Fuel containment and recycling system

• US 6,558,825 B1
• Filed: 05/12/2000
• Issued: 05/06/2003
• Est. Priority Date: 05/12/2000
• Status: Expired due to Fees

• Current Assignee: Reveo, Inc.
• Original Assignee: Reveo, Inc.
• Inventors: Chang, Yuen-Ming, Faris, Sadeg M., Yao, Wayne, Tsai, Tsepin
• Primary Examiner(s): Ryan, Patrick
• Assistant Examiner(s): ANTHONY, JULIAN
• Application Number:
  US09/570,798
• Time in Patent Office: 1,089 Days
• Field of Search: 429/17, 429/19, 429/27, 429/34
• US Class Current: 429/404
• CPC Class Codes: H01M 10/4214 Arrangements for moving electrodes or electrolyte
• CPC Class Codes: H01M 12/06 with one metallic and one gaseous electrode
• CPC Class Codes: H01M 2300/0014 Alkaline electrolytes
• CPC Class Codes: H01M 4/02 Electrodes composed of, or comprising, active material
• CPC Class Codes: H01M 50/77 with external circulating path
• CPC Class Codes: H01M 6/5011 for several cells simultaneously or successively
• CPC Class Codes: H01M 6/5077 Regeneration of reactants or electrolyte
• CPC Class Codes: H01M 8/18 Regenerative fuel cells, e.g. redox flow batteries or secondary fuel cells
• CPC Class Codes: H01M 8/225 Fuel cells in which the fuel is based on materials comprising particulate active material in the form of a suspension, a dispersion, a fluidised bed or a paste
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

An energy conversion system, comprising: a reservoir container including at least two chambers of inversely variable volume for respectively storing a quantity of fuel and receiving a quantity of exhaust; a means for decreasing the volume of the first chamber while concurrently increasing the volume of the second chamber; at least one energy conversion device; first means for communicating fuel between the at least one energy conversion device and a first of the chambers in the reservoir container; and second means for communicating exhaust between the at least one energy conversion device and a second of the chambers in the reservoir container. The reservoir container may be transported to a recharging/refilling station or recharged in-situ. A particular application for metal-air fuel cell power systems is shown and described.

Claims

1. A fuel cell system comprising:

at least one fuel cell element including a cathode;

a reservoir container including at least two chambers of inversely variable volume for respectively storing a quantity of fuel and receiving a quantity of exhaust, said reservoir container adapted for storing a quantity of electrochemical anode material and a quantity of reaction products, wherein said first chamber comprises a first subchamber for holding fresh anode material and a second subchamber for holding electrolyte for the at least one fuel cell element, and said system further includes means for mixing fresh anode and electrolyte material from the respective first and second subchambers prior to communication to the at least one fuel cell element;

means for decreasing the volume of said first chamber while concurrently increasing the volume of said second chamber;

first means for communicating fuel between said at least one fuel cell element and a first of said chambers in said reservoir container; and

second means for communicating exhaust between said at least one fuel cell element and a second of said chambers in said reservoir container.

2. The fuel cell element of claim 1, further comprising:

means for regenerating the reaction products into fresh electrochemical anode material in said reservoir container; and

means for varying the respective volumes of said first and second chambers as fresh anode material is delivered to said fuel cell element and reaction products are delivered to said reservoir.

3. The fuel cell element of claim 1, wherein said first means for communicating and said second means for communicating respectively comprise at least one conduit coupling said at least one fuel cell element to said reservoir, each conduit including electrically insulative valves to selectively enable communication of fresh anode material and reaction products to and from a single fuel cell element in a group of electrically interconnected cell elements.

4. The fuel cell clement of claim 1, wherein said second chamber comprises a first subchamber for holding anode reaction material and a second subchamber for holding used electrolyte, and said system further comprises means for separating the anode reaction material from the used electrolyte.

5. The fuel cell element of claim 1 wherein said anode material comprises metal, and said cathode includes an air depolarizer element.

6. The fuel cell element of claim 5 wherein said material derived from said means for mixing fresh anode and electrolyte material from the respective first and second subchambers is a fluid paste comprised of 65% metal 10 granules by weight, and 35% gel electrolyte by weight.

7. The fuel cell element of claim 6, wherein said gel electrolyte comprises up to 5% polyacrylamide, 35% KOH, and water.

8. The fuel cell element of claim 6, wherein said cathode is enclosed in a gelled separator element.

9. The fuel cell element of claim 1, wherein said cathode comprises a metal foam substrate having an active layer, and a hydrophobic microporous gas diffusion layer disposed on at least one surface of the metal foam substrate.

10. For use in an energy conversion system having at least one energy conversion device, a reservoir container for storing a quantity of fuel and a quantity of exhaust, the reservoir container comprising:

a container body connectable to the at least one energy conversion device and including at least two chambers of inversely variable volume disposed within said container body for respectively storing a quantity of fuel and receiving a quantity of exhaust; and

means for decreasing the volume of said first chamber while concurrently increasing the volume of said second chamber,

wherein said reservoir has at least one flexible wall and the system includes means for compressing the flexible wall to force anode material out of said reservoir and into the at least one fuel cell element.

11. In an energy conversion system, a method for supplying fuel to, and collecting exhaust from, an energy conversion device, comprising the steps of:

connecting to the energy conversion device a reservoir container having at least two chambers for respectively supplying a quantity of fuel to and receiving exhaust from the energy conversion device;

inversely varying the volume of the first and second of said chambers in said reservoir to supply fuel to said energy conversion device and receive exhaust from said energy conversion device;

disconnecting said container from said energy conversion device;

converting the exhaust into fuel within said container; and

reconnecting said container to said energy conversion device to supply fresh fuel thereto from the second of said chambers and to receive exhaust in the first of said chambers.

12. In a fuel cell power system, a method for supplying fuel to, and collecting reaction products from, at least one fuel cell element, comprising the steps of:

connecting to the fuel cell a reservoir container having least two chambers for respectively supplying anode fluid to and receiving reaction products from the fuel cell element;

inversely varying the volume of the first and second of said chambers in said reservoir to supply anode fluid to said fuel cell and to receive reaction products from said fuel cell element;

disconnecting said container from said fuel cell;

converting the reaction products in the second of said chambers into fuel; and

reconnecting said container to said fuel cell to supply fresh anode fluid thereto from the second of said chambers and to receive reaction products in the first of said chambers.