Pouch-Type Secondary Battery and Battery Module Having the Same

Patent metadata

Field	Value
Publication number	US-2022320635-A1
Application number	US-202217570799-A
Country	US
Kind code	A1
Filing date	Jan 7, 2022
Priority date	Mar 30, 2021
Publication date	Oct 6, 2022
Grant date	—

Abstract

A pouch-type secondary battery includes an electrode assembly, in which a plurality of positive electrodes and a plurality of negative electrodes are alternately stacked with separators therebetween, and a pouch which is formed by sealing a pair of cases integrally connected to each other by a folding portion and includes an accommodation portion that accommodates the electrode assembly. A plurality of outer walls forming a perimeter of the accommodation portion may include a folding portion-side outer wall, which includes the folding portion, and a sealing portion-side outer wall which is connected to a sealing portion in which the pair of cases are fused to each other. An average distance between ends of the plurality of negative electrodes and the folding portion-side outer wall may be about 0.6 mm or less.

First claim

What is claimed is:

1 . A pouch-type secondary battery comprising:
an electrode assembly including positive electrodes and negative electrodes alternately stacked with separators therebetween; and a pouch including a pair of cases integrally connected to each other at a folding portion, the pouch including walls defining a perimeter of an accommodation portion for accommodating the electrode assembly, the walls comprising: a folding portion-side outer wall comprising the folding portion; and a sealing portion-side outer wall connected to a sealing portion at which the pair of cases are fused together, wherein an average distance between ends of the negative electrodes and the folding portion-side outer wall is approximately equal to or less than 0.6 mm.

2 . The pouch-type secondary battery of claim 1 , wherein, with respect to a plurality of locations spaced apart from each other in a longitudinal direction of the folding portion-side outer wall, the average distance between the ends of the negative electrodes and the folding portion-side outer wall is approximately equal to or less than 0.5 mm.

3 . The pouch-type secondary battery of claim 1 , wherein a maximum distance between the ends of the negative electrodes and the folding portion-side outer wall is approximately equal to or less than 0.8 mm.

4 . The pouch-type secondary battery of claim 1 , wherein the ends of the negative electrodes protrude further toward the folding portion-side outer wall than ends of the positive electrodes, and
the average distance between the ends of the negative electrodes and the folding portion-side outer wall is less than an average distance between the ends of the negative electrodes and the ends of the positive electrodes.

5 . The pouch-type secondary battery of claim 4 , wherein a distance between each of the ends of the negative electrodes and the folding portion-side outer wall is less than half a distance between each of the ends of the negative electrodes and each of the ends of the positive electrodes.

6 . The pouch-type secondary battery of claim 1 , wherein the folding portion has a groove shape extending from one end to another end of the folding portion-side outer wall.

7 . The pouch-type secondary battery of claim 1 , wherein the accommodation portion comprises:
a first rounded edge connecting a top or bottom surface of the accommodation portion to the folding portion-side outer wall; a second rounded edge connecting the top or the bottom surface of the accommodation portion to the sealing portion-side outer wall; a third rounded edge connecting the folding portion-side outer wall to the sealing portion-side outer wall; and a corner to which the first rounded edge, the second rounded edge, and the third rounded edge are connected.

8 . The pouch-type secondary battery of claim 7 , wherein a virtual plane, which is in contact with an innermost side of the folding portion and oriented parallel to a stacking direction of the electrode assembly, passes through at least one of the top surface, the bottom surface, or the first edge of the accommodation portion.

9 . The pouch-type secondary battery of claim 7 , wherein a radius of curvature of the third rounded edge is greater than a radius of curvature of the first rounded edge and a radius of curvature of the second rounded edge.

10 . The pouch-type secondary battery of claim 7 , wherein a radius of curvature of the corner increases in a direction from a peripheral region to a central region.

11 . The pouch-type secondary battery of claim 7 , wherein the pouch comprises a protrusion portion which connects an edge of the sealing portion to the folding portion and protrudes further than the edge of the sealing portion in a width direction of the accommodation portion, and
a boundary between the protrusion portion and the folding portion is positioned further outward, in a longitudinal direction of the folding portion, than a boundary between the first edge and the corner.

12 . The pouch-type secondary battery of claim 1 , wherein the pouch is manufactured by forming a pouch film,
wherein the pouch film comprises: a sealant layer made of a first polymer and formed as an innermost layer; a surface protection layer made of a second polymer and formed as an outermost layer; and a moisture barrier layer provided between the surface protection layer and the sealant layer, the moisture barrier layer being formed of a metal including an alloy no. AA80XX series aluminum alloy, wherein a thickness of the moisture barrier layer is between about 50 μm and about 80 μm, and a thickness of the sealant layer is between about 60 μm and about 100 μm.

13 . The pouch-type secondary battery of claim 12 , wherein the aluminum alloy is AA8021.

14 . The pouch-type secondary battery of claim 12 , wherein the aluminum alloy comprises between about 1.3 wt % and about 1.7 wt % of iron and approximately 0.2 wt % or less of silicon, and has a grain size of between about 10 μm and about 13 μm.

15 . The pouch-type secondary battery of claim 12 , wherein the thickness of the moisture barrier layer is between about 55 μm and about 65 μm, and
the thickness of the sealant layer is between about 75 μm and about 85 μm.

16 . The pouch-type secondary battery of claim 12 , wherein the pouch film further comprises a drawing assistance layer stacked between the surface protection layer and the moisture barrier layer, the drawing assistance layer including a third polymer.

17 . The pouch-type secondary battery of claim 16 , wherein a thickness of the drawing assistance layer is between about 20 μm and about 50 μm.

18 . A battery module, comprising:
a housing; a plurality of the pouch-type secondary batteries according to claim 1 stacked vertically within the housing; and a cooling unit provided on a bottom surface inside the housing and configured to cool the plurality of the pouch-type secondary batteries.

19 . A pouch-type secondary battery comprising:
an electrode assembly including positive electrodes and negative electrodes alternately stacked with separators therebetween; and a pouch including a pair of cases integrally connected to each other at a folding portion, the pouch including outer walls defining a perimeter of an accommodation portion accommodating the electrody assembly, the walls comprising: a folding portion-side outer wall comprising the folding portion; and a sealing portion-side outer wall connected to a sealing portion at which the pair of cases are fused together, wherein ends of the plurality of negative electrodes protrude further toward the folding portion-side outer wall than ends of the plurality of positive electrodes protrude toward the folding portion-side, and a distance between each of the ends of the negative electrodes and the folding portion-side outer wall is less than half a distance between each of the ends of the negative electrodes and each of the ends of the positive electrodes.

20 . A battery module comprising:
a housing; a plurality of secondary batteries according to claim 19 stacked vertically within the housing; and a cooling unit provided on a bottom surface inside the housing and configured to cool the plurality of secondary batteries.

Assignees

• Lg Energy Solution Ltd

Inventors

• Oh Se Young
• Ha Jeong Min
• Kim Sin Woong
• Kim Geun Hee
• Kim Hyun Beom
• Kwon Hyung Ho

Classifications

• H01M50/105 Primary

  Pouches or flexible bags · CPC title

• H01M50/186

  characterised by the disposition of the sealing members · CPC title

• H01M50/188

  the sealing members being arranged between the lid and terminal · CPC title

• H01M10/613

  Cooling or keeping cold · CPC title

• H01M50/119

  Metals · CPC title