Magnetic composites and methods for improved electrolysis

• US 6,207,313 B1
• Filed: 07/30/1999
• Issued: 03/27/2001
• Est. Priority Date: 08/25/1994
• Status: Expired due to Fees

• Current Assignee: University of Iowa Research Foundation
• Original Assignee: University of Iowa Research Foundation
• Inventors: Leddy, Johna, Amarasinghe, Sudath, Zook, Lois Anne
• Primary Examiner(s): Bell, Bruce F.
• Application Number:
  US09/362,495
• Time in Patent Office: 606 Days
• Field of Search: 204/290.01, 204/291, 204/292, 204/293, 204/294, 429/40, 429/44, 427/77, 427/115, 427/372.2, 427/388.1
• US Class Current: 429/535
• CPC Class Codes: B03C 1/00 Magnetic separation
• CPC Class Codes: B03C 1/01 by addition of magnetic adjuvants
• CPC Class Codes: B03C 1/025 High gradient magnetic separators
• CPC Class Codes: B03C 1/034 characterised by the matrix elements
• CPC Class Codes: B03C 1/035 Open gradient magnetic separators, i.e. separators in which the gap is unobstructed, characterised by the configuration of the gap
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: C23C 24/00 Coating starting from inorganic powder spraying of the coating material in molten state C23C4/00; solid state diffusion C23C8/00 - C23C12/00
• CPC Class Codes: C23C 24/08 by application of heat or pressure and heat C23C24/04 takes precedence
• 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: C23C 4/12 characterised by the method of spraying
• CPC Class Codes: C23C 6/00 Coating by casting molten material on the substrate
• CPC Class Codes: C25D 5/007 Electroplating using magnetic fields, e.g. magnets
• CPC Class Codes: C25D 7/001 Magnets
• CPC Class Codes: G21F 9/12 by absorption; by adsorption; by ion-exchange
• CPC Class Codes: H01F 1/0027 Thick magnetic films forming thick magnetic films H01F41/16
• CPC Class Codes: H01F 1/0054 Coated nanoparticles, e.g. nanoparticles coated with organic surfactant
• CPC Class Codes: H01F 1/009 bidimensional, e.g. nanoscale period nanomagnet arrays H01F10/007 takes precedence
• CPC Class Codes: H01F 1/37 in a bonding agent
• CPC Class Codes: H01F 10/007 ultrathin or granular films H01F10/005 and H01F10/3227 take precedence; applying ultrathin or granular layers to substrates H01F41/301
• CPC Class Codes: H01F 41/24 : from liquids
• CPC Class Codes: H01F 41/26 : using electric currents , e.g. electroplating
• CPC Class Codes: H01F 41/301 : for applying ultrathin or granular layers ultrathin or granular layers H01F10/007
• CPC Class Codes: H01M 10/42 : Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells H01M10/60 takes precedence
• CPC Class Codes: H01M 2300/0082 : Organic polymers
• CPC Class Codes: H01M 4/02 : Electrodes composed of, or comprising, active material
• CPC Class Codes: H01M 4/86 : Inert electrodes with catalytic activity, e.g. for fuel cells
• CPC Class Codes: H01M 4/8605 : Porous electrodes
• CPC Class Codes: H01M 4/8657 : layered
• CPC Class Codes: H01M 4/8803 : Supports for the deposition of the catalytic active composition H01M4/90 takes precedence
• CPC Class Codes: H01M 4/8857 : Casting, e.g. tape casting, vacuum slip casting
• CPC Class Codes: H01M 4/8878 : Treatment steps after deposition of the catalytic active composition or after shaping of the electrode being free-standing body
• CPC Class Codes: H01M 4/8882 : Heat treatment, e.g. drying, baking
• CPC Class Codes: H01M 4/9016 : Oxides, hydroxides or oxygenated metallic salts
• CPC Class Codes: H01M 4/9083 : on carbon or graphite
• CPC Class Codes: H01M 4/926 : on carbon or graphite
• CPC Class Codes: H01M 50/124 : having a layered structure
• CPC Class Codes: H01M 50/1245 : characterised by the external coating on the casing
• CPC Class Codes: H01M 8/00 : Fuel cells; Manufacture thereof
• CPC Class Codes: H01M 8/1004 : characterised by membrane-electrode assemblies [MEA] H01M8/12 takes precedence
• CPC Class Codes: H01M 8/1009 : with one of the reactants being liquid, solid or liquid-charged H01M8/12 takes precedence
• CPC Class Codes: H01M 8/249 : comprising two or more groupings of fuel cells, e.g. modular assemblies
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02E 60/50 : Fuel cells
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 428/2991 : Coated
• CPC Class Codes: Y10T 428/2998 : including synthetic resin or polymer

Abstract

Magnetic composites exhibit distinct flux properties due to gradient interfaces. The composites can be used to improve fuel cells and batteries and effect transport and separation of different chemical species. Devices utilizing the composites include an electrode and improved fuel cells and batteries. Some composites, disposed on the surface of electrodes, prevent passivation of those electrodes and enable direct reformation of liquid fuels. Methods involving these composites provide distinct ways for these composites to be utilized.

Claims

1. A method of making an electrode having a surface coating of a magnetic composite, wherein the electrode resists passivation, comprising the steps of:

providing an electrode;

casting a casting mixture onto the surface of the electrode, said casting mixture comprising an ion exchange polymer, magnetic particles, and a solvent; and

evaporating the solvent from the surface of the electrode to yield an electrode having a surface coating of the magnetic composite, wherein the resulting coated electrode resists passivation.

2. The method of claim 1, further comprising the step of:

after casting the casting mixture, arranging the electrode in an external magnetic field before evaporation of the solvent.

3. The method of claim 2, further comprising the step of:

removing the electrode from the external magnetic field after evaporation of the solvent.

4. The method of claim 1, wherein said casting step comprises casting a casting mixture further comprising particles containing a catalyst.

5. The method of claim 4, wherein the step of casting a casting mixture comprises platinum, platinum-coated carbon, platinum/ruthenium, ruthenium, palladium, rhodium, cobalt, nickel, a porphyrin, a platinum-iron alloy, a platinum-cobalt alloy, a platinum-nickel alloy, a transition metal, or combinations thereof as the catalyst.

6. The method of claim 1, wherein said casting step comprises casting a casting mixture further comprising:

carbon particles having a platinum catalyst disposed on the surface of the carbon particles.

7. The method of claim 6, wherein the step of casting a casting mixture comprises the platinum catalyst disposed on the surface of the carbon particles by from about 5% to about 99.99% by weight of the carbon particles as part of the casting mixture.

8. The method of claim 6, wherein the step of casting a casting mixture comprises magnetic particles that have diameters in the range of from about 0.1 μ

m to about 50 μ

m.

9. The method of claim 6, wherein the step of casting a casting mixture comprises magnetic particles that comprise from about 2% to about 90% by weight of magnetizable or magnetic material.

10. The method of claim 1, wherein said providing an electrode step comprises providing an anode.

11. The method of claim 1, wherein the step of casting a casting mixture comprises casting an ion exchange polymer that comprises from about 15% to about 99.99% by weight of the casting mixture.

12. The method of claim 1, wherein the step of evaporating the solvent comprises producing the surface coating with a thickness in the range of from about 0.5 μ

m to about 100 μ

m.

13. The method of claim 1, wherein the step of casting a casting mixture comprises said casting mixture comprising an electron conductor, and said electron conductor may comprise carbon.

14. A method of making an electrode having a surface coating of a magnetic composite, wherein the electrode resists passivation, comprising the steps of:

providing an electrode;

forming a suspension comprising magnetic particles and a polymeric material in a solvent;

depositing the suspension on the electrode; and

evaporating the solvent to form a magnetic composite coating on the electrode.

15. The method of claim 14, wherein the step of forming a suspension comprises magnetic particles that comprise an iron oxide, a samarium cobalt, a neodymium alloy, nickel, cobalt, iron, neodymium iron boron, a lanthanide, or combinations thereof.

16. The method of claim 14, wherein the step of forming a suspension comprises polymeric material that is an ion exchange polymer.