Positive Electrode Additive and Positive Electrode for Lithium Secondary Battery Containing Same

Patent metadata

Field	Value
Publication number	US-2023369602-A1
Application number	US-202218025980-A
Country	US
Kind code	A1
Filing date	May 6, 2022
Priority date	May 25, 2021
Publication date	Nov 16, 2023
Grant date	—

Abstract

The present technology relates to a positive electrode additive for a lithium secondary battery and a positive electrode for a lithium secondary battery including the same, wherein the positive electrode additive contains a carbon material on a surface of a lithium cobalt oxide represented by Chemical Formula 1 to improve the low electrical conductivity of the positive electrode additive, and an effect of improving the problem caused by the amount of gases generated during initial charging and discharging (i.e., “activation”) is excellent, and thus a positive electrode and lithium secondary battery including the positive electrode additive have excellent electrical performance.

First claim

1 . A positive electrode additive containing:
a lithium cobalt oxide represented by Chemical Formula 1 below; and a carbon material adsorbed onto a surface of the lithium cobalt oxide:
Li p Co (1-q) M 1 q O 4   Chemical Formula 1

wherein in Chemical Formula 1 above, M 1 denotes one or more elements selected from the group consisting of W, Cu, Fe, V, Cr, Ti, Zr, Zn, Al, In, Ta, Y, La, Sr, Ga, Sc, Gd, Sm, Ca, Ce, Nb, Mg, B, and Mo, and p and q are 5≤p≤7 and 0≤q≤0.5, respectively.

2 . The positive electrode additive of claim 1 , wherein the carbon material includes one or more of carbon nanotubes, carbon nanofibers, graphite, graphene, carbon black, Ketjen black, or acetylene black.

3 . The positive electrode additive of claim 1 , wherein the carbon material has a surface that is modified with one or more functional groups selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group, an amide group, a sulfone group, and a sulfide group.

4 . The positive electrode additive of claim 1 , wherein the carbon material has a surface that contains one or more of monoethanolamine, diethanolamine, triethanolamine, diethylenetriamine, triethylenetetraamine, trisaminoC1-3alkylamine, polyC1-3alkyleneamine, or polyC1-3alkyleneimine.

5 . The positive electrode additive of claim 1 , wherein the carbon material is adsorbed onto 70% or more of an entire surface of the lithium cobalt oxide.

6 . The positive electrode additive of claim 1 , wherein a content of the carbon material ranges from 0.1 to 20 parts by weight with respect to 100 parts by weight of the lithium cobalt oxide.

7 . The positive electrode additive of claim 1 , wherein an average thickness of the adsorbed carbon material ranges from 10 nm to 200 nm.

8 . The positive electrode additive of claim 1 , wherein an average particle size of the lithium cobalt oxide ranges from 0.1 to 10 μm.

9 . The positive electrode additive of claim 1 , wherein the lithium cobalt oxide has a tetragonal structure with a space group of P4 2 /nmc.

10 . A positive electrode for a lithium secondary battery, the positive electrode comprising:
a positive electrode current collector; and a positive electrode mixture layer positioned on the positive electrode current collector and containing a positive electrode active material, the positive electrode additive according to claim 1 , and a binder.

11 . The positive electrode of claim 10 , wherein the positive electrode active material is a lithium metal composite oxide represented by Chemical Formula 2 below:
Li x [Ni y Co z Mn w M 2 v ]O u   [Chemical Formula 2]
wherein in Chemical Formula 2 above, M 2 denotes one or more elements selected from the group consisting of W, Cu, Fe, V, Cr, Ti, Zr, Zn, Al, In, Ta, Y, La, Sr, Ga, Sc, Gd, Sm, Ca, Ce, Nb, Mg, B, and Mo, and x, y, z, w, v, and u are 1.0≤x≤1.30, 0≤y<0.95, 0<z≤0.5, 0<w≤0.5, 0≤v≤0.2, and 1.5≤u≤4.5, respectively.

12 . The positive electrode of claim 10 , wherein the positive electrode active material is included in an amount of 80 to 99.5 parts by weight with respect to 100 parts by weight of the positive electrode mixture layer.

13 . The positive electrode of claim 10 , wherein the positive electrode additive is included in an amount of 0.1 to 5 parts by weight with respect to 100 parts by weight of the positive electrode mixture layer.

14 . The positive electrode of claim 10 , wherein the positive electrode further includes a conductive material,
wherein the conductive material is included in an amount of 2 parts by weight or less with respect to 100 parts by weight of the positive electrode mixture layer.

Assignees

• Lg Energy Solution Ltd

Inventors

• Kim Ji Hye
• Oh Sang Seung
• Kim Hye Hyeon
• Jo Chi Ho
• Yoo Tae Gu

Classifications

• H01M4/628 Primary

  Inhibitors, e.g. gassing inhibitors, corrosion inhibitors · CPC title

• H01M10/0525

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

• H01M4/505

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

• H01M4/131 Primary

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