Method of forming electrochemical gas sensor

• US 10,908,115 B2
• Filed: 09/28/2018
• Issued: 02/02/2021
• Est. Priority Date: 05/28/2014
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Liu, Ling, Zhang, Yan, Zheng, Qian
• Primary Examiner(s): Talbot, Brian K
• Application Number:
  US16/146,476
• Publication Number:
  US 20190094171A1
• Time in Patent Office: 858 Days
• Field of Search: 427 58, 427115
• CPC Class Codes: B05D 1/26 performed by applying the liquid or other fluent material from an outlet device in contact with, or almost in contact with, the surface
• CPC Class Codes: B05D 1/28 performed by transfer from the surfaces of elements carrying the liquid or other fluent material, e.g. brushes, pads, rollers
• CPC Class Codes: B05D 3/02 by baking B05D3/04 takes precedence
• CPC Class Codes: B05D 5/12 to obtain a coating with specific electrical properties
• CPC Class Codes: C23C 30/00 Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process C23C26/00, C23C28/00 take precedence
• CPC Class Codes: G01N 27/403 Cells and electrode assemblies
• CPC Class Codes: G01N 27/404 Cells with anode, cathode and cell electrolyte on the same side of a permeable membrane which separates them from the sample fluid , e.g. Clark-type oxygen sensors
• CPC Class Codes: G01N 27/4045 for gases other than oxygen
• CPC Class Codes: H01M 4/8668 Binders
• CPC Class Codes: H01M 4/8807 Gas diffusion layers
• CPC Class Codes: H01M 4/8828 Coating with slurry or ink
• CPC Class Codes: H01M 4/8832 Ink jet printing
• CPC Class Codes: H01M 4/8882 Heat treatment, e.g. drying, baking
• CPC Class Codes: H01M 4/90 Selection of catalytic material
• CPC Class Codes: H05K 3/12 using thick film techniques, e.g. printing techniques to apply the conductive material or similar techniques for applying conductive paste or ink patterns
• CPC Class Codes: H05K 3/125 by ink-jet printing
• CPC Class Codes: H05K 3/227 Drying of printed circuits
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A gas detector includes an electrochemical gas sensor. The sensor includes a plurality of electrodes. At least one of the electrodes is formed of a catalyst/binder slurry which is halftone printed onto a substrate. The composite printed element and substrate are sintered to form the electrode.

Claims

1. A method comprising:

heating a slurry comprising at least a catalyst and a binder;

halftone printing the heated slurry in a predetermined shape onto a substrate, the substrate having a porosity;

sintering the printed shape and substrate; and

incorporating the sintered shape and the substrate as an electrode into an electrochemical gas sensor,

wherein a composition of the slurry comprises 75% weight Platinum black, 10% weight graphite and 15% weight perfluorinated ion electrolyte solution.

2. The method of claim 1, wherein a response time for the electrochemical gas sensor comprising the composition is less than 30 seconds for 20.9% oxygen in air.

3. The method of claim 1, wherein the catalyst comprises at least one of:

platinum, platinum black, a mixture of graphite and platinum, a mixture of carbon and platinum black, a noble metal, or mixtures thereof.

4. The method of claim 1, wherein the binder comprises at least one of a perfluorinated ion electrolyte solution or a copolymer of tetrafluoroethylene and a sulfonic acid.

5. The method of claim 1, wherein a response time for the electrochemical gas sensor comprising said electrode is between 24 seconds and 47 seconds for 20.9% oxygen in air.

6. The method of claim 1, wherein a ratio of the catalyst to the binder is between 4:

1 and 7.5;

1.

7. The method of claim 1, wherein the catalyst comprises 80% by weight of Platinum black and 20% by weight of graphite.

8. The method of claim 1, wherein said substrate comprises polytetrafluoroethylene.

9. The method of claim 1, wherein said electrode is a sensing electrode.