KR-102960449-B1 - MULTILAYER FILM AND EXTERIOR MATERIAL FOR SECONDARY BATTERY COMPRISING SAME

KR102960449B1KR 102960449 B1KR102960449 B1KR 102960449B1KR-102960449-B1

Abstract

The present invention relates to a multilayer film and an exterior material for a secondary battery comprising the same. Specifically, one embodiment provides a multilayer film for an exterior material of a secondary battery comprising a laminate in which an outer layer, a barrier layer, and an inner layer are sequentially laminated, wherein the outer layer comprises a substrate layer and a coating layer located on the outer surface of the substrate layer, and the coating layer comprises aerogel particles.

Inventors

최성지
신재호
두승균
김종안
정겨운
김민수

Assignees

동원시스템즈 주식회사

Dates

Publication Date: 20260507
Application Date: 20211215

Claims (13)

It includes a laminate in which an outer layer, a barrier layer, and an inner layer are sequentially stacked, and The above outer layer comprises a substrate layer and a coating layer located on the outer surface of the substrate layer, and The above substrate layer comprises PET (polyethylene terephthalate), nylon, or a combination thereof, and The above coating layer contains aerogel particles, and The barrier layer comprises a metal layer and a surface treatment layer located on one or both sides of the metal layer. The above surface treatment layer comprises an acrylic polymer or a salt thereof, and one or more of a chromium compound and a phosphate compound. The above inner layer is formed in a single layer or multilayer structure, Multilayer film for casing of secondary batteries.
In paragraph 1, The above aerogel particles are one or more selected from the group comprising silica aerogel particles, alumina aerogel particles, carbon aerogel particles, titania aerogel particles, and zirconia aerogel particles. Multilayer film for casing of secondary batteries.
In paragraph 1, A multilayer film for an exterior material of a secondary battery, wherein the specific surface area of the above aerogel particles is 3 to 200 m² /g.
In paragraph 1, A multilayer film for an exterior material of a secondary battery, wherein the average particle size of the aerogel particles is 0.01 to 5 μm.
In claim 1, the surface treatment layer is a multilayer film for an exterior material of a secondary battery comprising 40 to 60 weight% of an acrylic polymer, 20 to 30 weight% of a chromium-based compound, and 20 to 30 weight% of a phosphate-based compound.
In claim 1, the coating layer further comprises a binder, and The binder is one or more selected from the group comprising polyvinyl alcohol, carboxymethylcellulose, hydroxypropylcellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers including ethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin, and nylon. Multilayer film for casing of secondary batteries.
A multilayer film for an exterior material of a secondary battery according to claim 6, wherein the weight ratio of aerogel particles and binder in the coating layer is 1:9 to 9:1.
In paragraph 1, A multilayer film for an exterior material of a secondary battery, wherein the thickness ratio of the substrate layer and the coating layer is 1:9 to 9:1.
In paragraph 1, A multilayer film for an exterior material of a secondary battery, wherein the thickness of the above-mentioned substrate layer is 15 to 30 μm.
In paragraph 1, A multilayer film for an exterior material of a secondary battery, wherein the thickness of the coating layer is 0.01 to 100 μm.
In paragraph 1, The above inner layer is formed as a three-layer structure of the first to third layers, and The first layer above is in contact with the metal layer and comprises a polar polypropylene-based resin, The above third layer comprises a random polypropylene-based resin or a propylene terpolymer (PP terpolymer) as the innermost layer, and The second layer exists between the first layer and the third layer and comprises PP (polypropylene), PVDC (polyvinylidene chloride), EVOH (ethylene vinyl alcohol copolymer), PE (polyethylene), COC (cycloolefin copolymer), or PVC (poly vinyl chloride). Multilayer film for casing of secondary batteries.
An outer casing for a secondary battery comprising a multilayer film according to any one of claims 1 to 11.
In Clause 12, the above-mentioned exterior material is an exterior material of a secondary battery that is a pouch-type exterior material.

Description

Multilayer film and exterior material for secondary battery comprising the same This invention relates to a multilayer film and an exterior material for a secondary battery containing the same. A secondary battery is a battery capable of repeated charging and discharging, and consists of a positive electrode, a negative electrode, an electrolyte, a separator, and an outer casing that houses them; depending on the shape of the outer casing, it can be classified into cylindrical, prismatic, coin, pouch, etc. The above pouch-type outer material includes a laminate in which an outer layer, a barrier layer, and an inner layer are sequentially laminated, and the outer layer is generally made of a material such as PET (polyethylene terephthalate) or nylon. However, while the aforementioned secondary battery may generate fire or heat from within due to various causes, the commonly used outer layer material has the problem of spreading this to the outside rather than suppressing it. Hereinafter, embodiments of the present invention will be described in detail. However, these are presented as examples and are not intended to limit the present invention, and the present invention is defined only by the scope of the claims set forth below. The terms used herein are for describing exemplary embodiments only and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. "Combinations of these" refers to mixtures of components, laminates, composites, copolymers, alloys, blends, reaction products, etc. Terms such as "include," "equip," or "have" are intended to specify the existence of the implemented features, numbers, steps, components, or combinations thereof, and should be understood as not excluding in advance the existence or addition of one or more other features, numbers, steps, components, or combinations thereof. In the drawings, thicknesses have been enlarged to clearly represent various layers and regions, and the same reference numerals have been used for similar parts throughout the specification. When a part such as a layer, film, region, or plate is described as being "on" or "on" another part, this includes not only cases where it is "immediately on" another part, but also cases where there is another part in between. Conversely, when a part is described as being "immediately on" another part, it means that there is no other part in between. “Layers” include not only shapes formed on the entire surface when viewed in a plan view, but also shapes formed on some surfaces. “Particle size” or “average particle size” may be measured by methods widely known to those skilled in the art, for example, by measuring with a particle size analyzer, or by measuring with transmission electron microscope images or scanning electron microscope images. Alternatively, the average particle size value may be obtained by measuring using dynamic light scattering and performing data analysis to count the number of particles for each particle size range and then calculating from thereon. Unless otherwise defined, the average particle size may refer to the diameter (D50) of a particle whose cumulative volume in the particle size distribution is 50% by volume. “Thickness” may be measured, for example, through photographs taken with an optical microscope such as a scanning electron microscope. "(Meta)acrylate" means that both "acrylate" and "methacrylate" are possible. (Multilayer film for secondary battery casings) One embodiment provides a multilayer film for an exterior material of a secondary battery, comprising a laminate in which an outer layer, a barrier layer, and an inner layer are sequentially stacked, wherein the outer layer comprises a substrate layer and a coating layer located on the outer surface of the substrate layer, and the coating layer comprises aerogel particles. A fire occurs when the three elements of combustion—oxygen, combustible material, and ignition source—are present simultaneously and in the same place, and a fire does not occur if any one of them is absent. Heat diffusion provides the ignition source, the material of the cell becomes the combustible material, and oxygen in the air becomes the medium that promotes the exothermic reaction. The above multilayer film can neutralize the three elements of heat diffusion (convection, conduction, and radiation) among the three elements of combustion. Specifically, the above multilayer film suppresses heat diffusion from the inside to the outside of the secondary battery through aerogel particles included in the coating layer of the outer layer, and furthermore, can provide a self-extinguishing function in the event of a fire occurring inside or outside the secondary battery. Accordingly, the above multilayer film is suitable for application as an exterior material for a secondary battery. The components of the above-mentioned multilayer film are described in detail below. oute