Secondary Battery

Patent metadata

Field	Value
Publication number	US-2023411772-A1
Application number	US-202218030447-A
Country	US
Kind code	A1
Filing date	Apr 15, 2022
Priority date	Apr 15, 2021
Publication date	Dec 21, 2023
Grant date	—

Abstract

Disclosed herein is a secondary battery having a vent member. The secondary battery may include an electrode assembly; an electrode lead attached to the electrode assembly; a case including an accommodation portion for accommodating the electrode assembly and a sealing portion containing a sealant resin and formed to seal the electrode assembly; a lead film formed to surround a part of an outer surface of the electrode lead and interposed between the electrode lead and the case; and a vent member containing a linear low-density polyethylene having a comonomer with a carbon number of 6 or more, wherein the sealing portion has a vent inducing region including the vent member, and a width of the vent inducing region is smaller than a width of the sealing portion other than the vent inducing region.

First claim

1 . A secondary battery, comprising:
an electrode assembly; an electrode lead attached to the electrode assembly; a case including an accommodation portion for accommodating the electrode assembly and a sealing portion containing a sealant resin and formed to seal the electrode assembly; a lead film formed to surround a part of an outer surface of the electrode lead and interposed between the electrode lead and the case; and a vent member containing a linear low-density polyethylene having a comonomer with a carbon number of 6 or more, wherein the sealing portion has a vent inducing region including the vent member, and a width of the vent inducing region is smaller than a width of the sealing portion other than the vent inducing region.

2 . The secondary battery according to claim 1 ,
wherein the width of the vent inducing region is 40% to 80% of the width of the sealing portion other than the vent inducing region.

3 . The secondary battery according to claim 1 ,
wherein a tape is inserted so that the width of the vent inducing region is smaller than the width of the sealing portion other than the vent inducing region.

4 . The secondary battery according to claim 3 ,
wherein the tape contains polyimide, polyethylene terephthalate (PET), or a mixture thereof.

5 . The secondary battery according to claim 1 ,
wherein a resin is inserted so that the width of the vent inducing region is smaller than the width of the sealing portion other than the vent inducing region, and the resin contains a fluorine-based resin, a silicone resin, or a mixture thereof.

6 . (canceled)

7 . The secondary battery according to claim 1 ,
wherein the vent inducing region is formed in the sealing portion on a different side of the case than the electrode leads.

8 . The secondary battery according to claim 1 ,
wherein the linear low-density polyethylene having a comonomer with a carbon number of 6 or more is a linear low-density polyethylene having a comonomer with a carbon number of 6 to 8.

9 . The secondary battery according to claim 1 ,
wherein the linear low-density polyethylene having a comonomer with a carbon number of 6 or more has a lower melting point than the sealant resin.

10 . The secondary battery according to claim 1 ,
wherein the vent member melts at 100° C. to 120° C. to vent a gas, or wherein the vent member is vented at a pressure of 1.5 atm or above.

11 . (canceled)

12 . The secondary battery according to claim 1 ,
wherein the vent member has a maximum sealing strength of less than 6 kgf/15 mm at 100° C. or above.

13 . (canceled)

14 . The secondary battery according to claim 1 ,
wherein the vent member has a maximum sealing strength of 6 kgf/15 mm or more at room temperature to 60° C.

15 . (canceled)

16 . The secondary battery according to claim 1 ,
wherein the linear low-density polyethylene having a comonomer with a carbon number of 6 or more is polymerized in the presence of a metallocene catalyst.

17 . The secondary battery according to claim 1 ,
wherein in the linear low-density polyethylene having a comonomer with a carbon number of 6 or more, a content of the comonomer with a carbon number of 6 or more is 15 weight % or less, based on 100 weight % of the linear low-density polyethylene having a comonomer with a carbon number of 6 or more.

18 . The secondary battery according to claim 1 ,
wherein the linear low-density polyethylene having a comonomer with a carbon number of 6 or more has a poly dispersity index (PDI) of 4 or less.

19 . The secondary battery according to claim 1 ,
wherein a difference between a crystallization temperature of the sealant resin and a crystallization temperature of the linear low-density polyethylene having a comonomer with a carbon number of 6 or more is 10° C. or less.

20 . The secondary battery according to claim 19 ,
wherein the linear low-density polyethylene having a comonomer with a carbon number of 6 or more has a crystallization temperature of 90° C. to 115° C.

21 . The secondary battery according to claim 1 ,
wherein the linear low-density polyethylene having a comonomer with a carbon number of 6 or more has a lower melting point of 100° C. to 130° C.

22 . The secondary battery according to claim 1 ,
wherein the linear low-density polyethylene having a comonomer with a carbon number of 6 or more has a weight-average molecular weight of 100,000 g/mol to 400,000 g/mol.

23 . The secondary battery according to claim 1 ,
wherein the secondary battery is a pouch-type secondary battery.

24 - 25 . (canceled)

26 . The secondary battery according to claim 1 ,
wherein a content of the comonomer with a carbon number of 6 or more is 5 weight % to 15 weight %, based on 100 weight % of the linear low-density polyethylene.

27 - 29 . (canceled)

Assignees

• Lg Energy Solution Ltd

Inventors

• Kang Min-Hyeong
• Kim Sang-Hun
• Song Dae-Woong
• Yu Hyung-Kyun
• Lim Hun-Hee
• Hwang Soo-Ji

Classifications

• H01M50/3425 Primary

  in the form of rupturable membranes or weakened parts, e.g. pierced with the aid of a sharp member · CPC title

• H01M50/178

  for pouch or flexible bag cells · CPC title

• H01M50/375

  Vent means sensitive to or responsive to temperature · CPC title

• H01M50/105

  Pouches or flexible bags · CPC title

• H01M50/342 Primary

  Non-re-sealable arrangements · CPC title