Electrolysis transistor

• US 20080296173A1
• Filed: 05/29/2008
• Published: 12/04/2008
• Est. Priority Date: 05/29/2007
• Status: Active Grant

• Current Assignee: Transphorm, Inc (Kohlberg Kravis Roberts & Company LP)
• Original Assignee: Transphorm, Inc (Kohlberg Kravis Roberts & Company LP)
• Inventors: Parikh, Primit, Mishra, Umesh, Shen, Likun, McCarthy, Lee, Lai, Rakesh
• Granted Patent: US 9,096,939 B2
• Time in Patent Office: Days
• US Class Current: 205/742
• CPC Class Codes: C25B 1/02 Hydrogen or oxygen
• CPC Class Codes: C25B 1/04 by electrolysis of water
• CPC Class Codes: C25B 1/55 Photoelectrolysis
• CPC Class Codes: C25B 11/00 Electrodes; Manufacture thereof not otherwise provided for
• CPC Class Codes: C25B 11/075 consisting of a single catalytic element or catalytic compound
• CPC Class Codes: C25B 15/00 Operating or servicing cells
• CPC Class Codes: C25B 9/65 Means for supplying current; Electrode connections; Electric inter-cell connections
• CPC Class Codes: Y02E 60/36 Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
• CPC Class Codes: Y02P 20/133 Renewable energy sources, e.g. sunlight

Abstract

An electrolysis transistor for providing high-density electrochemistry and products utilizing the same, and high-efficiency electrolysis and electrochemical processes is disclosed. The electrolysis transistor may comprise an electrolyte, one or more working electrodes for transferring charge to or from said electrolyte, and one or more gate structures for altering electrode over-voltage and modifying the barrier at the electrode-electrolyte interface, reducing the voltage necessary for electrolysis. An electrochemical or photo-electrochemical cell may incorporate one or more of these electrolysis transistors.

Claims

1. An electrolysis transistor, comprising:

an electrolyte;

one or more working electrodes for transferring charge to or from said electrolyte; and

one or more gate structures for altering electrode over-voltage and modifying the barrier at the electrode-electrolyte interface, reducing the voltage necessary for electrolysis.

2. The transistor of claim 1, wherein said one or more gate structures is appropriately spaced from said one or more working electrodes so a relative bias is formed between them, altering electric charge, field, and potential between said one or more working electrodes and said electrolyte and modifying the potential of said one or more working electrodes.

3. The transistor of claim 1, wherein said one or more working electrodes comprises a cathode and/or an anode.

4. The transistor of claim 1, wherein said one or more gate structures and said one or more working electrodes are on a substrate.

5. The transistor of claim 4, wherein said substrate is a conductor, a semiconductor, an insulator, or composites thereof.

6. The transistor of claim 1, wherein a gate potential is applied relative to said working electrode(s) to modify the electric field and potential along one or more surfaces of said one or more working electrodes and to increase charge transfer between said working electrode(s) and said electrolyte, facilitating electrochemical, electrolytic, or electrosynthetic reactions in said electrolyte.

7. The transistor of claim 1, wherein said one or more gate structures is coated with an insulating material to prevent current from flowing through said gate structure(s), allowing the barrier to electrolysis to be lowered at a surface of said one or more working electrodes.

8. The transistor of claim 1, wherein said one or more working electrodes comprises a roughened surface to further enhance field modification at said working electrode(s).

9. The transistor of claim 1, wherein said one or more gate structures is proximal to at least one said working electrode and is less than 100 nm.

10. The transistor of claim 9, wherein said proximal gate structure directly lowers the barrier to electrolysis at a surface of said one or more working electrodes under said gate.

11. The transistor of claim 1, wherein said one or more gate structures is overhanging, cantilevered, or suspended over said working electrode.

12. The transistor of claim 11, wherein a surface of a working electrode beneath said suspended gate structure is etched to create a patterned surface beneath said gate, said patterned surface increasing the working surface contributing to electrolysis.

13. The transistor of claim 1, wherein at least one of said one or more gate structures is remote from said one or more working electrodes to reduce the barrier to electrolysis.

14. The transistor of claim 13, wherein at least another one of said one or more gate structures is proximate to said one or more working electrodes.

15. The transistor of claim 1, wherein said electrolysis occurs at a current density >

1A/cm2, efficiency of >

40% in a neutral electrolyte system, and at room temperature and pressure.

16. The transistor of claim 1, wherein the peak current density is >

5 A/cm2

17. The transistor of claim 1, wherein said working electrodes comprise a stacked, proximal anode and cathode, and said one or more gate structures are located remotely from said anode and cathode.

18. The transistor of claim 17, wherein commingled hydrogen and oxygen are generated.

19. The transistor of claim 1, wherein said working electrodes comprise a proximal anode and cathode formed as a planar, interdigitated electrode pair.

20. The transistor of claim 19, wherein either the anode or cathode act as a counter electrode, thus increasing efficiency due to pH change at said counter electrode.

21. The transistor of claim 1, wherein said working electrodes comprise an anode and cathode that are separated in space.

22. The transistor of claim 21, wherein said spacing is less than 100 μ

m.

23. The transistor of claim 21, wherein separated hydrogen and oxygen are generated.

24. The transistor of claim 1, further comprising an electrochemical or photo-electrochemical cell generating hydrogen and/or oxygen.

25. A method for increasing the output of electrolysis transistors, comprising:

providing an electrolyte, one or more working electrodes, and one or more gate structures;

altering electrochemical, electrolytic, or electrosynthetic reactions and altering over-voltages by modifying an electric field and potential in a region between said electrolyte and said electrodes and/or gate structures to create conditions facilitating the transfer of electrons between said electrolyte and said electrodes.

26. The method of claim 25, wherein the electric charge, field, and potential are modified by using at least one gate structure and at least one working electrode wherein a bias is applied between them.

27. An electrochemical cell, comprising:

an electrolyte; and

one or more gated electrodes for altering electrode over-voltage and modifying the barrier at the electrode-electrolyte interface, reducing the voltage necessary for electrolysis.

28. The cell of claim 27, wherein said gated electrodes reduce over-voltage at both an anode and cathode of said cell, wherein an electrolytic reaction occurs at one of the gated electrodes and an electrosynthetic reaction occurs at another of the gated electrodes.