ALL-SOLID SECONDARY BATTERY AND METHOD FOR PREPARING ALL-SOLID SECONDARY BATTERY

• US 20200136178A1
• Filed: 09/11/2019
• Published: 04/30/2020
• Est. Priority Date: 10/30/2018
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd., Samsung SDI Company Limited
• Original Assignee: Samsung Electronics Co. Ltd., Samsung SDI Company Limited
• Inventors: Ku, Junhwan, Lee, Minsuk, Kang, Hyorang
• Granted Patent: US 11,450,881 B2
• Time in Patent Office: Days
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/0562 Solid materials
• CPC Class Codes: H01M 10/0585 of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
• CPC Class Codes: H01M 2004/021 Physical characteristics, e.g. porosity, surface area
• CPC Class Codes: H01M 4/0404 by coating on electrode collectors
• CPC Class Codes: H01M 4/0435 Rolling or calendering
• CPC Class Codes: H01M 4/38 of elements or alloys
• CPC Class Codes: H01M 4/382 Lithium H01M4/405 takes precedence
• CPC Class Codes: H01M 4/5815 Sulfides
• CPC Class Codes: H01M 4/583 Carbonaceous material, e.g. graphite-intercalation compounds or CFx

Abstract

An all-solid secondary battery including: an anode layer including a first anode active material layer; a cathode layer including a cathode active material layer; a solid electrolyte layer between the anode layer and the cathode layer; and an anode current collector on the anode layer and opposite the solid electrolyte layer, wherein a maximum roughness depth R_max of a surface of the first anode active material layer is about 3.5 micrometers or less.

Claims

1. An all-solid secondary battery comprising:

an anode layer including a first anode active material layer;

a cathode layer including a cathode active material layer;

a solid electrolyte layer between the anode layer and the cathode layer; and

an anode current collector on the anode layer and opposite the solid electrolyte layer,

wherein a maximum roughness depth R_max of a surface of the first anode active material layer is about 3.5 micrometers or less.

2. The all-solid secondary battery of claim 1,

wherein a mean roughness Ra of a surface of the first anode active material layer is about 0.15 micrometers or less.

3. The all-solid secondary battery of claim 1,

wherein a root mean square roughness Rq of the surface of the first anode active material layer is about 0.2 micrometers or less.

4. The all-solid secondary battery of claim 1,

wherein a thickness of the first anode active material layer is about 50% or less of a thickness of the cathode active material layer, and

the thickness of the first anode active material layer is about 1 micrometers to about 20 micrometers.

5. The all-solid secondary battery claim 1,

wherein the first anode active material layer includes an anode active material and a binder.

6. The all-solid secondary battery of claim 5,

wherein the anode active material has a particle shape and an average particle size of the anode active material is 4 micrometers or less.

7. The all-solid secondary battery of claim 5,

wherein the anode active material includes at least one of a carbon containing anode active material and a metal or metalloid anode active material, and wherein the carbon containing anode active material includes amorphous carbon.

8. The all-solid secondary battery of claim 7,

wherein the metal or metalloid anode active material includes at least one of gold, platinum, palladium, silicon, silver, aluminum, bismuth, tin, and zinc.

9. The all-solid secondary battery of claim 5,

wherein the anode active material includes a mixture of first particles including amorphous carbon and second particles including a metal or metalloid, and the amount of the second particles is about 8 weight percent to about 60 weight percent, with respect to a total weight of the mixture.

10. The all-solid secondary battery of claim 1, further comprising:

a film including an element capable of forming an alloy with lithium on the anode current collector,

wherein the film is between the anode current collector and the first anode active material layer.

11. The all-solid secondary battery of claim 10,

wherein a thickness of the film is about 1 nanometer to about 800 nanometers.

12. The all-solid secondary battery of claim 1, further comprising:

a second anode active material layer between the anode current collector and the first anode active material layer, or between the solid electrolyte layer and the first anode active material layer,

wherein the second anode active material layer is a metal layer including lithium or a lithium alloy.

13. The all-solid secondary battery of claim 1,

wherein the anode current collector, the first anode active material layer, and an area therebetween are a Li-free area not including lithium.

14. The all-solid secondary battery of claim 13, wherein the Li-free area does not include lithium in an initial state of the all-solid secondary battery, or in a state after discharging the all-solid secondary battery.

15. The all-solid secondary battery of claim 1,

wherein the solid electrolyte layer comprises a sulfide solid electrolyte.

16. The all-solid secondary battery of claim 15,

wherein the sulfide solid electrolyte includes at least one of Li₂S—

P₂S₅, Li₂S—

P₂S₅—

LiX wherein X is a halogen, Li₂S—

P₂S₅—

Li₂O, Li₂S—

P₂S₅—

Li₂O—

LiI, Li₂S—

SiS₂, Li₂S—

SiS₂—

LiI, Li₂S—

SiS₂—

LiBr, Li₂S—

SiS₂—

LiCl, Li₂S—

SiS₂—

B₂S₃—

LiI, Li₂S—

SiS₂—

P₂S₅—

LiI, Li₂S—

B₂S₃, Li₂S—

P₂S₅—

Z_mS_n wherein m and n are positive numbers, and Z is one of Ge, Zn or Ga, Li₂S—

GeS₂, Li₂S—

SiS₂—

Li₃PO₄, Li₂S—

SiS₂-Li_pMO_q wherein p and q are positive numbers, and M is one of P, Si, Ge, B, Al, Ga, and In, Li_7-xPS_6-xCl_x wherein 0≤

x≤

2, Li_7-xPS_6-xBr_x wherein 0≤

x≤

2, and Li_7-xPS_6-xI_x wherein 0≤

x≤

2.

17. The all-solid secondary battery of claim 15,

wherein the sulfide solid electrolyte is an argyrodite-type compound including at least one of Li₆PS₅Cl, Li₆PS₅Br, and Li₆PS₅I.

18. A method of preparing an all-solid secondary battery, the method comprising:

preparing a first laminate by placing an anode active material layer on an anode current collector; and

preparing an anode layer by pressing the first laminate. preparing a second laminate by placing a solid electrolyte layer on a cathode layer;

preparing a third laminate by placing the anode layer on the second laminate such that the solid electrolyte layer and the anode active material layer contact each other; and

pressing the third laminate to prepare the all-solid secondary battery.

19. The method of claim 18,

wherein the pressing is roll pressing or flat pressing.

20. The method of claim 19,

wherein the pressing is performed at about 20°

C. to about 90°

C.

21. The method of claim 18, wherein a maximum roughness depth R_max of a surface of the anode active material layer included in the anode layer is 3.5 micrometers or less.