comprising:

one or more first electrodes, each having a first tab provided to one surface thereof;

one or more second electrodes, each having a second tab provided to one surface thereof, the second electrodes being alternately stacked with the first electrodes; and

a separator interposed between the first and second electrodes and folded a plurality of times so that the same surfaces of the separator face each other, the separator having one or more tab through-holes through which the first or second tabs protrude at folded portions of the separator.

2. The electrode assembly according to claim 1, wherein the first electrode further comprises a positive electrode collecting plate and a positive electrode active material layer.

3. The electrode assembly according to claim 1, wherein the second electrode further comprises a negative electrode collecting plate and a negative electrode active material layer.

4. The electrode assembly according to claim 1, wherein two folds of the separator are interposed between the first and second electrodes.

5. The electrode assembly according to claim 1, wherein the separator surrounds the tab regions and upper and lower surfaces of the first and second electrodes.

6. The electrode assembly according to claim 1, wherein the tab through-holes are arranged in a zigzag form.

7. The electrode assembly according to claim 1, wherein the first and second tabs extend, respectively, to the exterior of the separator through the tab through-holes.

8. The electrode assembly according to claim 7, wherein the first and second tabs extended to the exterior are spaced apart from each other in a horizontal direction.

9. The electrode assembly according to claim 1, wherein the tab through-holes are elliptical in shape.

10. The electrode assembly according to claim 9, wherein the tab through-holes are formed using a thermal fusion method.

11. The electrode assembly according to claim 9, wherein the length of the tab through-holes is longer by about 1.0 to 2.0 mm than the width of each of the first and second tabs.

12. The electrode assembly according to claim 1, wherein the separator is selected from the group consisting of at least one of polyethylene, polypropylene and polyvinylidene fluoride.

13. The electrode assembly according to claim 1, wherein the separator is folded at an interval longer by about 4.0 mm than the longitudinal length of the second electrode.

14. A secondary battery comprising:

the electrode assembly according to claim 1; and

an outer casing having the electrode assembly built therein.

15. The secondary battery according to claim 14, wherein the outer casing includes a pouch type or can type outer casing.

16. The secondary battery according to claim 15, wherein the pouch type outer casing is made of a laminate sheet including a metal layer and a resin layer.

17. The secondary battery according to claim 15, wherein the pouch type outer casing further comprises a sealing portion.

18. The secondary battery according to claim 17, wherein the sealing portion is formed along an outer circumferential surface of the pouch type outer casing, and the pouch type outer casing is sealed by thermally fusing the sealing portion.

19. A method of precisely aligning electrodes in an electrode assembly comprising a plurality of positive electrode plates, a plurality of negative electrode plates and a separator, the method comprising:

folding the separator a plurality of times;

placing tab through-holes at the folds of the separator in a zig-zag pattern;

attaching first tabs on the positive electrode plates at the same position on an edge of each positive electrode plate;

attaching second tabs on the negative electrode plate at the same position on an edge of each negative electrode plate such that the first and second tabs are at opposite ends of the same edge of the respective positive and negative electrode plates;

inserting the positive electrode plates in alternate folds of the separator with the first tabs extending through the tab through-holes at one end of the zig-zag pattern such that the first tabs align;

inserting the negative electrode plates in the other alternate folds of the separator with the second tabs extending through the tab through holes at the other end of the zig-zag pattern such that the second tabs align; and

welding the first tabs together and welding the second tabs together.

20. A method of manufacture of a secondary battery with enhanced stability comprising:

forming a battery casing with a pouch to receive the electrode assembly of claim 19, a lid and a circumferential surface around the pouch;

placing the electrode assembly in the pouch;

placing a sealing portion on the circumferential surface;

injecting electrolyte into the pouch;

closing the lid on the pouch, circumferential surface and sealing portion; and

thermally fusing the sealing portion.