Positive electrode for rechargeable lithium battery and rechargeable lithium battery including same

Patent metadata

Field	Value
Publication number	US-11631848-B2
Application number	US-201916414629-A
Country	US
Kind code	B2
Filing date	May 16, 2019
Priority date	May 23, 2018
Publication date	Apr 18, 2023
Grant date	Apr 18, 2023

Abstract

Disclosed are a positive electrode for a rechargeable lithium battery and a rechargeable lithium battery including the same. The positive electrode includes a current collector and a positive electrode layer on the current collector, the positive electrode layer including a nickel-based positive active material of Chemical Formula 1 having a BET specific surface area of about 0.5 m2/g to about 2.5 m2/g, a metal fluoride, a conductive material, and a binder, wherein an amount of the metal fluoride is about 1 wt % to about 10 wt % based on 100 wt % of the positive electrode layer. In Chemical Formula 1, 0.9≤a≤1.1, 0.8≤x≤0.98, 0.01≤y≤0.01≤z≤0.1, x+y+z=1, and A is Mn or Al.LiaNixCoyAzO2  Chemical Formula 1

First claim

What is claimed is:

1. A positive electrode for a rechargeable lithium battery, comprising:
a current collector; and
a positive electrode layer on the current collector, the positive electrode layer comprising a physical mixture of a nickel-based positive active material represented by Chemical Formula 1 having a BET specific surface area of about 0.5 m 2 /g to about 2.5 m 2 /g, metal fluoride particles, a conductive material, and a binder,
wherein an amount of the metal fluoride particles is about 2 wt % to about 10 wt % based on 100 wt % of the positive electrode layer,
Li a Ni x Co y A z O 2   [Chemical Formula 1]

wherein, in Chemical Formula 1, 0.9≤a≤1.1, 0.8≤x≤0.98, 0.01≤y≤0.1, 0.01≤z≤0.1, x+y+z=1, and A is Mn or Al,
wherein the metal fluoride particles comprise Al fluoride particles, Mg fluoride particles, Zr fluoride particles, Bi fluoride particles, or a combination thereof,
wherein the metal fluoride particles have an average particle diameter (D50) of about 0.1 μm to about 3 μm, and
wherein the nickel-based positive active material represented by Chemical Formula 1 has a residual lithium content of about 0.05 wt % to about 0.3 wt % based on 100 wt % of the nickel-based positive active material.

2. The positive electrode of claim 1 , wherein the positive active material is a mixture of a large-diameter active material and a small-diameter active material.

3. The positive electrode of claim 1 , wherein the positive active material is a mixture of a large-diameter active material having an average particle diameter (D50) in a range of about 15 μm to about 20 μm and a small-diameter active material having an average particle diameter (D50) in a range of about 3 μm to about 5 μm.

4. The positive electrode of claim 1 , wherein a mixing ratio of the large-diameter active material and the small-diameter active material is a weight ratio of about 60:40 to about 80:20.

5. The positive electrode of claim 1 , wherein the nickel-based positive active material is washed with water.

6. A method of manufacturing the positive electrode for a rechargeable lithium battery of claim 1 , the method comprising:
mixing the nickel-based positive active material represented by Chemical Formula 1, the metal fluoride particles, the binder, and the conductive material in a solvent to prepare a positive active material composition; and
coating the positive active material composition on a current collector.

7. The method of claim 6 , wherein before preparing the positive active material composition, the positive active material is washed with water.

8. A rechargeable lithium battery comprising:
the positive electrode of claim 1 ;
a negative electrode comprising a negative active material; and
an electrolyte.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Choi Jaeho
• Han Jungmin

Classifications

• H01M10/0525

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

• H01M4/131 Primary

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

• H01M2004/028

  Positive electrodes · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title