KR-20260063522-A - SUBSTRATE FOR RECHARGEABLE BATTERY, METHOD FOR MANUFACTURING THE SAME AND ELECTRODE INCLUDING THE SAME

Abstract

The electrode substrate of the present invention comprises a metal foil and a conductive binder layer formed on the metal foil and having protrusions randomly distributed thereon, wherein the protrusions have a needle-like shape with a width that decreases as they move away from the surface of the metal foil.

Inventors

• 김민식
• 조재호
• 정성민
• 문정기
• 권일경
• 유홍렬

Assignees

• 삼성에스디아이 주식회사

Dates

Publication Date

20260507

Application Date

20241030

Claims (20)

1. metal foil, A conductive binder layer formed on the metal foil and comprising randomly distributed protrusions Includes, The above-mentioned protrusions are electrode substrates having a needle-like shape, with their width decreasing as they move away from the surface of the metal foil.
2. In paragraph 1, The above conductive binder layer is a substrate for electrodes composed of a conductive material and a binder.
3. In paragraph 1, An electrode substrate having a height of 1㎛ to 20㎛ for the above-mentioned protrusions.
4. In paragraph 1, An electrode substrate having a width of 0.5㎛ to 100㎛ for the above-mentioned protrusions.
5. In paragraph 1 The side of the above-mentioned protrusion is a concave curved surface toward the center of the protrusion. An electrode substrate.
6. In paragraph 1, The conductive binder layer is a lower layer formed on the metal foil. Includes more, The above-mentioned protrusion is located on the lower layer and is integrally formed with the lower layer.
7. In paragraph 6, The thickness of the above lower layer is non-uniform for the electrode substrate.
8. A metal foil, a substrate formed on the metal foil and randomly distributed, comprising needle-shaped protrusions that decrease in width as they move away from the surface of the metal foil, Active material layer formed on the above substrate Includes, The above active material layer is an electrode for a secondary battery that is a self-supporting film.
9. In paragraph 8, The above self-supporting film is an electrode for a secondary battery formed by a dry process.
10. In paragraph 8, The above description includes an electrode active portion in which the active material layer is formed and an electrode non-active portion in which the active material layer is not formed, and An electrode for a secondary battery in which a conductive binder layer of the above-described material is exposed on the electrode-free portion.
11. In paragraph 8, The above conductive binder layer is an electrode for a secondary battery composed of a conductive material and a binder.
12. In paragraph 8, An electrode for a secondary battery having a height of 1 μm to 20 μm and a width of 0.5 μm to 100 μm of the above-mentioned protrusion.
13. In paragraph 8 The side of the above-mentioned protrusion has a concave curved surface toward the center of the protrusion. An electrode for a secondary battery.
14. In paragraph 8, The conductive binder layer is a lower layer formed on the metal foil. Includes more, The above-mentioned protrusion is located on the lower layer and is integrally formed with the lower layer, forming an electrode for a secondary battery.
15. In Paragraph 14, The thickness of the above lower layer is non-uniform for a secondary battery electrode.
16. Step of preparing the first metal foil, Step of forming a primer layer on the first metal foil, A step of attaching a second metal foil on the primer layer, A step of separating the first metal foil and the second metal foil to divide the primer layer, Step of curing the above primer layer to form a conductive binder layer A method for manufacturing an electrode substrate comprising
17. In Paragraph 16, In the step of dividing the primer layer, A method for manufacturing an electrode substrate in which a plurality of protrusions are formed while the primer layer is divided in the thickness direction.
18. In Paragraph 17, A method for manufacturing an electrode substrate having a symmetrical structure in which the protrusions of the first metal foil and the protrusions of the second metal foil are.
19. In Paragraph 16, In the step of forming the primer layer above, A method for manufacturing an electrode substrate in which the viscosity of the primer layer is 20 cp to 10,000 cp.
20. In Paragraph 16, In the step of forming the conductive binder layer, The above curing is a method for manufacturing an electrode substrate by drying at a temperature of 80°C to 180°C for less than 60 seconds.

Description

Substrate for rechargeable battery, method for manufacturing the same, and electrode including the same The present invention relates to a substrate for a secondary battery, a method for manufacturing the same, and an electrode comprising the same. With the technological development of portable devices, the demand for secondary batteries as an energy source is increasing. Unlike primary batteries, secondary batteries are batteries that undergo repeated charging and discharging. These secondary batteries can form a cylindrical or jellyroll-shaped electrode assembly by overlapping a positive electrode, a separator, and a negative electrode and then winding them, or form a stacked electrode assembly by separating them into sheets and then stacking them. Electrodes for secondary batteries are manufactured using a wet method in which an active material containing a solvent is applied onto a substrate, and a drying process is included to remove the solvent. During this drying process, as the solvent evaporates, relatively light particles float to the surface, resulting in non-uniform composition within the electrode plate and making it difficult to manufacture thick-film electrode plates. To address this, research is being conducted on solvent-free dry electrode plates, in which an electrode is formed by fabricating an active material, binder, and conductive material into a film form and laminating it onto a substrate. These dry electrode plates are not only easy to thicken as they do not require the use of solvents, but are also economical as they can reduce the costs associated with solvent recycling and drying processes. However, when laminating a film-type active material onto a substrate, the adhesion between the active material and the substrate is weak, causing the active material to detach. The information described above disclosed in the background technology of this invention is intended only to enhance understanding of the background of the present invention and may therefore include information that does not constitute prior art. The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings. FIG. 1 is a cross-sectional view of a substrate for a secondary battery according to one embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of a substrate for a secondary battery according to another embodiment of the present invention. FIG. 3 is a schematic diagram illustrating a method for forming a substrate according to an embodiment of the present invention. FIG. 4 is a schematic cross-sectional view of an electrode according to one embodiment of the present invention. FIG. 5 is a schematic diagram illustrating a method for forming an electrode according to an embodiment of the present invention. FIG. 6 is a schematic perspective view of a secondary battery according to one embodiment of the present invention. FIG. 7 is a schematic perspective view of a secondary battery according to another embodiment of the present invention. Figure 8 is a cross-sectional view of the line VIII-VIII' in Figure 7. Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings. Instead, based on the principle that the inventor can appropriately define the concepts of terms to best describe their invention, they should be interpreted in a meaning and concept consistent with the technical spirit of the present invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. It should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application. Additionally, as used herein, “comprise, include” and/or “comprising, including” specify the presence of the mentioned features, numbers, steps, actions, parts, elements, and/or groups thereof, and do not exclude the presence or addition of one or more other features, numbers, actions, parts, elements, and/or groups. Additionally, to aid in understanding the invention, the attached drawings are not drawn to actual scale, and the dimensions of some components may be exaggerated. Furthermore, the same reference numerals may be assigned to identical components in different embodiments. Although terms such as "first," "second," etc., are used to describ