Porous electrode used for conductive material-filled polymer composite

• US 6,277,510 B1
• Filed: 01/10/2000
• Issued: 08/21/2001
• Est. Priority Date: 07/30/1999
• Status: Expired due to Fees

• Current Assignee: Industrial Technology Research Institute
• Original Assignee: Industrial Technology Research Institute
• Inventors: Chou, Shu-Chin, Yeh, Wei-Wen, Chang, Kun-Huang, Lin, Chen-Ron
• Primary Examiner(s): Bell, Bruce F.
• Application Number:
  US09/479,971
• Time in Patent Office: 589 Days
• Field of Search: 219/241, 219/253, 429/40, 429/42, 429/44, 429/33, 429/30, 204/290.03, 204/290.05, 204/291, 204/292, 204/293, 428/457, 428/458, 428/460, 428/462, 205/205, 205/219, 205/232, 205/236, 205/245, 205/246, 205/261, 205/271, 205/273
• US Class Current: 204/293
• CPC Class Codes: H01C 1/1406 Terminals or electrodes formed on resistive elements having positive temperature coefficient
• CPC Class Codes: H01C 7/02 having positive temperature coefficient ceramics C04B

Abstract

The present invention provides a porous electrode used for a conductive material-filled polymer composite. At least one surface of the porous electrode is an open porous structure, which includes a plurality of macropores and micropores randomly distributed and interconnected with each other. The conductive material-filled polymer composite includes a polymer substrate and conductive particles filled therein. When the surface of the open porous structure of the porous electrode is bonded with the conductive material-filled polymer composite, the conductive particles in the conductive material-filled polymer composite can be trapped in the macropores of the porous structure, and the polymer substrate in the conductive material-filled polymer composite can be immersed into the micropores of the porous structure. This enables a better direct contact between the conductive particles and the porous electrode. There is good adhesion strength between the porous electrode and the conductive material-filled polymer composite, and the interfacial resistance is decreased.

Claims

1. An electrode assembly comprising:

porous electrode, wherein at least one surface of the porous electrode is an open porous structure, the porous structure including a plurality of macropores and micropores which are randomly distributed and interconnected with each other, and conductive material-filled polymer composite comprising a polymer substrate with conductive particles therein, the surface of the open type porous structure of the porous electrode contacting the conductive material-filled polymer composite so that the conductive particles in the conductive material-filled polymer composite are trapped in the macropores of the porous structure, and the polymer substrate of the conductive material-filled polymer composite is immersed into the micropores of the porous structure so as to enable a better direct contact between the conductive particles and the porous electrode.

2. The electrode assembly as claimed in claim 1, wherein the diameter of the macropore is larger than ten times of the particle size of the conductive particle.

3. The electrode assembly as claimed in claim 1, wherein the diameter of the micropore is smaller than the particle size of the conductive particle, so that the conductive particle will not pass through the micropore.

4. The electrode assembly as claimed in claim 1, wherein the porous structure of the porous electrode has a thickness that is larger than twenty times of the particle size of the conductive particle.

5. The electrode assembly as claimed in claim 1, which is prepared by subjecting an electrode substrate to composite electroplating, chemical etching, galvanic etching, or electroforming.

6. The assembly as claimed in claim 5, wherein the electrode substrate is selected from the group consisting of nickel foil, nickel alloy foil, copper foil passivated with Ni—

Zn, and copper foil passivated with Ni.

7. The electrode assembly as claimed in claim 5, which is prepared by subjecting the electrode substrate to composite electroplating.

8. The electrode assembly as claimed in claim 7, wherein the electroplating solution used for composite electroplating is a nickel-containing electroplating solution.

9. The electrode assembly as claimed in claim 1, wherein the conductive material-filled polymer composite has PTC or ZTC behavior.

10. The electrode assembly as claimed in claim 9, wherein the polymer substrate of the conductive material-filled polymer composite is thermoplastic polymer material, resin material, or thermosetting polymer material.

11. The electrode assembly as claimed in claim 10, wherein the polymer substrate is polyethylene or fluorine-based polymer material.

12. The electrode assembly as claimed in claim 10, wherein the conductive particle of the conductive material-filed polymer composite is selected from the group consisting of carbon black, graphite, metal powders, and metal-coated powders.