Stepwise electrode assembly having variously-shaped corner and secondary battery, battery pack and device comprising the same

• US 9,685,679 B2
• Filed: 11/20/2015
• Issued: 06/20/2017
• Est. Priority Date: 05/29/2012
• Status: Active Grant

• Current Assignee: LG Energy Solution Limited (LG Corporation)
• Original Assignee: LG Chem Limited (LG Corporation)
• Inventors: Ryu, Seung-Min, Kwon, Sung-Jin, Ahn, Soon-Ho, Kim, Dong-Myung, Kim, Ki-Woong, Kim, Young-Hoon
• Primary Examiner(s): Conley, Helen O
• Application Number:
  US14/947,707
• Publication Number:
  US 20160126597A1
• Time in Patent Office: 578 Days
• CPC Class Codes: H01M 10/0413 Large-sized flat cells or batteries for motive or stationary systems with plate-like electrodes
• CPC Class Codes: H01M 10/0431 Cells with wound or folded electrodes H01M10/045 takes precedence
• CPC Class Codes: H01M 10/0436 Small-sized flat cells or batteries for portable equipment
• CPC Class Codes: H01M 10/0463 Cells or batteries with horizontal or inclined electrodes
• CPC Class Codes: H01M 10/052 Li-accumulators
• 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 10/058 Construction or manufacture
• 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 10/0587 of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
• CPC Class Codes: H01M 4/139 Processes of manufacture
• 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 29/49117 Conductor or circuit manufacturing

Abstract

There is provided an electrode assembly having steps including: a first electrode stair including at least one first electrode unit; and a second electrode stair including at least one second electrode unit having an area different from that of the first electrode unit, wherein the first electrode stair and the second electrode stair are stacked to be adjacent, separated by at least one separator as a boundary therebetween and including one or more electrode laminates having steps formed by a difference between areas of the first electrode stair and the second electrode stair, and shapes of the corners of the first electrode stair and the second electrode stair having steps are different. There is also provided a secondary battery including the electrode assembly. Secondary batteries having various designs without restriction in shapes of corners of electrode units can be provided.

Claims

1. An electrode assembly comprising:

a first electrode stair including at least one first electrode unit; and

a second electrode stair including at least one second electrode unit having an area different from that of the first electrode unit,

wherein the first electrode stair and the second electrode stair are stacked to be adjacent, separated by at least one separator as a boundary therebetween and including one or more electrode laminates having steps formed by a difference between the areas of the first electrode stair and the second electrode stair,

wherein an electrode of the at least one first electrode units includes;

a planar sheet of material having a first end and an opposed second end, and

a tab extending away from the first end of the planar sheet,

wherein the planar sheet has a generally rectangular perimeter, with at least one corner of the perimeter having an asymmetric structure with respect to a central axis normal to the planar sheet,

wherein the planar sheet extends along a length direction, extends along a width direction, defines a maximum length along the length direction, and defines first and second linear edges spaced apart along the width direction, each of the first and second linear edges being shorter than the maximum length,

wherein the first and second linear edges each include a first endpoint adjacent the first end of the planar sheet and a second endpoint adjacent the second end of the planar sheet,

wherein the perimeter of the planar sheet at the first and second endpoints of each of the first and second linear edges extends toward the opposing linear edge in a direction substantially parallel to the width direction, and

wherein a depth of the first endpoints measured from the first end of the planar sheet is smaller than a depth of the second endpoints measured from the second end of the planar sheet.

2. The electrode assembly of claim 1, wherein at least one of the first and second electrode stairs forming the electrode laminate has a rounded corner forming a step.

3. The electrode assembly of claim 1, wherein the first electrode stair and the second electrode stair forming the electrode laminate have rounded corners forming steps, and curvatures of the rounded corners are different.

4. The electrode assembly of claim 1, wherein, in the electrode laminate, the first electrode stair and the second electrode stair share at least two sides and three corners.

5. The electrode assembly of claim 1, wherein, in the electrode laminate, the first electrode stair and the second electrode stair share at least two sides and two corners.

6. The electrode assembly of claim 1, wherein, in the electrode laminate, the first electrode stair and the second electrode stair share at least one side and two corners.

7. The electrode assembly of claim 1, wherein, in the electrode laminate, the first electrode stair and the second electrode stair share at least one side and one corner.

8. The electrode assembly of claim 1, wherein, in the electrode laminate, the first electrode stair and the second electrode stair share at least one corner.

9. The electrode assembly of claim 1, wherein, in the electrode laminate, the first electrode stair and the second electrode stair share only a portion of one side.

10. The electrode assembly of claim 1, wherein, in the electrode laminate, the first electrode stair is stacked within a surface of the second electrode stair, and all the sides and corners have steps.

11. The electrode assembly of claim 1, wherein, in the electrode laminate, the first electrode stair shares at least one side of the second electrode stair, and has steps in all the corners.

12. The electrode assembly of claim 1, wherein, in the electrode laminate, the electrode units are stacked such that the areas thereof are reduced in a height direction in which the electrode units are stacked.

13. The electrode assembly of claim 1, wherein, in the electrode laminate, one of mutually adjacent electrode units is included within a stacked surface of the other electrode unit.

14. The electrode assembly of claim 1, wherein the electrode units have electrode tabs corresponding to respective electrodes and the respective sizes of the electrode tabs are equal or different.

15. The electrode assembly of claim 14, wherein the electrode tabs are attached to one end portion of the electrode unit or facing end portions of the electrode unit.

16. The electrode assembly of claim 1, wherein the electrode unit is independently selected from the group including a negative electrode, a positive electrode, and a unit cell alternately stacked with at least one negative electrode and at least one positive electrode with a separator interposed therebetween.

17. The electrode assembly of claim 16, wherein the unit cell is selected from the group consisting of a jelly roll unit cell, a stacked unit cell, and a stacked-and- folded unit cell.

18. The electrode assembly of claim 17, wherein the unit cell includes at least one step.

19. The electrode assembly of claim 1, wherein, facing electrodes of the electrode unit and the adjacent electrode unit having different areas which face each other with the separator interposed therebetween as a boundary have different polarities.

20. The electrode assembly of claim 19, wherein a facing electrode of an electrode unit having a larger area, between the electrode unit and the adjacent electrode unit having different areas, is a negative electrode.

21. The electrode assembly of claim 1,

wherein the at least one second electrode unit extends along the length direction, extends along the width direction, defines a maximum length along the length direction, and defines first and second linear edges spaced apart along the width direction, each of the first and second linear edges of the at least one second electrode unit being shorter than the maximum length of the at least one second electrode unit, and

wherein a perimeter of the at least one second electrode unit at endpoints of each of the first and second linear sides of the at least one second electrode unit extends toward the opposing linear side in a direction substantially parallel to the width direction.

22. A secondary battery, wherein the electrode assembly of claim 1 is received in a battery case.

23. The secondary battery of claim 22, wherein the battery case is a pouch.

24. The secondary battery of claim 23, wherein the battery case receives the electrode assembly such that the case is tightly attached to a surface of the electrode assembly and has a step or a sloped surface corresponding to a shape of the electrode assembly.

25. The secondary battery of claim 23, wherein the secondary battery is a lithium ion secondary battery or a lithium ion polymer secondary battery.

26. A device comprising one or more secondary batteries of claim 22.

27. The device of claim 26, wherein a system component of the device is positioned in a surplus space of the secondary battery.

28. The secondary battery of claim 26, wherein the device is a portable phone, a portable computer, a smart phone, a smart pad, a net book, a light electronic vehicle (LEV), an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a power storage device.