Rechargeable lithium battery

Patent metadata

Field	Value
Publication number	US-11710820-B2
Application number	US-202016864858-A
Country	US
Kind code	B2
Filing date	May 1, 2020
Priority date	May 3, 2019
Publication date	Jul 25, 2023
Grant date	Jul 25, 2023

Abstract

A rechargeable lithium battery including an electrode assembly includes a positive electrode including a positive current collector and a positive active material layer disposed on the positive current collector; a negative electrode including a negative current collector, a negative active material layer disposed on the negative current collector, and a negative electrode functional layer disposed on the negative active material layer; and a separator, wherein the positive active material layer includes a first positive active material including at least one of a composite oxide of metal selected from cobalt, manganese, nickel, and a combination thereof and lithium and a second positive active material including a compound represented by Chemical Formula 1, the negative electrode functional layer includes flake-shaped polyethylene particles, and a battery capacity is greater than or equal to about 3.5 Ah.

Li a Fe 1−x1 M x1 PO 4   [Chemical Formula 1]

In Chemical Formula 1, 0.90≤a≤1.8, 0≤x1≤0.7, and M is Mn, Co, Ni, or a combination thereof.

First claim

What is claimed is:

1. A rechargeable lithium battery, comprising:
an electrode assembly, comprising:
a positive electrode, comprising:
a positive current collector; and
a positive active material layer disposed on the positive current collector;

a negative electrode, comprising:
a negative current collector;
a negative active material layer disposed on the negative current collector; and
a negative electrode functional layer disposed on the negative active material layer; and

a separator;
wherein the negative electrode functional layer comprises flake-shaped polyethylene particles,
wherein capacity of the rechargeable lithium battery is greater than or equal to about 3.5 Ah, and
wherein the positive active material layer comprises:
a first positive active material, comprising:
at least one of a composite oxide of a metal selected from cobalt, manganese, nickel, and a combination thereof and lithium and a second positive active material comprising a compound represented by Chemical Formula 1,
Li a Fe 1−x1 M x1 PO 4   [Chemical Formula 1]

wherein 0.90≤a≤1.8, 0≤x1≤0.7, and M is Mn, Co, Ni, or a combination thereof,
wherein a thickness of the flake-shaped polyethylene particles is about 0.2 μm to about 4 μm.

2. The rechargeable lithium battery of claim 1 , wherein the capacity of the rechargeable lithium battery is greater than or equal to about 4.0 Ah.

3. The rechargeable lithium battery of claim 1 , wherein the capacity of the rechargeable lithium battery is greater than or equal to about 5.0 Ah.

4. The rechargeable lithium battery of claim 1 , wherein the electrode assembly is to be contained in a battery case having a volume of greater than or equal to about 24 cc.

5. The rechargeable lithium battery of claim 4 , wherein the battery case is a cylindrical case having a diameter of greater than or equal to about 21 mm and a height of greater than or equal to about 70 mm.

6. The rechargeable lithium battery of claim 1 , wherein the first positive active material is included in an amount of about 80 wt % to about 97 wt % based on a total weight of the positive active material layer.

7. The rechargeable lithium battery of claim 1 , wherein the first positive active material and the second positive active material are included in a weight ratio of about 97:3 to about 80:20.

8. The rechargeable lithium battery of claim 1 , wherein the positive active material layer further comprises a positive electrode functional layer disposed on the positive active material layer.

9. The rechargeable lithium battery of claim 8 , wherein
the first positive active material is in the positive active material layer, and
the second positive active material is in at least one of the positive active material layer and the positive electrode functional layer.

10. The rechargeable lithium battery of claim 1 , wherein the first positive active material comprises one of LiCoO 2 , Li b M 1 1−y1−z1 M 2 y1 M 3 z1 O 2 (0.9≤b≤1.8, 0≤y1≤1, 0≤z1≤1, 0≤y1+z1≤1, M 1 , M 2 , and M 3 are independently a metal of Ni, Co, Mn, Al, Sr, Mg, or La), and a combination thereof.

11. The rechargeable lithium battery of claim 1 , wherein the second positive active material comprises LiFePO 4 .

12. The rechargeable lithium battery of claim 1 , wherein an average particle size (D50) of the flake-shaped polyethylene particle is about 1 μm to about 8 μm.

13. The rechargeable lithium battery of claim 1 , wherein a ratio of the long axis length relative to the short axis length of the flake-shaped polyethylene particles is about 1 to about 5.

14. The rechargeable lithium battery of claim 1 , wherein the negative electrode functional layer further comprises an inorganic particle and a binder.

15. The rechargeable lithium battery of claim 14 , wherein a ratio of sum amount of the flake-shaped polyethylene particles and the inorganic particles over an amount of the binder is within a range of weight ratio of about 80:20 to about 99:1.

16. The rechargeable lithium battery of claim 14 , wherein a ratio of the flake-shaped polyethylene particles over the inorganic particles is in a range of weight ratio of about 95:5 to about 10:90.

17. The rechargeable lithium battery of claim 1 , wherein the negative electrode functional layer is about 1 μm to about 10 μm thick.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Lee Dongmyung
• Kim Kijun
• Yoo Heeeun
• Yoon Yeonhee
• Lee Kyuseo
• Ha Jaehwan

Classifications

• H01M4/364 Primary

  as mixtures · CPC title

• H01M4/366

  as layered products · CPC title

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M4/525

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

• H01M4/5825

  Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines · CPC title