Lithium composite oxide and lithium secondary battery comprising the same

Patent metadata

Field	Value
Publication number	US-2021135212-A1
Application number	US-202017035680-A
Country	US
Kind code	A1
Filing date	Sep 29, 2020
Priority date	Oct 31, 2019
Publication date	May 6, 2021
Grant date	—

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), and the atomic ratio of boron (B) and nickel (Ni) in a surface region of the lithium composite oxide satisfies Expression 1 below:
0.2≤B/Ni≤29.0.   [Expression 1]

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 M1 z M2 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 the surface region of the lithium composite oxide to the 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 the interface between the primary particles and the surface of the secondary particle.

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 M3 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 at least a part of the surface of the secondary particle; and a second oxide layer covering at least a part of the surface of the secondary particle not covered by the first oxide layer and the surface of the first oxide layer, wherein 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

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M4/131

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

• C01P2002/85

  by XPS, EDX or EDAX data · CPC title

• C01G53/50 Primary

  of the type (MnO2)n-, e.g. Li(NixMn1-x)O2 or Li(MyNixMn1-x-y)O2 · CPC title

• H01M10/052

  Li-accumulators · CPC title