Washer for detecting electrolyte leakage, and secondary battery comprising same

Patent metadata

Field	Value
Publication number	US-10497992-B2
Application number	US-201615554311-A
Country	US
Kind code	B2
Filing date	Apr 15, 2016
Priority date	Apr 15, 2015
Publication date	Dec 3, 2019
Grant date	Dec 3, 2019

Abstract

The present disclosure relates to a case for a secondary battery and a secondary battery having the same. More specifically, it relates to a case for a secondary battery having a washer for detecting leakage with a structure improved so as to check leakage of an electrolyte and a secondary battery having the same.
A lithium ion secondary battery according to the present disclosure provides an effect of easily checking the leakage of an electrolyte with naked eyes through the color change of a washer when a trace amount of the electrolyte leaks.

First claim

What is claimed is:

1. A secondary battery, comprising:
a metal can having an upper open end;
an electrode assembly comprising a cathode, a separator and an anode in the metal can; and
a washer covering the metal can upper open end,
wherein the washer comprises:
a polymer film layer; and
an adhesion layer formed on one side of the polymer film layer,
wherein the adhesion layer comprises an adhesive component and an indicator component and experiences a color change upon contact with an electrolyte,
wherein the polymer film layer is made of a transparent material or a semitransparent material so that the color change of the adhesion layer is observable from outside of the secondary battery through the polymer film layer, and
wherein the washer is mounted on a beading portion of the metal can, surrounds an upper cap of a cap assembly of the metal can, and seals the upper end of the cap assembly of the metal can.

2. The secondary battery according to claim 1 , wherein the polymer film layer comprises one or more polymer resin selected from a group consisting of a polyolefin-based polymer resin, an acryl-based polymer resin, a polycarbonate-based polymer resin, a vinyl-based polymer resin, an ABS (acrylonitrile butadiene styrene) resin, a polystyrene-based polymer resin, polycarbonate-based polymer resin, tetrafluoroethylene, Teflon, polybutyl terephthalate and polyethylene terephthalate.

3. The secondary battery according to claim 2 , wherein the polyolefin-based resin is one or more selected from a group consisting of low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), ultra-high-molecular-weight polyethylene (UHMWPE), polypropylene, polybutene, polymethylpentene and a copolymer thereof.

4. The secondary battery according to claim 1 , wherein the polymer film layer comprises one or more selected from a group consisting of polypropylene, a polycarbonate-based polymer resin and polyethylene terephthalate.

5. The secondary battery according to claim 1 , wherein the adhesive component comprises one or more selected from a group consisting of an acryl-based adhesive compound, a rubber-based adhesive compound, a silicone-based adhesive compound and a vinyl ether-based adhesive compound.

6. The secondary battery according to claim 5 , wherein the acryl-based adhesive compound comprises a homopolymer or a copolymer of an acrylic acid ester based-monomer, or a copolymer of the acrylic acid ester based-monomer with a monomer selected from acrylic acid, 2-hydroxyethyl acrylate and vinyl acetate.

7. The secondary battery according to claim 1 , wherein the indicator component comprises one or more selected from a group consisting of thymol blue, bromophenol blue, methyl orange, bromophenol green, methyl red, bromocresol purple, bromothymol blue (BTB), phenolphthalein, thymolphthalein, indigo carmine and phenol red.

8. The secondary battery according to claim 1 , wherein the washer is fixed to the upper side of the cap assembly through adhesion or mechanical coupling.

9. The secondary battery according to claim 1 , wherein the washer has a thickness of 0.05-2 mm.

10. The secondary battery according to claim 1 , wherein the metal can is a cylindrical metal can.

Assignees

• Lg Chemical Ltd

Inventors

• Lee Je-Jun
• Shin Hang-Soo
• Kim Do-Gyun
• Lee Byoung-Gu
• Jung Sang-Sok

Classifications

• H01M10/0525 Primary

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

• H01M2300/0017

  Non-aqueous electrolytes · CPC title

• H01M2220/30

  Batteries in portable systems, e.g. mobile phone, laptop · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M10/4228 Primary

  Leak testing of cells or batteries · CPC title