Positive active material, positive electrode including the same, and lithium secondary battery including the positive active material

Patent metadata

Field	Value
Publication number	US-2018062172-A1
Application number	US-201715685334-A
Country	US
Kind code	A1
Filing date	Aug 24, 2017
Priority date	Aug 26, 2016
Publication date	Mar 1, 2018
Grant date	—

Abstract

A positive active material, a positive electrode, and a lithium secondary battery, the positive active material including a lithium cobalt oxide compound, wherein the lithium cobalt oxide compound includes magnesium in a range of about 0.1 mol % to about 2 mol %, based on a total number of moles of transition metals in the lithium cobalt oxide compound, and a thickness of a lithium layer in the lithium cobalt oxide compound is in a range of about 2.62 Å to about 2.65 Å.

First claim

What is claimed is:

1 . A positive active material comprising a lithium cobalt oxide compound, wherein:
the lithium cobalt oxide compound includes magnesium in a range of about 0.1 mol % to about 2 mol %, based on a total number of moles of transition metals in the lithium cobalt oxide compound, and a thickness of a lithium layer in the lithium cobalt oxide compound is in a range of about 2.62 Å to about 2.65 Å.

2 . The positive active material as claimed in claim 1 , wherein magnesium is doped in a cobalt-containing transition metal layer in the lithium cobalt oxide compound.

3 . The positive active material as claimed in claim 1 , wherein a lithium/cobalt molar ratio in the lithium cobalt oxide compound is about 1±α, wherein 0≦α≦0.025.

4 . The positive active material as claimed in claim 1 , wherein a lithium/cobalt molar ratio in the lithium cobalt oxide compound is 1.

5 . The positive active material as claimed in claim 1 , wherein an average particle diameter (D50) in the lithium cobalt oxide compound is in a range of about 1 μm to about 50 μm.

6 . The positive active material as claimed in claim 1 , wherein the positive active material further includes at least one selected from LiNiO 2 , LiMnO 2 , LiMn 2 O 4 , Li(Ni a Co b Al c )O 2 , Li(Ni a Co b Mn c )O 2 , in which 0<α<1, 0<b<1, 0<c<1, and a+b+c=1, LiNi 1-Y Co Y O 2 , LiCo 1-Y Mn Y O 2 , LiNi 1-Y Mn Y O 2 , which 0≦Y<1, Li(Ni a Co b Mn c )O 4 , in which 0<α<2, 0<b<2, 0<c<2, and a+b+c=2, LiMn 2-z Ni z O 4 , LiMn 2-z Co z O 4 , in which 0<Z<2, LiCoPO 4 , LiFePO 4 , LiFePO 4 , V 2 O 5 , TiS, and MoS.

7 . A positive electrode for a lithium secondary battery, the positive electrode including the positive active material as claimed in claim 1 .

8 . A lithium secondary battery, comprising:
a positive electrode including the positive active material as claimed in claim 1 ; a negative electrode facing the positive electrode; and an electrolyte between the positive electrode and the negative electrode.

9 . The lithium secondary battery as claimed in claim 8 , wherein the lithium secondary battery operates at a voltage in a range of about 4.3 V to about 4.6 V.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Park Sooyoun
• Kim Changwook
• You Yongchan
• Lee Daehoe
• Cho Sangwoo

Classifications

• H01M4/131

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

• H01M4/1391

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

• H01M4/525 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

• H01M10/0525

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

• H01M4/5825

  Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines · CPC title