Cathode active material for lithium secondary battery and lithium secondary battery including the same

Patent metadata

Field	Value
Publication number	US-12107256-B2
Application number	US-202318093215-A
Country	US
Kind code	B2
Filing date	Jan 4, 2023
Priority date	Mar 8, 2021
Publication date	Oct 1, 2024
Grant date	Oct 1, 2024

Abstract

The cathode active material for a lithium secondary battery according to embodiments of the present invention includes lithium-transition metal composite oxide particles including a plurality of primary particles, and the lithium-transition metal composite oxide particles have a lithium-potassium-containing portion formed between the primary particles. Thereby, it is possible to improve life-span properties and capacity properties by preventing the layer structure deformation of the primary particles and removing residual lithium.

First claim

What is claimed is:

1. A cathode active material for a lithium secondary battery comprising:
a lithium-transition metal composite oxide particle including a plurality of primary particles,
wherein the lithium-transition metal composite oxide particle comprises a lithium-potassium-containing portion formed between the primary particles,
wherein a sulfur content of the lithium-transition metal composite oxide particle measured through a carbon-sulfur (CS) analyzer is 1,100 to 4,500 ppm based on a total weight of the lithium-transition metal composite oxide particle.

2. The cathode active material for a lithium secondary battery according to claim 1 , wherein the lithium-potassium-containing portion comprises a lithium-potassium-sulfur-containing portion including lithium, potassium and sulfur.

3. The cathode active material for a lithium secondary battery according to claim 1 , wherein the primary particles have a hexagonal close-packed structure.

4. The cathode active material for a lithium secondary battery according to claim 3 , wherein the lithium-transition metal composite oxide particle has no primary particle having a face centered cubic structure.

5. The cathode active material for a lithium secondary battery according to claim 1 , wherein a potassium concentration of the lithium-potassium-containing portion measured through energy dispersive spectroscopy (EDS) is greater than the potassium concentration in the primary particles measured through the EDS.

6. The cathode active material for a lithium secondary battery according to claim 5 , wherein an average potassium signal value of the lithium-potassium-containing portion measured through the EDS is 1.2 to 4 times greater than the average potassium signal value in the primary particles measured through the EDS.

7. The cathode active material for a lithium secondary battery according to claim 1 , wherein a content of lithium carbonate (Li 2 CO 3 ) remaining on the surface of the lithium-transition metal composite oxide particle is 2,500 ppm or less, and a content of lithium hydroxide (LiOH) remaining on the surface of the lithium-transition metal composite oxide particle is 2,500 ppm or less.

8. A lithium secondary battery comprising:
a cathode comprising a cathode active material layer including the cathode active material for a lithium secondary battery according to claim 1 ; and
an anode disposed to face the cathode.

9. A method of manufacturing a cathode active material for a lithium secondary battery, comprising:
preparing a preliminary lithium-transition metal composite oxide particle;
mixing the preliminary lithium-transition metal composite oxide particle with a potassium compound aqueous solution; and
performing a heat treatment on the mixed preliminary lithium-transition metal composite oxide particle and the potassium compound aqueous solution, to prepare a lithium-transition metal composite oxide particle comprising a plurality of primary particles and a lithium-potassium-containing portion formed between the primary particles,
wherein a sulfur content of the lithium-transition metal composite oxide particle measured through a carbon-sulfur (CS) analyzer is 1,100 to 4,500 ppm based on a total weight of the lithium-transition metal composite oxide particle.

10. The method of manufacturing a cathode active material for a lithium secondary battery according to claim 9 , wherein the potassium compound aqueous solution is formed by mixing a solvent with potassium compound powder, and
an input amount of the potassium compound powder is 0.2 to 1.9% by weight based on a total weight of the preliminary lithium-transition metal composite oxide particle.

11. The method of manufacturing a cathode active material for a lithium secondary battery according to claim 10 , wherein an input amount of the solvent is 2 to 15% by weight based on the total weight of the preliminary lithium-transition metal composite oxide particle.

12. The method of manufacturing a cathode active material for a lithium secondary battery according to claim 10 , wherein the potassium compound powder is potassium hydrogen sulfate (KHSO 4 ) powder.

13. The method of manufacturing a cathode active material for a lithium secondary battery according to claim 9 , wherein the heat treatment is performed at 200 to 400° C. under an oxygen atmosphere.

14. The method of manufacturing a cathode active material for a lithium secondary battery according to claim 9 , wherein the preliminary lithium-transition metal composite oxide particle is mixed with the potassium compound aqueous solution without water washing treatment.

Assignees

• Sk On Co Ltd

Inventors

• Park Sang Min
• Lee Tae Kyoung
• Kim Sang Bok
• Kim Jik Soo
• Shin Sang Hye
• Shim Yu Na
• Yoon Jeong Bae

Classifications

• C01G53/82

  Compounds containing nickel, with or without oxygen or hydrogen, and containing two or more other elements · CPC title

• H01M10/0525

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

• H01M4/1393

  of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• H01M4/1391

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