Secondary Battery

Patent metadata

Field	Value
Publication number	US-2023420796-A1
Application number	US-202218035794-A
Country	US
Kind code	A1
Filing date	Apr 15, 2022
Priority date	Apr 15, 2021
Publication date	Dec 28, 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 configured to accommodate the electrode assembly therein; 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, wherein the case contains a sealant layer, and a thermal conductive layer is included in the sealant layer.

First claim

1 . A secondary battery, comprising:
an electrode assembly; an electrode lead attached to the electrode assembly; a case configured to accommodate the electrode assembly therein; 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, wherein the case contains a sealant layer, and a thermal conductive layer is included in the sealant layer.

2 . The secondary battery according to claim 1 ,
wherein the thermal conductive layer is located in a core of the sealant layer.

3 . The secondary battery according to claim 1 ,
wherein the thermal conductive layer includes thermally conductive particles including boron nitride, aluminum nitride, or a mixture thereof.

4 . (canceled)

5 . The secondary battery according to claim 1 ,
wherein the thermal conductive layer is in a film shape including thermally conductive particles and a binder.

6 . (canceled)

7 . The secondary battery according to claim 1 ,
wherein the case includes a sealing portion formed to seal the electrode assembly, and the vent member is located in the sealing portion.

8 . The secondary battery according to claim 7 ,
wherein the vent member is located in the sealing portion at a corner of the case where the electrode lead is exposed to the outside.

9 . The secondary battery according to claim 7 ,
wherein the sealing portion contains a sealant resin, and the vent member has a lower melting point than the sealant resin.

10 . The secondary battery according to claim 1 ,
wherein the vent member is vented at a temperature between 100° C. and 120° C.

11 . The secondary battery according to claim 10 ,
wherein the vent member is vented at a pressure of 1.5 atm or above.

12 . The secondary battery according to claim 1 ,
wherein the vent member has a maximum sealing strength of less than 6 kgf/15 and an average sealing strength of less than 4.5 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 equal to or greater than 6 kgf/15 mm and an average sealing strength equal to or greater than 4.5 kgf/15 mm between room temperature and 60° C.

15 . (canceled)

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

17 . The secondary battery according to claim 16 ,
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.

18 . The secondary battery according to claim 16 ,
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.

19 . The secondary battery according to claim 16 ,
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.

20 . The secondary battery according to claim 16 ,
wherein the case includes a sealing portion formed to seal the electrode assembly, the sealing portion contains a sealant resin, and 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.

21 . The secondary battery according to claim 20 ,
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.

22 . The secondary battery according to claim 1 ,
wherein the vent member has a melting point of between 100° C. and 130° C.

23 . The secondary battery according to claim 16 ,
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.

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

Assignees

• Lg Energy Solution Ltd

Inventors

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

Classifications

• H01M50/198

  characterised by physical properties, e.g. adhesiveness or hardness · CPC title

• H01M50/197

  having a layered structure · CPC title

• H01M50/126

  comprising three or more layers · CPC title

• H01M10/653

  characterised by electrically insulating or thermally conductive materials · CPC title

• H01M50/375 Primary

  Vent means sensitive to or responsive to temperature · CPC title