WO-2026095367-A1 - SEPARATOR FOR ELECTROCHEMICAL DEVICE AND ELECTROCHEMICAL DEVICE INCLUDING SAME

WO2026095367A1WO 2026095367 A1WO2026095367 A1WO 2026095367A1WO-2026095367-A1

Abstract

The present invention provides a separator for an electrochemical device and an electrochemical device having same applied thereto, the separator 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 (both inclusive).

Inventors

KIM, MIN JI
KIM, JI HYEON
HWANG, SEON WOO
KA, KYUNG RYUN
KIM, MIN GYU

Assignees

주식회사 엘지에너지솔루션

Dates

Publication Date: 20260507
Application Date: 20250924
Priority Date: 20241101

Claims (11)

porous polymer substrate; and A porous coating layer formed on at least one surface of the above-mentioned porous polymer substrate and comprising inorganic particles, and A separator for an electrochemical device, wherein the dielectric constant of the porous coating layer is 250 or more and 10,000 or less.
In paragraph 1, The above inorganic particles comprise BaTiO3 or SrTiO3 , a separator for an electrochemical device.
In paragraph 2, The above inorganic particles are separators for electrochemical devices having a dielectric constant of 250 or more and 10,000 or less.
In paragraph 2 The above inorganic particles are separators for electrochemical devices, having a particle size of 300 nm or more and 1,000 nm or less.
In paragraph 2 A separator for an electrochemical device, wherein the crystal structure of the above-mentioned inorganic particles is tetragonal.
In paragraph 1, A separator for an electrochemical device, wherein the thickness of the porous coating layer is 0.3 μm or more and 3.0 μm or less.
In paragraph 1 A separator for an electrochemical device comprising 80 parts by weight or more and 99 parts by weight or less of the inorganic particles based on 100 parts by weight of the porous coating layer.
In paragraph 1, The above porous coating layer further comprises an acrylic binder, a separator for an electrochemical device.
In paragraph 1, A separator for an electrochemical device having a gas generation amount of 1,500 μL or less.
An electrochemical device comprising an anode, a cathode, a separator disposed between the anode and the cathode, and an electrolyte, wherein The above-mentioned separator is an electrochemical device according to claim 1.
In Paragraph 10, The above electrochemical device is an electrochemical device that is a lithium secondary battery.

Description

Separator for an electrochemical device and an electrochemical device including the same This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0153212 dated November 1, 2024 and Korean Patent Application No. 10-2025-0137403 dated September 23, 2025, and all contents disclosed in the documents of said Korean patent applications are incorporated herein as part of this specification. The present invention relates to a separator for an electrochemical device and an electrochemical device including the same. Electrochemical devices convert chemical energy into electrical energy using electrochemical reactions; recently, lithium-ion batteries, which offer high energy density and voltage, long cycle life, and applicability to various fields, are widely used. A lithium secondary battery may include an electrode assembly manufactured with a positive electrode, a negative electrode, and a separator disposed between the positive and negative electrodes, and the electrode assembly may be manufactured by housing it in a case together with an electrolyte. Hereinafter, each component of the present invention is described in more detail so that a person skilled in the art to which the present invention pertains can easily implement it; however, this is merely an example, and the scope of the rights of the present invention is not limited by the following. In this specification, the term “comprising” is used when listing materials, compositions, devices, and methods useful for the present invention, and is not limited to the examples listed. In this specification, “electrochemical device” may refer to a primary battery, a secondary battery, a supercapacitor, etc. In this specification, “size” refers to the diameter D50 at the 50% point of the cumulative distribution of the number of particles according to size. The size can be measured using a laser diffraction method. Specifically, after dispersing the object to be measured in a dispersion medium, it is introduced into a commercially available laser diffraction size measuring device (e.g., Microtrac S3500) to measure the difference in diffraction patterns according to particle size as the particles pass through a laser beam, thereby calculating the size distribution. The size can be measured by calculating the particle diameter at the point that is 50% of the cumulative distribution of the number of particles according to size in the measuring device. In this specification, “permittivity” is a unitless physical quantity representing the magnitude of polarization produced by a dielectric in response to an external electric field. The permittivity may be measured at a temperature of 25°C using the ASTM D150 standard test method. At this time, the sintering temperature for preparing the specimen may be 1100°C, and the thickness of the compressed plate may be approximately 1.55 mm. As used herein, “about,” “approximately,” and “substantially” are used to mean a range of values or degrees or approximations thereof, taking into account inherent manufacturing and material tolerances (e.g., ±5%). Among the components of an electrochemical device, the separator comprises a porous polymer substrate with a porous structure located between the anode and cathode. It serves to isolate the anode and cathode, prevent electrical short circuits between the two electrodes, and allow the passage of electrolytes and ions. Although the separator itself does not participate in electrochemical reactions, its physical properties, such as wettability to the electrolyte, degree of porosity, and thermal shrinkage rate, affect the performance and safety of the electrochemical device. Accordingly, various methods are being attempted to modify the physical properties of a coating layer by adding a coating layer to a porous polymer substrate to enhance the physical properties of the separator, and by adding various materials to the coating layer. For example, inorganic materials may be added to the coating layer to improve the mechanical strength of the separator, or inorganic materials or hydrates may be added to the coating layer to improve the flame retardancy and heat resistance of the porous polymer substrate. Conventional inorganic materials used to impart heat resistance, such as Al₂O₃and AlOOH, have the characteristic of adsorbing moisture due to functional groups such as hydroxyl and carboxyl groups exposed on the surface. This characteristic increases the moisture content contained in the separator and contributes to side reactions such as electrolyte decomposition, causing problems that reduce the stability and lifespan of the electrochemical device by generating gas during assembly, storage, transportation, or operation of the electrochemical device. The present invention provides a technology that improves the stability of an electrochemical device including a separator by controlling the dielectric constant of a porous coating layer included in the s