Rechargeable lithium battery

Patent metadata

Field	Value
Publication number	US-11705585-B2
Application number	US-201916460779-A
Country	US
Kind code	B2
Filing date	Jul 2, 2019
Priority date	Jul 3, 2018
Publication date	Jul 18, 2023
Grant date	Jul 18, 2023

Abstract

Disclosed is a rechargeable lithium battery including a positive electrode including a positive active material layer; and a negative electrode including a negative active material layer and a negative functional layer on the negative active material layer, wherein the functional layer includes flake-shaped polyethylene particles, and the positive active material layer includes a first positive active material including one or more composite oxides of lithium and a metal selected from cobalt, manganese, nickel, and a combination thereof, and a second positive active material including a compound represented by Chemical Formula 1 and. In Chemical Formula 1, 0.90≤a≤1.8, 0≤x≤0.7, and M is Mg, Co, Ni, or a combination thereof.LiaFe1−xMxPO4  [Chemical Formula 1]

First claim

What is claimed is:

1. A rechargeable lithium battery, comprising:
a negative electrode comprising a negative current collector, a negative active material layer on the negative current collector, and a negative functional layer on the negative active material layer; and
a positive electrode comprising a positive electrode current collector and a positive active material layer on the positive electrode current collector,
wherein the negative functional layer comprises flake-shaped polyethylene particles, having a ratio of a major axis length to a minor axis length of 2.4 to 4.5,

and
the positive active material layer comprises a first positive active material comprising one or more composite oxides of lithium and a metal selected from cobalt, manganese, nickel, and a combination thereof, and a second positive active material comprising a compound represented by Chemical Formula 1:
Li a Fe 1-x M x PO 4   [Chemical Formula 1]

wherein, in Chemical Formula 1, 0.90≤a≤1.8, 0≤x≤0.7, and M is Mg, Co, Ni, or a combination thereof.

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

3. The rechargeable lithium battery of claim 1 , wherein the flake-shaped polyethylene particles have a thickness of 0.2 μm to 4 μm.

4. The rechargeable lithium battery of claim 1 , wherein the negative functional layer further comprises inorganic particles and a binder.

5. The rechargeable lithium battery of claim 4 , wherein a weight ratio of the sum of the flake-shaped polyethylene particles and the inorganic particles to the binder is 80:20 to 99:1.

6. The rechargeable lithium battery of claim 4 , wherein a weight ratio of the flake-shaped polyethylene particles to the inorganic particles is 95:5 to 10:90.

7. The rechargeable lithium battery of claim 1 , wherein the negative functional layer has a thickness of 1 μm to 10 μm.

8. The rechargeable lithium battery of claim 1 , wherein a ratio of a thickness of the negative active material layer to a thickness of the negative functional layer is 50:1 to 10:1.

9. The rechargeable lithium battery of claim 1 , wherein the first positive active material is included in an amount of 70 wt % to 99 wt % based on a total weight of the positive active material layer.

10. The rechargeable lithium battery of claim 1 , wherein the second positive active material is included in an amount of 1 wt % to 15 wt % based on a total weight of the positive active material layer.

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

12. The rechargeable lithium battery of claim 11 , wherein the first positive active material is included in the positive active material layer and
the second positive active material is included in at least one selected from the positive active material layer and the positive functional layer.

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

Assignees

• Samsung Sdi Co Ltd

Inventors

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

Classifications

• H01M10/4235 Primary

  Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence) · CPC title

• H01M4/13 Primary

  Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof · 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

• H01M4/622

  being polymers · CPC title

• H01M10/052

  Li-accumulators · CPC title