Granted Patent B2

US 12,381,204 · App. 17/347,742 · Granted Aug 5, 2025

Inventors: Jun Hee Han (Daejeon, KR); Hyo Mi Kim (Daejeon, KR); Moon Sung Kim (Daejeon, KR); Sang Baek Ryu (Daejeon, KR); Seung Hyun Yook (Daejeon, KR); Hwan Ho Jang (Daejeon, KR)

Assignee: SK On Co., Ltd.

H01M4/366H01M4/133H01M4/364H01M4/483H01M4/587H01M10/0525H01M2004/021H01M2004/027

Abstract

Claims (18)

1. A negative electrode for a lithium secondary battery, comprising:

a current collector;

a first negative electrode active material layer disposed on the current collector and including a first graphite-based active material containing artificial graphite and natural graphite, and a first silicon-based active material; and

a second negative electrode active material layer disposed on the first negative electrode active material layer and including a second graphite-based active material containing artificial graphite and natural graphite, and a second silicon-based active material,

wherein the first graphite-based active material has a content of the artificial graphite equal to or less than that of the natural graphite, and the second graphite-based active material has a content of the artificial graphite greater than that of the natural graphite,

wherein the second graphite-based active material contains the artificial graphite and the natural graphite in a weight ratio of 80:20 to 60:40, wherein a thickness ratio between the first negative electrode active material layer and the second negative electrode active material layer is greater than 3:7 and equal to or less than 5:5, and

further comprising a third negative electrode active material layer disposed on the second negative electrode active material layer and including a third graphite-based active material containing artificial graphite,

wherein the third graphite-based active material is a granular-type artificial graphite.

2. The negative electrode for a lithium secondary battery of claim 1 , wherein the first graphite-based active material contains the artificial graphite and the natural graphite in a weight ratio of 5:95 to 50:50.

3. The negative electrode for a lithium secondary battery of claim 1 , wherein the first negative electrode active material layer includes 0.1 to 35% by weight of the first silicon-based active material, based on the total weight of the active material, and

the second negative electrode active material layer includes 0.1 to 35% by weight of the second silicon-based active material, based on the total weight of the active material.

4. The negative electrode for a lithium secondary battery of claim 3 , wherein the first negative electrode active material layer includes 6 to 30% by weight of the first silicon-based active material, based on the total weight of the active material, and

the second negative electrode active material layer includes 6 to 30% by weight of the second silicon-based active material, based on the total weight of the active material.

5. The negative electrode for a lithium secondary battery of claim 1 , wherein the third graphite-based active material has a particle size of 13 to 20 μm.

6. The negative electrode for a lithium secondary battery of claim 1 , wherein the third negative electrode active material layer has a density of 1.55 to 1.8 g/cm 3 .

7. The negative electrode for a lithium secondary battery of claim 1 , wherein a thickness of the third negative electrode active material layer is 0.5 to 15% based on the total thickness of the negative electrode active material layers.

8. The negative electrode for a lithium secondary battery of claim 1 , wherein the first negative electrode active material layer and the second negative electrode active material layer have a continuous concentration gradient of the active material at an interface therebetween.

9. A lithium secondary battery comprising the negative electrode of claim 1 ; a positive electrode; a separator; and an electrolyte.

Assignments (2)

Priority Claims (1)

Continuity (1)

References Cited (17)