Positive electrode for lithium air batteries, method of manufacturing the positive electrode, and lithium air battery including the positive electrode

Patent metadata

Field	Value
Publication number	US-11069900-B2
Application number	US-201916433519-A
Country	US
Kind code	B2
Filing date	Jun 6, 2019
Priority date	Nov 2, 2018
Publication date	Jul 20, 2021
Grant date	Jul 20, 2021

Abstract

The present disclosure relates to a positive electrode for lithium air batteries, a method of manufacturing the positive electrode, and a lithium air battery including the positive electrode, and more particularly to a positive electrode for lithium air batteries, wherein the positive electrode is manufactured through a dry process instead of a conventional wet process and a mixture of a positive electrode active material and a binder is ball-milled under specific conditions, thereby reducing or preventing a swelling phenomenon due to a solvent and increasing the force of coupling between the positive electrode active material and the binder, whereby it is possible to manufacture a high-density electrode and to improve the durability of the electrode, and wherein the lifespan of a lithium air battery is increased when the positive electrode is applied to the battery.

First claim

What is claimed is:

1. A method of manufacturing a positive electrode for lithium air batteries, the method comprising:
ball-milling a mixture of 70 to 99 wt % of a positive electrode active material and 1 to 30 wt % of a binder to manufacture an electrode mixture; and
applying the electrode mixture to release paper and rolling the electrode mixture to manufacture the positive electrode,
wherein a mixing ratio of the electrode mixture to a ball put into a reaction vessel is 1:150 to 1:350 in a weight ratio.

2. The method according to claim 1 , wherein, at the step of manufacturing the electrode mixture, ball-milling is performed using a planetary mill.

3. The method according to claim 1 , wherein, at the step of manufacturing the electrode mixture, ball-milling is performed in a state in which the electrode mixture and the ball are put in the reaction vessel.

4. The method according to claim 1 , wherein the ball comprises a first ball and a second ball, and a diametric ratio of the first ball to the second ball is 1 to 5:1.

5. The method according to claim 4 , wherein a weight ratio of the first ball to the second ball is 1:1 to 3.5.

6. The method according to claim 1 , wherein the ball is made of one selected from among zirconia, tool steel, stainless steel, and cemented carbide.

7. The method according to claim 1 , wherein the step of manufacturing the electrode mixture is performed for 5 to 8 cycles under conditions of a rotation speed of 50 to 200 rpm and a time of 5 to 15 minutes.

8. The method according to claim 1 , wherein the positive electrode active material is at least one selected from a group consisting of carbon black, carbon nanotubes (CNT), graphene, and reduced graphene oxide (rGO).

9. The method according to claim 1 , wherein the binder is polytetrafluoroethylene (PTFE).

10. The method according to claim 1 , wherein a density of the positive electrode is 100 to 500 mg/cc.

11. The method according to claim 1 , wherein the positive electrode has a porous structure having a pore size of 10 nm to 100 μm.

12. The method according to claim 1 , wherein the positive electrode has a thickness of 10 to 200 μm.

13. The method according to claim 1 , further comprising heat-treating the rolled and manufactured positive electrode after the step of manufacturing the positive electrode.

14. The method according to claim 13 , wherein, at the step of heat-treating the positive electrode, heat-treating is performed at a temperature of 150 to 300° C. for 10 minutes to 2 hours.

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Jin Dae Gun
• Kwon Eun Ji
• Hwang Jee Youn
• Jang Ji Hoon
• Oh Gwang Seok
• Kim Won Keun
• Seo Samuel

Classifications

• H01M12/08

  composed of a half-cell of a fuel-cell type and a half-cell of the secondary-cell type · CPC title

• H01M4/96 Primary

  Carbon-based electrodes · CPC title

• H01M4/8896 Primary

  Pressing, rolling, calendering (membrane electrode assemblies H01M8/1004) · CPC title

• H01M4/8882

  Heat treatment, e.g. drying, baking · CPC title

• H01M4/8828

  Coating with slurry or ink · CPC title