Negative electrode and solid-state secondary battery including the same

Patent metadata

Field	Value
Publication number	US-12456735-B2
Application number	US-202117249046-A
Country	US
Kind code	B2
Filing date	Feb 18, 2021
Priority date	Feb 18, 2020
Publication date	Oct 28, 2025
Grant date	Oct 28, 2025

Abstract

A negative electrode includes a negative electrode current collector and a first negative electrode active material layer on the negative electrode current collector, wherein the negative electrode current collector includes a first metal substrate including a first metal, and a coating layer positioned on the first metal substrate and containing a second metal, the second metal having a greater Mohs hardness than the first metal.

First claim

What is claimed is:

1. A negative electrode comprising:
a negative electrode current collector; and
a first negative electrode active material layer on the negative electrode current collector,
wherein the negative electrode current collector comprises:
a first metal current collector comprising a first metal; and
a coating layer on a top surface and on a side surface of the first metal current collector, the coating layer comprising a second metal, the second metal having a greater Mohs hardness than the first metal, and

wherein the first negative electrode active material layer is only on one side of the negative electrode current collector, the one side being over the top surface, and
wherein the coating layer on the side surface of the first metal current collector is separated from a side surface of the first negative electrode active material layer,
wherein an end of the first negative electrode active material layer extends further than an end of the first metal current collector in an extension direction of the negative electrode and overlaps with the coating layer on the side surface of the first metal current collector in a thickness direction of the negative electrode, and
wherein a negative electrode active material in the first negative electrode active material layer comprises a mixture of first particles comprising amorphous carbon and second particles composed of a metal and/or metalloid, the second particles composed of the metal and/or metalloid being contained in an amount of about 8 wt % to 60 wt % with respect to a total weight of the mixture.

2. The negative electrode of claim 1 , wherein the first metal has a Mohs hardness of 5.5 or less.

3. The negative electrode of claim 1 , wherein the first metal is at least one selected from copper (Cu), nickel (Ni), stainless steel (SUS), iron (Fe), and cobalt (Co).

4. The negative electrode of claim 1 , wherein the second metal has a Mohs hardness of 6.0 or more.

5. The negative electrode of claim 1 , wherein the second metal is at least one selected from titanium (Ti), manganese (Mn), niobium (Nb), tantalum (Ta), iridium (Ir), vanadium (V), rhenium (Re), osmium (Os), tungsten (W), chromium (Cr), boron (B), ruthenium (Ru), and rhodium (Rh).

6. The negative electrode of claim 1 , wherein the coating layer is 1 μm or less in thickness.

7. The negative electrode of claim 1 , wherein the coating layer is inert to a sulfide-based solid electrolyte.

8. The negative electrode of claim 1 , wherein the first negative electrode active material layer comprises a negative electrode active material and a binder, the negative electrode active material being in a form of particles and having has an average particle diameter of 4 μm or less.

9. The negative electrode of claim 8 , wherein the negative electrode active material comprises a carbon-based negative electrode active material and/or a metal and/or metalloid negative electrode active material.

10. The negative electrode of claim 9 , wherein the carbon-based negative electrode active material comprises at least one selected from amorphous carbon and crystalline carbon.

11. The negative electrode of claim 8 , wherein the metal or metalloid negative electrode active material comprises at least one selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn).

12. The negative electrode of claim 1 , wherein the first negative electrode active material layer is about 1 μm to about 20 μm in thickness.

13. A solid-state secondary battery comprising:
a positive electrode;
the negative electrode according to claim 1 ; and
a solid electrolyte layer between the positive electrode and the negative electrode,
wherein the solid electrolyte layer comprises a sulfide-based solid electrolyte.

14. The solid-state secondary battery of claim 13 , wherein the positive electrode comprises a positive electrode current collector and a positive electrode active material layer on the positive electrode current collector,
and the solid-state secondary battery further comprises an inactive member around a side surface of the positive electrode active material layer, the inactive member being at a peripheral portion of the positive electrode current collector, and extending to an end of the positive electrode current collector.

15. The solid-state secondary battery of claim 13 , wherein the sulfide-based solid electrolyte comprises at least one selected from among Li 2 S—P 2 S 5 , Li 2 S—P 2 S 5 —LiX (where X is a halogen), Li 2 S—P 2 S 5 —Li 2 O, Li 2 S—P 2 S 5 —Li 2 O—LiI, Li 2 S—SiS 2 , Li 2 S—SiS 2 —LiI, Li 2 S—SiS 2 —LiBr, Li 2 S—SiS 2 —LiCl, Li 2 S—SiS 2 —B 2 S 3 —LiI, Li 2 S—SiS 2 —P 2 S 5 —LiI, Li 2 S—B 2 S 3 , Li 2 S—P 2 S 5 —Z m S n (where m and n are positive numbers, and Z is one of Ge, Zn, or Ga), Li 2 S—GeS 2 , Li 2 S—SiS 2 —Li 3 PO 4 , and Li 2 S—SiS 2 —Li p MO q (where p and q are positive numbers, and M is one of P, Si, Ge, B, Al, Ga, or In).

16. The solid-state secondary battery of claim 13 , wherein the sulfide-based solid electrolyte comprises at least one selected from Li 7 P 3 S 11 , Li 7 PS 6 , Li 4 P 2 S 6 , Li 3 PS 6 , Li 3 PS 4 , and Li 2 P 2 S 6 .

17. The solid-state secondary battery of claim 13 , wherein the sulfide-based solid electrolyte comprises an argyrodite solid electrolyte represented by Formula 1:
Li + 12−n−x A n+ X 2− 6−x Y − x , and  Formula 1

wherein in Formula 1, A is P, As, Ge, Ga, Sb, Si, Sn, Al, In, Ti, V, Nb or Ta,
X is S, Se or Te,
Y is Cl, Br, I, F, CN, OCN, SCN, or N3, and
1≤n≤5 and 0≤x≤2.

18. The solid-state secondary battery of claim 17 , wherein the argyrodite solid electrolyte is at least one selected from Li 7−x PS 6−x Cl x (where 0≤x≤2), Li 7−x PS 6−x Br x (where 0≤x≤2), and Li 7−x PS 6−x I x (where 0≤x≤2).

19. The solid-state secondary battery of claim 13 , further comprising a second negative electrode active material layer:
positioned between the negative electrode current collector and the first negative electrode active material layer in the negative electrode, or between the solid electrolyte layer and the first negative electrode active material layer; or
positioned between the negative electrode current collector and the first negative electrode active material layer in the negative electrode, and between the solid electrolyte layer and the first negative electrode active material layer,
wherein the second negative electrode active material layer is a metal layer comprising lithium or a lithium alloy.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Lee Minsuk

Classifications

• H01M2300/0068

  inorganic · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M10/0562

  Solid materials · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/661 Primary

  Metal or alloys, e.g. alloy coatings (H01M4/669 take precedence) · CPC title