# US 11,908,636 B2 · Gas diffusion layer, method for making the same and photoelectrode

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- Number: US 11,908,636 B2
- Document ID: US11908636B2
- Status: Granted
- Kind: B2
- Application number: 18/080,166
- Filed: 2022-12-13
- Published: 2023-06-22
- Granted: 2024-02-20
- Earliest claimed: 2021-12-21
- Assignees: Toyota Jidosha Kabushiki Kaisha
- Applicants: Toyota Jidosha Kabushiki Kaisha
- Inventors: Hannah Johnson; Sachin Kinge; Marina Caretti; Jun-Ho Yum; Kevin Sivula; Elizaveta Mensi
- Web page: https://patentgrep.com/patent/US11908636B2

## CPC

- C25B 11/032: Gas diffusion electrodes
- H01G 9/20: Light-sensitive devices
- C25B 1/55: Photoelectrolysis
- C25B 11/057: consisting of a single element or compound
- H01G 9/0029: {Processes of manufacture}
- H01G 9/042: characterised by the material (H01G11/22 takes precedence)
- Y02E 60/50: Fuel cells
- C25B: ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR (anodic or cathodic protection C23F13/00; single-crystal growth C30B)
- H01G: CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE (selection of specified materials as dielectric H01B3/00; capacitors having potential barriers H10D1/62, H10K10/10)
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

Method for making a gas diffusion layer for an electrode, the method including processing quartz wool with water in a blender to form a suspension, filtering the suspension to remove water and contaminants, to form a cake of entangled quartz fibres, annealing the cake of entangled quartz fibres without complete melting of the fibres to obtain a porous quartz felt having pore size greater than 1 μm and coating the porous quartz felt with a conductive material. Gas diffusion layer for an electrode and photoelectrode including the gas diffusion layer.

## Claims

### Claim 1

A method for making a gas diffusion layer for an electrode, the method comprising:
processing quartz wool with water in a blender to form a suspension;
filtering the suspension to remove the water, to form a cake of entangled quartz fibers;
annealing the cake of the entangled quartz fibers without complete melting of the entangled quartz fibers to obtain a porous quartz felt having a pore size greater than 1 μm, the annealing being at 1250° C. to 1350° C. with an annealing plateau time of 5 minutes to 3 hours; and
coating the porous quartz felt with a conductive material.

### Claim 2 (depends on 1)

The method according to claim 1, wherein the porous quartz felt has a transmittance equal to or greater than 30%, at wavelength between 400 and 800 nm, and the conductive material is a transparent conductive material.

### Claim 3 (depends on 1)

The method according to claim 1, wherein the cake of entangled quartz fibers is pressed before annealing.

### Claim 4 (depends on 1)

The method according to claim 1, wherein the porous quartz felt has a reflectance equal to or greater than 20%, at wavelength between 400 and 800 nm and for a resistivity equal to or less than 100 Ω/sq.

### Claim 5 (depends on 1)

The method according to claim 1, wherein the quartz wool has a fiber diameter equal to or greater than 1 μm and equal to or smaller than 15 μm.

### Claim 6 (depends on 1)

The method according to claim 1, wherein the entangled quartz fibers have an average length equal to or greater than 50 microns and equal to or smaller than 5 millimeters.

### Claim 7 (depends on 1)

The method according to claim 1, wherein a porosity of the porous quartz felt is equal to or greater than 10% and equal to or smaller than 90%.

### Claim 8

A gas diffusion layer for an electrode comprising partially melted entangled quartz fibers formed by annealing entangled quartz fibers at 1250° C. to 1350° C. with an annealing plateau time of 5 minutes to 3 hours, the partially melted entangled quartz fibers having a pore size greater than 1 μm, and a conductive material coated on the partially melted entangled quartz fibers.

### Claim 9 (depends on 8)

The gas diffusion layer according to claim 8, wherein the gas diffusion layer has a transmittance equal to or greater than 15% at wavelengths between 400 nm and 800 nm.

### Claim 10 (depends on 8)

The gas diffusion layer according to claim 8, wherein the gas diffusion layer has a sheet resistance equal to or smaller than 40 Ω/sq.

### Claim 11 (depends on 8)

The gas diffusion layer according to claim 8, wherein a porosity of the gas diffusion layer is equal to or greater than 10% and equal to or smaller than 90%.

### Claim 12 (depends on 8)

The gas diffusion layer according to claim 8, wherein the conductive material is fluorine doped tin oxide.

### Claim 13 (depends on 8)

The gas diffusion layer according to claim 8, wherein the conductive material includes zinc oxide or silver nanowires.

### Claim 14 (depends on 8)

A photoelectrode comprising the gas diffusion layer according to claim 8.