Positive electrode and secondary battery including same

Patent metadata

Field	Value
Publication number	US-12531249-B2
Application number	US-202418594948-A
Country	US
Kind code	B2
Filing date	Mar 4, 2024
Priority date	Feb 7, 2018
Publication date	Jan 20, 2026
Grant date	Jan 20, 2026

Abstract

A positive electrode and a secondary battery including the same are provided. The positive electrode includes a current collector and a positive electrode active material layer disposed on the current collector, wherein the positive active material layer includes a positive electrode active material, a binder, and a multi-walled carbon nanotube, wherein the multi-walled carbon nanotube has an average length of 1-2 μm and has a length standard deviation of 0.5 μm or less.

First claim

The invention claimed is:

1 . A lithium ion battery comprising:
a first electrode, a second electrode, an electrolyte, and a separator interposed between the first electrode and the second electrode, wherein the first electrode comprises a current collector and a first electrode active material layer disposed on the current collector, wherein the first electrode active material layer comprises a lithium oxide containing at least one transition metal, multi-walled carbon nanotubes, and a binder, wherein the multi-walled carbon nanotubes have an average length of 1 μm to 2 μm and a length standard deviation at 0.5 μm or less, wherein no multi-walled carbon nanotube having a length exceeding 3 μm is included in the first electrode active material layer, wherein the first electrode active material layer contains the multi-walled carbon nanotubes in an amount from 0.1 wt. % to 1 wt. % with respect to a total weight of the first electrode active material layer.

2 . The lithium ion battery of claim 1 , wherein substantially all of the multi-walled carbon nanotubes in the first electrode active material layer have the length of 0.5 μm to 3 μm with an average length of 1 μm to 2 μm and a length standard deviation at 0.5 μm or less.

3 . The lithium ion battery of claim 1 , wherein the first electrode active material layer comprises a conductive material which consists essentially of the multi-walled carbon nanotubes having the length of 0.5 μm to 3 μm with an average length of 1 μm to 2 μm and a length standard deviation at 0.5 μm or less.

4 . The lithium ion battery of claim 1 , wherein the length of the multi-walled carbon nanotubes observable in the first electrode active material layer is between 0.5 μm and 3 μm.

5 . The lithium ion battery of claim 1 , wherein the length of the multi-walled carbon nanotubes observable in the first electrode active material layer is under 2.5 μm.

6 . The lithium ion battery of claim 1 , wherein the multi-walled carbon nanotubes observed in the first electrode active material layer have the length of 0.5 μm to 3 μm with an average length of 1 μm to 2 μm and a length standard deviation at 0.5 μm or less.

7 . The lithium ion battery of claim 1 , wherein the average length of the multi-walled carbon nanotubes observed in the first electrode active material layer is from 1 μm to 1.4 μm.

8 . The lithium ion battery of claim 1 , wherein the length standard deviation of the multi-walled carbon nanotubes observable in the first electrode active material layer is from 0.3 μm to 0.5 μm.

9 . The lithium ion battery of claim 1 , wherein the first electrode active material layer contains the multi-walled carbon nanotubes in an amount from 0.2 to 0.7 wt. % with respect to the total weight of the first electrode active material layer.

10 . The lithium ion battery of claim 1 , wherein the first electrode active material layer contains the lithium oxide containing at least one transition metal in an amount from 96 to 99 wt. % with respect to a total weight of the first electrode active material layer.

11 . The lithium ion battery of claim 1 , wherein the lithium oxide containing at least one transition metal comprising at least one selected from the group consisting of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium copper oxide, vanadium oxide, lithium nickel composite oxide, and lithium manganese composite oxide.

12 . A method of making the lithium ion battery of claim 1 , the method comprising:
providing a first electrode slurry comprising a lithium oxide containing at least one transition metal, multi-walled carbon nanotubes, a dispersant, a binder, and a solvent; applying the first electrode slurry onto a current collector; and subsequently drying the first electrode slurry on the current collector to evaporate the solvent and to provide on the current collector the first electrode active material layer of the lithium ion battery, wherein the multi-walled carbon nanotubes have an average length of 1 μm to 2 μm and a length standard deviation at 0.5 μm or less, wherein no multi-walled carbon nanotube having a length exceeding 3 μm is included in the first electrode active material layer, wherein the first electrode active material layer contains the multi-walled carbon nanotubes in an amount from 0.1 wt. % to 1 wt. % with respect to a total weight of the first electrode active material layer.

13 . The method of claim 12 , wherein substantially all of the multi-walled carbon nanotubes in the first electrode active material layer have the length of 0.5 μm to 3 μm with an average length of 1 μm to 2 μm and a length standard deviation at 0.5 μm or less.

14 . The method of claim 12 , wherein the first electrode active material layer comprises a conductive material which consists essentially of the multi-walled carbon nanotubes having the length of 0.5 μm to 3 μm with an average length of 1 μm to 2 μm and a length standard deviation at 0.5 μm or less.

15 . The method of claim 12 , wherein the length of the multi-walled carbon nanotubes observable in the first electrode active material layer is between 0.5 μm and 3 μm.

16 . The method of claim 12 , wherein the length of the multi-walled carbon nanotubes observable in the first electrode active material layer is under 2.5 μm.

17 . The method of claim 12 , wherein the multi-walled carbon nanotubes observed in the first electrode active material layer have the length of 0.5 μm to 3 μm with an average length of 1 μm to 2 μm and a length standard deviation at 0.5 μm or less.

18 . The method of claim 12 , wherein the average length of the multi-walled carbon nanotubes contained in the first electrode slurry is from 1 μm to 1.4 μm.

19 . The method of claim 12 , wherein the length standard deviation of the multi-walled carbon nanotubes contained in the first electrode slurry is from 0.3 μm to 0.5 μm.

20 . The method of claim 12 , wherein the first electrode slurry contains the multi-walled carbon nanotubes in an amount from 0.2 to 0.7 wt. % with respect to the total weight of the first electrode slurry excluding the solvent.

21 . The method of claim 12 , wherein providing the first electrode slurry comprises:
providing a mixture comprising bundle-type multi-walled carbon nanotubes and the dispersant; and processing the mixture to unbundle at least part of the bundle-type multi-walled carbon nanotubes to provide the multi-walled carbon nanotubes having a length between 0.5 μm and 3 μm with an average length from 1 μm to 2 μm and a length standard deviation at 0.5 μm or less.

22 . The method of claim 21 , wherein processing the mixture comprises providing the first electrode slurry comprises milling the mixture.

Assignees

• Lg Energy Solution Ltd

Inventors

• Yoo Jung Woo
• Kim Ye Lin
• Kim Tae Gon

Classifications

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M10/0525

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

• H01M4/623

  fluorinated polymers · CPC title

• H01M4/38

  of elements or alloys · CPC title

• H01M4/1393

  of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title