Disposable working electrode for an electrochemical cell

• US 20030111340A1
• Filed: 02/20/2002
• Published: 06/19/2003
• Est. Priority Date: 12/18/2001
• Status: Active Grant

• Current Assignee: Dionex Corporation (Thermo Fisher Scientific Incorporated)
• Original Assignee: Dionex Corporation (Thermo Fisher Scientific Incorporated)
• Inventors: Cheng, Jun, Avdalovic, Nebojsa, Jandik, Petr
• Granted Patent: US 6,783,645 B2
• Time in Patent Office: Days
• US Class Current: 204/275.1
• CPC Class Codes: G01N 27/307 Disposable laminated or multilayered electrodes G01N27/3272 takes precedence
• CPC Class Codes: H01M 4/86 Inert electrodes with catalytic activity, e.g. for fuel cells
• CPC Class Codes: H01M 4/8867 Vapour deposition
• CPC Class Codes: H01M 4/9058 of noble metals or noble-metal based alloys
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

A flow-through electrochemical cell assembly with a disposable working electrode structure, including (a) a perimeter wall defining a sample flow channel including an inlet and an outlet, (b) a sample inlet line in fluid communication with the sample flow channel inlet, (c) a sample outlet line providing fluid communication between the sample flow channel outlet and a remote reference electrode, and (d) a disposable working electrode structure comprising an electrically conductive and electrochemically active working electrode region bound as a layer, directly or indirectly, to an electrically insulating substrate surface. The substrate surface is in fluid-sealing relationship with the sample flow channel, and the working electrode region is in fluid communication with said sample flow channel. The working electrode is vapor deposited, directly or indirectly, onto the organic polymer substrate through a mask, and a fluid seal is formed between said working electrode region and perimeter wall.

Claims

1. A flow-through electrochemical cell assembly comprising

(a) a perimeter wall defining a sample flow channel including an inlet and an outlet,

(b) a sample inlet line in fluid communication with said sample flow channel inlet,

(c) a sample outlet line providing fluid communication between said sample flow channel outlet and a remote reference electrode, and

(d) a disposable working electrode structure comprising an electrically conductive and electrochemically active working electrode region bound as a layer, directly or indirectly, to an electrically insulating substrate surface, said substrate surface being in fluid-sealing relationship with said sample flow channel, said working electrode region being in fluid communication with said sample flow channel, said working electrode structure being readily removable from said electrochemical cell assembly.

2. The flow-through electrochemical cell assembly of claim 1 in which said working electrode structure further comprises an electrically conductive contact region bound as a layer, directly or indirectly, to said substrate surface and an electrically conductive lead providing an electric path between said working electrode region and said contact region, said contact region being bound to said substrate surface out of fluid contact with said sample flow channel.

3. The flow-through electrochemical cell assembly of claim 1 further comprising an electrically conductive connection pin having a first end in removable contact with said contact region and a second end adapted for electrical connection to a power source.

4. The flow-through electrochemical cell assembly of claim 1 in which said perimeter wall comprises a gasket forming a fluid-tight seal at the periphery of said sample flow channel.

5. The flow-through electrochemical cell assembly of claim 1 in which said working electrode region is exposed directly to said sample flow channel, without an intermediate layer.

6. The flow-through electrochemical cell assembly of claims 1 or 2 in which said working electrode region is between about 100 Å

and 10,000 Å

thick.

7. The flow-through electrochemical cell assembly of claim 1 in which said working electrode region is formed by vapor deposition of electrically conductive and electrochemically active material, directly or indirectly, onto said substrate

8. The flow-through electrochemical cell assembly of claim 1 in which said substrate comprises an organic polymer.

9. The flow-through electrochemical cell assembly of claim 8 in which said organic polymer is selected from the group consisting of polyester, polycarbonate, polyolefin, polyimide and polyetherimide.

10. The flow-through electrochemical cell assembly of claim 1 in which said working electrode region comprises a metal or a carbonaceous material.

11. The flow-through electrochemical cell assembly of claim 1 in which said working electrode region is bound through an intermediate adhesion layer to said substrate.

12. The flow-through electrochemical cell assembly of claim 11 in which said adhesion layer is formed by vapor deposition onto said substrate.

13. The flow-through electrochemical cell assembly of claim 11 in which said adhesion layer is between about 50 Å

and 5000 Å

thick.

14. The flow-through electrochemical cell assembly of claim 11 in which said adhesion layer is formed of a material selected from the group consisting of titanium, tungsten, chromium, and alloys thereof.

15. The flow-through electrochemical cell of claim 1 in which said sample flow inlet is in fluid communication with a liquid chromatographic separator or flow injection analysis apparatus.

16. A method for making a disposable working electrode structure and sample flow channel for use in an electrochemical cell assembly, said method comprising:

(a) vapor depositing electrically conductive and electrochemically active material, directly or indirectly, onto an organic polymer substrate through a mask to form a pattern of a working electrode region, and

(b) forming a fluid seal between said working electrode region and a perimeter wall to define a fluid sample flow channel with said working electrode region in direct fluid contact with said fluid sample flow channel.

17. The method of claim 16 in which said vapor deposition is through said mask which mask forms a pattern of an electrically conductive lead interconnecting said working electrode and an electrically conductive contact region forming said disposable working electrode structure.

18. The method of claim 16 further comprising, before step (a), vapor depositing an adhesion layer onto said organic polymer substrate through a mask, wherein step (a) is performed by vapor depositing said electrically conductive material and electrochemically active onto said adhesion layer.

19. The method of claim 18 in which said adhesion layer is formed of a material selected from the group consisting of titanium, tungsten, chromium, and alloys thereof

20. The method of claim 16 in which said organic polymer is selected from the group consisting of polyester, polycarbonate, polyolefin, polyimide and polyetherimide.