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

Patent metadata

Field	Value
Publication number	US-2020403239-A1
Application number	US-201916961672-A
Country	US
Kind code	A1
Filing date	Jan 14, 2019
Priority date	Jan 12, 2018
Publication date	Dec 24, 2020
Grant date	—

Abstract

Provided is a positive active material in which a compound containing lithium, a transition metal, and oxygen is doped with a doping metal, the positive active material including lithium (Li) layers, in which the lithium layers may include a first lithium layer including only lithium and a second lithium layer in which at least a part of the lithium of the first lithium layer is substituted with a transition metal.

First claim

1 . A positive active material including lithium, a transition metal, and oxygen, and including lithium (Li) layers and transition metal layers,
wherein the lithium layers include a first lithium layer including only lithium and a second lithium layer in which at least a part of the lithium of the first lithium layer is regularly substituted with the transition metal, the transition metal layer includes a first transition metal layer including only the transition metal, and a second transition metal layer in which at least a part of the first transition metal layer is regularly substituted with lithium, and the second lithium layers and the second transition metal layers are alternately and regularly provided.

2 . The positive active material of claim 1 , wherein an a-axis of a lattice formed by the second lithium layer and the second transition metal layer includes an increased long range ordering lattice.

3 . The positive active material of claim 1 , wherein
a lattice formed by the second lithium layer and the second transition metal layer includes a superlattice in which an a-axis increases two times of a lattice formed by the first lithium layer and the first transition metal layer.

4 . The positive active material of claim 1 , wherein the first lithium layers and the first transition metal layers are alternately and regularly arranged, and the second lithium layers and the second transition metal layers are alternately and regularly arranged, and
a lattice formed by the second lithium layers and the second transition metal layers includes a superlattice.

5 . The positive active material of claim 1 , wherein in the second lithium layer, a half of the lithium of the first lithium layer is substituted with the transition metal,
in the second transition metal layer, a half of the transition metal of the first transition metal layer is substituted with lithium, and the transition metal of the second lithium layer is obtained through an exchange of the transition metal of the first transition metal layer and the lithium of the second lithium layer, so that the lithium and the transition metal of the second lithium layer are alternately and repeatedly arranged, and the transition metal and the lithium of the second transition metal layer are alternately and repeatedly provided while corresponding to the lithium and the transition metal of the second lithium layer, respectively.

6 . The positive active material of claim 1 , further comprising:
a doping metal, wherein substitution energy of the lithium and the transition metal decreases by the doping metal, so that a part of the lithium of the first lithium layer is substituted with a transition metal to form the second lithium layer, and a part of the transition metal of the first transition metal is substituted with lithium to form a second transition metal layer.

7 . The positive active material of claim 6 , wherein the doping metal includes at least one of zirconium, boron, titanium, aluminum, and tungsten.

8 . The positive active material of claim 1 , wherein the transition metal includes one or more of nickel, cobalt, and manganese, and
a concentration of at least one of nickel, cobalt, and manganese in the positive active material has a concentration gradient in at least a part of the positive active material in a direction from a center to a surface of the positive active material.

9 . A positive active material, comprising:
a first lithium layer in which lithium is regularly arranged; and a second lithium layer in which lithium and a transition metal are regularly arranged; a first transition metal layer in which the transition metal is regularly arranged; and a second transition metal layer in which the transition metal and lithium are regularly arranged, wherein the second lithium layer and the second transition metal layer are alternately provided, and as a result of an electron diffraction pattern fora [010] zone axis or a [100] zone axis, a first diffraction spot group which corresponds to a lattice formed by the first lithium layer and the first transition metal layer and is formed by aligning one or more diffraction spots having relatively high strength in one direction, and a second diffraction spot group which corresponds to a lattice formed by the second lithium layer and the second transition metal layer and is formed by aligning one or more diffraction spots having relatively lower strength than the strength of the diffraction spot included in the first diffraction spot group in one direction are observed.

10 . The positive active material of claim 9 , wherein in the second lithium layer, the lithium and the transition metal are alternately arranged,
in the second transition metal layer, the transition metal and the lithium are alternately arranged, a lattice formed by the second lithium layer and the second transition metal layer includes a superlattice, and the superlattice includes six lithium elements and one transition metal element.

11 . The positive active material of claim 9 , wherein the first diffraction spot group and the second diffraction spot group are alternately and regularly arranged, and
the first diffraction spot group and the second diffraction spot group are provided while being spaced apart from each other at the same interval.

12 .- 14 . (canceled)

Assignees

• Iucf Hyu

Inventors

• Sun Yang-Kook
• Yoon Chong-Seung

Classifications

• C01G53/82

  Compounds containing nickel, with or without oxygen or hydrogen, and containing two or more other elements · CPC title

• C01P2006/40

  Electric properties · CPC title

• C01P2004/03

  obtained by SEM · CPC title

• C01P2002/77

  by unit-cell parameters, atom positions or structure diagrams · CPC title

• C01P2002/72

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