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CN-122003763-A - Gasket for electrochemical device and electrochemical device

CN122003763ACN 122003763 ACN122003763 ACN 122003763ACN-122003763-A

Abstract

The invention provides a gasket for an electrochemical device with excellent low water vapor permeability and an electrochemical device using the same. A gasket for electrochemical devices, which comprises polybutylene terephthalate and has a compression ratio of 5% or more when mounted.

Inventors

  • YAMADA MASAHIKO
  • Liu Koufuyan
  • KATO TAKETO
  • Niu Daozun

Assignees

  • 大金工业株式会社

Dates

Publication Date
20260508
Application Date
20240930
Priority Date
20230929

Claims (12)

  1. 1. A gasket for an electrochemical device, which comprises polybutylene terephthalate and has a compression ratio of 5% or more when mounted.
  2. 2. The gasket of claim 1 wherein the compression ratio is less than the fracture compression ratio.
  3. 3. The gasket of claim 1 or 2, wherein the water vapor transmission coefficient is less than 0.010g/1000 hours.
  4. 4. A gasket according to any one of claims 1 to 3, in contact with an electrolyte.
  5. 5. An electrochemical device comprising the gasket according to any one of claims 1 to 4.
  6. 6. A gasket for an electrochemical device, which comprises a polymer and has a compression ratio of 20% to 75% when mounted.
  7. 7. The gasket of claim 6 wherein the compression ratio is less than the fracture compression ratio.
  8. 8. The gasket of claim 6 or 7 wherein the water vapor transmission coefficient is less than 0.010g/1000 hours.
  9. 9. The gasket of any one of claims 6 to 8, wherein the gasket comprises a polymer having a fluorine substitution rate of 95% or less.
  10. 10. The gasket of any one of claims 6 to 9, wherein the gasket comprises at least one polymer selected from the group consisting of polyethylene, polypropylene, polybutylene terephthalate, and polyphenylene sulfide.
  11. 11. The gasket of any one of claims 6 to 10 in contact with an electrolyte.
  12. 12. An electrochemical device having the gasket of any one of claims 6 to 11.

Description

Gasket for electrochemical device and electrochemical device Technical Field The present disclosure relates to gaskets for electrochemical devices and electrochemical devices. Background The use of a resin such as Perfluoroalkoxyalkane (PFA) as a sealing member (gasket) for an electrochemical device such as a lithium ion secondary battery is known (see, for example, patent documents 1 to 4). Prior art literature Patent literature Patent document 1 Japanese patent application laid-open No. 2017-174732 Patent document 2 International publication No. 2020/066050 Patent document 3 International publication No. 2014/049645 Patent document 4 Japanese patent laid-open No. 2021-141045 Disclosure of Invention Technical problem to be solved by the invention An object of the present disclosure is to provide a gasket for an electrochemical device excellent in low water vapor permeability and an electrochemical device using the same. Means for solving the technical problems The present disclosure (1) is a gasket for an electrochemical device, comprising polybutylene terephthalate, having a compression ratio of 5% or more when mounted. The present disclosure (2) is the gasket of the present disclosure (1), wherein the compression ratio is less than the fracture compression ratio. The gasket of the present disclosure (3) is the gasket of the present disclosure (1) or (2), wherein the water vapor transmission coefficient is less than 0.010g/1000 hours. The present disclosure (4) is a gasket in any combination with any one of the present disclosure (1) to (3), which is in contact with an electrolyte. The present disclosure (5) is an electrochemical device provided with a gasket optionally combined with any one of the present disclosure (1) to (4). The present disclosure (6) is a gasket for an electrochemical device, comprising a polymer, wherein the compression ratio at the time of installation is 20% to 75%. The present disclosure (7) is the gasket of the present disclosure (6), wherein the compression ratio is less than the fracture compression ratio. The gasket of the present disclosure (8) is the gasket of the present disclosure (6) or (7), wherein the water vapor transmission coefficient is less than 0.010g/1000 hours. The present disclosure (9) is a gasket optionally combined with any one of the present disclosure (6) to (8), comprising a polymer having a fluorine substitution rate of 95% or less. The present disclosure (10) is a gasket in any combination with any one of the present disclosure (6) to (9), comprising at least one polymer selected from the group consisting of polyethylene, polypropylene, polybutylene terephthalate, and polyphenylene sulfide. The present disclosure (11) is a gasket in any combination with any one of the present disclosure (6) to (10), which is in contact with an electrolyte. The present disclosure (12) is an electrochemical device comprising a gasket optionally combined with any one of the present disclosure (6) to (11). ADVANTAGEOUS EFFECTS OF INVENTION According to the present disclosure, a gasket for an electrochemical device excellent in low water vapor permeability and an electrochemical device using the same can be provided. Drawings Fig. 1 is a schematic cross-sectional view showing the constitution of a portion of an electrochemical device including a gasket. Fig. 2 is a schematic cross-sectional view of a permeation test jig used in the water vapor permeation test. Detailed Description Even when a material that has been conventionally considered to have poor water vapor permeability is used for the gasket, it has been found that the water vapor permeability can be reduced by setting the compression ratio at the time of mounting on the electrochemical device to be within a specific range. The present disclosure is specifically described below. The present disclosure provides a gasket for an electrochemical device (hereinafter also referred to as gasket (1) of the present disclosure), which comprises polybutylene terephthalate (PBT), and has a compression ratio of 5% or more at the time of installation. The gasket (1) of the present disclosure has the above-described structure, and is excellent in low water vapor permeability. In the present specification, the gasket (1) of the present disclosure and the gasket (2) of the present disclosure described below are collectively referred to as "gasket of the present disclosure" unless otherwise specified. The compression ratio of the gasket (1) of the present disclosure at the time of installation is preferably at least 5%, more preferably at least 15%, more preferably at least 20%, more preferably at least 25%, more preferably at least 30%, particularly preferably at least 40%, and further preferably less than 75%, more preferably at most 70%, more preferably at most 65%, more preferably less than 65%, from the viewpoint of further improvement of low water vapor permeability. The compression ratio can be calculated by the following equ