Positive active material for rechargeable lithium battery and rechargeable lithium battery including the same

Patent metadata

Field	Value
Publication number	US-2018102537-A1
Application number	US-201715722953-A
Country	US
Kind code	A1
Filing date	Oct 2, 2017
Priority date	Oct 6, 2016
Publication date	Apr 12, 2018
Grant date	—

Abstract

A positive active material for a rechargeable lithium battery and a rechargeable lithium battery including the same are provided. The positive active material includes a lithium intercalation compound and a Si-containing TiO 2 present on the surface of the compound. When TiO 2 is present on the surface of the lithium intercalation compound, the rate characteristics and low temperature characteristics of batteries including the lithium intercalation compound may be improved. Further, when Si-containing TiO 2 is present on the surface of the lithium intercalation compound, the cycle-life characteristic and high temperature storage characteristics of batteries including the lithium intercalation compound may be further improved, compared to batteries having only TiO 2 . As such, the positive active material including Si-containing TiO 2 provides a rechargeable lithium battery having excellent rate capability, low temperature characteristics, cycle-life characteristics and high temperature storage characteristics.

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 Si-containing TiO 2 present on the surface of the compound.

2 . The positive active material of claim 1 , wherein the Ti is included in a molar amount of about 0.05 mol % to about 2.0 mol % based on 100 mol % of the lithium intercalation compound.

3 . The positive active material of claim 1 , wherein the Si is included in a molar amount of about 0.1 mol % to about 25 mol % based on 100 mol % of the Ti.

4 . The positive active material of claim 1 , wherein the Si-containing TiO 2 is included in a molar amount of about 0.04 wt % to about 1.6 wt % based on 100 wt % of the lithium intercalation compound.

5 . The positive active material of claim 1 , wherein the Si-containing TiO 2 has an average particle diameter (D50) of about 10 nm to about 300 nm.

6 . The positive active material of claim 1 , wherein the Si-containing TiO 2 has a layer-type or island-type form.

7 . The positive active material of claim 1 , wherein the Si-containing TiO 2 is present on the surface of the lithium intercalation compound in a thickness of about 20 nm to about 300 nm.

8 . The positive active material of claim 1 , wherein the lithium intercalation compound has an average particle diameter (D50) of about 15 μm to about 20 μm.

9 . 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.

10 . The rechargeable lithium battery of claim 9 , wherein the Ti is included in a molar amount of about 0.05 mol % to about 2.0 mol % based on 100 mol % of the lithium intercalation compound.

11 . The rechargeable lithium battery of claim 9 , wherein the Si is included in a molar amount of about 0.1 mol % to about 25 mol % based on 100 mol % of the Ti.

12 . The rechargeable lithium battery of claim 9 , wherein the Si-containing TiO 2 is included in a molar amount of about 0.04 wt % to about 1.6 wt % based on 100 wt % of the lithium intercalation compound.

13 . The rechargeable lithium battery of claim 9 , wherein the Si-containing TiO 2 has an average particle diameter (D50) of about 10 nm to about 300 nm.

14 . The rechargeable lithium battery of claim 9 , wherein the Si-containing TiO 2 has a layer-type or island-type form.

15 . The rechargeable lithium battery of claim 9 , wherein the Si-containing TiO 2 is present on the surface of the lithium intercalation compound in a thickness of about 20 nm to about 300 nm.

16 . The rechargeable lithium battery of claim 9 , wherein the lithium intercalation compound has an average particle diameter (D50) of about 15 μm to about 20 μm.

17 . A method of forming a positive active material for a rechargeable lithium battery, the method comprising:
providing a lithium intercalation compound; and coating a Si-containing TiO 2 on the surface of the compound.

18 . The method of claim 17 , wherein the Si-containing TiO 2 is coated in a layer-type or island-type form.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Kim Jihyun
• Kim Changwook
• Park Sooyoun
• Sheem Kyouyoon
• Je Hyunjoo

Classifications

• H01M4/134

  Electrodes based on metals, Si or alloys · CPC title

• C01P2004/62

  Submicrometer sized, i.e. from 0.1-1 micrometer · CPC title

• H01M4/623

  fluorinated polymers · CPC title

• H01M10/052

  Li-accumulators · CPC title

• C01G51/42 Primary

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