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

Patent metadata

Field	Value
Publication number	US-2016149215-A1
Application number	US-201514948100-A
Country	US
Kind code	A1
Filing date	Nov 20, 2015
Priority date	Nov 21, 2014
Publication date	May 26, 2016
Grant date	—

Abstract

A positive active material for a rechargeable lithium battery includes a lithium intercalation compound; and lithium titanium oxide represented by Chemical Formula 1 on the surface of the lithium intercalation compound surface.
Li 4-x M x Ti y O 12-z .   Chemical Formula 1

In the Chemical Formula 1,
0<x≦3, 1≦y≦5, −0.3≦z≦0.3, and M is an element selected from Mg, Al, Ga, La, Tb, Gd, Ce, Pr, Nd, Sm, Ba, Sr, Ca, and combinations thereof.

First claim

What is claimed is:

1 . A positive active material for a rechargeable lithium battery, the positive active material comprising
a lithium intercalation compound; and a lithium titanium oxide represented by Chemical Formula 1 on the surface of the lithium intercalation compound:
Li 4-x M x Ti y O 12-z ,   Chemical Formula 1

wherein 0<x≦3, 1≦y≦5, −0.3≦z≦0.3, and M is selected from the group consisting of Mg, Al, Ga, La, Tb, Gd, Ce, Pr, Nd, Sm, Ba, Sr, Ca, and combinations thereof.

2 . The positive active material for a rechargeable lithium battery of claim 1 , wherein the lithium titanium oxide is Li 4-x M x Ti 5 O 12 (0<x≦3).

3 . The positive active material for a rechargeable lithium battery of claim 1 , wherein the lithium titanium oxide has a spinel structure.

4 . The positive active material for a rechargeable lithium battery of claim 1 , wherein the lithium titanium oxide is included in an amount of about 2.0 wt % to about 6.0 wt % based on 100 wt % of the positive active material.

5 . The positive active material for a rechargeable lithium battery of claim 1 , wherein the lithium intercalation compound is an M-doped compound, and
wherein M is selected from the group consisting of Mg, Al, Ti, La, Tb, Gd, Ce, Pr, Nd, Sm, Ba, Sr, Ca, and combinations thereof.

6 . The positive active material for a rechargeable lithium battery of claim 5 , wherein the M is doped in an amount of about 0.1 mol % to about 2 mol % based on 100 mol % of the lithium intercalation compound.

7 . A method of preparing a positive active material for a rechargeable lithium battery, the method comprising:
mixing titanium compound-containing liquid and a lithium intercalation compound to prepare a mixture; drying the mixture to obtain a dried product; and heat-treating the dried product.

8 . The method of claim 7 , wherein the titanium compound-containing liquid has a concentration of about 1.5 wt % to about 3.0 wt % of a titanium compound based on the total amount of the liquid.

9 . The method of claim 7 , wherein a mixing ratio of the titanium compound-containing liquid and lithium intercalation compound is a weight ratio in a range from about 0.0092:1 to about 0.073:1.

10 . The method of claim 7 , wherein the drying the mixture is performed at about 60° C. to about 100° C. for about 6 hours to about 24 hours.

11 . The method of claim 7 , wherein the heat-treating the dried product is performed at about 700° C. to about 950° C. for about 3 hours to about 20 hours.

12 . The method of claim 7 , wherein the lithium intercalation compound is an M-doped compound.

13 . A rechargeable lithium battery comprising:
a positive electrode including the positive active material of claim 1 ; a negative electrode including a negative active material; and an electrolyte.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Shim Jae-Hyun
• Lee Ki-Soo
• Kim Ho
• Lee Jae-Han
• Lee Se-Hee
• Ju Hyeon-Ah
• Song Joo-Han
• Lee Yoon-Hee

Classifications

• H01M10/0525

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

• H01M2220/30

  Batteries in portable systems, e.g. mobile phone, laptop · CPC title

• H01M4/485 Primary

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

• C01G51/42

  containing alkali metals, e.g. LiCoO2 · CPC title

• C01G23/005

  Alkali titanates · CPC title