Case assembly, prismatic secondary battery, and fabrication method thereof

Patent metadata

Field	Value
Publication number	US-2016079579-A1
Application number	US-201514846233-A
Country	US
Kind code	A1
Filing date	Sep 4, 2015
Priority date	Sep 16, 2014
Publication date	Mar 17, 2016
Grant date	—

Abstract

Provided are a case assembly, a prismatic secondary battery, and a method of fabricating the prismatic secondary battery. The prismatic secondary battery includes: an electrode assembly including a first electrode plate, a second electrode plate, and a separator between the first and second electrode plates; a case formed of a first material, wherein an electrode assembly accommodation cavity is formed in the case to accommodate the electrode assembly, and an opening through which the electrode assembly is to be inserted is formed in a portion of the case is formed in a portion of the case; and a cap plate sealing the opening. A gas discharge hole is formed in the case to discharge gas generated during a pre-charging operation. The gas discharge hole is sealed with a gas seal formed of a second material.

First claim

What is claimed is:

1 . A prismatic secondary battery comprising:
an electrode assembly comprising a first electrode plate, a second electrode plate, and a separator between the first and second electrode plates; a case formed of a first material, wherein an electrode assembly accommodation cavity is formed in the case to accommodate the electrode assembly, and an opening through which the electrode assembly is to be inserted is formed in a portion of the case; and a cap plate sealing the opening, wherein a gas discharge hole is formed in the case to discharge gas generated during a pre-charging operation, and the gas discharge hole is sealed with a gas seal formed of a second material.

2 . The prismatic secondary battery of claim 1 , wherein the gas discharge hole communicates with the electrode assembly accommodation cavity, and
the gas seal is thermally fused to a portion of the case in which the gas discharge hole is formed.

3 . The prismatic secondary battery of claim 2 , wherein the gas discharge hole is formed in a bottom portion of the case that is opposite the opening formed in a top portion of the case, and
the gas seal is thermally fused to at least a region of the bottom portion of the case, the region surrounding the gas discharge hole.

4 . The prismatic secondary battery of claim 3 , wherein the gas seal comprises:
a first sealing part covering the gas discharge hole; and a second sealing part extending from the first sealing part and thermally fused to a connection region of the bottom portion of the case along a periphery of the gas discharge hole.

5 . The prismatic secondary battery of claim 3 , wherein the gas seal covers the gas discharge hole,
extends along a periphery of the gas discharge hole from the bottom portion of the case to a connection region of a lateral portion of the case connecting the bottom portion of the case and the top portion of the case, and is thermally fused to the connection region.

6 . The prismatic secondary battery of claim 3 , wherein the gas seal is thermally fused to an inner wall surface of the case that forms the gas discharge hole.

7 . The prismatic secondary battery of claim 1 , wherein the case comprises a can formed of a metallic material.

8 . The prismatic secondary battery of claim 1 , wherein the gas seal is formed of a flexible pouch-type material and comprises:
a thin metal layer; and a bonding layer formed on at least one surface of the metal layer and thermally fused to the case.

9 . The prismatic secondary battery of claim 1 , wherein the case comprises:
a first surface; a second surface separate from the first surface; third surfaces forming lateral surfaces that connect the first and second surfaces; and a fourth surface located opposite the opening and forming a bottom surface that connects the first surface, the second surfaces, and the third surface, wherein the first surface, the second surface, the third surfaces, and the fourth surface are continuously connected to form the electrode assembly accommodation cavity, and the gas discharge hole is formed in the fourth surface.

10 . The prismatic secondary battery of claim 1 , wherein the electrode assembly comprises a plurality of sub-electrode assemblies which have different sizes and are stacked in a stepped structure.

11 . A method of fabricating a prismatic secondary battery, the method comprising:
preparing a case assembly by coupling a gas collection unit to a case, wherein the case comprises a gas discharge hole and an electrode assembly accommodation cavity formed to accommodate an electrode assembly comprising a first electrode plate, a second electrode plate, and a separator; inserting the electrode assembly into the electrode assembly accommodation cavity; filling the electrode assembly accommodation cavity with an electrolyte; pre-charging the electrode assembly and collecting gas, which is generated from the electrode assembly during the pre-charging, in the gas collection unit through the gas discharge hole; and completing the fabricating of the prismatic secondary battery by forming a gas seal to seal the gas discharge hole and removing the gas collection unit.

12 . The method of claim 11 , wherein the case comprises a can formed of a metallic material;
the gas seal comprises a flexible pouch-type material; the gas collection unit comprises a main body in which a space is formed to collect gas discharged through the gas discharge hole, and a connection part formed on an end of the main body; and the connection part is thermally fused to a connection region of a bottom portion of the case in which the gas discharge hole is formed.

13 . The method of claim 11 , wherein the case comprises a can formed of a metallic material;
the gas seal comprises a flexible pouch-type material; the gas collection unit comprises a space to collect gas therein; and an end lower surface of the gas collection unit is thermally fused to a connection region of a lateral portion of the case, the connection region being adjacent to a bottom portion of the case in which the gas discharge hole is formed.

14 . The method of claim 11 , wherein the case comprises a can formed of a metallic material;
the gas seal comprises a flexible pouch-type material; the gas collection unit comprises a space to collect gas therein; and an outer surface of the gas collection unit is thermally fused to an inner wall surface of the case that forms the gas discharge hole.

15 . The method of claim 11 , wherein the gas collection unit is formed of a flexible pouch-type material and comprises:
a thin metal layer; and a bonding layer formed on at least one surface of the metal layer and thermally fused to the case.

16 . The method of claim 11 , wherein the gas seal sealing the gas discharge hole is formed by applying heat and pressure to the gas collection unit to fuse a portion of the gas collection unit, and
the gas collection unit is cut at a position close to a sealed region to separate the gas collection unit from the case.

17 . A case assembly of a prismatic secondary battery, the case assembly comprising:
a case formed of a first material, wherein an electrode assembly accommodation cavity is formed in the case to accommodate an electrode assembly comprising a first electrode plate, a second electrode plate, and a separator disposed between the first and second electrode plates, and a gas discharge hole is formed in the case to discharge gas therethrough; and a gas collection unit formed of a second material and coupled to the case in which the gas discharge hole is formed, the gas collection unit comprising a space to collect gas discharged through the gas discharge hole.

18 . The case assembly of claim 17 , wherein the case comprises a can formed of a metallic material.

19 . The case assembly of claim 17 , wherein the gas collection unit is formed of a flexible pouch-type material and comprises:
a thin metal layer; and a bonding layer formed on at least one surface of the metal layer.

20 . The case assembly of claim 17 , wherein the gas discharge hole is formed in a portion of the case, and
the gas collection unit is thermally fused to a connection region of the portion of the case in which the gas discharge hole is formed.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Jung Kangkook

Classifications

• H01M10/52 Primary

  Removing gases inside the secondary cell, e.g. by absorption (vent plugs or other mechanical arrangements for facilitating escape of gases H01M50/30) · CPC title

• H01M50/14

  for protecting against damage caused by external factors · CPC title

• H01M50/627

  Filling ports · CPC title

• H01M50/119

  Metals · CPC title

• H01M50/103

  prismatic or rectangular (H01M50/109, H01M50/11 take precedence) · CPC title