Electrode assembly having high flexibility and battery cell including the same

Patent metadata

Field	Value
Publication number	US-2018287103-A1
Application number	US-201715767541-A
Country	US
Kind code	A1
Filing date	Mar 31, 2017
Priority date	Mar 31, 2016
Publication date	Oct 4, 2018
Grant date	—

Abstract

The present invention provides an electrode assembly having a one directionally spiral-wound structure with a separator sheet interposed between a positive electrode sheet and a negative electrode sheet, wherein the electrode assembly has a horizontal length (x) equal to or more than three times a vertical length (y), and both side end portions of the electrode assembly are bent together in the same direction by a curvature radius (R) satisfying the following Equation 1:
S [{1/ln( x/y )}* t]=R   1

wherein t is an average thickness (mm) of the spiral-wound electrode assembly, x is the horizontal length of the electrode assembly, and y is the vertical length of the electrode assembly, and S is a constant of 8 or more, and ln(x/y)≥1.

First claim

1 . An electrode assembly having a one directionally spiral-wound structure with a separator sheet interposed between a positive electrode sheet and a negative electrode sheet,
wherein the electrode assembly has a horizontal length (x) equal to or more than three times a vertical length (y), and both side end portions of the electrode assembly are bent together in the same direction by a curvature radius (R) satisfying the following Equation 1:
S[{ 1/ln( x/y )}* t]=R   1

wherein t is an average thickness (mm) of the spiral-wound electrode assembly, x is the horizontal length of the electrode assembly, and y is the vertical length of the electrode assembly, and S is a constant of 8 or more, and ln(x/y)≥1.

2 . The electrode assembly of claim 1 , wherein the curvature radius (R) is 5 mm to 20 mm.

3 . The electrode assembly of claim 1 , wherein the horizontal length (x) is 50 mm to 500 mm.

4 . The electrode assembly of claim 1 , wherein a positive electrode lead and a negative electrode lead protrude side by side in a parallel direction to the vertical length (y).

5 . The electrode assembly of claim 1 , wherein S is a constant of 9 to 12.

6 . The electrode assembly of claim 1 , wherein the electrode assembly has a structure having relatively increased flexibility for deformation into a curved shape by dispersing stress in a direction of the relatively long horizontal length.

7 . The electrode assembly of claim 1 , wherein the spiral-winding is performed five times or less.

8 . A battery cell having a structure in which the electrode assembly of claim 1 is stored in a variable battery case together with an electrolyte solution,
wherein both side end portions of the electrode assembly and the battery case in positions of facing each other are bent together in the same direction, so that a curved surface is formed on an outer surface of the battery cell.

Assignees

• Lg Chemical Ltd

Inventors

• You Min Kyu
• Kang Sung Joong
• Kim Ji Young

Classifications

• H01M10/0525 Primary

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M10/0431 Primary

  Cells with wound or folded electrodes (H01M10/045 takes precedence) · CPC title

• H01M10/0587

  of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators · CPC title

• H01M10/0436

  Small-sized flat cells or batteries for portable equipment · CPC title

• H01M50/136

  Flexibility or foldability · CPC title