Electrochemically activated C-MEMS electrodes for on-chip micro-supercapacitors

Patent metadata

Field	Value
Publication number	US-9892869-B2
Application number	US-201213441268-A
Country	US
Kind code	B2
Filing date	Apr 6, 2012
Priority date	Apr 6, 2011
Publication date	Feb 13, 2018
Grant date	Feb 13, 2018

Abstract

Disclosed herein are methods of manufacturing micro-super capacitors from C-MEMS structures.

First claim

What is claimed is:

1. A method for forming an electrochemical double layer capacitor, comprising:
electrochemically activating a surface of a C-MEMS carbon structure in the presence of 0.1 M to 2 M acid in an aqueous solution by exposing the surface to an electrochemical cell to increase the surface area of the C-MEMS carbon structure by at least 100-fold and thereby increase the double layer capacitance of the C-MEMS carbon structure, wherein electrochemically activating the surface of the C-MEMS comprises:
anodizing the surface of the C-MEMS carbon structure by applying a positive voltage using the electrochemical cell; and
negatively polarizing the anodized C-MEMS carbon structure by applying a negative voltage using the electrochemical cell, and wherein
the C-MEMS carbon structure is a patterned and pyrolized negative tone photoresist polymer, and the pattern of the patterned and pyrolized negative tone photoresist polymer is created through a photolithography process.

2. The method of claim 1 , wherein the activating further comprises applying a voltage of from 1.5 to 4 V with respect to a Ag/AgCl reference electrode.

3. The method of claim 2 , wherein the positive voltage is applied for about 15 minutes to about 45 min.

4. The method of claim 1 , wherein the acid comprises sulfuric acid, nitric acid, phosphoric acid, hydrochloric acid, or a mixture thereof.

5. The method of claim 1 , wherein the acid has a concentration of about 0.5 M to about 2 M.

6. The method of claim 1 , wherein the increase in surface area is 500 times or greater than the surface area of the C-MEMS carbon structure prior to activation.

7. The method of claim 1 , further comprising forming the C-MEMS carbon structure by
spin coating a negative tone photoresist polymer on a substrate;
exposing the negative tone photoresist polymer to UV light to form a first intermediate;
spin coating a second negative tone photoresist polymer on the first intermediate to form a second intermediate; and
exposing the second intermediate to UV light and pyrolizing the resulting material to form the C-MEMS carbon structure.

8. The method of claim 7 , comprising:
applying a positive voltage of 1.9 V with respect to a Ag/AgCl reference electrode for about 10 minutes to about 30 minutes in the presence of a 0.5M aqueous sulfuric acid solution to the C-MEMS carbon structure; and
negatively polarizing the C-MEMS carbon structure by applying a potential difference of −0.3 V.

9. The method of claim 8 , wherein the negative tone photoresist polymer comprises SU-8.

10. The method of claim 1 , wherein the negative tone photoresist polymer comprises SU-8.

11. A method of activating a surface of a C-MEMS carbon structure to form an electrochemical double layer capacitor comprising:
applying a voltage of 1.5 to 4 V with respect to a Ag/AgCI reference electrode to the surface for about 15 minutes to about 45 minutes in the;
negatively polarizing the C-MEMS carbon structure by applying a potential difference;

and wherein the C-MEMS carbon structure is a patterned and pyrolized negative tone photoresist polymer.

12. The method of claim 11 , wherein the negative tone photoresist polymer comprises SU-8.

13. A method of activating a surface of a C-MEMS carbon structure to form an electrochemical double layer capacitor, comprising:
applying a positive voltage with respect to a Ag/AgCl reference electrode to the C-MEMS carbon structure in the presence of a 0.1 M to 2 M acid in an aqueous solution for at least 10 minutes to produce an anodized C-MEMS carbon structure;
negatively polarizing the anodized C-MEMS carbon structure by applying a negative voltage with respect to a Ag/AgCl reference electrode to produce a C-MEMS carbon structure having increased double-layer capacitance.

Assignees

• Beidaghi Majid
• Wang Chunlei
• Chen Wei
• The Florida International Univ Board Of Trustees

Inventors

• Beidaghi Majid
• Wang Chunlei
• Chen Wei

Classifications

• H01G11/64 Primary

  characterised by additives · CPC title

• H01G11/04

  Hybrid capacitors · CPC title

• Y02E60/13

  Energy storage using capacitors · CPC title

• H01G11/24 Primary

  characterised by structural features of the materials making up or comprised in the electrodes, e.g. form, surface area or porosity; characterised by the structural features of powders or particles used therefor · CPC title