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KR-20260064812-A - NEGATIVE ELECTRODE SLURRY, MANUFACTURING METHOD OF NEGATIVE ELECTRODE SLURRY AND NEGATIVE ELECTRODE FOR RECHARGEABLE LITHIUM BATTERY

KR20260064812AKR 20260064812 AKR20260064812 AKR 20260064812AKR-20260064812-A

Abstract

The present invention relates to a cathode slurry, a method for manufacturing the same, and a cathode manufactured using the cathode slurry. The cathode slurry comprises a first cathode active material including a silicon composite; and a second cathode active material which is a carbon-based material, wherein the silicon composite includes a silicon-based active material and a one-dimensional carbon nanostructure, and the one-dimensional carbon nanostructure is fixed in a dispersed form on the surface of the silicon-based active material, and the second cathode active material is a carbon-based material different from the one-dimensional carbon nanostructure.

Inventors

  • 설종헌
  • 윤지희
  • 김특영
  • 전성호
  • 신동현
  • 황태현
  • 김재홍
  • 김민재
  • 남중현
  • 김호
  • 유정근

Assignees

  • 삼성에스디아이 주식회사

Dates

Publication Date
20260508
Application Date
20241029

Claims (20)

  1. A first negative active material comprising a silicon composite; and It includes a second negative electrode active material which is a carbon-based material, The above silicon composite comprises a silicon-based active material and a one-dimensional carbon nanostructure, and The above-mentioned one-dimensional carbon nanostructure is fixed in a dispersed form on the surface of the above-mentioned silicon-based active material, and The second cathode active material is a carbon-based material different from the one-dimensional carbon nanostructure, Cathode slurry.
  2. In paragraph 1, On the surface of the second negative electrode active material, the one-dimensional carbon nanostructure is omitted so that the carbon-based material is exposed. Cathode slurry.
  3. In paragraph 1, The average particle size (D50) of the first negative electrode active material is 1 μm to 30 μm, Cathode slurry.
  4. In paragraph 1, The above one-dimensional carbon nanostructure comprises at least one of carbon nanotubes (CNT), carbon nanofibers (CNFs), graphene nanoribbons (GNRs), carbon nano belts, carbon nano rods, or combinations thereof. Cathode slurry.
  5. In paragraph 1, The above silicone composite further comprises a thermoplastic binder, and The above one-dimensional carbon nanostructure is fixed to the surface of the silicon-based active material via the thermoplastic binder, Cathode slurry.
  6. In paragraph 5, The above thermoplastic binder comprises at least one of phenoxy resin, polypropylene (PP), polyvinylidene fluoride (PVDF), polyvinylidene chloride (PVC), or a combination thereof. Cathode slurry.
  7. In paragraph 1, The content of the above-mentioned one-dimensional carbon nanostructure is 0.05 to 3 weight% with respect to the total weight of the above-mentioned first negative electrode active material, Cathode slurry.
  8. In paragraph 1, The content of the thermoplastic binder is 0.05 to 3 weight% with respect to the total weight of the first cathode active material, Cathode slurry.
  9. In paragraph 1, The weight ratio of the first negative electrode active material and the second negative electrode active material is 1:50 to 1:5, Cathode slurry.
  10. In paragraph 1, The above second negative electrode active material comprises graphite, Cathode slurry.
  11. In paragraph 1, The second negative electrode active material comprises artificial graphite, natural graphite, or a mixture thereof. Cathode slurry.
  12. In paragraph 1, The above cathode slurry further comprises at least one of a conductive material, a dispersant, a binder, or a combination thereof, Cathode slurry.
  13. A step of preparing a first negative electrode active material precursor comprising a silicon-based active material, a one-dimensional carbon nanostructure, and a thermoplastic binder; A step of manufacturing a first cathode active material by grinding the first cathode active material precursor with a ball mill; and The method includes the step of mixing the first cathode active material and the second cathode active material, wherein The first negative electrode active material is a silicon composite in which the one-dimensional carbon nanostructure is fixed to the surface of a silicon-based active material via the thermoplastic binder, and The second cathode active material is a carbon-based material different from the one-dimensional carbon nanostructure, Method for manufacturing cathode slurry.
  14. In Paragraph 13, The first negative electrode active material precursor is in the form of aggregated silicon composites, Method for manufacturing cathode slurry.
  15. In Paragraph 13, The above grinding is performed using balls with a diameter of 0.1 mm to 30 mm, Method for manufacturing cathode slurry.
  16. In Paragraph 13, The above grinding is performed for 30 minutes to 48 hours, Method for manufacturing cathode slurry.
  17. In Paragraph 13, The weight ratio of the ball to the first cathode active material precursor at the time of grinding is 2:1 to 8:1, Method for manufacturing cathode slurry.
  18. In Paragraph 13, The average particle size (D50) of the first negative electrode active material is 1 μm to 30 μm, Method for manufacturing cathode slurry
  19. In Paragraph 13, The first negative electrode active material and the second negative electrode active material are mixed in a weight ratio of 1:50 to 1:5. Method for manufacturing cathode slurry.
  20. It includes a negative electrode current collector and a negative electrode active material layer located on the negative electrode current collector, The above negative electrode active material layer comprises a first negative electrode active material comprising a silicon composite, and a second negative electrode active material which is a carbon-based material, and The above silicon composite comprises a silicon-based active material and a one-dimensional carbon nanostructure, and The above-mentioned one-dimensional carbon nanostructure is fixed in a dispersed form on the surface of the above-mentioned silicon-based active material, and The second cathode active material is a carbon-based material different from the one-dimensional carbon nanostructure, cathode.

Description

Negative electrode slurry, manufacturing method of negative electrode slurry and negative electrode for rechargeable lithium battery The present invention relates to a cathode slurry, a method for manufacturing a cathode slurry, and a cathode for a lithium secondary battery. Recently, accompanied by the rapid proliferation of battery-powered electronic devices such as mobile phones, laptop computers, and electric vehicles, the demand for high-energy-density, high-capacity rechargeable batteries is rapidly increasing. Accordingly, research and development to improve the performance of lithium-ion batteries is actively underway. A lithium secondary battery is a battery comprising a positive electrode and a negative electrode containing an active material capable of lithium ion intercalation and deintercalation, and an electrolyte, which produces electrical energy through oxidation and reduction reactions when lithium ions are intercalated or deintercalated from the positive and negative electrodes. FIG. 1 is a conceptual diagram briefly illustrating a lithium secondary battery according to embodiments of the present invention. FIGS. 2 to 5 are schematic diagrams illustrating a lithium secondary battery according to one embodiment, where FIG. 2 is a cylindrical type, FIG. 3 is a prismatic type, and FIGS. 4 and 5 are pouch-type battery shapes. FIG. 6 is a cross-sectional view of a negative electrode for a lithium secondary battery according to embodiments of the present invention. FIG. 7 is a cross-sectional view of a negative electrode active material layer according to one embodiment of the present invention. FIG. 8 is a cross-sectional view of a negative electrode active material layer according to Comparative Example 1 of the present invention. FIG. 9 is a cross-sectional view of a negative electrode active material layer according to Comparative Example 2 of the present invention. FIG. 10 is a simplified figure showing a first cathode active material according to one embodiment of the present invention. FIG. 11 is a simplified figure showing the first cathode active material according to Comparative Example 2 of the present invention. FIG. 12 is a flowchart illustrating a method for manufacturing a cathode slurry according to one embodiment of the present invention. FIG. 13 is a graph showing the capacity retention rate of a lithium secondary battery according to embodiments and comparative examples of the present invention. FIG. 14 is a photograph of a cathode manufactured according to the embodiments and comparative examples of the present invention. In order to fully understand the structure and effects of the present invention, preferred embodiments of the present invention are described with reference to the attached drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various forms and various modifications can be made. The description of these embodiments is provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention. In this specification, when a component is described as being on another component, it means that it may be formed directly on the other component or that a third component may be interposed between them. Additionally, in the drawings, the thicknesses of the components are exaggerated for the effective description of the technical content. Throughout the specification, parts indicated by the same reference numeral represent the same components. The embodiments described herein will be described with reference to cross-sectional and/or plan views, which are exemplary illustrations of the invention. In the drawings, the thicknesses of films and regions are exaggerated for effective description of the technical content. Accordingly, the regions illustrated in the drawings are schematic in nature, and the shapes of the regions illustrated in the drawings are intended to illustrate specific forms of regions of the device and are not intended to limit the scope of the invention. Although terms such as first, second, third, etc., have been used to describe various components in the various embodiments of this specification, these components should not be limited by such terms. These terms are used merely to distinguish one component from another. The embodiments described and illustrated herein also include their complementary embodiments. The terms used herein are for describing the embodiments and are not intended to limit the invention. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. As used herein, 'comprises' and/or 'comprising' do not exclude the presence or addition of one or more other components to the mentioned components. In this specification, "combination of these" may mean a mixture of components, a laminate, a composite, a copolymer, an alloy, a blend