Negative active material for rechargeable lithium battery, and rechargeable lithium battery including same

Patent metadata

Field	Value
Publication number	US-12355068-B2
Application number	US-202017097659-A
Country	US
Kind code	B2
Filing date	Nov 13, 2020
Priority date	Nov 19, 2019
Publication date	Jul 8, 2025
Grant date	Jul 8, 2025

Abstract

A negative active material for a rechargeable lithium battery and a rechargeable lithium battery including the same, the negative active material including secondary particles of agglomerated primary particles, the primary particles including Si particles and a first ceramic oxide on a surface of the Si particles; and amorphous carbon, wherein the amorphous carbon surrounds a surface of the primary particles and a surface of the secondary particles.

First claim

What is claimed is:

1. A negative active material for a rechargeable lithium battery, the negative active material comprising:
secondary particles of agglomerated primary particles, the primary particles being Si particles and a first ceramic oxide on a surface of the Si particles; and
amorphous carbon, the amorphous carbon further including a second ceramic oxide therein,
wherein:
the secondary particles have a D50 average particle diameter of about 4 μm to about 20 μm,
the amorphous carbon surrounds a surface of the primary particles and a surface of the secondary particles,
the Si particles include a non-compounded silicon core,
the Si particles have an aspect ratio of about 3 to about 15,
the first ceramic oxide includes ZrO 2 ,
the second ceramic oxide is ZrO 2 , Al 2 O 3 , or a combination thereof,
the negative active material includes the first ceramic oxide in an amount of about 0.1 wt % to about 5 wt %, based on a total weight of the negative active material,
a mixing ratio of the ceramic oxide and the silicon may be about 0.02:1 to about 0.5:1 by weight, and
regarding the negative active material, a peak intensity ratio ((ISi(111)/I(ZrO2)) of a peak intensity (ISi(111)) at a Si(111) plane relative to a peak intensity ((I(ZrO2)) of the first ceramic oxide is about 7 to about 20, as measured by X-ray diffraction analysis using a CuKα ray.

2. The negative active material for a rechargeable lithium battery as claimed in claim 1 , wherein the first ceramic oxide is in the form of:
a continuous layer on the surface of the Si particles, or
discontinuous islands or dots on the surface of the Si particles.

3. The negative active material for a rechargeable lithium battery as claimed in claim 1 , wherein the first ceramic oxide on the surface of the Si particles has a thickness of about 50 nm or less.

4. The negative active material for a rechargeable lithium battery as claimed in claim 1 , wherein particles of the second ceramic oxide have a size of about 30 nm or less.

5. The negative active material for a rechargeable lithium battery as claimed in claim 1 , wherein the Si particle is a flake type particle.

6. The negative active material for a rechargeable lithium battery as claimed in claim 1 , wherein the Si particles have a size of about 10 nm to about 200 nm.

7. The negative active material for a rechargeable lithium battery as claimed in claim 1 , wherein a full width at half maximum, FWHM (111), of a diffraction peak at a (111) plane found by X-ray diffraction of the Si particles using a CuKα ray is about 0.4 degrees to about 5 degrees.

8. A rechargeable lithium battery, comprising:
a negative electrode including the negative active material as claimed in claim 1 ;
a positive electrode; and
an electrolyte.

9. The negative active material for a rechargeable lithium battery as claimed in claim 1 , wherein:
the first ceramic oxide includes ZrO 2 , or
the second ceramic oxide includes ZrO 2 .

Assignees

• Samsung Sdi Co Ltd

Inventors

• Won Jongmin
• Kim Young-Min
• Kim Jaemyung
• Nah Jaehou
• Shin Changsu
• Lee Dae-Hyeok

Classifications

• H01M4/625

  Carbon or graphite · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M4/628

  Inhibitors, e.g. gassing inhibitors, corrosion inhibitors · CPC title

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• H01M4/386

  Silicon or alloys based on silicon · CPC title