KR-102963205-B1 - Negative electrode and all-solid-state battery containing the same

Abstract

The present invention relates to a negative electrode that provides good binding properties and electrical conductivity while reducing the binder content, and an all-solid-state battery comprising the same. The negative electrode for an all-solid-state battery according to the present invention comprises a negative electrode active material and a binder having a cyanide resin.

Inventors

• 황치현
• 정윤채
• 유지상

Assignees

• 한국전자기술연구원

Dates

Publication Date

20260511

Application Date

20231101

Claims (12)

1. Cathode active material; A binder comprising a cyanide resin; and Includes carbon material and metal particles; and A negative electrode for an all-solid-state battery, characterized in that the above cyanide resin is in an amount of 4 to 7 parts by weight based on 100 parts by weight of the carbon material and metal particles.
2. In paragraph 1, A negative electrode for an all-solid-state battery, characterized in that the above-mentioned cyanide resin is represented by the following chemical formula, the molar ratio of m to n is 3 to 7:7 to 3, and the total molecular weight is 10,000 to 1,000,000 g/mol. [Chemical Formula 1]
3. delete
4. In paragraph 1, A negative electrode for an all-solid-state battery, characterized in that the above carbon material is non-graphite carbon.
5. In paragraph 4, A negative electrode for an all-solid-state battery, characterized in that the metal particles include Ag, Zn, Al, Sn, Mg, Ge, In, Au, Pd, or a combination thereof and have a nano size.
6. delete
7. In paragraph 1, A negative electrode for an all-solid-state battery characterized by the binding force of the above negative electrode being 10 mN or more.
8. A cathode comprising a binder having a cathode active material, a carbon material, metal particles, and a cyanide resin; and An all-solid-state battery characterized in that the above-mentioned cyanide resin is in an amount of 4 to 7 parts by weight based on 100 parts by weight of the above-mentioned carbon material and metal particles.
9. In paragraph 8, An all-solid-state battery characterized in that the above-mentioned cyanide resin is represented by the following chemical formula, the molar ratio of m to n is 3 to 7:7 to 3, and the total molecular weight is 10,000 to 1,000,000 g/mol. [Chemical Formula 1]
10. delete
11. In paragraph 8, The above carbon material is non-graphite carbon, and The above-mentioned metal particles comprise Ag, Zn, Al, Sn, Mg, Ge, In, Au, Pd, or a combination thereof and are characterized by having a nano size.
12. In paragraph 8, An all-solid-state battery characterized by the bonding force of the above-mentioned negative electrode being 10 mN or more.

Description

Negative electrode and all-solid-state battery containing the same The present invention relates to an all-solid-state battery, and more specifically, to a negative electrode that provides good binding properties and electrical conductivity while reducing the binder content, and an all-solid-state battery including the same. As the demand for electric vehicles and large-capacity power storage devices increases, various batteries have been developed to meet this need. Lithium-ion batteries have been widely commercialized due to their superior energy density and power output characteristics among various types of rechargeable batteries. Among lithium-ion batteries, those containing a liquid-type electrolyte including an organic solvent (hereinafter referred to as "liquid-type rechargeable batteries") are primarily used. However, liquid-type rechargeable batteries have been criticized for causing battery expansion due to the decomposition of the liquid electrolyte through electrode reactions and the risk of ignition caused by leakage of the liquid electrolyte. To address these issues with liquid-type rechargeable batteries, lithium-ion batteries utilizing solid electrolytes with excellent stability (hereinafter referred to as "all-solid-state batteries") are attracting attention. In such all-solid-state batteries, the negative electrode layer is composed of carbon materials, alloys, lithium metals, and carbon/metal composites. Among these, in all-solid-state batteries having a negative electrode layer using carbon-based materials and metals as negative electrode active materials, lithium migrating from the positive electrode must be uniformly deposited within the negative electrode layer to prevent dendrites from growing toward the solid electrolyte layer and the positive electrode active material layer. To solve these problems, an all-solid-state battery has been proposed in which a negative electrode layer capable of lithium absorption is placed between the negative electrode current collector and the solid electrolyte layer. However, in such all-solid-state batteries, metallic lithium precipitated at the interface between the solid electrolyte layer and the negative electrode current collector grows as dendrites toward the positive active material layer through the pores of the solid electrolyte layer, causing frequent short circuits. Therefore, improvements in the conductivity characteristics of the cathode layer are required to enable the smooth deposition of lithium metal. FIG. 1 is a drawing showing an all-solid-state battery according to the present invention. Figure 2 is a graph showing the results of evaluating the bonding strength of the cathode according to the comparative example and the example. Figure 3 is a graph showing the initial output characteristics of a battery with a negative electrode applied according to a comparative example and an embodiment. Figure 4 is a graph showing the lifespan characteristics of a battery with a negative electrode applied according to a comparative example and an example. It should be noted that in the following description, only the parts necessary for understanding the embodiments of the present invention are explained, and the description of other parts will be omitted to the extent that it does not deviate from the gist of the present invention. The terms and words used in the specification and claims described below should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention. Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely preferred embodiments of the invention and do not represent all aspects of the technical spirit of the invention; therefore, it should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application. Hereinafter, embodiments of the present invention will be described in more detail with reference to the attached drawings. FIG. 1 is a drawing showing an all-solid-state battery according to the present invention. Referring to FIG. 1, the all-solid-state battery (10) according to the present invention includes a negative electrode (20), a positive electrode (30), and a solid electrolyte layer (40). It has a structure in which a negative electrode (20) is stacked on one side centered on the solid electrolyte layer (40), and a positive electrode (30) is stacked on the other side. The negative electrode (20) includes a negative electrode current collector (22) and a negative electrode active material layer (24) located on the negative electrode current collector (22). The negative electrode current collector (22) can be made of a material that does not r