Separator including substrate, first layer with lithium iron phosphate particles, and second layer with organic particles, and lithium battery including the same

Patent metadata

Field	Value
Publication number	US-11527801-B2
Application number	US-202016791065-A
Country	US
Kind code	B2
Filing date	Feb 14, 2020
Priority date	Feb 18, 2019
Publication date	Dec 13, 2022
Grant date	Dec 13, 2022

Abstract

A separator includes a substrate, a first layer on the substrate, the first layer including LiFePO4 (LFP) particles, and a second layer on the substrate, the second layer including organic particles having a melting point in a range of about 100° C. to about 130° C.

First claim

What is claimed is:

1. A separator, comprising:
a substrate;
a first layer directly on the substrate, the first layer including a first binder and LiFePO 4 (LFP) particles; and
a second layer on the substrate, the second layer including:
organic particles having a melting point in a range of about 100° C. to about 130° C.,
a second binder, and
an inorganic material, a weight by parts of the inorganic material being larger than a weight by parts of the organic particles, based on a total weight of the second layer,

wherein the first layer with the LFP particles is an outermost layer of the separator, the first layer directly contacting a cathode.

2. The separator as claimed in claim 1 , wherein the first layer is on a first surface of the substrate, and the second layer is on second surface of the substrate, the second surface being opposite the first surface.

3. The separator as claimed in claim 1 , wherein a porosity between the LFP particles in the first layer is in a range of about 30% to about 80%.

4. The separator as claimed in claim 1 , wherein the LFP particles and the first binder in the first layer are mixed at a weight ratio in a range of 2:8 to 8:2.

5. The separator as claimed in claim 1 , wherein the first binder is at least one of carboxymethyl cellulose (CMC), polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride-co-trichloroethylene, polymethylmethacrylate, polybutylacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, polyvinyl alcohol, polyethylene-co-vinyl acetate, polyethylene oxide, polyarylate, celluloseacetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylcellulose, cyanoethylsucrose, and pullulan.

6. The separator as claimed in claim 1 , wherein a thickness of the first layer is in a range of about 0.1 μm to about 5.0 μm.

7. The separator as claimed in claim 1 , wherein the melting point of the organic particles is the same as a melting point of the substrate.

8. The separator as claimed in claim 1 , wherein the organic particles are included in the second layer at an amount of at least about 10% by weight (wt %) based on the total weight of the second layer.

9. The separator as claimed in claim 1 , wherein the organic particles include at least one of polypropylene (PP), polyethylene (PE), polystyrene (PS), polyvinylidene fluoride (PVDF), polymethylmethacrylate (PMMA), an acrylate-based compound, polyacrylonitrile (PAN), and an azodicarbonamide-based compound.

10. The separator as claimed in claim 1 , wherein the organic particles include particle-type particles, plate-type particles, flake-type particles, or a mixture thereof.

11. The separator as claimed in claim 1 , wherein the organic particles and the inorganic material are mixed at a weight ratio in a range of at least 2:8.

12. The separator as claimed in claim 1 , wherein the second binder is at least one of a sulfonate-based compound or a derivative thereof, an acrylamide-based compound or a derivative thereof, an acrylonitrile-based compound or a derivative thereof, a copolymer thereof, or a mixture thereof.

13. The separator as claimed in claim 1 , wherein the inorganic material includes inorganic particles of at least two types having different particle diameters.

14. The separator as claimed in claim 1 , wherein a thickness of the second layer is in a range of about 0.1 μm to about 5.0 μm.

15. The separator as claimed in claim 1 , further comprising an electrode adhesion layer on the second layer.

16. The separator as claimed in claim 15 , wherein a thickness of the electrode adhesion layer is in a range of about 0.3 μm to about 0.5 μm.

17. A lithium battery, comprising:
an anode; and
the separator as claimed in claim 1 , the separator being between the cathode and the anode.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Lee Jungyoon
• Kim Yongkyoung
• Kim Yangseob

Classifications

• H01M10/0525 Primary

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

• H01M50/434

  Ceramics · CPC title

• H01M50/446

  Composite material consisting of a mixture of organic and inorganic materials · CPC title

• H01M50/461

  with adhesive layers between electrodes and separators · CPC title

• H01M50/431 Primary

  Inorganic material · CPC title