Positive electrode for all-solid-state battery, method of preparing the same, and all-solid-state battery

Patent metadata

Field	Value
Publication number	US-2023307695-A1
Application number	US-202218081543-A
Country	US
Kind code	A1
Filing date	Dec 14, 2022
Priority date	Mar 24, 2022
Publication date	Sep 28, 2023
Grant date	—

Abstract

A positive electrode for an all-solid-state battery, a method of preparing the same, and an all-solid-state battery including the same are provided. The positive electrode for an all-solid-state battery includes a positive electrode active material including a first positive electrode active material including a lithium nickel-based composite oxide and being in a form of secondary particles in which a plurality of primary particles are aggregated and at least a portion of the primary particles are radially arranged; a second positive electrode active material including a lithium nickel-based composite oxide and being in a form of single particles; a solid electrolyte; a conductive agent; and a binder.

First claim

What is claimed is:

1 . A positive electrode for an all-solid-state battery, the positive electrode comprising:
a first positive electrode active material comprising a lithium nickel-based composite oxide and being in a form of secondary particles comprising a secondary particle in which a plurality of primary particles are aggregated and at least a portion of the primary particles are radially arranged; a second positive electrode active material comprising a lithium nickel-based composite oxide and being in a form of single particles; a solid electrolyte; a conductive agent; and a binder.

2 . The positive electrode of claim 1 , wherein
based on a total weight of the first positive electrode active material, the second positive electrode active material, the solid electrolyte, the conductive agent, and the binder, the positive electrode comprises about 55 wt % to about 99.7 wt % of the positive electrode active material; about 0.1 wt % to about 35 wt % of the solid electrolyte; about 0.1 wt % to about 5 wt % of the conductive agent; and about 0.1 wt % to about 5 wt % of the binder.

3 . The positive electrode of claim 1 , wherein
the first positive electrode active material comprises a zirconium-containing coating layer on a surface of the secondary particles, and the second positive electrode active material comprises a zirconium-containing coating layer on a surface of the single particles.

4 . The positive electrode of claim 1 , wherein
the secondary particle of the first positive electrode active material comprise an inner portion in which the primary particles and pores are irregularly arranged, and an outer portion in which at least a portion of the primary particles are radially arranged as a region around the inner portion.

5 . The positive electrode of claim 4 , wherein
a radius ratio of a radius of the inner portion to a total radius of the secondary particle of the first positive electrode active material is about 50% to about 55%, and/or a volume ratio of a volume of the outer portion to a total volume of the secondary particle is less than or equal to about 87%.

6 . The positive electrode of claim 1 , wherein
the secondary particle of the first positive electrode active material comprise plate-shaped primary particles, at least a portion of the plate-shaped primary particles have a long axis arranged in a radial direction, an average length of the plate-shaped primary particles along the long axis is about 150 nm to about 500 nm, an average thickness of the plate-shaped primary particles is about 100 nm to about 200 nm, and a ratio of the average thickness to the average length is about 1:2 to about 1:5.

7 . The positive electrode of claim 4 , wherein
an inner portion of the secondary particle of the first positive electrode active material comprises pores having a larger size than pores in an outer portion, a pore size in the inner portion of the secondary particle is about 150 nm to about 1 μm, and a pore size in the outer portion of the secondary particle is less than 150 nm.

8 . The positive electrode of claim 1 , wherein
an average particle diameter (D50) of the secondary particles of the first positive electrode active material is about 5 μm to about 20 μm, and an average particle diameter (D50) of the single particles of the second positive electrode active material is about 0.05 μm to about 8 μm.

9 . The positive electrode of claim 1 , wherein,
about 50 wt % to about 90 wt % of the first positive electrode active material, and about 10 wt % to about 50 wt % of the second positive electrode active material, are in a positive electrode active material of the positive electrode.

10 . The positive electrode of claim 1 , wherein, in each of the first positive electrode active material and the second positive electrode active material, each of the lithium nickel-based composite oxides is the same as or different from each other, and is each independently represented by Chemical Formula 1:
Li a1 Ni x1 M 1 y1 M 2 1−x1−y1 O 2−z X z ;  Chemical Formula 1
wherein, in Chemical Formula 1, 0.9≤a1≤1.8, 0.3≤x1≤1, 0≤y1≤0.7, and 0≤z≤0.1, M 1 and M 2 are independently at least one element of Al, B, Ba, Ca, Ce, Co, Cr, Fe, Mg, Mn, Mo, Nb, Si, Sr, Ti, V, W, or Zr, and X is at least one element of F, P, or S.

11 . The positive electrode of claim 1 , wherein
the solid electrolyte is a sulfide-based solid electrolyte, and the sulfide-based solid electrolyte comprises Li 2 S—P 2 S 5 , Li 2 S—P 2 S 5 —LiI, Li 2 S—P 2 S 5 —LiBr, Li 2 S—P 2 S 5 —LiCl, Li 2 S—P 2 S 5 —Li 2 O, Li 2 S—P 2 S 5 —Li 2 O—LiI, Li 2 S—P 2 S 5 —Li 2 O—LiCl, 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 (wherein m and n is each an integer and Z is Ge, Zn, or Ga), Li 2 S—GeS 2 , Li 2 S—SiS 2 —Li 3 PO 4 , Li 2 S—SiS 2 —Li p MO q (wherein p and q are integers and M is P, Si, Ge, B, Al, Ga, or In), or a combination thereof.

12 . The positive electrode of claim 11 , wherein the solid electrolyte is an argyrodite-type sulfide-based solid electrolyte.

13 . The positive electrode of claim 1 , wherein an average particle diameter (D50) of the solid electrolyte is less than or equal to about 5.0 μm.

14 . A method of preparing a positive electrode for an all-solid-state battery, the method comprising
mixing a first positive electrode active material precursor, being in a form of secondary particles comprising a secondary particle in which a plurality of primary particles are aggregated, and comprising a nickel-based composite hydroxide, a second positive electrode active material, being in a form of single particles, and comprising a lithium nickel-based composite oxide, and a lithium raw material; performing a heat-treatment to prepare a positive electrode active material; mixing the positive electrode active material, a solid electrolyte, a conductive agent, and a binder to prepare a positive electrode active material composition; and applying the positive electrode active material composition on a positive electrode current collector and drying the same to obtain the positive electrode of claim 1 .

15 . The method of claim 14 , wherein the heat-treatment is performed at a temperature of about 650° C. to about 850° C. for about 5 hours to about 25 hours.

16 . The method of claim 14 , wherein
after the mixing of the first positive electrode active material precursor, the second positive electrode active material and the lithium raw material, and the performing of the heat treatment, the method comprises mixing a zirconium raw material with the positive electrode active material and performing a reheat-treatment.

17 . The method of claim 14 , wherein based on a total weight of the positive electrode active material, the solid electrolyte, the conductive agent, and the binder, the positive electrode active material composition comprises:
about 55 wt % to about 99.7 wt % of the positive electrode active material; about 0.1 wt % to about 35 wt % of the solid electrolyte; about 0.1 wt % to about 5 wt % of the conductive agent; and about 0.1 wt % to about 5 wt % of the binder are mixed.

18 . An all-solid-state battery, comprising:
the positive electrode of claim 1 , a negative electrode, and a solid electrolyte layer between the positive electrode and the negative electrode.

19 . The all-solid-state battery of claim 18 , wherein
the negative elect

Assignees

• Samsung Sdi Co Ltd

Inventors

• Yun Pilsang
• Kim Hyunbeom
• Kim Do-Yu
• You Yongchan

Classifications

• H01M10/0525 Primary

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

• H01M10/0562

  Solid materials · CPC title

• H01M4/525 Primary

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• H01M4/621

  Binders · CPC title

• H01M4/1391

  of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title