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KR-102962081-B1 - Insulation layer composition for secondary battery and secondary battery comprising the same

KR102962081B1KR 102962081 B1KR102962081 B1KR 102962081B1KR-102962081-B1

Abstract

An insulating layer composition for a secondary battery according to one embodiment of the present disclosure comprises inorganic particles; a binder; an organic solvent; and a dispersant, wherein the dispersant comprises a copolymer having an acidic group. A secondary battery according to one embodiment of the present disclosure comprises: a current collector; an electrode disposed on the current collector; and an insulating layer comprising an insulating material on at least one side of the electrode, wherein the insulating material comprises an insulating layer composition for the secondary battery.

Inventors

  • 김종혁
  • 김세희
  • 정영기

Assignees

  • 나모케미칼 주식회사

Dates

Publication Date
20260508
Application Date
20241111

Claims (12)

  1. It comprises inorganic particles; a binder; an organic solvent; and a dispersant, The above-mentioned dispersant is an insulating layer composition for a secondary battery comprising an alkylol ammonium salt copolymer, wherein The particle size D99 of the particles included in the above composition is greater than 5 µm and less than 9 µm, and The above composition and the insulating layer formed therefrom are insulating layer compositions for secondary batteries satisfying the following formula. 100 < R/T <350 (In the above formula, R is the viscosity of the composition (cp), and T is the thickness of the insulating layer after drying (um))
  2. delete
  3. In paragraph 1, An insulating layer composition for a secondary battery, wherein the above-mentioned dispersant is included in an amount of 0.5 to 7.0 parts by weight per 100 parts by weight of inorganic particles.
  4. In paragraph 1, An insulating layer composition for a secondary battery, wherein the above-mentioned inorganic particles comprise at least one selected from the group consisting of alumina, aluminum hydroxide, barium titanium oxide, magnesium oxide, magnesium hydroxide, clay, titanium oxide, glass powder, and boehmite.
  5. In paragraph 1, The above binder is polyacrylic acid, polymethacrylic acid, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, butadiene-acrylic acid copolymer, butadiene-methacrylic acid copolymer, polyvinylsulfonate, chlorosulfonated polyethylene, perfluorosulfonated ionomer, sulfonated polystyrene, styrene-acrylic acid copolymer, sulfonated butyl rubber, polyvinylidene fluoride (PVdF), polyvinylidene fluoride-hexafluoropropylene (PVdF-HFP), polyvinylpyrrolidone, polyacrylonitrile, polyvinylidene fluoride-trichloroethylene, polyvinylidene fluoride-chlorotrifluoroethylene (PVdF-TFE), polymethyl methacrylate, polyvinyl acetate, ethylene-co-vinyl acetate copolymer, polyethylene oxide, An insulating layer composition for a secondary battery comprising at least one selected from the group consisting of cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl pullulan, cyanoethyl polyvinyl alcohol, cyanoethyl cellulose, cyanoethyl sucrose, pullulan, carboxymethylcellulose, acrylonitrile styrene butadiene copolymer, and polyimide.
  6. In paragraph 1, An insulating layer composition for a secondary battery, wherein the above organic solvent comprises at least one selected from the group consisting of acetone, tetrahydrofuran, methylene chloride, dimethylformamide, dimethylacetamide, ethanol, methanol, and N-methyl-2-pyrrolidone (NMP).
  7. In paragraph 1, With respect to 100 parts by weight of the above composition, 4.9 to 32.5 parts by weight of the above inorganic particles; 0.1 to 2.5 parts by weight of the above dispersant; 5 to 15 parts by weight of the above binder; and An insulating layer composition for a secondary battery comprising 50 to 90 parts by weight of the above organic solvent.
  8. delete
  9. In paragraph 1, An insulating layer composition for a secondary battery, wherein the viscosity of the above composition is 500 to 10,000 cp.
  10. In paragraph 1, An insulating layer composition for a secondary battery, wherein the thickness of the insulating layer formed from the above composition is 1 to 50 μm.
  11. delete
  12. The whole house; Electrode disposed on the above current collector; and The above electrode includes an insulating layer comprising an insulating material on at least one side thereof, and The above insulating material is a secondary battery comprising a composition according to any one of claims 1, 3 to 7, and 9 to 10.

Description

Insulation layer composition for secondary battery and secondary battery comprising the same The present disclosure relates to an insulating layer composition for a secondary battery and a secondary battery comprising the same. Recently, the development of secondary battery technology and the demand for it have been rapidly increasing, and in particular, research on secondary batteries with higher energy density, excellent lifespan, and high output characteristics is actively underway. Meanwhile, as secondary batteries with higher energy density are being applied in various fields, research is being conducted to improve insulation between electrodes by forming an insulating layer on the outer edge of the electrode active material layer in order to construct safer electrodes. Conventional electrode insulating layers are formed using polymers with high heat and chemical resistance; however, these polymer electrode insulating layers suffer from reduced adhesion under high-temperature conditions and issues such as shrinkage during coating layer formation, which compromise battery safety. To address these problems, a technology has been proposed to improve the heat resistance and shrinkage issues of the insulating layer by using an insulating coating composition containing inorganic particles. However, insulating layer compositions containing inorganic particles proposed to date lack the dispersibility of the inorganic particles, resulting in linear uncoated areas caused by clumping during coating and non-uniformity of the insulating layer after drying. In addition, there are problems such as weakened adhesion due to the non-uniformity of the insulating layer and partial degradation of insulation performance due to the non-uniform insulating layer. FIG. 1 is a cross-sectional view of a secondary battery according to various embodiments of the present disclosure. Hereinafter, various embodiments of this document are described with reference to the accompanying drawings. The embodiments and the terms used therein are not intended to limit the technology described in this document to specific embodiments and should be understood to include various modifications, equivalents, and/or substitutions of said embodiments. Insulating layer composition for secondary batteries The insulating layer composition for a secondary battery according to the present disclosure may be formed on at least one side of an electrode to prevent an internal short circuit of the secondary battery. An insulating layer composition for a secondary battery according to the present disclosure may include inorganic particles, a binder, and a dispersant. An insulating layer composition for a secondary battery according to the present disclosure may include inorganic particles, a binder, an organic solvent, and a dispersant. The insulating layer composition for a secondary battery according to the present disclosure may include a copolymer containing acidic groups as a dispersant. The insulating layer composition for a secondary battery according to the present disclosure provides excellent dispersibility and phase stability, thereby exhibiting excellent insulating properties when applied as an insulating layer for an electrode. The insulating layer composition for a secondary battery according to the present disclosure has excellent coating properties, so when the insulating layer is coated, it exhibits a uniform coating thickness and can exhibit uniform insulation characteristics. The insulating layer composition for a secondary battery according to the present disclosure has excellent adhesion properties, so it can improve the battery stability of a secondary battery including it as an insulating layer. (1) Inorganic particles The insulating layer composition for a secondary battery according to the present disclosure may include inorganic particles. The inorganic particles may include, as a non-limiting example, at least one selected from the group consisting of alumina, aluminum hydroxide, barium titanium oxide, magnesium oxide, magnesium hydroxide, clay, titanium oxide, glass powder, and boehmite. Preferably, the inorganic particles may contain boehmite. The boehmite may be aluminum oxide-hydroxide. The diameter of the inorganic particles may be in the range of 0.001 to 10 μm to form an insulating layer of uniform thickness and appropriate porosity. Inorganic particles may be included in an amount of 4.9 to 32.5 parts by weight per 100 parts by weight of the insulating layer composition for a secondary battery. Preferably, inorganic particles may be included in an amount of 7.8 to 30.0 parts by weight per 100 parts by weight of the insulating layer composition for a secondary battery. Inorganic particles may be included in an amount of, for example, 50 to 90 parts by weight based on the total weight of the insulating layer. Preferably, inorganic particles may be included in an amount of 50 to 85 parts by weight based on the total weight of the