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US-20260128466-A1 - SEPARATOR FOR ELECTROCHEMICAL DEVICE AND ELECTROCHEMICAL DEVICE INCLUDING THE SAME

US20260128466A1US 20260128466 A1US20260128466 A1US 20260128466A1US-20260128466-A1

Abstract

The present disclosure provides a separator for an electrochemical device and an electrochemical device employing the same, in which the separator includes a porous polymer substrate and a porous coating layer formed on at least one surface of the porous polymer substrate and containing inorganic particles, and the dielectric constant of the porous coating layer is 250 to 10,000.

Inventors

  • Min Ji Kim
  • Ji Hyeon KIM
  • Seon Woo HWANG
  • Kyung Ryun KA
  • Min Gyu Kim

Assignees

  • LG ENERGY SOLUTION, LTD.

Dates

Publication Date
20260507
Application Date
20251031
Priority Date
20241101

Claims (11)

  1. 1 . A separator for an electrochemical device comprising: a porous polymer substrate; and a porous coating layer formed on at least one surface of the porous polymer substrate and containing inorganic particles, wherein the dielectric constant of the porous coating layer is 250 to 10,000.
  2. 2 . The separator for the electrochemical device according to claim 1 , wherein the inorganic particles contain BaTiO 3 or SrTiO 3 .
  3. 3 . The separator for the electrochemical device according to claim 2 , wherein the inorganic particles have a dielectric constant of 250 to 10,000.
  4. 4 . The separator for the electrochemical device according to claim 2 , wherein the particle size of the inorganic particles is 300 nm to 1,000 nm.
  5. 5 . The separator for the electrochemical device according to claim 2 , wherein the crystal structure of the inorganic particles is tetragonal.
  6. 6 . The separator for the electrochemical device according to claim 1 , wherein the thickness of the porous coating layer is 0.3 μm to 3.0 μm.
  7. 7 . The separator for the electrochemical device according to claim 1 , wherein the inorganic particles are included in an amount of 80 parts to 99 parts by weight relative to 100 parts by weight of the porous coating layer.
  8. 8 . The separator for the electrochemical device according to claim 1 , wherein the porous coating layer further includes an acrylic binder.
  9. 9 . The separator for the electrochemical device according to claim 1 , wherein the gas generation amount of the separator for the electrochemical device is 1,500 μl or less.
  10. 10 . An electrochemical device comprising: a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and an electrolyte, wherein the separator is the separator according to claim 1 .
  11. 11 . The electrochemical device according to claim 10 , wherein the electrochemical device is a lithium secondary battery.

Description

CROSS REFERENCES TO RELATED APPLICATIONS This application is based on and claims priority from Korean Patent Application No. 10-2024-0153212, filed on Nov. 1, 2024 and Korean Patent Application No. 10-2025-0137403, filed on Sep. 23, 2025, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. TECHNICAL FIELD The present disclosure relates to a separator for an electrochemical device, and an electrochemical device including the same. BACKGROUND An electrochemical device converts chemical energy into electrical energy by using electrochemical reactions. In recent years, lithium secondary batteries, which have a high energy density, a high voltage, and a long cycle life and can be used in various fields, are widely used. A lithium secondary battery may include an electrode assembly manufactured by combining a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode, and may be manufactured by accommodating the electrode assembly, together with an electrolyte, in a case. SUMMARY The present disclosure provides a separator for an electrochemical device and an electrochemical device including the same, in which the stability of the electrochemical device can be improved by adjusting the dielectric constant of a porous coating layer. Meanwhile, the present disclosure is not limited to the above-mentioned features, and other unmentioned features will be clearly understood by those skilled in the art from the following description. A separator for an electrochemical device provided in one embodiment of the present disclosure includes a porous polymer substrate, and a porous coating layer formed on at least one surface of the porous polymer substrate and containing inorganic particles, and the dielectric constant of the porous coating layer is about 250 to 10,000. According to one embodiment of the present disclosure, the inorganic particles may contain BaTiO3 or SrTiO3. According to one embodiment of the present disclosure, the inorganic particles may have a dielectric constant of about 250 to 10,000. According to one embodiment of the present disclosure, the particle size of the inorganic particles is 300 nm to 1,000 nm. According to one embodiment of the present disclosure, the crystal structure of the inorganic particles may be tetragonal. According to one embodiment of the present disclosure, the thickness of the porous coating layer may be about 0.3 μm to 3.0 μm. According to one embodiment of the present disclosure, the inorganic particles may be included in an amount of about 80 parts to 99 parts by weight relative to 100 parts by weight of the porous coating layer. According to one embodiment of the present disclosure, the porous coating layer may further include an acrylic binder. According to one embodiment of the present disclosure, the gas generation amount of the separator for the electrochemical device may be 1,500 μl or less. An electrochemical device provided in one embodiment of the present disclosure includes a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and an electrolyte. In the electrochemical device, the separator is the separator based on one embodiment of the present disclosure. The separator for an electrochemical device and the electrochemical device according to the present disclosure may have improved stability. DETAILED DESCRIPTION Hereinafter, each component of the present disclosure will be described in more detail so that those with ordinary knowledge in the technical field to which the present disclosure belongs can easily implement it. However, this is merely an example, and the scope of the present disclosure is not limited by the following contents. In the present specification, “include” is used to list materials, compositions, devices, and methods useful for the present disclosure, but is not limited to the listed examples. In the present specification, “electrochemical device” may mean a primary battery, a secondary battery, or a supercapacitor. In the present specification, the “particle size” refers to a diameter D50 at the point of 50% in the cumulative distribution of the number of particles based on the particle size. The particle size may be measured by using a laser diffraction method. Specifically, a measurement target is dispersed in a dispersion medium, and then is introduced into a commercially available laser diffraction particle size measurement device (e.g., Microtrac S3500). Then, when the particles pass through laser beam, the particle size distribution is calculated by measuring the difference in the diffraction pattern according to the particle size. The particle size may be measured by calculating the particle diameter at the point of 50% in the cumulative distribution of the number of particles based on the particle size, in the measuring device. T