# US 11,114,673 B2 · Cathode for lithium air battery comprising hollow structure and method of manufacturing same

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- Number: US 11,114,673 B2
- Document ID: US11114673B2
- Status: Granted
- Kind: B2
- Application number: 16/704,273
- Filed: 2019-12-05
- Published: 2020-11-26
- Granted: 2021-09-07
- Earliest claimed: 2019-05-23
- Assignees: Hyundai Motor Company; Kia Motors Corporation; Industry-Academic Cooperation Foundation, Yonsei University
- Applicants: Hyundai Motor Company; Kia Motors Corporation; Industry-Academic Cooperation Foundation, Yonsei University
- Inventors: Gwang Seok Oh; Katie Heeyum Lim; Heejun Kweon; Hansung Kim
- Web page: https://patentgrep.com/patent/US11114673B2

## CPC

- H01M 4/96: Carbon-based electrodes
- H01M 4/8605: {Porous electrodes}
- H01M 4/8875: {Methods for shaping the electrode into free-standing bodies, like sheets, films or grids, e.g. moulding, hot-pressing, casting without support, extrusion without support}
- H01M 4/8882: {Heat treatment, e.g. drying, baking}
- H01M 12/08: composed of a half-cell of a fuel-cell type and a half-cell of the secondary-cell type
- H01M 4/382: {Lithium (H01M4/405 takes precedence)}
- H01M 2004/8689: {Positive electrodes}
- Y02E 60/10: Energy storage using batteries
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

The present disclosure relates to a cathode for a lithium air battery and a method of manufacturing the same, and more particularly to a method of manufacturing a cathode for a lithium air battery, in which a hollow structure including a carbon material having a nitrogen functional group is synthesized through electrospinning of a thermally decomposable polymer, coating with a nitrogen-containing polymer and heat treatment, and is utilized without a binder as a cathode carbon material for a lithium air battery, thereby increasing the performance and lifespan of a lithium air battery.

## Claims

### Claim 1

A method of manufacturing a cathode for a lithium air battery, comprising:
preparing a fibrous polymer by electrospinning a spinning solution including a thermally decomposable polymer;
manufacturing a fibrous structure comprising a core including the fibrous polymer and a sheath including a nitrogen-containing polymer by coating a surface of the fibrous polymer with the nitrogen-containing polymer;
manufacturing a film comprising a plurality of the fibrous structures, wherein the fibrous structures are randomly entangled; and
obtaining a sheet by heat-treating the film.

### Claim 2 (depends on 1)

The method of claim 1, wherein the thermally decomposable polymer comprises one selected from the group consisting of polystyrene (PS), poly(methyl methacrylate) (PMMA) and combinations thereof.

### Claim 3 (depends on 1)

The method of claim 1, wherein the nitrogen-containing polymer comprises at least one selected from the group consisting of polydopamine (PDA), polyacrylonitrile (PAN), polypyrrole (PPy), polyaniline (PANI) and combinations thereof.

### Claim 4 (depends on 1)

The method of claim 1, wherein the manufacturing the fibrous structure further comprising:
adding the fibrous polymer to a polymer solution including one selected from the group consisting of a nitrogen-containing monomer, the nitrogen-containing polymer and combinations thereof; and
performing stirring.

### Claim 5 (depends on 1)

The method of claim 1, wherein a thickness of the nitrogen-containing polymer on the surface of the fibrous polymer is from about 10 nm to about 100 nm.

### Claim 6 (depends on 5)

The method of claim 5, wherein the coating of the surface of the fibrous polymer with the nitrogen-containing polymer is performed from about 1 to about 10 times.

### Claim 7 (depends on 1)

The method of claim 1, further comprising subjecting the fibrous structure to ultrasonication before manufacturing the film.

### Claim 8 (depends on 1)

The method of claim 1, wherein the sheet is obtained by thermally decomposing the core of the fibrous structure and carbonizing the sheath of the fibrous structure through the heat-treating of the film to yield a sheet comprising a plurality of hollow structures that are randomly entangled and each of the hollow structures including a carbon material having a nitrogen functional group.

### Claim 9 (depends on 1)

The method of claim 1, wherein the sheet is obtained by heat-treating the film at a temperature ranging from a thermal decomposition temperature of the core to a carbonizing temperature of the sheath.

### Claim 10 (depends on 1)

The method of claim 1, wherein the heat-treating is conducted at a temperature of about 600° C. to about 900° C. for about 1 hr to about 3 hr.

### Claim 11 (depends on 8)

The method of claim 8, wherein the nitrogen functional group includes graphic nitrogen (graphitic-N).

### Claim 12 (depends on 8)

The method of claim 8, wherein a length of one or more of the hollow structures is about 0.5 μm to about 300 μm.

### Claim 13 (depends on 8)

The method of claim 8, wherein a diameter of one or more of the hollow structures is about 2 μm to about 10 μm.