Direct methanol feed fuel cell and system

• US 7,425,384 B2
• Filed: 09/01/2004
• Issued: 09/16/2008
• Est. Priority Date: 10/12/1993
• Status: Expired due to Fees

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Kindler, Andrew, Narayanan, Sekharipuram R., Frank, Harvey A., Surampudi, Subbarao, Chun, William, Halpert, Gerald, Jeffries-Nakamura, Barbara
• Primary Examiner(s): Kalafut; Stephen J.
• Application Number:
  US10/932,521
• Publication Number:
  US 20060046133A1
• Time in Patent Office: 1,476 Days
• Field of Search: 429/40, 429/42, 429/44, 429/15
• US Class Current: 429/410
• CPC Class Codes: H01M 2300/0082 Organic polymers
• CPC Class Codes: H01M 4/8605 Porous electrodes
• CPC Class Codes: H01M 4/8663 Selection of inactive substances as ingredients for catalytic active masses, e.g. binders, fillers
• CPC Class Codes: H01M 4/921 Alloys or mixtures with metallic elements
• CPC Class Codes: H01M 8/0202 Collectors; Separators, e.g. bipolar separators; Interconnectors
• CPC Class Codes: H01M 8/0228 in the form of layered or coated products
• CPC Class Codes: H01M 8/0234 Carbonaceous material
• CPC Class Codes: H01M 8/0247 characterised by the form characterised by a channel configuration H01M8/0258
• CPC Class Codes: H01M 8/04156 with product water removal
• CPC Class Codes: H01M 8/04186 of liquid-charged or electrolyte-charged reactants
• CPC Class Codes: H01M 8/04194 Concentration measuring cells
• CPC Class Codes: H01M 8/04201 Reactant storage and supply, e.g. means for feeding, pipes
• CPC Class Codes: H01M 8/0687 Reactant purification by the use of membranes or filters
• 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 8/1011 Direct alcohol fuel cells [DAFC], e.g. direct methanol fuel cells [DMFC]
• CPC Class Codes: H01M 8/1018 Polymeric electrolyte materials
• CPC Class Codes: H01M 8/22 Fuel cells in which the fuel is based on materials comprising carbon or oxygen or hydrogen and other elements; Fuel cells in which the fuel is based on materials comprising only elements other than carbon, oxygen or hydrogen
• CPC Class Codes: H01M 8/2455 with liquid, solid or electrolyte-charged reactants
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

Improvements to non acid methanol fuel cells include new formulations for materials. The platinum and ruthenium are more exactly mixed together. Different materials are substituted for these materials. The backing material for the fuel cell electrode is specially treated to improve its characteristics. A special sputtered electrode is formed which is extremely porous.

Claims

1. A direct fed methanol fuel cell comprising:

an anode, including an electrochemical catalyst associated therewith, wherein the catalyst includes at least one platinum-substitute material from the group consisting of palladium, tungsten, rhodium, iron, cobalt, nickel, molybdenum, niobium, and zirconium replacing at least some of the platinum used as the catalyst;

a cathode; and

a proton conducting solid polymer electrolyte membrane, coupled between said anode and cathode;

an ionomer added to the anode,

wherein said fuel cell operates using a methanol fuel which is substantially free of liquid acid electrolyte.

2. A fuel cell as in claim 1, further comprising a direct fed methanol fuel cell comprising:

an anode, including an electrochemical catalyst associated therewith, wherein the catalyst includes at least one platinum-substitute material from the group consisting of palladium, tungsten, rhodium, iron, cobalt, nickel, molybdenum, niobium, and zirconium replacing at least some of the platinum used as the catalyst; and

a cathode material for enhancing wetting of the anode by the fuel in the anode.

3. A method, comprising:

forming a direct fed methanol fuel cell having an anode, a solid polymer proton conducting electrolyte membrane, coupled to said anode, and a cathode, said anode including an electrochemical catalyst material associated therewith, where the catalyst material includes platinum, ruthenium, and also includes a platinum substitute material from the group consisting of palladium, tungsten, rhodium, iron, cobalt and nickel, molybdenum, niobium, and zirconium; and

operating said direct fed methanol fuel cell to carry out an electrochemical reaction, by using a methanol fuel which is substantially free of liquid acid electrolyte.

4. A method as in claim 3, wherein said forming further comprises adding an ionomer to the anode.

5. A direct fed methanol fuel cell system, comprising:

an anode, a proton conducting solid polymer electrolyte membrane, coupled to the anode, and a cathode also coupled to another side of the proton conducting solid electrolyte membrane, the anode having an electrochemical catalyst formed as an ink thereon, said catalyst ink including platinum, ruthenium, and titanium, and the system is operational to receive a methanol fuel which is substantially free of liquid acid electrolyte.

6. A system as in claim 5 wherein said catalyst includes one of titanium alkoxide, titanium butoxide, titanium isopropoxide or TiCl₄.

7. A system as in claim 5 wherein said catalyst includes platinum-ruthenium-TiO₂, formed in a 50-25-25 (Pt--Ru--TiO₂) combination.