Lithium composite oxide and lithium secondary battery comprising the same

Patent metadata

Field	Value
Publication number	US-12126017-B2
Application number	US-202017035680-A
Country	US
Kind code	B2
Filing date	Sep 29, 2020
Priority date	Oct 31, 2019
Publication date	Oct 22, 2024
Grant date	Oct 22, 2024

Abstract

The present invention relates to a lithium composite oxide capable of improving capacity and lifetime characteristics of a lithium secondary battery and a lithium secondary battery including the same. According to the present invention, since the atomic ratio of boron (B) and nickel (Ni) in the surface region of the lithium composite oxide including primary particles enabling lithium intercalation and deintercalation and secondary particles formed by aggregating the primary particles is in a specific range, the stability of the lithium composite oxide may be improved, and thus it is possible to improve the capacity and lifetime characteristics of the lithium secondary battery using the lithium composite oxide as a positive electrode active material.

First claim

What is claimed is:

1. A lithium composite oxide, comprising:
primary particles enabling lithium intercalation and deintercalation and secondary particles formed by aggregating the primary particles,
wherein the lithium composite oxide comprises i) nickel (Ni) and cobalt (Co), ii) at least one selected from manganese (Mn) and aluminum (Al) and iii) boron (B),
wherein the atomic ratio of boron (B) and nickel (Ni) in a surface region of the secondary particles satisfies Expression 1 below:
0.2≤B/Ni≤29.0,  [Expression 1]

wherein the surface region is from the outermost surface of the secondary particles to a depth of 10 nm of the secondary particles, and
wherein a ratio of the atomic ratio of boron (B) and nickel (Ni) in the surface region of the secondary particles and the atomic ratio of boron (B) and nickel (Ni) in the total composition of the secondary particles is 160 to 1,500.

2. The lithium composite oxide of claim 1 , wherein the lithium composite oxide is represented by Formula 1 below:
Li w Ni 1−(x+y+z) Co x B y M 1 z M 2 z′ O 2   [Formula 1]

(Here,
M1 is at least one selected from Mn and Al,
M2 is at least one selected from Mn, Ba, Ce, Hf, Ta, Cr, F, Mg, Al, Cr, V, Ti, Fe, Zr, Zn, Si, Y, Nb, Ga, Sn, Mo, W, P, Sr, Ge, Nd, Gd and Cu,
M1 and M2 are different elements, and
0.5≤w≤1.5, 0<x≤0.50, 0<y≤0.20, 0≤z≤0.20, and 0≤z′≤0.20).

3. The lithium composite oxide of claim 1 , wherein the atomic ratio (B/Ni) of boron (B) and nickel (Ni) in the lithium composite oxide has a gradient that decreases from a surface region of the lithium composite oxide to a core region of the lithium composite oxide.

4. The lithium composite oxide of claim 1 , comprising:
a coating layer in which a boron (B)-containing oxide is present, which covers at least a part of an interface between the primary particles, or at least a part of the surface region of the secondary particles, or both at least the part of the interface between the primary particles and at least the part of the surface region of the secondary particles.

5. The lithium composite oxide of claim 4 , wherein the coating layer further comprises at least one oxide represented by Formula 2 below:
Li a M 3 b O c   [Formula 2]

(Here, M3 is at least one selected from Ni, Mn, Co, Fe, Cu, Nb, Mo, Ti, Al, Cr, Zr, Zn, Na, K, Ca, Mg, Pt, Au, B, P, Eu, Sm, W, Ce, V, Ba, Ta, Sn, Hf, Ce, Gd and Nd, 0≤a≤6, 0≤b≤8, and 2≤c≤13).

6. The lithium composite oxide of claim 5 , wherein the coating layer comprises:
a first oxide layer covering a part of the surface region of the secondary particles; and
a second oxide layer covering another part of the surface region of the secondary particles, which is not covered by the first oxide layer, and covering the surface of the first oxide layer,
wherein the at least one oxide represented by Formula 2 is present in the first oxide layer, and the boron-containing oxide is present in the second oxide layer.

7. A lithium secondary battery using a positive electrode comprising the lithium composite oxide according to claim 1 .

Assignees

• Ecopro Bm Co Ltd

Inventors

• Choi Moon Ho
• Suh Jun Won
• Yun Jin Kyeong
• Lee Jung Han
• Yun Mi Hye
• Choi Seung Woo
• Choe Gwang Seok
• Jang Ye Ri
• Bae Joong Ho

Classifications

• H01M10/052

  Li-accumulators · CPC title

• H01M4/62

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title

• H01M4/366

  as layered products · CPC title

• H01M4/485

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

• C01P2002/85

  by XPS, EDX or EDAX data · CPC title