Cathode material for lithium-air battery and method of manufacturing cathode using same

Patent metadata

Field	Value
Publication number	US-11757151-B2
Application number	US-202016950426-A
Country	US
Kind code	B2
Filing date	Nov 17, 2020
Priority date	Jun 17, 2020
Publication date	Sep 12, 2023
Grant date	Sep 12, 2023

Abstract

The present invention relates to a cathode material for a lithium-air battery and a method of manufacturing a cathode using the same. The cathode material of the present invention includes a solvent component and thus includes an electrolyte in a small amount compared to a conventional cathode material, thereby reducing the weight of a cathode manufactured using the cathode material, ultimately increasing the energy density of a lithium-air battery including the cathode.

First claim

What is claimed is:

1. A cathode, comprising:
a current collector; and
a cathode slurry layer formed on the current collector and comprising a cathode material,
wherein the cathode material comprises a carbon material, an electrolyte, a solvent component and a binder,
wherein the electrolyte comprises a lithium salt and an ionic liquid,
a mass ratio of the carbon material and the electrolyte is 1:2-20,
an amount of the solvent component is 50 to 250 mL per g of the carbon material, and
wherein the cathode slurry layer has a thickness of 700 to 1000 μm.

2. The cathode of claim 1 , wherein the carbon material comprises one or more selected from the group consisting of carbon nanotubes (CNTs), carbon nanofibers, carbon nanobelts and mixtures thereof.

3. The cathode of claim 1 , wherein the ionic liquid comprises one or more selected from the group consisting of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMI-TFSI), diethylmethylammonium trifluoromethanesulfonate ([dema][TfO]), dimethylpropylammonium trifluoromethanesulfonate ([dmpa][TfO]), diethylmethylammonium trifluoromethanesulfonylimide ([dema][TFSI]), methylpropylpiperidinium trifluoromethanesulfonylimide ([mpp][TFSI]) and mixtures thereof.

4. The cathode of claim 1 , wherein the solvent component comprises N-methyl-2-pyrrolidone (NMP).

5. The cathode of claim 1 , wherein the binder comprises poly(diallyldimethylammonium) bis (trifluoromethanesulfonyl)imide (PDDA-TFSI).

6. The cathode of claim 1 , wherein an amount of the binder is 15 to 25 parts by weight based on 100 parts by weight of the carbon material.

7. A method of manufacturing a cathode, comprising:
preparing a cathode slurry comprising a cathode;
forming a cathode slurry layer by applying the cathode slurry on a current collector; and
heat-treating the cathode slurry layer,
wherein the cathode comprises a carbon material, an electrolyte, a solvent component and a binder,
wherein the electrolyte comprises a lithium salt and an ionic liquid, and
a mass ratio of the carbon material and the electrolyte is 1:2-20,
wherein an amount of the solvent component is 50 to 250 mL per g of the carbon material, and
wherein the cathode slurry layer has a thickness of 700 to 1000 μm.

8. The method of claim 7 , wherein the heat-treating is performed in a vacuum at room temperature for 22 to 48 hr.

9. A lithium-air battery, comprising:
the cathode of claim 1 ;
an anode enabling deposition and dissociation of lithium; and
a polymer electrolyte interposed between the cathode and the anode,

wherein the lithium-air battery has a charge/discharge voltage of 2 to 4.7 V and a charge/discharge capacity of 12 to 25 mAh/cm 2 .

10. The cathode of claim 1 , wherein the cathode comprises a carbon material loaded in an amount of 3.00 to 6.00 mg/cm 2 .

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp
• Seoul Nat Univ R&Db Foundation

Inventors

• Son Sam Ick
• Bae Young Joon
• Park Hyeok Jun
• Kang Ki Suk
• Ko Young Min
• Park Sung Kwan

Classifications

• H01M4/8828 Primary

  Coating with slurry or ink · CPC title

• H01M4/96 Primary

  Carbon-based electrodes · CPC title

• H01M12/08 Primary

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

• H01M4/8668

  Binders · CPC title

• H01M4/8663

  Selection of inactive substances as ingredients for catalytic active masses, e.g. binders, fillers · CPC title