Positive Electrode Material, Positive Electrode, and Lithium Secondary Battery Which Include Spinel-Structured Lithium Manganese-Based Positive Electrode Active Material

Patent metadata

Field	Value
Publication number	US-2020083524-A1
Application number	US-201816611126-A
Country	US
Kind code	A1
Filing date	Nov 6, 2018
Priority date	Nov 6, 2017
Publication date	Mar 12, 2020
Grant date	—

Abstract

The present disclosure relates to a positive electrode material including a spinel-structured lithium manganese-based first positive electrode active material and a lithium nickel-manganese-cobalt-based second positive electrode active material, wherein the first positive electrode active material includes a lithium manganese oxide represented by Formula 1 and a coating layer which is disposed on a surface of the lithium manganese oxide, the second positive electrode active material is represented by Formula 2, and an average particle diameter of the second positive electrode active material is greater than an average particle diameter of the first positive electrode active material, and a positive electrode and a lithium secondary battery which include the positive electrode material:
Li 1+a Mn 2-b M 1 b O 4-c A c   [Formula 1]

Li 1+x [Ni y Co z Mn w M 2 v ]O 2-p B p   [Formula 2]

First claim

1 . A positive electrode material comprising:
a spinel-structured lithium manganese-based first positive electrode active material and a lithium nickel-manganese-cobalt-based second positive electrode active material; the first positive electrode active material comprises a lithium manganese oxide represented by Formula 1 and a coating layer which is disposed on a surface of the lithium manganese oxide, the coating layer includes at least one coating element selected from the group consisting of aluminum (Al), titanium (Ti), tungsten (W), boron (B), fluorine (F), phosphorus (P), magnesium (Mg), nickel (Ni), cobalt (Co), iron (Fe), chromium (Cr), vanadium (V), copper (Cu), calcium (Ca), zinc (Zn), zirconium (Zr), niobium (Nb), molybdenum (Mo), strontium (Sr), antimony (Sb), bismuth (Bi), silicon (Si), and sulfur (S); the second positive electrode active material is represented by Formula 2; and an average particle diameter (D 50 ) of the second positive electrode active material is greater than an average particle diameter (D 50 ) of the first positive electrode active material:
Li 1+a Mn 2-b M 1 b O 4-c A c   [Formula 1]

wherein, in Formula 1, M 1 is at least one element selected from the group consisting of Al, lithium (Li), Mg, Zn, B, W, Ni, Co, Fe, Cr, V, ruthenium (Ru), Cu, cadmium (Cd), silver (Ag), yttrium (Y), scandium (Sc), gallium (Ga), indium (In), arsenic (As), Sb, platinum (Pt), gold (Au), and Si, A is at least one element selected from the group consisting of F, chlorine (Cl), bromine (Br), iodine (I), astatine (At), and S, 0≤a≤0.2, 0<b≤0.5, and 0≤c≤0.1, and
Li 1+x [Ni y Co z Mn w M 2 v ]O 2-p B p   [Formula 2]

wherein, in Formula 2, M 2 is at least one element selected from the group consisting of W, Cu, Fe, V, Cr, Ti, Zr, Zn, Al, In, tantalum (Ta), Y, lanthanum (La), Sr, Ga, Sc, gadolinium (Gd), samarium (Sm), Ca, cerium (Ce), Nb, Mg, B, and Mo, B is at least one element selected from the group consisting of F, Cl, Br, I, At, and S, 0≤x≤0.3, 0.50≤y<1, 0<z<0.35, 0<w<0.35, 0≤v≤0.1, and 0≤p≤0.1.

2 . The positive electrode material of claim 1 , wherein the positive electrode material has a bimodal particle diameter distribution in which second positive electrode active material particles having an average particle diameter (D 50 ) of 4 μm to 20 μm, and first positive electrode active material particles having an average particle diameter (D 50 ) corresponding to 10% to 75% of the average particle diameter (D 50 ) of the second positive electrode active material particles are included.

3 . The positive electrode material of claim 1 , wherein the positive electrode material has a bimodal particle diameter distribution in which the first positive electrode active material has an average particle diameter (D 50 ) of 1 μm to 15 μm, and the second positive electrode active material has an average particle diameter (D 50 ) of 8 μm to 20 μm.

4 . The positive electrode material of claim 1 , wherein the coating layer has a thickness of 1 nm to 1,000 nm.

5 . The positive electrode material of claim 1 , wherein the lithium manganese-based first positive electrode active material has a specific surface area of 0.1 m 2 /g to 1.5 m 2 /g.

6 . The positive electrode material of claim 1 , wherein the lithium manganese-based first positive electrode active material is in a form of a primary particle or a secondary particle formed by agglomeration of a plurality of primary particles.

7 . The positive electrode material of claim 6 , wherein the secondary particle is formed by agglomeration of at least 2 and up to 50 primary particles.

8 . The positive electrode material of claim 1 , wherein the lithium manganese-based first positive electrode active material comprises a lithium boron composite oxide and a lithium tungsten composite oxide.

9 . The positive electrode material of claim 1 , wherein the first positive electrode active material and the second positive electrode active material are included in a weight ratio of 10:90 to 90:10.

10 . The positive electrode material of claim 1 , wherein the positive electrode material has a rolling density of 2.5 g/cc to 3.4 g/cc when rolled with a force of 2,000 kgf/cm 2 .

11 . A positive electrode comprising a positive electrode collector, and a positive electrode active material layer formed on the positive electrode collector,
wherein the positive electrode active material layer comprises the positive electrode material having a bimodal particle diameter distribution of claim 1 .

12 . A lithium secondary battery comprising the positive electrode of claim 11 .

13 . The positive electrode material of claim 4 , wherein the coating layer is in the form of a film and has a thickness of 1 nm to 100 nm.

14 . The positive electrode material of claim 4 , wherein the coating layer is in the form of oxide particles and has a thickness of 10 nm to 1,000 nm.

15 . The positive electrode material of claim 1 , wherein the doping element M 1 is present in an amount of 500 ppm to 40,000 ppm.

16 . A method of forming the positive electrode material of claim 1 , comprising the steps of:
preparing the first positive electrode active material; preparing the second positive electrode active material; and mixing the first positive electrode active material and the second positive electrode active material together.

17 . The method of claim 16 , wherein the step of preparing the first positive electrode active material comprises:
forming a M 1 -doped lithium manganese oxide represented by Formula 1; mixing the lithium manganese oxide represented by Formula 1 with a coating raw material; and performing a heat treatment to form a coating layer.

18 . The method of claim 17 , wherein the mixing step further comprises mixing the first positive electrode active material and the second positive electrode active material together in a weight ratio of 10:90 to 90:10.

Assignees

• Lg Chemical Ltd

Inventors

• Baek So Ra
• Jung Wang Mo
• Kang Min Suk
• Lee Sang Wook
• Lho Eun Sol
• Wang Wen Xiu

Classifications

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• H01M4/505

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

• H01M4/366 Primary

  as layered products · CPC title

• H01M4/131

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

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title