Portable electronic device powered by proton exchange membrane fuel cell

• US 6,447,945 B1
• Filed: 12/12/2000
• Issued: 09/10/2002
• Est. Priority Date: 12/12/2000
• Status: Expired due to Fees

• Current Assignee: General Atomics, Inc.
• Original Assignee: General Atomics, Inc.
• Inventors: Streckert, Holger H., Blue, Linden P.
• Primary Examiner(s): Bell, Bruce F.
• Application Number:
  US09/735,698
• Time in Patent Office: 637 Days
• Field of Search: 700/286, 700/195, 428/570, 428/402, 428/627, 428/634, 429/34, 429/42, 429/40, 429/26, 204/267, 204/270
• US Class Current: 429/421
• CPC Class Codes: G06F 1/1616 with folding flat displays, e.g. laptop computers or notebooks having a clamshell configuration, with body parts pivoting to an open position around an axis parallel to the plane they define in closed position
• CPC Class Codes: G06F 1/1635 Details related to the integration of battery packs and other power supplies such as fuel cells or integrated AC adapter
• CPC Class Codes: G06F 1/203 for portable computers, e.g. for laptops
• CPC Class Codes: H01M 8/04156 with product water removal
• CPC Class Codes: H01M 8/065 by dissolution of metals or alloys; by dehydriding metallic substances
• CPC Class Codes: H01M 8/0656 by electrochemical means H01M8/065 takes precedence
• CPC Class Codes: H01M 8/1007 with both reactants being gaseous or vaporised H01M8/12 takes precedence
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y10T 428/12181 Composite powder [e.g., coated, etc.]
• CPC Class Codes: Y10T 428/12576 Boride, carbide or nitride component
• CPC Class Codes: Y10T 428/12625 Free carbon containing component
• CPC Class Codes: Y10T 428/2982 Particulate matter [e.g., sphere, flake, etc.]

Abstract

A portable electronic device incorporates PEM fuel cells and is designed to operate by the reaction of hydrogen from a hydride-containing fuel container and oxygen from the air, while efficiently removing the product water by a novel water transportation system. Temperature is effectively controlled by placing a plurality of fuel cell subunits as a generally planar array in the lid of the PC adjacent a heat transfer plate. A particularly efficient resupply system is provided where an electrolyzer that supplies H₂ at a pressure sufficient to continue to power the PC and simultaneously recharge an operatively-connected container and a second spare container in the electrolyzer.

Claims

1. A portable electronic device which is powered by a proton exchange membrane (PEM) fuel cell that produces water as a by-product of electricity generation, which device comprises

a two-piece case,

a CPU in a first piece of said case,

a display screen in a second piece of said case,

a fuel cell for providing electric power which creates water as a by-product in one of said pieces of said case, which piece also contains an exit opening to the exterior, and

a hydrophilic water transporter for transferring said by-product water away from said fuel cell, which water transporter is located along a perimeter boundary of said piece of said case that contains said fuel cell,

said water transporter including a perforated outer generally tubular holder which is associated with said exit opening and a generally coaxial perforated inner tube of lesser diameter with elongated hydrophilic wick material disposed within said inner tube,

whereby said water transporter adsorbs water in the vicinity of said fuel cell and said adsorbed water is distributed along and throughout said hydrophilic wick, aiding its evaporation into air in the annular region between said perforated inner and outer tubes, and subsequently exits from said case as water vapor via said exit opening.

2. The device according to claim 1 wherein said inner tube and said outer tubular holder include generally radially extending stand-offs which maintain said generally coaxial spaced apart relationship.

3. The device according to claim 1 wherein said elongated wick material is generally circular in cross-section and has a diameter so as to fit closely within said inner perforated tube.

4. The device according to claim 1 wherein said porous outer holder is formed as an integral part of said piece of said case.

5. The device according to claim 4 wherein said fuel cell is located in said second piece of said case and said water transporter is formed as two separate units with one unit being located along each one of two parallel side edges of said piece of said case in which said display screen is located, which case is generally rectangular in shape.

6. The device according to claim 5 wherein said case includes blower means and conduit means arranged so that said conduit means supplies a stream of air pressurized by said blower means centrally between two side-by-side fuel cells so that air flows through parallel channels past the cathodes and then transversely through said coaxial tube arrangement and out said exit opening.

7. The device according to claim 6 wherein a single blower means supplies air to cool said CPU and then through said conduit means to a cathode side of said fuel cell and thereafter through said coaxial conduit arrangement.

8. The device according to claim 6 wherein said elongated wick material comprises an elongated body that includes a bundle of strands of hydrophilic fibrous material.

9. The device according to claim 8 wherein individual strands from said bundle branch from said elongated body and individually extend into said parallel air flow channels so as to guard against potential water droplet blockage of an individual air flow channel.

10. A portable electronic device which is powered by a proton exchange membrane (PEM) fuel cell in combination with an electrolyzer unit for recharging a hydrogen reservoir, which combination comprises

(a) an electronic device disposed within a carrying case along with a fuel cell, a first hydrogen reservoir and a conduit arrangement interconnecting said hydrogen reservoir and said fuel cell,

said conduit arrangement includes a line leading to a recharging connector which transverses a wall of said case,

said hydrogen reservoir being detachably connected to said conduit arrangement to permit its optional removal and replacement, and

(b) an electrolyzer unit including means for generating hydrogen gas and supplying said generated gas (i) to a second hydrogen reservoir detachably connected to said electrolyzer unit and (ii) to flexible tubing for connection to said conduit arrangement and therethrough to both said fuel cell and to said first hydrogen reservoir,

whereby said electrolyzer can supply hydrogen gas to power said device while simultaneously recharging said first and second reservoirs.

11. The combination according to claim 10 wherein said first and second hydrogen reservoirs contain a mass of powder having a high surface area which powder is an alloy including manganese, titanium, vanadium and zirconium, said alloy having the ability to chemically absorb hydrogen in hydride form.

12. The combination according to claim 11 wherein said alloy can be reversibly converted to a hydride by recharging with a supply of hydrogen gas at an absolute pressure of about 1.5 atmospheres at ambient temperature.

13. The combination according to claim 12 wherein said device is a PC having a two-piece hinged case and said conduit arrangement contains a passageway through a hinge of said case to said fuel cell which is in the other piece thereof from that piece containing said first container.

14. The combination according to claim 10 wherein said line leading to said recharging connector has a check valve that allows hydrogen flow in only one direction.

15. The combination according to claim 14 wherein said electrolyzer includes a check valve which allows flow only in one direction out through said flexible conduit.

16. A portable personal computer (PC) which is powered by a proton exchange membrane (PEM) fuel cell that produces water as a by-product of electricity generation, which device comprises

a two-piece case,

a CPU in a first piece of said case,

a display screen in a second piece of said case,

hinge means interconnecting said two case pieces,

blower means residing in said first piece of said case for circulating cooling air past said CPU,

fuel cell means for providing electric power which creates water as a by-product in said second piece of said case,

said fuel cell means being electrically connected to said CPU through said hinge means,

said first case piece being formed with air entrance means through which said blower means takes suction, and said second case piece being formed with air exit means, and

passageway means extending through said hinge means and interconnecting the interiors of said two case pieces, so that air blown past said CPU flows through said passageway means and then through said PEM fuel cell means, providing oxygen thereto, taking up by-product water as vapor, and carrying said water vapor exterior of said second case piece through said air exit means.

17. The portable PC according to claim 16 wherein said fuel cell means includes at least two thin flat fuel cells in a side-by-side array located behind said display screen and interconnected to one another in series electrical connection with the cathode surface of each facing the rear of said display screen and with air being supplied to parallel flow channels extending across said cathodes from a manifold located centrally between said two fuel cells.

18. The portable PC according to claim 17 wherein at least four fuel cells are provided in two stacks in a generally planar array and electrically connected in series.

19. The portable PC according to claim 18 wherein said case second piece includes flat plate means having good thermal conductivity in a wall section of said case adjacent to the anode sides of said fuel cells in said plurality of stacks which plate collects heat therefrom and radiates such heat exterior of said case.

20. The portable PC according to claim 18 wherein said first case piece is a base section, said second case piece is a lid section and contains a conduit arrangement constructed so that air flowing into said lid section of said case through said passageway means flows into central manifold means located between said two stacks whence it is distributed across said cathode surfaces in parallel flow channels.