[go: up one dir, main page]

WO2000057500A1 - Plaque en graphite mince bipolaire munie de joints d'etancheite correspondants et de champ de courant en tissu de carbone, destinee a etre utilisee dans une pile a combustible - Google Patents

Plaque en graphite mince bipolaire munie de joints d'etancheite correspondants et de champ de courant en tissu de carbone, destinee a etre utilisee dans une pile a combustible Download PDF

Info

Publication number
WO2000057500A1
WO2000057500A1 PCT/US2000/007644 US0007644W WO0057500A1 WO 2000057500 A1 WO2000057500 A1 WO 2000057500A1 US 0007644 W US0007644 W US 0007644W WO 0057500 A1 WO0057500 A1 WO 0057500A1
Authority
WO
WIPO (PCT)
Prior art keywords
gasket
fuel cell
bipolar plate
assembly
graphite
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US2000/007644
Other languages
English (en)
Inventor
George A. Marchetti
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US09/314,784 external-priority patent/US6284401B1/en
Application filed by Individual filed Critical Individual
Priority to AU41750/00A priority Critical patent/AU4175000A/en
Publication of WO2000057500A1 publication Critical patent/WO2000057500A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/02—Details
    • H01M8/0271—Sealing or supporting means around electrodes, matrices or membranes
    • H01M8/0273—Sealing or supporting means around electrodes, matrices or membranes with sealing or supporting means in the form of a frame
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/02—Details
    • H01M8/0202—Collectors; Separators, e.g. bipolar separators; Interconnectors
    • H01M8/0204—Non-porous and characterised by the material
    • H01M8/0213—Gas-impermeable carbon-containing materials
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells

Definitions

  • the present invention relates to electrochemical fuel cells, and more particularly, to ionomer membrane fuel cells.
  • This invention was made with government support under Grant No. DE-FG01-97EE15679 from the United States Department of Energy/Energy Related Inventions Program. The government has certain rights in the invention.
  • a bipolar plate is the backbone of an ionomer membrane fuel cell stack or battery.
  • An ionomer membrane is virtually any ion-conducting membrane.
  • the most technically advanced type of ion-conducting membrane currently available for fuel cell applications is the proton-exchange membrane, such as the Nafion series of membranes, the Dow membrane, etc.
  • the fuel cell electrodes are hot-pressed or otherwise affixed to the membrane to form a unitized assembly.
  • Bipolar plates, and associated gas seals, enclose the membrane and electrode assembly ("MEA") in a fuel cell.
  • Typical state-of-the-art bipolar plates are made of graphite that is compressed into a single block.
  • Gas flow channels (the "flow-field” channels) are generally machined into the graphite block and permit the flow of the reactant gases from the manifolds and through the flow-field to the electrodes of the fuel cell.
  • Bipolar plates serve three primary functions in overall fuel cell operation. First, they conduct electricity from the fuel side of the electrochemical reaction to the oxidant side of the reaction, where water is produced. Second, they separate the fuel and oxidant gases and prevent cross-mixing of the reactant gases in the cell. Third, they allow gases from the manifolds to reach the appropriate fuel cell electrode.
  • the gas seals or gaskets (the “gaskets”) serve to contain the gases within the fuel cell and also prevent cross-mixing of the reactant gases.
  • Graphite is an excellent material for use in fuel cell applications because it is relatively inert in the corrosive electrochemical environment of the cell. Although the material cost of graphite is not high, the manufacturing methods currently employed result in very costly bipolar plates. Also, because state-of-the-art bipolar graphite plates are compressed into a block, they tend to be relatively thick. A relatively thick plate is also required in order to accommodate the channels of the flow-field. Separate cooling plates are often included in fuel cell designs, which may further add thickness to the fuel cell stack.
  • the thickness of the graphite bipolar plates increase, the number of cells that can be placed in a given spatial volume decreases
  • some state-of-the-art ionomer membrane fuel cells utilizing a standard machined graphite bipolar plate, may be approximately 100 mils (ca 2 5 mm) or more thick Up to ten cells can therefore be stacked per lineal inch of fuel cell stack using these types of cells
  • the thickness of the bipolar plate could be reduced, however, much thinner fuel cells could be produced and the cell "stacking density" (1 e , the number of cells in a given volumet ⁇ c space) could be correspondingly increased
  • An increase m stacking density would be particularly beneficial in portable and transportation-related applications where more compact and light-weight fuel cell stacks and fuel cell batte ⁇ es are desirable
  • One embodiment of the present invention includes a graphite plate because of its proven performance in ionomer membrane fuel cell stacks and its relatively low cost
  • the term ' graphite refers to any mate ⁇ al which is p ⁇ ma ⁇ ly composed of graphite, including mate ⁇ als composed of graphite, graphite flakes or graphite powders
  • the invention is a thm graphite bipolar plate with associated gaskets for use as a component m an ionomer membrane fuel cell, fuel cell stack or batten
  • the graphite bipolar plate and gaskets of this invention in certain embodiments are onh about 40 mils thick in total
  • the invention further includes a carbon or graphite cloth ("carbon cloth”) flow-field, as hereafter described Unlike state-of-the-art graphite bipolar plates, the invention does not have flow-field channels machined into the graphite Rather, the reactant gases enter the anode and cathode of
  • Figure 1 illustrates a top plan view of a graphite sheet with manifold slots and the carbon cloth flow-field
  • Figures 2, 3, 4 and 5 illustrate a top plan view of the port channel side of a four slot gasket
  • Figure 6 illustrates a top plan view of the membrane side of a four slot gasket
  • Figure 7 illustrates a top plan view of a membrane and electrode assembly wherein the electrodes fit into the electrode seating area of the PGA
  • Figure 8 illustrates a graphical view of a N/I curve for a single cell
  • Figure 9 illustrates a graphical view of a N/I curve for a fuel cell with 2 MEAs and a bipolar plate
  • the present invention comprises a thm graphite bipolar plate with associated gaskets and a carbon cloth flow-field for use as a component m an ionomer membrane fuel cell, fuel cell stack or batten
  • This invention was made with government support under Grant No DE- FG01-97EE 15679 from the United States Depa ⁇ ment of Energ /Energy Related Inventions Program The government has certain ⁇ ghts m the invention
  • a graphite sheet 2 such as Alfa
  • the graphite sheet used in the preferred embodiment is 10 mils thick and has a densitx of about ca 1 13 grams per cubic centimeter
  • the graphite is first compressed in a rotary press or by other means
  • Manifolds 3, 4, 5 and 6 are then cut or stamped out of the graphite Normally, there will be four manifold slots
  • the slots are for fuel in 3, fuel out 4, oxidant m 5, and oxidant out 6
  • the fuel may be hydrogen, a hydrogen- ⁇ ch gas, methanol, etc
  • the oxidant may be oxygen, air, etc
  • the graphite may be extended to form a thermal control fin, if desired, as shown m Figure 1
  • the rigid material used is polycarbonate and all such rigid mate ⁇ als that may be used as gaskets in the present invention are hereafter gene ⁇ cally referred to, without limitation, as "polycarbonate"
  • Manifolds 12, 13, 14 and 15 are cut or stamped out of the polvcarbonate gasket 1 1 as illustrated in Figure 2 and the electrode seating area 20 is likewise cut or stamped out
  • the polycarbonate may be molded to comp ⁇ se the gasket mam body
  • the polycarbonate is slightly roughened on both surfaces
  • Port channels 16, 17, 18 and 19 are sawed, scored, molded or otherwise impressed into two of the inte ⁇ or legs of each gasket as illustrated in Figure 2
  • the port channels can be located in va ⁇ ous numbers and at va ⁇ ous positions and intervals along the inte ⁇ or legs, as illustrated in Figure 5
  • FIG. 3 illustrates the gasket 21 which is placed on the opposite side of the graphite plate from the first gasket 1 1 and which has port channels 26, 27. 28 and 29 that are rotated 90 " with respect to the port channels of the first gasket 11
  • the manifolds 22, 23, 24 and 25 of the gasket 21 are also illustrated
  • a compressible gasket mate ⁇ al such as certain commercially-available automotive sihcone gasket mate ⁇ als, is applied to each surface of the gasket mam body
  • the gasket mate ⁇ al is applied to the entire surface of the "membrane side" of the gasket, as illustrated in Figure 6
  • the "membrane side" of the gasket 55 is that surface of the gasket which is adjacent to the ionomer membrane, as hereinafter described
  • the gasket mate ⁇ al is applied onfy to a po ⁇ ion of the surface of the "plate side" of the gasket 41 and 51. as illustrated m Figures 4 and 5 No gasket material is applied in the "port areas" defined by the dotted lines m Figures 4 and 5 Consequently, reactant gases from the manifolds enter the electrode seating area of the gasket by means of the port channels in the gasket
  • the gasket material forms a gas-tight seal with the remainder of the plate and also w ith the membrane of the MEA, when the MEA is inserted into the PGA A piece of carbon cloth 7 is then cut approximately to the size of the electrode seating area as illustrated in Figure 1 .
  • the non-port edges of the carbon cloth and the MEA are sealed and attached to the graphite with gasket material.
  • a slight gap between the carbon cloth and the interior legs of the gaskets where the port channels are located allows for distribution of the reactant gases along the length of the carbon cloth flow-field.
  • the reactant gases flow through the manifolds and into the port channels of the gasket. See, e.g., Figure 4.
  • the compressible gasket material on the rigid gasket main body prevents the gases from cross-mixing in the cell.
  • the gases are thereby distributed to the appropriate side of the graphite plate, either the fuel or the oxidant side.
  • the gases then flow into the gap on the first surface of the plate and along the length of the carbon cloth flow field. See, Figure 1.
  • the gases flow through the carbon cloth and into the appropriate fuel cell electrode.
  • the gases, and the product water formed on the oxidant side of the electrochemical reaction exit the cell through the carbon cloth, the opposite gap, the opposite port channel and the opposite manifold.
  • the other reactant gas is directed through the gasket ports to the second surface of the plate and into the second surface flow-field, which flow-field may be smooth graphite, an impressed flow-field or carbon cloth, depending on the operating condition parameters.
  • FIG. 1 Other embodiments of the present invention may include a thermal control fin 8, as illustrated in Figure 1.
  • the graphite may be extended beyond the edge of the gasket to form the fin. Adjacent graphite fins may then be separated by an electronic insulating material to prevent short circuits between the fins.
  • the thermal control fin permits air or liquid cooling of the fuel cell stack. It should also be noted that the thermal control function also allows the fuel cell stack to be heated in cold weather. By heating the fluid with, for example, a high resistance coil and a chemical battery, heat is transferred into the fuel cell stack via the fins of the graphite sheets.
  • the MEA61 can be inserted in the electrode seating area and sealed along the non-port edge as shown in Figure 7.
  • the membrane portion 62 of the MEA is substantially the same width and length as the gasket. Slots 64, 65, 66 and 67 are cut in the membrane, which match the slots in the PGA.
  • the fuel cell electrode 63 is also illustrated.
  • the PGAs may be fabricated to ha ⁇ e one of many types of symmet ⁇ es such as squares o ⁇ als.
  • the four-slot PGA illustrated herein is designed for operation on pressu ⁇ zed fuel and oxidant gases
  • the PGA may be adapted for operation with atmospheric pressure air or in a convection mode by eliminating one or both of internal oxidant manifolds
  • the present invention meets the c ⁇ te ⁇ a, discussed above, for a thin graphite bipolar plate that is compatible with an ionomer membrane-type MEA in a fuel cell
  • the graphite plate and gaskets prevent cross-mixing of the reactant gases in the cell
  • the gases are dist ⁇ ubbed to the approp ⁇ ate fuel cell electrode (either fuel or oxidant) by mechanisms of the manifolds, port channels in the gaskets, the first surface carbon cloth flow-field and the second surface flow-field
  • the graphite sheet and carbon cloth comp ⁇ se a low-resistance, electronic pathway for the flow of electrons generated by the electrochemical reaction in a bipolar configuration
  • the carbon cloth serves not only as a flow-field but also as a soft, sp ⁇ ng-type electronic contact within each cell Thermal control may be achieved by a mechanism of the thermal conductivity of the graphite fin
  • one embodiment of the present invention is comp ⁇ sed of relatively inexpensive precursor mate ⁇ als graphite sheet, a rigid mate ⁇ al such as polycarbonate, gasket mate ⁇ al, and carbon cloth No machining is employed All of the component parts of the bipolar plate and associated gaskets can be stamped or cut. thereby enabling the potential reduction of manufacturing costs
  • the present invention further increases the cell stacking density of ionomer membrane fuel cells beyond that currently possible with state-of-the-art bipolar plates About twenty cells per lmeal inch can be stacked using the present invention
  • the component or precursor mate ⁇ als are relatively inexpensive and light-weight m order to minimize the cost and weight of the invention
  • Figure 8 illustrates the representative performance of a single-cell fuel cell unit, using an MEA manufactured bv BCS Technolog ⁇ of Bryan
  • Texas Figure 9 illustrates the representative performance of a two-cell unit which includes one of the embodiments of the PGA of the present invention. 1 e , a non-fin embodiment with a smooth graphite surface on the fuel side of the PGA
  • the heat produced bv the electrochemical fuel cell reaction is used in this particular non-fin tw o-cell embodiment to increase internal cell temperature which, m turn, increases the power generated by each of the cells.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Sustainable Development (AREA)
  • Sustainable Energy (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Fuel Cell (AREA)

Abstract

L'invention concerne une plaque en graphite mince munie de joints d'étanchéité (11, 21, 41, 51) correspondants et d'un champ de courant (7) en tissu de carbone. La plaque, les joints d'étanchéité (11, 21, 41, 51) et le champ de courant (7) comprennent un assemblage 'plaque et joints d'étanchéité' destiné à être utilisé dans une pile à combustible, un ensemble ou une batterie de piles à combustible à membrane ionomère.
PCT/US2000/007644 1999-03-25 2000-03-23 Plaque en graphite mince bipolaire munie de joints d'etancheite correspondants et de champ de courant en tissu de carbone, destinee a etre utilisee dans une pile a combustible Ceased WO2000057500A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU41750/00A AU4175000A (en) 1999-03-25 2000-03-23 Thin graphite bipolar plate with associated gaskets and carbon cloth flow-field for use in a fuel cell

Applications Claiming Priority (8)

Application Number Priority Date Filing Date Title
US12607099P 1999-03-25 1999-03-25
US60/126,070 1999-03-25
US13000199P 1999-04-19 1999-04-19
US60/130,001 1999-04-19
US09/314,784 1999-05-19
US09/314,784 US6284401B1 (en) 1999-04-19 1999-05-19 Thin graphite bipolar plate with associated gaskets and carbon cloth flow-field for use in an ionomer membrane fuel cell
US16610899P 1999-11-17 1999-11-17
US60/166,108 1999-11-17

Publications (1)

Publication Number Publication Date
WO2000057500A1 true WO2000057500A1 (fr) 2000-09-28

Family

ID=27494616

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2000/007644 Ceased WO2000057500A1 (fr) 1999-03-25 2000-03-23 Plaque en graphite mince bipolaire munie de joints d'etancheite correspondants et de champ de courant en tissu de carbone, destinee a etre utilisee dans une pile a combustible

Country Status (2)

Country Link
AU (1) AU4175000A (fr)
WO (1) WO2000057500A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6752937B2 (en) 2001-12-17 2004-06-22 Quantum Composites, Inc. Highly conductive molding compounds having an increased distribution of large size graphite particles
US6780536B2 (en) 2001-09-17 2004-08-24 3M Innovative Properties Company Flow field

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5798188A (en) * 1997-06-25 1998-08-25 E. I. Dupont De Nemours And Company Polymer electrolyte membrane fuel cell with bipolar plate having molded polymer projections
US5798187A (en) * 1996-09-27 1998-08-25 The Regents Of The University Of California Fuel cell with metal screen flow-field

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5798187A (en) * 1996-09-27 1998-08-25 The Regents Of The University Of California Fuel cell with metal screen flow-field
US5798188A (en) * 1997-06-25 1998-08-25 E. I. Dupont De Nemours And Company Polymer electrolyte membrane fuel cell with bipolar plate having molded polymer projections

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6780536B2 (en) 2001-09-17 2004-08-24 3M Innovative Properties Company Flow field
US6752937B2 (en) 2001-12-17 2004-06-22 Quantum Composites, Inc. Highly conductive molding compounds having an increased distribution of large size graphite particles

Also Published As

Publication number Publication date
AU4175000A (en) 2000-10-09

Similar Documents

Publication Publication Date Title
EP1135821B1 (fr) Conception de plaque bipolaire en feuille metallique destinee aux piles a combustible a membrane polymere pour electrolyte
US6974648B2 (en) Nested bipolar plate for fuel cell and method
US8865366B2 (en) Fuel cell with protruded gas diffusion layer
US7309542B2 (en) Membrane electrode assembly and fuel cell
JP4727972B2 (ja) 燃料電池スタック
US5045413A (en) Fully internal mainfolded fuel cell stack
US5342706A (en) Fully internal manifolded fuel cell stack
JP5318382B2 (ja) 燃料電池スタック
US20050064270A1 (en) Fuel cell bipolar separator plate
US6503654B2 (en) Thin graphite bipolar plate with associated gaskets and carbon cloth flow-field for use in an ionomer membrane fuel cell
WO2003092105A1 (fr) Ensemble de plaques bipolaires presentant des colonnes transversales
US6284401B1 (en) Thin graphite bipolar plate with associated gaskets and carbon cloth flow-field for use in an ionomer membrane fuel cell
US7759014B2 (en) Fuel cell having a seal member
US7846613B2 (en) Fuel cell with separator having a ridge member
US8003273B2 (en) Polymer electrolyte fuel cell and fuel cell sealing member for the same
EP1441405B1 (fr) Pile à combustible avec des couches de diffusion de gaz
JP2012248444A (ja) 燃料電池セル及び燃料電池セルスタック
WO2000057500A1 (fr) Plaque en graphite mince bipolaire munie de joints d'etancheite correspondants et de champ de courant en tissu de carbone, destinee a etre utilisee dans une pile a combustible
JP3866246B2 (ja) 燃料電池
EP3751650B1 (fr) Pile à combustible et empilement de piles à combustible la comprenant
US20060263663A1 (en) Temperature management of an end cell in a fuel cell stack
MXPA01005070A (en) Sheet metal bipolar plate design for polymer electrolyte membrane fuel cells
WO2005028711A1 (fr) Joint d'etancheite pour pile electrochimique

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AU BR CA JP

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: JP