Positive active material, manufacturing method thereof, and positive electrode and lithium battery including the material

• US 10,446,834 B2
• Filed: 07/23/2015
• Issued: 10/15/2019
• Est. Priority Date: 12/29/2014
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd., Samsung SDI Company Limited
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kapylou, Andrei, Kim, Donghan, Park, Jinhwan, Song, Jayhyok, Ahn, Sungjin, Yu, Byongyong
• Primary Examiner(s): Crepeau, Jonathan
• Assistant Examiner(s): Martin, Angela J
• Application Number:
  US14/806,969
• Publication Number:
  US 20160190555A1
• Time in Patent Office: 1,545 Days
• Field of Search: None
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 4/131 Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/366 as layered products
• CPC Class Codes: H01M 4/485 of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy H01M4/505, H01M4/525 take precedence
• CPC Class Codes: H01M 4/505 of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: H01M 4/602 Polymers
• CPC Class Codes: H01M 4/622 being polymers
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A positive active material including: a core including an overlithiated lithium transition metal oxide, and a coating layer which is disposed on at least a portion of a surface of the core, the coating layer including a polymer having an oxidation potential of about 4.4 volts to about 4.7 volts versus lithium metal. Also a manufacturing method thereof, and a positive electrode and a lithium battery including the positive active material.

Claims

1. A positive active material comprising:

a core comprising an overlithiated lithium transition metal oxide; and

a coating layer which is disposed on at least a portion of a surface of the core, the coating layer comprising an organic polymer having an oxidation potential of about 4.4 volts to about 4.7 volts versus lithium metal.

2. The positive active material of claim 1, wherein the overlithiated lithium transition metal oxide is represented by Formula 1:

xLi₂MO₃-(1−

x)LiM′

O₂ 

 

Formula 1

wherein in Formula 1,

M has an average oxidation number of +4 and is at least one element selected from Period 2 to Period 5 of the Periodic Table of the Elements,

M′

has an average oxidation number of +3 and is at least one element selected from Period 2 to Period 5 elements, and

0<

x<

1.

3. The positive active material of claim 2, wherein, in Formula 1, M is at least one metal selected from manganese, titanium, zirconium, tin, and molybdenum, and

M′

is at least one metal selected from nickel, cobalt, Mn, iron, aluminum, magnesium, zinc, copper, chromium, vanadium, and niobium.

4. The positive active material of claim 1, wherein the overlithiated lithium transition metal oxide is a positive active material represented by Formula 2:

xLi₂MnO₃-(1−

x)LiNi_aCo_bMn_cO₂ 

 

Formula 2

wherein in Formula 2, 0<

x<

1, 0<

a<

1, 0<

b<

1, 0<

c<

1, and a+b+c=1.

5. The positive active material of claim 1, wherein the overlithiated lithium transition metal oxide is a positive active material represented by Formula 3:

Li[Li_aNi_bCo_cMn_dM_f]O_2-xF_x 

 

Formula 3

wherein in Formula 3, M is at least one metal selected from Ti, V, Al, Mg, Cr, Fe, Zr, rhenium, boron, germanium, ruthenium, Sn, Nb, Mo, and platinum, and

a+b+c+d+f=1;

0<

a<

1, 0<

b<

1, 0<

c<

1, 0<

d<

1, and 0<

f<

1;

and 0<

x<

0.1.

6. The positive active material of claim 5, wherein, in Formula 3, M is at least one metal selected from Ti, V, Al, Mg, Cr, Fe, and Zr.

7. The positive active material of claim 5, wherein, in Formula 3, 0.1<

a<

0.25, 0.1<

b<

0.4, 0<

c<

0.2, and f=0, and

d satisfies 0.8<

(2a+b)/d<

1.2.

8. The positive active material of claim 1, wherein the overlithiated lithium transition metal oxide comprises particles having an average particle diameter of about 10 nanometers to about 500 micrometers.

9. The positive active material of claim 1, wherein the core is in the form of a secondary particle, the secondary particle comprising an agglomeration of primary particles.

10. The positive active material of claim 1, wherein the polymer comprises at least one selected from polypyrrole, polyaniline, polythiophene, and poly(3,4-ethylenedioxythiophene).

11. The positive active material of claim 10, wherein the polymer comprises polypyrrole.

12. The positive active material of claim 1, wherein an amount of the polymer is greater than about 0 weight percent and equal to or less than about 10 weight percent, based on a total weight of the positive active material.

13. The positive active material of claim 1, wherein the coating layer is on an entire surface of the core.

14. The positive active material of claim 1, wherein the coating layer is adhered to at least a portion of the surface of the core, and is simultaneously disposed between the plurality of cores.

15. A lithium battery comprising the positive active material of claim 1.

16. A method of manufacturing a positive active material of claim 1, the method comprising:

preparing a mixture which includes an overlithiated lithium transition metal oxide and an organic polymer having an oxidation potential of about 4.4 volts to about 4.7 volts versus lithium metal; and

heat treating the mixture to manufacture the positive active material.

17. The method of claim 16, wherein the heat treatment is performed at room temperature and in vacuum.

18. The method of claim 16, wherein the polymer is polypyrrole.

19. The method of claim 18, wherein the polymer is provided by contacting pyrrole with an oxidant.