Electrode assembly having indented portion formed on electrode plate, and secondary battery including same

Patent metadata

Field	Value
Publication number	US-10811665-B2
Application number	US-201615762342-A
Country	US
Kind code	B2
Filing date	Oct 18, 2016
Priority date	Dec 14, 2015
Publication date	Oct 20, 2020
Grant date	Oct 20, 2020

Abstract

The present invention relates to an electrode assembly including at least two electrode plates and a separator interposed between the electrode plates, wherein indented portions are formed from lower ends of opposite sides of the electrode tab in an opposite direction to an externally extending direction of the electrode tab in a side of the electrode body in which the electrode tab externally extends, in the electrode plates.

First claim

The invention claimed is:

1. An electrode assembly comprising
at least two electrode plates and a separator interposed between the electrode plates,
wherein each of the electrode plates includes:
a planar electrode body including a collector having one surface or opposite surfaces to which an electrode mixture containing an electrode active material is applied, the electrode body having a first indented portion and a second indented portion extending into the electrode body from a first edge of the electrode body to a respective first and second terminal end, the first edge defining an edge line that extends therealong, and
at least one electrode tab extending from the electrode body from an imaginary line connecting the first and second terminal ends of the respective first and second indented portions, the electrode tab extending away from the electrode body so as to be positioned between the first and second indented portions, the electrode tab including a portion of the collector to which an electrode mixture is not applied;

wherein the at least one electrode tab of each of the electrode plates is coupled to a respective electrode lead;
wherein a respective edge zone extends along both the electrode body and the electrode tab of each of the electrode plates in a region spanning between the respective edge line and the respective imaginary line; and
wherein the electrode mixture is applied to the collector of the respective electrode body in the edge zone, and an electrode mixture is not applied to the portion of the collector of the respective electrode tab in the edge zone.

2. The electrode assembly of claim 1 , wherein the electrode plates include a positive electrode plate and a negative electrode plate, and an area of the negative electrode plate is larger than that of the positive electrode plate.

3. The electrode assembly of claim 2 , wherein an area of the indented portions formed in the negative electrode plate is larger than that of the indented portions formed in the positive electrode plate.

4. The electrode assembly of claim 2 , wherein indented portions formed in the positive electrode plate and the negative electrode plate have shapes corresponding to each other.

5. The electrode assembly of claim 1 , wherein each of the indented portions has a portion having a shape selected from the group consisting of a polygon, a semi-circle, a semi-ellipse, and a polygonal shape in which at least one straight line segment has been replaced with a curved line segment.

6. The electrode assembly of claim 1 , wherein each external circumferential side of the indented portions includes a semicircular curved portion and one or two straight portions extended from the curved portion.

7. The electrode assembly of claim 6 , wherein the curved portion has a radius that is in a range of 1 mm to 6 mm.

8. The electrode assembly of claim 6 , wherein each length of the straight portions is in a range of 0 mm to 5 mm, exclusive.

9. The electrode assembly of claim 1 , wherein each area of the indented portions is in a range of 10.0 mm 2 to 40.0 mm 2 , exclusive.

10. The electrode assembly of claim 1 , wherein the indented portions are symmetrical with respect to the electrode tab.

11. The electrode assembly of claim 1 , wherein a length of the electrode tab is in a range of 2.0 mm to 10.0 mm, exclusive.

12. The electrode assembly of claim 1 , wherein the electrode assembly is a stacked, stacked/folded, or laminated/stacked electrode assembly.

13. A secondary battery, comprising:
the electrode assembly of claim 1 embedded in a battery case impregnated with an electrolytic solution, wherein an end portion of each of a positive electrode lead and a negative electrode lead protrude to an outside of the battery case.

14. The secondary battery of claim 13 , wherein a welded portion is formed at a coupling part between the positive electrode tabs and the positive electrode lead and between the negative electrode tabs and the negative electrode lead.

15. The secondary battery of claim 13 , wherein the battery case includes a concave-shaped accommodating portion for accommodating the electrode assembly and a sealing portion formed in an external circumferential surface of the accommodating portion to secure a sealing property of the battery case, and the sealing portion is positioned at an upper side portion of a welded portion between electrode tabs and an electrode lead.

16. The secondary battery of claim 15 , wherein a side of the accommodating portion is positioned at a lower end portion of the welded portion between the electrode tabs and the electrode lead.

17. The secondary battery of claim 13 , wherein the positive electrode lead and the negative electrode lead are respectively positioned on same planes as one positive electrode plate and one negative electrode plate, and
a portion of the imaginary line is bent at a gradually increasing angle as a distance from the positive electrode plate and the negative electrode plate which are positioned on the same planes as the positive electrode lead and the negative electrode lead.

18. The secondary battery of claim 16 , wherein a lead film is attached to each of the positive electrode lead and the negative electrode lead, and the lead film is interposed in the sealing portion.

19. The secondary battery of claim 13 , wherein the battery case is formed of a laminated sheet including a resin layer and a metal layer.

20. A battery pack comprising at least one secondary battery of claim 13 as a unit battery.

Assignees

• Lg Chemical Ltd

Inventors

• Oh Sei Woon
• Kim Hyun Min
• Lee Eun Ju
• Woo Sun Hwak

Classifications

• H01M10/0583 Primary

  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 title

• H01M50/105 Primary

  Pouches or flexible bags · CPC title

• H01M50/184

  characterised by their shape or structure · CPC title

• H01M50/533

  characterised by the shape of the leads or tabs · CPC title

• H01M50/202

  Casings or frames around the primary casing of a single cell or a single battery · CPC title