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

Patent metadata

Field	Value
Publication number	US-11870070-B2
Application number	US-201916771139-A
Country	US
Kind code	B2
Filing date	Jan 23, 2019
Priority date	Jan 24, 2018
Publication date	Jan 9, 2024
Grant date	Jan 9, 2024

Abstract

A positive electrode active material for a secondary battery includes a lithium composite transition metal oxide including nickel (Ni), cobalt (Co), and manganese (Mn), and a glassy coating layer formed on surfaces of particles of the lithium composite transition metal oxide, wherein, in the lithium composite transition metal oxide, an amount of the nickel (Ni) in a total amount of transition metals is 60 mol % or more, and an amount of the manganese (Mn) is greater than an amount of the cobalt (Co), and the glassy coating layer includes a glassy compound represented by Formula 1.

Li a M 1 b O c   [Formula 1]
wherein, M 1 is at least one selected from the group consisting of boron (B), aluminum (Al), silicon (Si), titanium (Ti), and phosphorus (P), and 1≤a≤4, 1≤b≤8, and 1≤c≤20.

First claim

The invention claimed is:

1. A method of preparing a positive electrode active material for a secondary battery, the method comprising:
preparing a lithium composite transition metal oxide including nickel (Ni), cobalt (Co), and manganese (Mn); and
forming a coating layer by dry mixing the lithium composite transition metal oxide with a coating source including at least one selected from the group consisting of boron (B), aluminum (Al), silicon (Si), titanium (Ti), and phosphorus (P), and performing a heat treatment at a temperature of 500° C. to 750° C.,
wherein, in the lithium composite transition metal oxide, an amount of the nickel (Ni) in a total amount of transition metals is 60 mol % or more, and an amount of the manganese (Mn) is greater than an amount of the cobalt (Co), and
the coating layer comprises a compound represented by Formula 1:
Li a M 1 b O c   [Formula 1]

wherein, in Formula 1, M 1 is at least one selected from the group consisting of B, Al, Si, Ti, and P, and 1≤a≤4, 1≤b≤8, and 1≤c≤20.

2. The method of claim 1 , wherein, in the forming of the coating layer, a lithium source is not added.

3. The method of claim 1 , wherein an amount of residual lithium by-products in the positive electrode active material is 1.0 wt % or less.

4. The method of claim 1 , wherein the coating source comprises a compound containing at least one selected from the group consisting of boron (B) and aluminum (Al).

5. The method of claim 1 , wherein, in the coating layer, boron and aluminum are included at a ratio of 0.3 part by weight:1 part by weight to 0.8 part by weight:1 part by weight.

6. The method of claim 1 , wherein the coating source is mixed in an amount of 0.02 part by weight to 2.0 parts by weight based on 100 parts by weight of the lithium composite transition metal oxide.

Assignees

• Lg Chemical Ltd
• Lg Energy Solution Ltd

Inventors

• Baek So Ra
• Kang Min Suk
• Lee Sang Wook
• Jung Wang Mo
• Lee Dong Hun
• Jeon Hye Lim
• Lho Eun Sol

Classifications

• 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

• C01B35/121

  of alkali metal · CPC title

• C01G53/50

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

• H01M4/0471

  involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis · CPC title

• H01M4/131

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