Positive Electrode Active Material For Lithium Secondary Battery, Method Of Preparing The Same, And Lithium Secondary Battery Including The Positive Electrode Active Material

Patent metadata

Field	Value
Publication number	US-2019288285-A1
Application number	US-201816347742-A
Country	US
Kind code	A1
Filing date	Feb 28, 2018
Priority date	Feb 28, 2017
Publication date	Sep 19, 2019
Grant date	—

Abstract

The present invention relates to a positive electrode active material for a lithium secondary battery which includes a lithium composite transition metal oxide including nickel (Ni), cobalt (Co), and manganese (Mn), wherein a portion of nickel (Ni) sites of the lithium composite transition metal oxide is substituted with tungsten (W), and an amount of a lithium tungsten oxide remaining on surfaces of lithium composite transition metal oxide particles is 1,000 ppm or less.

First claim

1 . A positive electrode active material for a lithium secondary battery, the positive electrode active material comprising a lithium composite transition metal oxide including nickel, cobalt, and manganese,
wherein a portion of nickel sites of the lithium composite transition metal oxide is substituted with tungsten, and an amount of a lithium tungsten oxide remaining on surfaces of lithium composite transition metal oxide particles is 1,000 ppm or less.

2 . The positive electrode active material for a lithium secondary battery of claim 1 , wherein the lithium composite transition metal oxide contains tungsten in an amount of 10 ppm to 5,000 ppm in a crystal structure.

3 . The positive electrode active material for a lithium secondary battery of claim 1 , wherein the lithium composite transition metal oxide contains tungsten in an amount of 2,000 ppm to 3,000 ppm in a crystal structure.

4 . The positive electrode active material for a lithium secondary battery of claim 1 , wherein, when (D 50 ) of the lithium composite transition metal oxide is denoted as d and a crystallite size of the lithium composite transition metal oxide is denoted as c, d/(1,000-c) is 0.05 or more.

5 . The positive electrode active material for a lithium secondary battery of claim 1 , wherein the lithium composite transition metal oxide has a crystallite size of 100 nm to 200 nm.

6 . The positive electrode active material for a lithium secondary battery of claim 1 , wherein the lithium composite transition metal oxide is a quaternary lithium composite transition metal oxide including nickel, cobalt, manganese, and aluminum.

7 . The positive electrode active material for a lithium secondary battery of claim 1 , wherein the positive electrode active material has D 50 of 3 μm to 6 μm and a {(D 90 -D 10 )/D 50 } of 0.6 or less.

8 . The positive electrode active material for a lithium secondary battery of claim 1 , wherein the lithium composite transition metal oxide is represented by Formula 1:
Li a Ni 1-x1-y1-z1 W z1 Co x1 M 1 y1 M 2 q1 O 2   [Formula 1]
wherein, in Formula 1, 1.0≤a≤1.5, 0<x1≤0.2, 0<y1≤0.2, 0<z1≤0.2, and 0≤q1≤0.1, M 1 comprises at least one of Mn and Al, and M 2 comprises at least one of barium, calcium, zirconium, titanium, magnesium, tantalum, niobium, or molybdenum.

9 . The positive electrode active material for a lithium secondary battery of claim 8 , wherein, in Formula 1, 06<x1+y1+z1≤0.2 is satisfied.

10 . A method of preparing a positive electrode active material for a lithium secondary battery, the method comprising:
preparing a metal solution including a nickel containing raw material, a cobalt containing raw material, a manganese containing raw material, and a tungsten containing raw material; preparing a positive electrode active material precursor by a co-precipitation reaction of the metal solution; mixing and sintering the positive electrode active material precursor and a lithium raw material to prepare a lithium composite transition metal oxide in which a portion of nickel sites is substituted with tungsten; and washing the sintered lithium composite transition metal oxide to remove a lithium tungsten oxide remaining on a surface of the lithium composite transition metal oxide.

11 . The method of claim 10 , wherein the tungsten containing raw material comprises at least one of Na 2 WO 4 , WO 3 , or H 2 WO 4 ).

12 . The method of claim 10 , wherein the metal solution comprises the tungsten containing raw material in an amount of 0.05 mol % to 0.5 mol % based on a total of the nickel containing raw material, the cobalt containing raw material, the manganese containing raw material, and the tungsten containing raw material.

13 . The method of claim 10 , wherein the positive electrode active material precursor is represented by Formula 2:
Ni 1-x2-y2-z2 W z2 Co x2 M 1 y2 (OH) 2   [Formula 2]
wherein, in Formula 2, 0<x2≤0.2, 0<y2≤0.2, and 0<z2≤0.2, and M 1 comprises at least one of Mn or Al.

14 . The method of claim 13 , wherein, in Formula 2, 0<x2+y2+z2≤0.2 is satisfied.

15 . The method of claim 10 , wherein a sintering temperature is in a range of 700° C. to 900° C.

16 . The method of claim 10 , wherein the washing is performed in a temperature range of −10° C. to 30° C.

17 . The method of claim 10 , wherein the lithium composite transition metal oxide contains tungsten in an amount of 10 ppm to 5,000 ppm in a crystal structure.

18 . The method of claim 10 , wherein an amount of the lithium tungsten oxide remaining on a surfaces of a lithium composite transition metal oxide particles after the washing is 1,000 ppm or less.

19 . A positive electrode for a lithium secondary battery, the positive electrode comprising a conductive agent, a binder, and the positive electrode active material for a lithium secondary battery of claim 1 .

20 . A lithium secondary battery comprising a negative electrode, the positive electrode for a lithium secondary battery of claim 19 , as separator, and an electrolyte.

Assignees

• Lg Chemical Ltd

Inventors

• Kim Ji Hye
• Park Byung Chun
• Baek So Ra
• Yoo Tae Gu
• Jung Wang Mo

Classifications

• H01M10/0525

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

• H01M4/131

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

• C01P2004/62

  Submicrometer sized, i.e. from 0.1-1 micrometer · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M4/364

  as mixtures · CPC title