Anode including graphite and silicon-based material having different diameters and lithium secondary battery including the same
The present disclosure relates to an anode for a lithium secondary battery, wherein an anode material layer is formed on at least one surface of an anode current collector, and the anode material layer includes large-particle graphite, a small-particle silicon-based material, and fine-particle graphite, and satisfies the following conditions 1 to 3: [Condition 1] Average diameter D50 of the large-particle graphite (D 1 ): 1 to 50 μm [Condition 2] Average diameter D50 of the small-particle silicon-based material (D 2 ): 0.155D 1 to 0.414D 1 [Condition 3] Average diameter D50 of the fine-particle graphite (D 3 ): 0.155D 1 to 0.414D 1 , or 0.155D 2 to 0.414D 2 .
1. An anode for a lithium secondary battery, wherein an anode material layer is disposed on at least one surface of an anode current collector, and the anode material layer comprises large-particle graphite, a small-particle silicon-based material, and fine-particle graphite, and satisfies the following conditions 1 to 3:
condition 1: a diameter D50 of the large-particle graphite (D 1 ) is 1 to 50 μm;
condition 2: a diameter D50 of the small-particle silicon-based material (D2) is 0.155D 1 to 0.414D 1 ; and
condition 3: a diameter D50 of the fine-particle graphite (D 3 ) is 0.155D 1 to 0.414D 1 , or 0.155D 2 to 0.414D 2 .
2. The anode for a lithium secondary battery of claim 1 ,
wherein the diameter D50 of the large-particle graphite (D 1 ) is 5 to 30 μm.
3. The anode for a lithium secondary battery of claim 1 ,
wherein the diameter D50 of the small-particle silicon-based material (D 2 ) is 0.2D 1 to 0.4D 1 .
4. The anode for a lithium secondary battery of claim 1 ,
wherein the diameter D50 of the fine-particle graphite (D 3 ) is 0.2D 1 to 0.4D 1 , or 0.2D 2 to 0.4D 2 .
5. The anode for a lithium secondary battery of claim 1 ,
wherein the small-particle silicon-based material comprises at least one selected from the group consisting of a Si/C composite, SiO x (0<x<2), metal-doped SiO x (0<x<2), pure Si, and a Si-alloy.
6. The anode for a lithium secondary battery of claim 5 ,
wherein the metal-doped SiO x (0<x<2) is doped with at least one metal selected from the group consisting of Li, Mg, Al, Ca and Ti.
7. The anode for a lithium secondary battery of claim 1 ,
wherein the anode material layer comprises 30 to 99 wt % of the large-particle graphite, 0.5 to 40 wt % of the small-particle silicon-based material, and 0.5 to 30 wt % of the fine-particle graphite, based on a total weight of the large-particle graphite, the small-particle silicon-based material and the fine-particle graphite.
8. The anode for a lithium secondary battery of claim 1 ,
wherein the anode material layer further comprises a conductive material, a binder, or a mixture thereof.
9. The anode for a lithium secondary battery of claim 8 ,
wherein the conductive material and the binder are contained in an amount of 0.1 to 30 wt % based on a total weight of the anode material layer, respectively.
10. A lithium secondary battery comprising the anode for a lithium secondary battery of claim 1 .