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

Patent metadata

Field	Value
Publication number	US-9716273-B2
Application number	US-201414329857-A
Country	US
Kind code	B2
Filing date	Jul 11, 2014
Priority date	Jul 11, 2013
Publication date	Jul 25, 2017
Grant date	Jul 25, 2017

Abstract

A positive active material for a rechargeable lithium battery includes a lithium composite metal oxide represented by Chemical Formula 1. A method of preparing the positive active material includes adding a lithium metal oxide represented by Chemical Formula 2 to a Zr salt-containing solution to obtain a mixed solution, drying the mixed solution to obtain a dried product, and heat-treating the dried product to prepare a lithium composite metal oxide represented by Chemical Formula 1. A rechargeable lithium battery includes a positive electrode including the positive active material.

Li a Zr b Ni c Co d M e Zr f O 2   [Chemical Formula 1]
where, 0.9≦a≦1.1, 0<b≦0.1, 0≦c≦1, 0≦d≦1, 0≦e≦1, 0≦f≦0.1, 0.9≦a+b≦1.1, c+d+e+f=1, and M is Mn or Al,

Li a Ni g Co h M i O 2   [Chemical Formula 2]
where, 0.9≦a≦1.1, 0≦g≦1, 0≦h≦1, 0≦i≦1, g+h+i=1 and M is Mn or Al.

First claim

What is claimed is:

1. A positive active material for a rechargeable lithium battery, comprising:
a lithium composite metal oxide represented by Chemical Formula 1:
Li a Zr b Ni c Co d M e Zr f O 2   [Chemical Formula 1]

wherein, a<1.1, 0<b≦0.1, 0≦c≦1, 0≦d≦1, 0≦e≦1, 0≦f≦0.1, 0.9≦a+b≦1.1, c+d+e+f=1, M is Mn or Al, and Zr is partially present in the position of at least Li in the lithium composite metal oxide.

2. The positive active material for a rechargeable lithium battery of claim 1 , wherein a<1.1, 0<b≦0.05, 0≦c≦1, 0≦d≦1, 0≦e≦1, 0≦f≦0.05, 0.9≦a+b≦1.1, c+d+e+f=1.

3. The positive active material for a rechargeable lithium battery of claim 1 , wherein the lithium composite metal oxide shows a peak at a 2θ value of about 19° to about 23° and a peak at a 2θ value of about 40° to about 45° in an XRD pattern using a CuKα ray.

4. The positive active material for a rechargeable lithium battery of claim 1 , wherein the lithium composite metal oxide has an Li:Zr atomic ratio of about 90:10 to 99.9:0.1 when Zr is present at a Li position of the lithium composite metal oxide.

5. A rechargeable lithium battery, comprising
a positive electrode including the positive active material according to claim 1 ;
a negative electrode; and
an electrolyte.

6. A method of preparing a positive active material for a rechargeable lithium battery, the method comprising:
adding a lithium metal oxide represented by Chemical Formula 2 to a Zr salt-containing solution to obtain a mixed solution; and
heat-treating the mixed solution to prepare a lithium composite metal oxide represented by Chemical Formula 1
Li a Zr b Ni c Co d M e Zr f O 2   [Chemical Formula 1]

wherein, a<1.1, 0<b≦0.1, 0≦c≦1, 0≦d≦1, 0≦e≦1, 0≦f≦0.1, 0.9≦a+b≦1.1, c+d+e+f=1, M is Mn or Al, and Zr is partially present in the position of at least Li in the lithium composite metal oxide;
Li a Ni g Co n M i O 2   [Chemical Formula 2]

wherein, 0.9≦a≦1.1, 0≦g≦1, 0≦h≦1, 0≦i≦1, g+h+i=1, and M is Mn or Al.

7. The method of claim 6 , wherein the Zr salt-containing solution is present in the mixed solution in an amount of about 0.1 to about 10 parts by mole based on 100 parts by mole of the lithium metal oxide.

8. The method of claim 6 , wherein the Zr salt-containing solution is an aqueous solution or an alcohol solution.

9. The method of claim 6 , wherein the Zr salt-containing solution is prepared by a method comprising:
adding a Zr salt to a first solvent to obtain a first solution;
adding citric acid to a second solvent to prepare a second solution;
mixing the first solution and the second solution to obtain a transparent solution; and
adding ethylene glycol to the transparent solution.

10. The method of claim 6 , wherein the heat-treating the mixed solution is performed at a temperature of about 350° C. to about 1000° C.

11. The method of claim 6 , further comprising drying the mixed solution to obtain a dried product, before heat-treating.

12. The method of claim 6 , wherein the heat-treating is performed by
performing a first heat-treatment on the mixed solution to obtain a mixture; and
performing a second heat-treatment on the mixture.

13. The method of claim 12 , wherein the first heat-treatment is performed at a temperature of about 80° C. to about 100° C.

14. The method of claim 12 , wherein the second heat-treatment is performed at a temperature of about 350° C. to about 1000° C.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Hong Ming-Zi
• Park Do-Hyung
• Kwon Seon-Young
• Moon Joong-Ho
• Kim Ji-Hyun
• Park Han-Eol
• Kim Min-Han
• Woo Myong-A
• Kim Ki-Hyun
• Choi Jong-Seo

Classifications

• C01P2002/88

  by thermal analysis data, e.g. TGA, DTA, DSC · 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

• H01M4/1391

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

• H01M4/505 Primary

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

• C01P2002/72

  by d-values or two theta-values, e.g. as X-ray diagram · CPC title