Fuel cell assembly for portable electronic device and interface, control, and regulator circuit for fuel cell powered electronic device

• US 20020197522A1
• Filed: 05/31/2002
• Published: 12/26/2002
• Est. Priority Date: 06/01/2001
• Status: Active Grant

• Current Assignee: Polyfuel, Inc.
• Original Assignee: Polyfuel, Inc.
• Inventors: Salamini, Alexey, Lawrence, Craig, MacGregor, Bruce, Bliven, David
• Granted Patent: US 7,005,206 B2
• Time in Patent Office: Days
• US Class Current: 429/447
• CPC Class Codes: H01M 2250/30 Fuel cells in portable systems, e.g. mobile phone, laptop
• CPC Class Codes: H01M 8/04186 of liquid-charged or electrolyte-charged reactants
• CPC Class Codes: H01M 8/04201 Reactant storage and supply, e.g. means for feeding, pipes
• CPC Class Codes: H01M 8/04208 Cartridges, cryogenic media or cryogenic reservoirs
• CPC Class Codes: H01M 8/04559 of fuel cell stacks
• CPC Class Codes: H01M 8/04597 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H01M 8/04865 Voltage
• CPC Class Codes: H01M 8/0488 of fuel cell stacks
• CPC Class Codes: H01M 8/0491 of fuel cell stacks
• CPC Class Codes: H01M 8/0494 of fuel cell stacks
• CPC Class Codes: H01M 8/1011 Direct alcohol fuel cells [DAFC], e.g. direct methanol fuel cells [DMFC]
• CPC Class Codes: Y02B 90/10 Applications of fuel cells in buildings
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A fuel cell assembly including a membrane electrode assembly, an anode plate, a cathode plate, a removable fuel cartridge, and a fuel delivery system. The assembly includes an anode, a cathode, and a polymer electrolyte membrane having a fuel side and an oxygen side. The fuel cartridge includes an expandable fuel bladder for receiving liquid fuel, an expandable pressure member in contact with the bladder for maintaining a positive pressure on the bladder, and a sealable exit port in fluid communication with the bladder. The fuel delivery system delivers fuel from the cartridge to the fuel side of the membrane. An Interface, Control, and Regulator Circuit for Fuel Cell Powered Electronic Device.

Claims

1. A removable fuel cartridge for a direct methanol fuel cell assembly comprising:

an expandable fuel bladder for receiving liquid methanol fuel;

an expandable pressure member in contact with said bladder for maintaining a positive pressure on said bladder; and

a sealable exit port in fluid communication with said bladder.

2. The removable fuel cartridge of claim 1 wherein said expandable fuel bladder is formed of a sheet plastic material.

3. The removable fuel cartridge of claim 2 wherein said sheet plastic material is substantially impervious to methanol.

4. The removable fuel cartridge of claim 1 wherein said expandable pressure member is a compressed foam member.

5. The removable fuel cartridge of claim 1 wherein said sealable exit port includes a septum.

6. A fuel cell assembly for a portable electronic device comprising:

membrane electrode assembly including an anode, a cathode, and a polymer electrolyte membrane having a fuel side and an oxygen side;

a removable fuel cartridge including an expandable fuel bladder for receiving liquid fuel, an expandable pressure member in contact with said bladder for maintaining a positive pressure on said bladder, and a sealable exit port in fluid communication with said bladder; and

a fuel delivery system for delivering fuel from said cartridge to said fuel side of said membrane, said circuit engageable with said port for fluidly connecting said bladder to said fuel side of said membrane.

7. The fuel cell assembly of claim 6 further comprising an enclosure adapted to engage a cellular phone body of a cellular phone, said fuel cell assembly adapted to replace a battery for the cellular phone.

8. The fuel cell assembly of claim 6 wherein said polymer electrolyte membrane electrode assembly comprises first and second catalysts positioned respectively on said fuel side and said oxygen side of said membrane.

9. The fuel cell assembly of claim 8 wherein said anode is in electrical communication with said first catalyst and said cathode is in electrical communication with said second catalyst.

10. The fuel cell assembly of claim 6 wherein said wherein said expandable fuel bladder is formed of a sheet plastic material, said sheet plastic material is impervious to methanol.

11. The fuel cell assembly of claim 6 wherein said expandable pressure member is a compressed foam member.

12. The fuel cell assembly of claim 6 wherein said sealable exit port includes a septum.

13. The fuel cell assembly of claim 6 wherein said fuel delivery system comprises a needle insertable into said sealable exit port.

14. The fuel cell assembly of claim 6 wherein said fuel delivery system comprises a manifold including a one-way valve for preventing fuel from flowing through said circuit away from said fuel side of said membrane.

16. The direct methanol fuel cell assembly of claim 15 wherein said polymer electrolyte membrane electrode assembly further comprises first and second catalysts positioned respectively on said fuel side and said oxygen side of said membrane, said anode is in electrical communication with said first catalyst and said cathode is in electrical communication with said second catalyst.

17. The direct methanol fuel cell assembly of claim 15 wherein said anode plate includes a post extending through said fuel chamber toward said anode for biasing said anode into contact with said membrane.

18. The direct methanol fuel cell assembly of claim 15 wherein said anode plate comprises an exhaust port for ejecting carbon dioxide from said fuel chamber.

19. The direct methanol fuel cell assembly of claim 15 further comprising:

a fuel delivery system for delivering fuel from said cartridge to said fuel side of said membrane;

said removable fuel cartridge including an expandable fuel bladder for receiving liquid fuel, an expandable pressure member in contact with said bladder for maintaining a positive pressure on said bladder, and a sealable exit port in fluid communication with said bladder;

wherein said circuit is engageable with said port for fluidly connecting said bladder to said fuel side of said membrane.

20. The direct methanol fuel cell assembly of claim 15 wherein said cathode plate forms an enclosure having a recess receiving said membrane electrode assembly, said anode plate, and said removable fuel cartridge.

21. The direct methanol fuel cell assembly of claim 20 wherein said enclosure includes an air groove formed on an outer surface of said enclosure, said oxygen port extending from a base of said groove into said recess for providing air to said oxygen side of said membrane.

15. A direct methanol fuel cell assembly for a portable electronic device comprising:

a membrane electrode assembly including an anode, a cathode, and a polymer electrolyte membrane having a fuel side and an oxygen side;

an anode plate including a fuel chamber fluidly connected to said fuel side of said membrane;

a removable fuel cartridge fluidly connected to said fuel chamber, and

a cathode plate including an oxygen port extending therethrough for providing air to said oxygen side of said membrane.

22. A power pack specifically adapted to replace a battery for a cellular phone having a cellular phone body, said power pack comprising:

a fuel cell assembly;

a removable fuel cartridge for providing fuel to said fuel cell assembly, said fuel cartridge including an expandable fuel bladder for receiving liquid fuel, an expandable pressure member in contact with said bladder for maintaining a positive pressure on said bladder, and a sealable exit port in fluid communication with said bladder, and

a housing adapted to removably engage the cellular phone body, said housing enclosing said fuel cell assembly and said fuel cartridge.

23. A power pack according to claim 22 wherein said fuel cartridge is specifically adapted for use with a power pack specifically designed for a specific model of a cellular phone.

24. A power pack according to claim 22, further comprising an interface circuit, the interface circuit comprising:

a DC-DC voltage boost circuit operating with an output voltage related feedback signal;

a storage capacitor coupled to and receiving charge generated by said boost circuit; and

a microcontroller coupled to said boost circuit for controlling operation or non-operation of said boost circuit.

25. A power pack according to claim 23 wherein said fuel cartridge is specifically adapted for use with a power pack specifically designed for a specific model of a cellular phone.

27. An interface circuit as in claim 26, wherein the interface circuit is specifically adapted for use with a specific model of a cellular phone.

28. An interface circuit as in claim 26, wherein the interface circuit is adapted to control and regulate power drawn from and charge and discharge of a fuel cell and maintain safe operation within predefined voltage, current, and power ranges.

26. An interface circuit for a fuel cell powered electronic device comprising:

a DC-DC voltage boost circuit operating with an output voltage related feedback signal;

a storage capacitor coupled to and receiving charge generated by said boost circuit; and

a microcontroller coupled to said boost circuit for controlling operation or non-operation of said boost circuit.

29. A method of controlling operation of a voltage boost converter circuit coupled to a fuel cell and another energy storage device.

30. A method for boosting a lower fuel cell voltage up to higher cellular phone voltage.