US20110244370A1 - Fuel cell plate flow field - Google Patents

Fuel cell plate flow field Download PDF

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Publication number
US20110244370A1
US20110244370A1 US13/127,990 US200813127990A US2011244370A1 US 20110244370 A1 US20110244370 A1 US 20110244370A1 US 200813127990 A US200813127990 A US 200813127990A US 2011244370 A1 US2011244370 A1 US 2011244370A1
Authority
US
United States
Prior art keywords
channels
inlet
flow
fuel cell
flow field
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.)
Abandoned
Application number
US13/127,990
Other languages
English (en)
Inventor
John H. Whiton
David A. Niezelski
Robert A. Love
Edward Gordon Schaub
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.)
Audi AG
Original Assignee
UTC Power Corp
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
Application filed by UTC Power Corp filed Critical UTC Power Corp
Assigned to UTC POWER CORPORATION reassignment UTC POWER CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: LOVE, ROBERT A., NIEZELSKI, DAVID A., SCHAUB, EDWARD GORDON, WHITON, JOHN H.
Publication of US20110244370A1 publication Critical patent/US20110244370A1/en
Assigned to UNITED TECHNOLOGIES CORPORATION reassignment UNITED TECHNOLOGIES CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: UTC POWER CORPORATION
Assigned to BALLARD POWER SYSTEMS INC. reassignment BALLARD POWER SYSTEMS INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: UNITED TECHNOLOGIES CORPORATION
Assigned to AUDI AG reassignment AUDI AG ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: BALLARD POWER SYSTEMS INC.
Assigned to AUDI AG reassignment AUDI AG CORRECTIVE ASSIGNMENT TO CORRECT ASSIGNEE ADDRESS PREVIOUSLY RECORDED AT REEL 035716, FRAME 0253. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT. Assignors: BALLARD POWER SYSTEMS INC.
Abandoned legal-status Critical Current

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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
    • H01M8/0202—Collectors; Separators, e.g. bipolar separators; Interconnectors
    • H01M8/0258—Collectors; Separators, e.g. bipolar separators; Interconnectors characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant
    • H01M8/026—Collectors; Separators, e.g. bipolar separators; Interconnectors characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant characterised by grooves, e.g. their pitch or depth
    • 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
    • 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
    • H01M8/0258—Collectors; Separators, e.g. bipolar separators; Interconnectors characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant
    • 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
    • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • 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
    • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • H01M8/04082—Arrangements for control of reactant parameters, e.g. pressure or concentration
    • H01M8/04089—Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants
    • 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
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M2008/1095—Fuel cells with polymeric electrolytes
    • 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
    • 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
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • This disclosure relates to a fuel cell plate flow field configuration.
  • a fuel cell includes an anode and a cathode arranged on either side of a membrane electrode assembly.
  • the anode and the cathode are provided by a plate, which includes a flow field.
  • the anode plate flow field delivers fuel to the membrane electrode assembly, and the cathode plate flow field delivers a reactant to the membrane electrode assembly.
  • the flow fields are provided by multiple channels that are provided fluid from an inlet manifold.
  • the channels have been arranged in a variety of configurations depending upon a variety of factors, such as packaging constraints. Typically, it is desirable to provide a manifold that is wider than inlets to the channels to ensure a generally even distribution of flow across the channels. Occasionally, it is not possible to supply each of the channel inlets with unobstructed flow from the inlet manifold. As a result, some of the channels receive a somewhat limited flow, which results in an uneven distribution of flow across the flow field. Uneven flow distribution can create temperature gradients across the plate and reduce the efficiency of the chemical reactions within the fuel cell. In the case of anode flow fields, insufficient hydrogen at a location can create carbon corrosion of the anode plates. In the case of cathode flow fields, insufficient oxygen at a location can cause high temperatures and cell voltage dropoff.
  • a method of manufacturing a fuel cell plate flow field in which a generally even flow distribution across the flow field is provided.
  • the method includes providing an inlet manifold in fluid communication with the flow field.
  • the flow field includes multiple channels for which some of the channels receive restricted flow from the inlet manifold as compared to other channels.
  • a relative pressure drop between the channels is altered with a pressure drop feature to encourage fluid flow from the inlet manifold to the channels with restricted flow, which results in a generally even flow distribution across the flow field.
  • first and second sets of channels are arranged in alternating relationship. Inlet passages from the inlet manifold are misaligned with the first channels to encourage fluid flow from across first set of channels in a balanced manner.
  • unobstructed channels include a shallow channel portion to increase the pressure drop along those channels. Cross-cuts can be used from the unobstructed channels to the obstructed channels to reduce the pressure drop along the obstructed channels.
  • FIG. 1 is a highly schematic view of a fuel cell.
  • FIG. 2 is a plan view of an example fuel cell plate having a flow field.
  • FIG. 3 is an enlarged view of a portion of the plate shown in FIG. 2 .
  • FIG. 4 is an enlarged view of another portion of the plate shown in FIG. 2 .
  • FIG. 5 is a plan view of another example fuel cell plate.
  • FIG. 6 is an enlarged perspective view of a portion of the fuel cell plate shown in FIG. 5 .
  • a fuel cell 10 is shown in a highly schematic fashion in FIG. 1 .
  • the fuel cell 10 includes a membrane electrode assembly 16 arranged between an anode 12 and a cathode 14 .
  • the membrane electrode assembly 16 comprises a proton exchange membrane arranged between gas diffusion layers, for example.
  • the anode 12 and the cathode 14 respectively provide fuel and reactant flow fields provided by channels in a solid or porous plate.
  • the flow fields are fluidly connected to flow field inlets and exhausts using either internal or external manifolds that are in fluid communication with their respective fluid flow component.
  • a plate 18 is illustrated in FIGS. 2-4 having internal inlet and exhaust manifolds 20 , 22 .
  • a flow field 24 is fluidly interconnected between the inlet and exhaust manifolds 20 , 22 .
  • the inlet and exhaust manifolds are arranged on opposite sides of the plate 18 .
  • Parallel channels 26 arranged between risers 28 provide the flow field 24 .
  • the channels 26 extend a length L and are parallel with one another along the length without any significant bends. That is, there are no right angle turns and a given channel does not double back on itself as is typical with some flow fields.
  • the flow field 24 has a width W 2 that is greater than the width of the inlet manifold 20 .
  • This configuration presents a challenge of evenly distributing fluid across the flow field 24 .
  • the channels outboard of the inlet manifold 20 are typically starved of fluid, resulting in an uneven chemical reaction at the proton exchange membrane and hot-cold spots on the plate 18 or carbon corrosion on the anode side.
  • the channels 26 are divided into first and second sets of channels 34 , 36 arranged in alternating relationship with one another to provide an interdigitated flow field.
  • the first set of channels 34 are fluidly interconnected by a lateral inlet passage 32 , extending a width W 2 , that is supplied fluid from the inlet manifold 20 through discrete, spaced apart inlet passages 30 .
  • the inlet passages 30 are generally evenly spaced laterally from one another and misaligned with the channels in the first set of channels 34 . This misalignment encourages even fluid distribution across the first set of channels 34 .
  • Each channel of the first set of channels 34 extends from the lateral inlet passage 32 to a first terminal end 38 , best shown in FIG. 4 .
  • Each channel of the second set of channels 36 extend from a second terminal end 40 , which is arranged near the lateral inlet passage 32 (best shown in FIG. 3 ), to a lateral exhaust passage 42 that fluidly interconnects the second set of channels 36 with one another.
  • a pair of lateral exhaust passages 42 interconnected to and parallel with one another, extending the width W 2 , as best shown in FIG. 4 .
  • the first terminal ends 38 are arranged near the lateral exhaust passages 42 .
  • Discrete exhaust passages 44 fluidly connect the lateral exhaust passages 42 to the exhaust manifold 22 .
  • fluid is supplied to the first set of channels 34 by the inlet manifold 20 via the inlet passages 30 . Since the first set of channels 34 is dead-ended at the first terminal ends 38 , fluid will flow into the gas diffusion layer of the membrane electrode assembly 16 , for example, and into the second set of channels 36 .
  • This interdigitated arrangement of channels provides a pressure drop feature between the first and second sets of channels 34 , 36 that evenly distributes flow across the flow field 24 . Fluid from the gas diffusion layer is provided to the proton exchange membrane for chemical reaction. From the second set of channels 36 , fluid is returned to the exhaust manifold 22 .
  • FIG. 5 Another plate 118 , which has an external inlet manifold 46 , is shown in FIG. 5 .
  • Fluid is supplied to a header within the plate 118 , which provides the lateral inlet passage 132 , through inlet passages 48 .
  • Flow from the inlet passages 48 encounters baffles 50 that distribute the flow within the header.
  • the flow field 124 has a width W 2 that is wider than the width of the manifold 46 , W 1 .
  • Flow to the first set of channels 134 is generally unobstructed. In the configuration shown in FIG. 5 , the flow becomes choked at the extremities within the header at a restricted flow region 52 such that flow to the second set of channels 136 is obstructed.
  • Risers 128 separate the first and second sets of channels 134 , 136 .
  • the first set of channels 134 which would otherwise be unobstructed, include shallow channel portions 58 providing a smaller cross-sectional area that create a pressure drop across the length L of the first set of channels 134 .
  • the second set of channels 136 include a channel depth D 1 that is greater than the channel depth D 2 associated with the shallow channel portion 58 , which is arranged near the header.
  • the first set of channels 134 may transition from the depth D 2 at the shallow channel portion 58 to the depth D 1 further downstream.
  • the length of the shallow channel portion 58 and its depth are selected to achieve a desired pressure drop that results in an even flow distribution across the flow field 124 .
  • the term “depth” is also intended to include width.

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)
US13/127,990 2008-11-17 2008-11-17 Fuel cell plate flow field Abandoned US20110244370A1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US2008/083718 WO2010056252A1 (en) 2008-11-17 2008-11-17 Fuel cell plate flow field

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2008/083718 A-371-Of-International WO2010056252A1 (en) 2008-11-17 2008-11-17 Fuel cell plate flow field

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US14/511,104 Division US9812715B2 (en) 2008-11-17 2014-10-09 Fuel cell plate flow field

Publications (1)

Publication Number Publication Date
US20110244370A1 true US20110244370A1 (en) 2011-10-06

Family

ID=42170190

Family Applications (2)

Application Number Title Priority Date Filing Date
US13/127,990 Abandoned US20110244370A1 (en) 2008-11-17 2008-11-17 Fuel cell plate flow field
US14/511,104 Active 2029-01-17 US9812715B2 (en) 2008-11-17 2014-10-09 Fuel cell plate flow field

Family Applications After (1)

Application Number Title Priority Date Filing Date
US14/511,104 Active 2029-01-17 US9812715B2 (en) 2008-11-17 2014-10-09 Fuel cell plate flow field

Country Status (6)

Country Link
US (2) US20110244370A1 (ko)
JP (1) JP2012508954A (ko)
KR (1) KR20110081267A (ko)
CN (1) CN102217126A (ko)
DE (1) DE112008004170B4 (ko)
WO (1) WO2010056252A1 (ko)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20170125818A (ko) * 2015-03-01 2017-11-15 노바사이트 리미티드 안구 운동성을 측정하는 시스템 및 방법
KR101693993B1 (ko) * 2015-05-20 2017-01-17 현대자동차주식회사 연료전지용 분리판
DE102021115601A1 (de) * 2021-06-16 2022-12-22 Ekpo Fuel Cell Technologies Gmbh Strömungselement, Bipolarplatte und Brennstoffzelleneinrichtung

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020086200A1 (en) * 2000-12-29 2002-07-04 Margiott Paul R. Hybrid fuel cell reactant flow fields
US20020110723A1 (en) * 2000-12-21 2002-08-15 Farkash Ron H. Variable pressure drop plate design

Family Cites Families (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4963442A (en) 1989-05-03 1990-10-16 Institute Of Gas Technology Internal manifolded molten carbonate fuel cell stack
US5514487A (en) 1994-12-27 1996-05-07 Ballard Power Systems Inc. Edge manifold assembly for an electrochemical fuel cell stack
US5686199A (en) 1996-05-07 1997-11-11 Alliedsignal Inc. Flow field plate for use in a proton exchange membrane fuel cell
JPH1116591A (ja) * 1997-06-26 1999-01-22 Matsushita Electric Ind Co Ltd 固体高分子型燃料電池、固体高分子型燃料電池システム及び電気機器
US5981098A (en) 1997-08-28 1999-11-09 Plug Power, L.L.C. Fluid flow plate for decreased density of fuel cell assembly
US6159629A (en) 1998-12-17 2000-12-12 Ballard Power Systems Inc. Volume effecient layered manifold assembly for electrochemical fuel cell stacks
JP4590047B2 (ja) 1999-08-13 2010-12-01 本田技研工業株式会社 燃料電池スタック
US6358642B1 (en) 1999-12-02 2002-03-19 General Motors Corporation Flow channels for fuel cell
US6586128B1 (en) * 2000-05-09 2003-07-01 Ballard Power Systems, Inc. Differential pressure fluid flow fields for fuel cells
US6632556B2 (en) 2000-12-19 2003-10-14 Utc Fuel Cells, Llc Manifold assembly for a fuel cell power plant
US6544681B2 (en) * 2000-12-26 2003-04-08 Ballard Power Systems, Inc. Corrugated flow field plate assembly for a fuel cell
EP1405359A2 (en) * 2001-02-12 2004-04-07 The Morgan Crucible Company Plc Flow field plate geometries
CN100459254C (zh) * 2001-02-12 2009-02-04 摩根坩埚有限公司 流场板几何结构
US6878477B2 (en) 2001-05-15 2005-04-12 Hydrogenics Corporation Fuel cell flow field plate
JPWO2003009411A1 (ja) 2001-07-18 2004-11-11 株式会社東芝 固体高分子型燃料電池スタック
US6844101B2 (en) 2002-01-04 2005-01-18 Ballard Power Systems Inc. Separator with fluid distribution features for use with a membrane electrode assembly in a fuel cell
KR100434779B1 (ko) 2002-01-10 2004-06-07 (주)퓨얼셀 파워 미세유로를 갖는 분리판 및 그 제조방법, 그리고 연료전지의 기체확산층
GB2387476B (en) * 2002-06-24 2004-03-17 Morgan Crucible Co Flow field plate geometries
US20040072056A1 (en) 2002-10-10 2004-04-15 Whiton John H. Cascade fuel inlet manifold for fuel cells
AU2004216063B2 (en) 2003-02-27 2009-02-19 Protonex Technology Corporation Externally manifolded membrane based electrochemical cell stacks
CA2546658A1 (en) * 2003-11-21 2005-06-16 Ird Fuel Cells A/S Modified gas outlet for improved reactant handling in fuel cell separator plates
JP2007005237A (ja) * 2005-06-27 2007-01-11 Honda Motor Co Ltd 燃料電池
JP2007220356A (ja) * 2006-02-14 2007-08-30 Toray Eng Co Ltd 固体高分子型燃料電池のセパレータ
CN100416902C (zh) * 2006-11-09 2008-09-03 上海交通大学 质子交换膜燃料电池交指-平行组合流场
JP2008171608A (ja) * 2007-01-10 2008-07-24 Sharp Corp 燃料電池
US20090208803A1 (en) * 2008-02-19 2009-08-20 Simon Farrington Flow field for fuel cell and fuel cell stack

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020110723A1 (en) * 2000-12-21 2002-08-15 Farkash Ron H. Variable pressure drop plate design
US20020086200A1 (en) * 2000-12-29 2002-07-04 Margiott Paul R. Hybrid fuel cell reactant flow fields

Also Published As

Publication number Publication date
DE112008004170T5 (de) 2012-04-05
US20150024303A1 (en) 2015-01-22
US9812715B2 (en) 2017-11-07
DE112008004170B4 (de) 2020-02-06
KR20110081267A (ko) 2011-07-13
JP2012508954A (ja) 2012-04-12
WO2010056252A1 (en) 2010-05-20
CN102217126A (zh) 2011-10-12

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Free format text: CORRECTIVE ASSIGNMENT TO CORRECT ASSIGNEE ADDRESS PREVIOUSLY RECORDED AT REEL 035716, FRAME 0253. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT;ASSIGNOR:BALLARD POWER SYSTEMS INC.;REEL/FRAME:036448/0093

Effective date: 20150506