EP-4738464-A1 - NEGATIVE ELECTRODE SLURRY, MANUFACTURING METHOD OF NEGATIVE ELECTRODE SLURRY AND NEGATIVE ELECTRODE FOR RECHARGEABLE LITHIUM BATTERY

Abstract

The present disclosure relates to a negative electrode slurry, a manufacturing method of the negative electrode slurry, and a negative electrode manufactured using the negative electrode slurry. The negative electrode slurry includes a first negative electrode active material including a silicon composite, and a second negative electrode active material including a carbon-based material. The silicon composite includes a silicon-based active material and a one-dimensional carbon nanostructure. The one-dimensional carbon nanostructure is fixed in a dispersed form on a surface of the silicon-based active material. The second negative electrode active material is a carbon-based material different from the one-dimensional carbon nanostructure.

Inventors

• YOO, Jungkeun
• NAM, JUNGHYUN
• KIM, HO
• YOON, JIHEE
• SEOL, Jongheon
• JEON, Seongho
• KIM, Teukyoung
• SHIN, Donghyun
• HWANG, Taehyun
• KIM, JAEHONG
• Kim, Minjae

Assignees

• SAMSUNG SDI CO., LTD.

Dates

Publication Date

20260506

Application Date

20251023

Claims (15)

1. A negative electrode slurry comprising: a first negative electrode active material (SC) comprising a silicon composite; and a second negative electrode active material (GPH) which is a carbon-based material, wherein the silicon composite comprises a silicon-based active material (SP) and a one-dimensional carbon nanostructure (CNS), the one-dimensional carbon nanostructure (CNS) is fixed in a dispersed form on a surface of the silicon-based active material (SP), and the second negative electrode active material (GPH) is a carbon-based material that is different from the one-dimensional carbon nanostructure (CNS).
2. The negative electrode slurry of claim 1, wherein the one-dimensional carbon nanostructure (CNS) is omitted on a surface of the second negative electrode active material (GPH) so that the carbon-based material is exposed.
3. The negative electrode slurry of claim 1 or 2, wherein an average particle diameter (D50) of the first negative electrode active material (SC) is in a range of ≥ 1 µm to ≤ 30 µm.
4. The negative electrode slurry according to any one of claims 1 to 3, wherein the one-dimensional carbon nanostructure (CNS) comprises at least one of carbon nanotubes (CNTs), carbon nanofibers (CNFs), graphene nanoribbons (GNRs), carbon nano belts, and carbon nano rods.
5. The negative electrode slurry according to any one of claims 1 to 4, wherein the silicon composite further comprises a thermoplastic binder (S100), and the one-dimensional carbon nanostructure (CNS) is fixed on the surface of the silicon-based active material (SP) via the thermoplastic binder (S100).
6. The negative electrode slurry according to any one of claims 1 to 5, wherein the content of the one-dimensional carbon nanostructure (CNS) is in a range of ≥ 0.05 wt% to ≤ 3 wt% relative to a total weight of the first negative electrode active material (SC).
7. The negative electrode slurry according to any one of claims 1 to 6, wherein the silicon composite further comprises a thermoplastic binder (S100), and the one-dimensional carbon nanostructure (CNS) is fixed on the surface of the silicon-based active material (SP) via the thermoplastic binder (S100), wherein the content of the thermoplastic binder (S100) is in a range of ≥ 0.05 wt% to ≤ 3 wt% relative to a total weight of the first negative electrode active material (SC).
8. The negative electrode slurry according to any one of claims 1 to 7, wherein a weight ratio of the first negative electrode active material (SC) to the second negative electrode active material (GPH) is in a range of about 1:50 to about 1:5.
9. A method of manufacturing a negative electrode slurry, the method comprising: preparing a first negative electrode active material (SC) precursor comprising a silicon-based active material (SP), a one-dimensional carbon nanostructure (CNS), and a thermoplastic binder (S100); pulverizing the first negative electrode active material (SC) precursor to prepare a first negative electrode active material (SC); and mixing the first negative electrode active material (SC) and a second negative electrode active material (GPH), wherein the first negative electrode active material (SC) comprises a silicon composite in which the one-dimensional carbon nanostructure (CNS) is fixed on a surface of the silicon-based active material (SP) via the thermoplastic binder (S100), and the second negative electrode active material (GPH) comprises a carbon-based material that is different from the one-dimensional carbon nanostructure (CNS).
10. The method of manufacturing a negative electrode slurry of claim 9, wherein the first negative electrode active material (SC) precursor comprises an agglomeration of multiple silicon composites.
11. The method of manufacturing a negative electrode slurry of claim 9 or 10, wherein the pulverizing is performed using balls having a diameter in a range of ≥ 0.1 mm to ≤ 30 mm.
12. The method of manufacturing a negative electrode slurry according to any one of claims 9 to 11, wherein the pulverizing is performed for a duration in a range of ≥ 30 minutes to ≤ 48 hours.
13. The method of manufacturing a negative electrode slurry according to any one of claims 9 to 12, wherein a weight ratio of balls and the first negative electrode active material (SC) precursor during the pulverizing is in a range of about 2:1 to about 8:1.
14. The method of manufacturing a negative electrode slurry according to any one of claims 9 to 13, wherein the first negative electrode active material (SC) and the second negative electrode active material (GPH) are mixed in a weight ratio in a range of about 1:50 to about 1:5.
15. A negative electrode comprising: a negative electrode current collector; and a negative electrode active material layer (AML2) on the negative electrode current collector, wherein the negative electrode active material layer (AML2) comprises a first negative electrode active material (SC) comprising a silicon composite, and a second negative electrode active material (GPH) comprising a carbon-based material, the silicon composite comprises a silicon-based active material (SP) and a one-dimensional carbon nanostructure (CNS), the one-dimensional carbon nanostructure (CNS) is fixed in a dispersed form on a surface of the silicon-based active material (SP), and the second negative electrode active material (GPH) comprises a carbon-based material that is different from the one-dimensional carbon nanostructure (CNS).

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This U.S. non-provisional patent application claims priority under 35 U.S.C. § 119 of Korean Patent Application No. 10-2024-0149715, filed on October 29, 2024, the entire contents of which are hereby incorporated by reference. BACKGROUND The present disclosure herein relates to a negative electrode slurry, a manufacturing method of the negative electrode slurry, and a negative electrode for a rechargeable lithium battery. With increasing spread of electronic devices that use batteries, such as, e.g., mobile phones, laptop computers, electric vehicles, and the like, the demand for rechargeable batteries with high energy density and high capacity is increasing. Accordingly, improving the performance of rechargeable lithium batteries may be advantageous. A rechargeable lithium battery typically includes a positive electrode and a negative electrode including active materials capable of intercalation and deintercalation of lithium ions, and an electrolyte. The rechargeable lithium battery produces electrical energy through the oxidation and reduction reactions while lithium ions are intercalated into and deintercalated from the positive electrode and negative electrode. SUMMARY Examples of the present disclosure include a negative electrode slurry for forming a negative electrode active material layer having high density and conductivity, and a manufacturing method of the negative electrode slurry. Another example of the present disclosure includes a negative electrode configured to improve the performance of a rechargeable lithium battery. Another example of the present disclosure includes a rechargeable lithium battery including the negative electrode and having desired or improved life characteristics and energy efficiency. A negative electrode slurry according to an example concept of the present disclosure may include a first negative electrode active material including a silicon composite, and a second negative electrode active material which is or includes a carbon-based material. The silicon composite may include a silicon-based active material and a one-dimensional carbon nanostructure, the one-dimensional carbon nanostructure may be fixed in a dispersed form on a surface of the silicon-based active material, and the second negative electrode active material may be or include a carbon-based material that is different from the one-dimensional carbon nanostructure. A method of manufacturing a negative electrode slurry according to another example of the present disclosure may include preparing a first negative electrode active material precursor including a silicon-based active material, a one-dimensional carbon nanostructure, and a thermoplastic binder, pulverizing the first negative electrode active material precursor by, e.g., a ball mill, to prepare a first negative electrode active material, and mixing the first negative electrode active material and a second negative electrode active material. The first negative electrode active material may be or include a silicon composite in which the one-dimensional carbon nanostructure is fixed on a surface of the silicon-based active material via the thermoplastic binder, and the second negative electrode active material may be or include a carbon-based material that is different from the one-dimensional carbon nanostructure. A negative electrode according to another example of the present disclosure may include a negative electrode current collector, and a negative electrode active material layer located on the negative electrode current collector. The negative electrode active material layer may include a first negative electrode active material including a silicon composite, and a second negative electrode active material which is or includes a carbon-based material. The silicon composite may include a silicon-based active material and a one-dimensional carbon nanostructure. The one-dimensional carbon nanostructure may be fixed in a dispersed form on a surface of the silicon-based active material, and the second negative electrode active material may be or include a carbon-based material that is different from the one-dimensional carbon nanostructure. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a conceptual diagram illustrating a rechargeable lithium battery according to example embodiments of the present disclosure.FIG. 2 to FIG. 5 are schematic diagrams illustrating rechargeable lithium batteries according to example embodiments, in which FIG. 2 may be a cylindrical battery, FIG. 3 may be a prismatic battery, and FIG. 4 and FIG. 5 may be pouch-type batteries.FIG. 6 is a cross-sectional view of a negative electrode for a rechargeable lithium battery according to example embodiments of the present disclosure.FIG. 7 is a cross-sectional view of a negative electrode active material layer according to an example embodiment of the present disclosure.FIG. 8 is a cross-sectional view of a negative electrode active material