Positive active material for rechargeable lithium battery, method of preparing the same, electrode including the same, and rechargeable lithium battery including the electrode

Patent metadata

Field	Value
Publication number	US-10790498-B2
Application number	US-201715761030-A
Country	US
Kind code	B2
Filing date	Nov 7, 2017
Priority date	Oct 20, 2017
Publication date	Sep 29, 2020
Grant date	Sep 29, 2020

Abstract

Provided is a monocrystalline cathode active material for a lithium secondary battery, the monocrystalline cathode active material being represented by the Formula of Li x P y Ni 1-a-b CO a A b O 2 .

First claim

The invention claimed is:

1. A cathode active material for a lithium secondary battery, the cathode active material being monocrystalline and represented by Formula 1:
Li x P y Ni 1-a-b Co a A b O 2   <Formula 1>

wherein, in Formula 1, 0.98≤x≤1.02, 0.0002<y≤0.007, 0<a≤0.2, 0≤b≤0.3, and A is at least one element selected from Mn, Al, Mg, and V
wherein, the P atom is located at a tetrahedral site of a monocrystalline layered structure.

2. The cathode active material of claim 1 , wherein the monocrystalline cathode active material is provided as single particles.

3. The cathode active material of claim 1 , wherein the monocrystalline cathode active material has an average particle diameter greater than about 1.5 μm and smaller than or equal to about 18 μm.

4. The cathode active material of claim 1 , wherein A in Formula 1 comprises Mn, Al, or a combination thereof.

5. The cathode active material of claim 1 , wherein, in Formula 1, A comprises Mn, and 0<b≤0.3.

6. The cathode active material of claim 1 , wherein, in Formula 1, A comprises Al, and 0<b≤0.05.

7. The cathode active material of claim 1 , wherein, the P atom is located inside a monocrystalline layered structure.

8. A method of preparing the cathode active material of claim 1 for a lithium secondary battery, the method comprising:
preparing a premixture of a lithium source and a transition metal source;
mixing the premixture under an oxidizing atmosphere to thereby obtain a lithium transition metal-containing mixture; and
thermally treating the lithium transition metal-containing mixture to thereby obtain a monocrystalline lithium transition metal composite oxide,
wherein the premixture further comprises a phosphorus source.

9. The method of claim 8 , wherein the mixing is performed using a mechanical mixing method.

10. The method of claim 8 , wherein the thermal treatment comprises a first thermal treatment step and a second thermal treatment step.

11. The method of claim 10 , wherein a thermal treatment temperature in the first thermal treatment step is higher than a thermal treatment temperature in the second thermal treatment step.

12. The method of claim 10 , wherein a thermal treatment time in the first thermal treatment step is shorter than a thermal treatment time in the second thermal treatment step.

13. The method of claim 8 , wherein the monocrystalline lithium transition metal composite oxide is provided as single particles and has a layered structure.

14. The method of claim 8 , wherein the monocrystalline lithium transition metal composite oxide has an average particle diameter of greater than 1.5 μm and less than 20 μm.

15. A cathode comprising the monocrystalline cathode active material according to claim 1 .

16. A lithium secondary battery comprising:
the cathode according to claim 15 ;
an anode; and
an electrolyte.

Assignees

• Ulsan Nat Inst Science & Tech Unist

Inventors

• Cho Jaephil
• Kim Jun Hyeok
• Ma Hyun Su

Classifications

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• H01M4/525 Primary

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

• C01P2004/61

  Micrometer sized, i.e. from 1-100 micrometer · CPC title

• H01M4/505

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

• H01M4/485

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