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-2023327107-A1
Application number	US-202318210427-A
Country	US
Kind code	A1
Filing date	Jun 15, 2023
Priority date	Jan 24, 2018
Publication date	Oct 12, 2023
Grant date	—

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

1 . A positive electrode active material for a secondary battery, the positive electrode active material comprising:
a lithium composite transition metal oxide including nickel, cobalt, and manganese; 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 in a total amount of transition metals is 60 mol % or more, and an amount of the manganese is greater than an amount of the cobalt, and the glassy coating layer comprises a glassy 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 boron, aluminum, silicon, titanium, and phosphorus, and 1≤a≤4, 1≤b≤8, and 1≤c≤20; wherein the positive electrode active material has a particle strength of 150 MPa or more.

2 . The positive electrode active material for a secondary battery of claim 1 , wherein an amount of residual lithium by-products in the positive electrode active material is 1.0 wt % or less.

3 . The positive electrode active material for a secondary battery of claim 1 , wherein the positive electrode active material has a particle strength of 200 MPa to 250 MPa.

4 . The positive electrode active material for a secondary battery of claim 1 , wherein the glassy coating layer comprises a lithium-boron-aluminum oxide.

5 . The positive electrode active material for a secondary battery of claim 4 , wherein, in the glassy 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 positive electrode active material for a secondary battery of claim 1 , wherein the lithium composite transition metal oxide is represented by Formula 2:
Li p Ni 1−(x1+y1+z1) Co x1 Mn y1 M 2 z1 M 3 q1 O 2   [Formula 2]
wherein, in Formula 2, M 2 is at least one element selected from the group consisting of aluminum, zirconium, boron, tungsten, magnesium, cerium, hafnium, tantalum, titanium, strontium, barium, phosphorus, and lanthanum, M 3 is at least one element selected from the group consisting of aluminum, zirconium, titanium, magnesium, tantalum, niobium, molybdenum, tungsten, and chromium, and 0.9≤p≤1.1, 0≤x1≤0.4, 0<y1≤0.4, 0≤z1≤0.1, 0≤q1≤0.1, x1<y1, and 0<x1+y1+z1≤0.4.

7 . The positive electrode active material for a secondary battery of claim 1 , wherein, in the lithium composite transition metal oxide, the amount of the nickel in the total amount of the transition metals is 80 mol % or more.

8 . The positive electrode active material for a secondary battery of claim 1 , wherein the glassy coating layer is formed on surfaces of primary particles of the lithium composite transition metal oxide.

9 . The positive electrode active material for a secondary battery of claim 1 , wherein the glassy coating layer is included in an amount of 0.02 part by weight to 0.2 part by weight based on 100 parts by weight of the lithium composite transition metal oxide.

10 . The positive electrode active material for a secondary battery of claim 1 , wherein the glassy coating layer is formed to a thickness of 20 nm to 100 nm.

11 . 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, cobalt, and manganese; and forming a glassy 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, aluminum, silicon, titanium, and phosphorus, and performing a heat treatment in a temperature range of 500° C. to 750° C., wherein, in the lithium composite transition metal oxide, an amount of the nickel in a total amount of transition metals is 60 mol % or more, and an amount of the manganese is greater than an amount of the cobalt, and the glassy coating layer comprises a glassy 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.

12 . The method of claim 11 , wherein, in the forming of the glassy coating layer, a lithium source is not added.

13 . The method of claim 11 , wherein an amount of residual lithium by-products in the positive electrode active material is 1.0 wt % or less.

14 . The method of claim 11 , wherein the coating source comprises a compound containing at least one selected from the group consisting of boron and aluminum.

15 . The method of claim 11 , wherein, in the glassy 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.

16 . The method of claim 11 , 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.

17 . The method of claim 11 , wherein the heat treatment is performed in a temperature range of 600° C. to 700° C.

18 . A positive electrode for a secondary battery, the positive electrode comprising the positive electrode active material of claim 1 .

19 . A lithium secondary battery comprising the positive electrode of claim 18 .

Assignees

• 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

• H01M4/0471

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

• H01M4/366 Primary

  as layered products · CPC title

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M10/0525

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