Polycrystalline lithium manganese oxide particles, preparation method thereof, and cathode active material including the same

Patent metadata

Field	Value
Publication number	US-10236499-B2
Application number	US-201414654966-A
Country	US
Kind code	B2
Filing date	Jul 25, 2014
Priority date	Jul 26, 2013
Publication date	Mar 19, 2019
Grant date	Mar 19, 2019

Abstract

Provided are polycrystalline lithium manganese oxide particles represented by Chemical Formula 1 and a method of preparing the same:

Li (1+x) Mn (2−x−y−f) Al y M f O (4−z)   <Chemical Formula 1>
where M is any one selected from the group consisting of boron (B), cobalt (Co), vanadium (V), lanthanum (La), titanium (Ti), nickel (Ni), zirconium (Zr), yttrium (Y), and gallium (Ga), or two or more elements thereof, 0≤x≤0.2, 0<y≤0.2, 0<f≤0.2, and 0≤z≤0.2.

According to an embodiment of the present invention, limitations, such as the Jahn-Teller distortion and the dissolution of Mn 2+ , may be addressed by structurally stabilizing the polycrystalline lithium manganese oxide particles. Thus, life characteristics and charge and discharge capacity characteristics of a secondary battery may be improved.

First claim

The invention claimed is:

1. Polycrystalline lithium manganese oxide particles represented by Chemical Formula 1:
Li (1+x) Mn (2−x−y−f) Al y M f O (4−z)   <Chemical Formula 1>

where M is boron (B), and 0≤x≤0.2, 0<y≤0.2, 0<f≤0.2, and 0≤z≤0.2; and
wherein the polycrystalline lithium manganese oxide particles are in a form of secondary particles in which two or more primary particles having an average crystal diameter of 152 nm to 300 nm are agglomerated,
and wherein the polycrystalline lithium manganese oxide particles have curved round shaped edges; and
wherein I(311)/I(111) of the lithium manganese oxide particles is 40% or more when a peak intensity ratio of I(111)/I(111) is defined as 100% in X-ray diffraction analysis.

2. The polycrystalline lithium manganese oxide particles of claim 1 , wherein, in Chemical Formula 1, f satisfies 0.001≤f≤0.03.

3. The polycrystalline lithium manganese oxide particles of claim 1 , wherein an average particle diameter (D 50 ) of the secondary particle is in a range of 5 μm to 20 μm.

4. The polycrystalline lithium manganese oxide particles of claim 1 , wherein an amount of B in the polycrystalline lithium manganese oxide particles is in a range of 700 ppm to 3,000 ppm.

5. The polycrystalline lithium manganese oxide particles of claim 1 , wherein I(400)/I(111) and I(440)/I(111) of the lithium manganese oxide particles are respectively 40% or more and 20% or more when a peak intensity ratio of I(111)/I(111) is defined as 100% in X-ray diffraction analysis.

6. The polycrystalline lithium manganese oxide particles of claim 1 , wherein a full width at half maximum (FWHM) of a (311) peak of the lithium manganese oxide particles in X-ray diffraction analysis is 0.3 degrees or less.

7. The polycrystalline lithium manganese oxide particles of claim 1 , wherein a Brunauer-Emmett-Teller (BET) specific surface area of the lithium manganese oxide particles is 0.5 m 2 /g or less.

8. A cathode active material comprising the polycrystalline lithium manganese oxide particles of claim 1 .

9. A cathode comprising the cathode active material of claim 8 .

10. A lithium secondary battery comprising the cathode of claim 9 .

11. Polycrystalline lithium manganese oxide particles represented by Chemical Formula 1:
Li (1+x) Mn (2−x−y−f) Al y M f O (4−z)   <Chemical Formula 1>

where M is boron (B), and 0≤x≤0.2, 0≤y≤0.2, 0<f≤0.2, and 0≤z≤0.2; and
wherein the polycrystalline lithium manganese oxide particles are in a form of secondary particles in which two or more primary particles having an average crystal diameter of 152 nm to 300 nm are agglomerated, and
wherein the polycrystalline lithium manganese oxide particles have curved round shaped edges, and
wherein the polycrystalline lithium manganese oxide particles have a Li 2 B 4 O 7 layer as a protective coating formed on the surfaces of the particles,
wherein I(311)/I(111) of the lithium manganese oxide particles is 40% or more when a peak intensity ratio of I(111)/I(111) is defined as 100% in X-ray diffraction analysis.

12. A method of preparing the polycrystalline lithium manganese oxide particles of claim 1 comprising:
(i) obtaining a precursor mixture including a polycrystalline manganese precursor, a lithium precursor, and a sintering aid; and
(ii) sintering the precursor mixture obtained in step (i), and
(iii) obtaining the polycrystalline manganese oxide particles of claim 1 .

13. The method of claim 12 , wherein the polycrystalline manganese precursor is in a form of secondary particles in which two or more primary particles having an average crystal diameter of 100 nm to 300 nm are agglomerated.

14. The method of claim 13 , wherein an average particle diameter (D 50 ) of the secondary particle is in a range of 9 μm to 25 μm.

15. The method of claim 14 , wherein the average particle diameter (D 50 ) of the secondary particle is in a range of 9 μm to 15 μm.

16. The method of claim 12 , wherein the polycrystalline manganese precursor comprises any one selected from the group consisting of MnCO 3 , Mn 3 O 4 , and Mn 2 O 3 , or a mixture of two or more thereof.

17. The method of claim 12 , wherein the polycrystalline manganese precursor comprises aluminum (Al) in an amount of 0.01 wt % to 10 wt %.

18. The method of claim 17 , wherein the polycrystalline manganese precursor comprises (Mn (1−y) Al y ) 3 O 4 (0<y≤0.2).

19. The method of claim 17 , wherein the polycrystalline manganese precursor is formed by coprecipitating an aluminum compound and any one selected from the group consisting of MnCO 3 , Mn 3 O 4 , MnSO 4 , and Mn 2 O 3 , or a mixture of two or more thereof.

20. The method of claim 19 , wherein the aluminum compound comprises any one selected from the group consisting of AlSO 4 , AlCl, and AlNO 3 , or a mixture of two or more thereof.

21. The method of claim 12 , wherein the sintering aid is the boron compound.

22. The method of claim 21 , wherein the boron compound comprises any one selected from the group consisting of boron, lithium tetraborate, boron oxide, and ammonium borate, or a mixture of two or more thereof.

23. The method of claim 12 , wherein the sintering aid is used in an amount of 0.2 parts by weight to 2 parts by weight based on a total weight of the polycrystalline manganese precursor.

24. The method of claim 12 , wherein the sintering is performed in a temperature range of 700° C. to 1,000° C.

25. The method of claim 12 , wherein the lithium precursor comprises any one selected from the group consisting of lithium chloride (LiCl), lithium carbonate (LiCO 3 ), lithium hydroxide (LiOH), lithium phosphate (Li 3 PO 4 ), and lithium nitrate (LiNO 3 ), or a mixture of two or more thereof.

Assignees

• Lg Chemical Ltd

Inventors

• Kwak Ick Soon
• Cho Seung Beom
• Chae Hwa Seok

Classifications

• C01P2002/52

  containing elements as dopants · CPC title

• C01G45/1242

  of the type (Mn2O4)-, e.g. LiMn2O4 or Li(MxMn2-x)O4 · 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

• H01M10/0525

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

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title