US20170047595A1 - Bipolar plate for fuel cell and fuel cell - Google Patents

Bipolar plate for fuel cell and fuel cell Download PDF

Info

Publication number
US20170047595A1
US20170047595A1 US15/339,938 US201615339938A US2017047595A1 US 20170047595 A1 US20170047595 A1 US 20170047595A1 US 201615339938 A US201615339938 A US 201615339938A US 2017047595 A1 US2017047595 A1 US 2017047595A1
Authority
US
United States
Prior art keywords
rib
fuel cell
bipolar plate
cell according
roughened surface
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
US15/339,938
Inventor
Li-Duan Tsai
Jiunn-Nan Lin
Chien-Ming Lai
Cheng-Hong Wang
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.)
Industrial Technology Research Institute ITRI
Original Assignee
Industrial Technology Research Institute ITRI
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 Industrial Technology Research Institute ITRI filed Critical Industrial Technology Research Institute ITRI
Priority to US15/339,938 priority Critical patent/US20170047595A1/en
Publication of US20170047595A1 publication Critical patent/US20170047595A1/en
Abandoned legal-status Critical Current

Links

Images

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
    • 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
    • H01M8/02—Details
    • H01M8/0202—Collectors; Separators, e.g. bipolar separators; Interconnectors
    • H01M8/0204—Non-porous and characterised by the material
    • H01M8/0206—Metals or alloys
    • 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
    • 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
    • H01M8/0223—Composites
    • 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
    • H01M8/0223—Composites
    • H01M8/0228—Composites in the form of layered or coated products
    • 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
    • H01M8/023—Porous and characterised by the material
    • 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

Definitions

  • the technical field relates to a bipolar plate for a fuel cell and a fuel cell.
  • a fuel cell is generally composed of a bipolar plate 100 with a membrane electrode assembly 102 in between.
  • the bipolar plate 100 is generally made of a graphite material or a metallic material, and the bipolar plate 100 may have a plurality of flow channels 100 a after mechanical processing (including milling, punching, stamping, . . . etc.) or chemical processing (including etching, electroplating . . . etc.).
  • the flow channels 100 a are used for fuel (e.g., hydrogen and oxygen) transportation.
  • fuel e.g., hydrogen and oxygen
  • the length, the sectional shape, and the size of the flow channels 100 a may affect electrochemical reaction in the membrane electrode assembly 102 , and further affects the overall electricity generation efficiency of the fuel cell.
  • the majority of the bipolar plate 100 further includes a plurality of ribs 104 .
  • the ribs 104 are used for supporting the membrane electrode assembly 102 , and transferring electrons during the electrochemical reaction of the fuel cell.
  • FIG. 1B merely illustrates a portion where the rib 104 depicted in FIG. 1A is in contact with the membrane electrode assembly 102 , wherein the membrane electrode assembly 102 includes a gas diffusion layer (GDL) 106 , a catalyst 108 , and a membrane 110 .
  • GDL gas diffusion layer
  • the rib 104 is generally made of a graphite material or a metallic material, the fuel may not be able to pass through the ribs 104 ; thus, the fuel may diffuse only within areas 112 .
  • the catalyst 108 within the overlap between the rib 104 and thereof may be lack of fuel; thereby, the electrochemical reactions of the catalyst 108 may be blocked, the effective utilization of the catalyst 108 may be decrease, and the material of the fuel-lacking area may be degraded.
  • One of exemplary embodiments comprises a bipolar plate for a fuel cell.
  • the bipolar plate has a plurality of flow channels, wherein a rib is defined between neighboring two of the flow channels, and a top surface of the rib is a roughened surface and a side surface of the rib is non-porous.
  • Another of exemplary embodiments comprises a bipolar plate for a fuel cell.
  • the bipolar plate has a plurality of flow channels, wherein a rib is defined between neighboring two of the flow channels, and a top surface of the rib is a roughened surface.
  • the roughened surface of the rib is made through surface polishing and ultrasonic cavitation techniques or an electrical discharge processing technique.
  • the fuel cell comprises a plurality of bipolar plates and at least one membrane electrode assembly (MEA) disposed among the bipolar plates.
  • MEA membrane electrode assembly
  • Each of the bipolar plates has a plurality of flow channels, and a rib is defined between neighboring two of the flow channels.
  • a top surface of the rib is a roughened surface and a side surface of the rib is non-porous.
  • FIG. 1A is a cross-sectional view of a conventional fuel cell.
  • FIG. 1B is an enlarged partial view of FIG. 1A .
  • FIG. 2 is a schematic cross-sectional view of a bipolar plate for a fuel cell according to a first exemplary embodiment.
  • FIG. 3 is a schematic cross-sectional view of a bipolar plate for a fuel cell according to a second exemplary embodiment.
  • FIG. 4 is a schematic cross-sectional view of a fuel cell according to a third exemplary embodiment.
  • FIG. 5A is a SEM picture of a bipolar plate in Reference Experiment.
  • FIG. 5B is a SEM picture of a bipolar plate in Experiment 1.
  • FIG. 5C is a SEM picture of a bipolar plate in Experiment 2.
  • FIG. 5D is a SEM picture of a bipolar plate in Experiment 3.
  • FIG. 6 is a polarization curve diagram of the fuel cells respectively using each of the bipolar plates provided in Reference Experiment and the Experiments on conditions of cell temperature at 66° C., the temperature of humidification being 60° C. at anode, and the temperature of humidification being 55° C. at cathode.
  • FIG. 7 is a polarization curve diagram of the fuel cells respectively using each of the bipolar plates provided in Reference Experiment and the Experiments on conditions of fuels with 65% RH and cell temperature at 70° C.
  • FIG. 2 is a schematic cross-sectional view of a bipolar plate for a fuel cell according to a first exemplary embodiment.
  • a bipolar plate 200 of the first exemplary embodiment has a plurality of flow channels 200 a , wherein a rib 202 is defined between neighboring two of the flow channels 200 a , and a top surface of the rib 202 is a roughened surface 202 a . Further, if a pore diameter of the roughened surface 202 a of the rib 202 is approximately between 20 ⁇ m and 200 ⁇ m, the fuel supply (lateral diffusion) capacity may be increased to improve overall performance of the fuel cell.
  • pore area fraction is the result of the following formula:
  • a R denotes the area of the top surface of the rib 202 ;
  • a P denotes the pore area of the roughened surface 202 a of the rib 202 .
  • the fuel supply capacity may also be increased to improve the overall performance of the fuel cell.
  • a side surface 202 b of the rib 202 may be a flat surface but is not limited thereto.
  • the flow channels 200 a are generally formed through mechanical processing, so that the bipolar plate 200 is an integral structure.
  • a material of the bipolar plate 200 may be metal, graphite, or a composite material.
  • the material of the bipolar plate 200 may be metal, such as aluminum, titanium, stainless steel, and so on.
  • a protection film may be formed on all surfaces of the bipolar plate 200 in order to prevent the metal from oxidation.
  • a titanium nitride thin film may be deposited on the surface of the bipolar plate 200 to prevent titanium from oxidation and to maintain the conductivity of titanium.
  • FIG. 3 is a schematic cross-sectional view of a bipolar plate for a fuel cell according to a second exemplary embodiment.
  • a bipolar plate 300 of the second exemplary embodiment has a plurality of flow channels 300 a , wherein a rib 302 is defined between neighboring two of the flow channels 300 a .
  • a top portion of the rib 302 has a porous structure 304 with hydrophobicity and a porosity range of, for example, 30%-80%.
  • the thickness T 0 of the porous structure 304 is approximately 1/10 to 3/10 of the thickness T r of the rib 302 .
  • the porous structure 304 is composed of a conductive material and a hydrophobic material but is not limited thereto.
  • the conductive material may be, for example, carbon black, graphite, carbon fiber, or metal;
  • the hydrophobic material includes any proper material, such as tetrafluoroethylene and the likes.
  • the addition amount of the hydrophobic material for example, is less than 60 wt %.
  • the material of the bipolar plate 300 may be referred to as those described in the first exemplary embodiment.
  • FIG. 4 is a schematic cross-sectional view of a fuel cell according to a third exemplary embodiment, wherein the reference numbers of the second exemplary embodiment are used to denote like or similar elements.
  • the fuel cell of the third exemplary embodiment includes two bipolar plates 300 and a membrane electrode assembly (MEA) 400 .
  • the MEA 400 at least includes a membrane 402 , a catalyst 404 , and a gas diffusion layer (GDL) 406 .
  • the MEA 400 between the bipolar plates 300 is in contact with the bipolar plates 300 through the GDL 406 .
  • a porous structure 304 on a top surface of a rib 302 is compressed in contact with the MEA 400 .
  • the porosity of the porous structure 304 is in inverse proportion to the compression degree of the porous structure 304 . The less the porosity, the greater the compression degree, and vice versa.
  • compression degree refers to the ratio of (T 0 ⁇ T x )/T 0 , which is the original thickness T 0 of the porous structure 304 minus the thickness T x after forming the fuel cell, and divided by the original thickness T 0 ; for example, the compression degree of the porous structure 304 of the third exemplary embodiment is approximately between 40% and 80%.
  • a graphite carbon plate is applied as a bipolar plate, and flow channels are formed on the bipolar plate through mechanical processing. The result is as shown in the SEM picture of FIG. 5A .
  • Experiment 1 is similar to Reference Experiment. Namely, a graphite carbon plate is applied as a bipolar plate, except that after the flow channels are formed, the top surface of the rib is roughened through applying surface polishing and ultrasonic cavitation techniques. The result is as shown in the SEM picture of FIG. 5B . Upon comparison of FIG. 5A and FIG. 5B , it is known that the surface of the rib in contact with the MEA may be roughened through applying the surface treatment technique, and the pore diameter thereof is approximately 20 ⁇ m.
  • Experiment 2 is similar to Reference Experiment. Namely, a graphite carbon plate is applied as a bipolar plate except that after the flow channels are formed, the top surface of the rib is roughened through applying an electrical discharge processing technique. The result is as shown in the SEM picture of FIG. 5C . Upon comparison of FIG. 5A and FIG. 5C , it is known that the surface of the rib in contact with the MEA is roughened through applying the surface treatment technique, and the pore diameter thereof is greater than 50 ⁇ m.
  • Experiment 3 is similar to Reference Experiment. Namely, a graphite carbon plate is applied as a bipolar plate, except that after the flow channels are formed, the structure of the top portion of the rib is changed to a porous structure through applying a porous material lamination technique. The result of changing the surface portion of the rib is as shown in the SEM picture of FIG. 5D .
  • the porous material structure is composed of conductive carbon powder, carbon fiber, and hydrophobic material.
  • the original porosity of the porous material is approximately 80%, while the hydrophobicity of the porous material is approximately 23%.
  • the compression degree of the porous material is approximately 50%, while the porosity thereof is approximately 60%.
  • Each “pore area fraction” of the bipolar plates is calculated from the SEM pictures of Reference Experiment and Experiments 1 and 2, and the roughness of the roughened surface of the rib of each of the bipolar plates is measured. The result is shown in TABLE 1 below.
  • Each of the bipolar plates provided in Reference Experiment and Experiments 1-3 is composed together with a MEA to form single cells, and a performance test is carried out on each of the single cells.
  • FIG. 6 is a polarization curve diagram of the fuel cells respectively using each of the bipolar plates provided in Reference Experiment and the Experiments under a humidified environment, in which the temperature of cell is 66° C., the temperature of anodic humidification is 60° C. and the temperature of cathodic humidification is 55° C.
  • the performance of the fuel cells in Experiments 1-3 is better than that in Reference Experiment.
  • FIG. 7 is a polarization curve diagram of the fuel cells respectively using each of the bipolar plates provided in Reference Experiment and the Experiments on conditions of fuels with 65% RH and cell temperature at 70° C. It is also apparent that the performance of the fuel cells in Experiments 1-3 is better than that in Reference Experiment.
  • the disclosure utilizes surface structure processing technique to roughen the surface of the rib and to form the porous structure thereof, so as to respectively improve transmission of electrons (by reducing contact resistance) and enhance the fuel supply (lateral diffusion) capacity. As such, the overall performance of the fuel cell may be improved.

Landscapes

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

Abstract

A bipolar plate for a fuel cell is provided. The bipolar plate for the fuel cell has a plurality of flow channels, and a rib is defined between neighboring two flow channels. A side surface of the rib is non-porous. A top surface of the rib may be a roughened surface in order to improve performance of the fuel cell.

Description

    CROSS-REFERENCE TO RELATED APPLICATION
  • This application is a divisional application of and claims the priority benefit of an application Ser. No. 13/565,753, filed on Aug. 2, 2012, now allowed, which claims the priority benefit of Taiwan application serial no. 100147421, filed on Dec. 20, 2011. The entirety of each of the above-mentioned patent applications is hereby incorporated by reference herein and made a part of this specification.
    • TECHNICAL FIELD
  • The technical field relates to a bipolar plate for a fuel cell and a fuel cell.
    • BACKGROUND
  • As shown in FIG. 1A, a fuel cell is generally composed of a bipolar plate 100 with a membrane electrode assembly 102 in between. The bipolar plate 100 is generally made of a graphite material or a metallic material, and the bipolar plate 100 may have a plurality of flow channels 100 a after mechanical processing (including milling, punching, stamping, . . . etc.) or chemical processing (including etching, electroplating . . . etc.). The flow channels 100 a are used for fuel (e.g., hydrogen and oxygen) transportation. Hence, the length, the sectional shape, and the size of the flow channels 100 a may affect electrochemical reaction in the membrane electrode assembly 102, and further affects the overall electricity generation efficiency of the fuel cell. In addition to the flow channels 100 a, the majority of the bipolar plate 100 further includes a plurality of ribs 104. The ribs 104 are used for supporting the membrane electrode assembly 102, and transferring electrons during the electrochemical reaction of the fuel cell.
  • FIG. 1B merely illustrates a portion where the rib 104 depicted in FIG. 1A is in contact with the membrane electrode assembly 102, wherein the membrane electrode assembly 102 includes a gas diffusion layer (GDL) 106, a catalyst 108, and a membrane 110. Since the rib 104 is generally made of a graphite material or a metallic material, the fuel may not be able to pass through the ribs 104; thus, the fuel may diffuse only within areas 112. In this case, the catalyst 108 within the overlap between the rib 104 and thereof may be lack of fuel; thereby, the electrochemical reactions of the catalyst 108 may be blocked, the effective utilization of the catalyst 108 may be decrease, and the material of the fuel-lacking area may be degraded.
    • SUMMARY
  • One of exemplary embodiments comprises a bipolar plate for a fuel cell. The bipolar plate has a plurality of flow channels, wherein a rib is defined between neighboring two of the flow channels, and a top surface of the rib is a roughened surface and a side surface of the rib is non-porous.
  • Another of exemplary embodiments comprises a bipolar plate for a fuel cell. The bipolar plate has a plurality of flow channels, wherein a rib is defined between neighboring two of the flow channels, and a top surface of the rib is a roughened surface. The roughened surface of the rib is made through surface polishing and ultrasonic cavitation techniques or an electrical discharge processing technique.
  • Yet another of exemplary embodiments comprises a fuel cell. The fuel cell comprises a plurality of bipolar plates and at least one membrane electrode assembly (MEA) disposed among the bipolar plates. Each of the bipolar plates has a plurality of flow channels, and a rib is defined between neighboring two of the flow channels. A top surface of the rib is a roughened surface and a side surface of the rib is non-porous.
  • Several exemplary embodiments accompanied with figures are described in detail below to further describe the disclosure in details.
    • BRIEF DESCRIPTION OF THE DRAWINGS
  • The accompanying drawings are included to provide further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments and, together with the description, serve to explain the principles of the disclosure.
  • FIG. 1A is a cross-sectional view of a conventional fuel cell.
  • FIG. 1B is an enlarged partial view of FIG. 1A.
  • FIG. 2 is a schematic cross-sectional view of a bipolar plate for a fuel cell according to a first exemplary embodiment.
  • FIG. 3 is a schematic cross-sectional view of a bipolar plate for a fuel cell according to a second exemplary embodiment.
  • FIG. 4 is a schematic cross-sectional view of a fuel cell according to a third exemplary embodiment.
  • FIG. 5A is a SEM picture of a bipolar plate in Reference Experiment.
  • FIG. 5B is a SEM picture of a bipolar plate in Experiment 1.
  • FIG. 5C is a SEM picture of a bipolar plate in Experiment 2.
  • FIG. 5D is a SEM picture of a bipolar plate in Experiment 3.
  • FIG. 6 is a polarization curve diagram of the fuel cells respectively using each of the bipolar plates provided in Reference Experiment and the Experiments on conditions of cell temperature at 66° C., the temperature of humidification being 60° C. at anode, and the temperature of humidification being 55° C. at cathode.
  • FIG. 7 is a polarization curve diagram of the fuel cells respectively using each of the bipolar plates provided in Reference Experiment and the Experiments on conditions of fuels with 65% RH and cell temperature at 70° C.
    •  DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS
  • FIG. 2 is a schematic cross-sectional view of a bipolar plate for a fuel cell according to a first exemplary embodiment.
  • With reference to FIG. 2, a bipolar plate 200 of the first exemplary embodiment has a plurality of flow channels 200 a, wherein a rib 202 is defined between neighboring two of the flow channels 200 a, and a top surface of the rib 202 is a roughened surface 202 a. Further, if a pore diameter of the roughened surface 202 a of the rib 202 is approximately between 20 μm and 200 μm, the fuel supply (lateral diffusion) capacity may be increased to improve overall performance of the fuel cell.
  • In the first exemplary embodiment, if a pore area fraction of the roughened surface 202 a of the rib 202 is approximately between 50% and 90%, the fuel supply capacity may also be increased. The so-called “pore area fraction” is the result of the following formula:

  • A P/(A R +A P)×100%
  • wherein AR denotes the area of the top surface of the rib 202; AP denotes the pore area of the roughened surface 202 a of the rib 202.
  • In addition, in the first exemplary embodiment, if roughness of the roughened surface 202 a of the rib 202 is approximately between 0.1 μm and 10 μm, the fuel supply capacity may also be increased to improve the overall performance of the fuel cell.
  • A side surface 202 b of the rib 202 may be a flat surface but is not limited thereto. The flow channels 200 a are generally formed through mechanical processing, so that the bipolar plate 200 is an integral structure.
  • In the first exemplary embodiment, a material of the bipolar plate 200 may be metal, graphite, or a composite material. For example, the material of the bipolar plate 200 may be metal, such as aluminum, titanium, stainless steel, and so on. A protection film may be formed on all surfaces of the bipolar plate 200 in order to prevent the metal from oxidation. For example, when the bipolar plate 200 is made of titanium, a titanium nitride thin film may be deposited on the surface of the bipolar plate 200 to prevent titanium from oxidation and to maintain the conductivity of titanium.
  • FIG. 3 is a schematic cross-sectional view of a bipolar plate for a fuel cell according to a second exemplary embodiment.
  • With reference to FIG. 3, a bipolar plate 300 of the second exemplary embodiment has a plurality of flow channels 300 a, wherein a rib 302 is defined between neighboring two of the flow channels 300 a. A top portion of the rib 302 has a porous structure 304 with hydrophobicity and a porosity range of, for example, 30%-80%. The thickness T0 of the porous structure 304 is approximately 1/10 to 3/10 of the thickness Tr of the rib 302.
  • In the second exemplary embodiment, the porous structure 304 is composed of a conductive material and a hydrophobic material but is not limited thereto. The conductive material may be, for example, carbon black, graphite, carbon fiber, or metal; the hydrophobic material includes any proper material, such as tetrafluoroethylene and the likes. The addition amount of the hydrophobic material, for example, is less than 60 wt %. The material of the bipolar plate 300 may be referred to as those described in the first exemplary embodiment.
  • FIG. 4 is a schematic cross-sectional view of a fuel cell according to a third exemplary embodiment, wherein the reference numbers of the second exemplary embodiment are used to denote like or similar elements.
  • With reference to FIG. 4, the fuel cell of the third exemplary embodiment includes two bipolar plates 300 and a membrane electrode assembly (MEA) 400. The MEA 400 at least includes a membrane 402, a catalyst 404, and a gas diffusion layer (GDL) 406. The MEA 400 between the bipolar plates 300 is in contact with the bipolar plates 300 through the GDL 406. More particularly, a porous structure 304 on a top surface of a rib 302 is compressed in contact with the MEA 400. As such, not only the fuel supply (lateral diffusion) capacity may be increased, but also the conductivity between the rib 302 and the GDL 406 may be ensured. For example, the porosity of the porous structure 304 is in inverse proportion to the compression degree of the porous structure 304. The less the porosity, the greater the compression degree, and vice versa.
  • The so-called “compression degree” refers to the ratio of (T0−Tx)/T0, which is the original thickness T0 of the porous structure 304 minus the thickness Tx after forming the fuel cell, and divided by the original thickness T0; for example, the compression degree of the porous structure 304 of the third exemplary embodiment is approximately between 40% and 80%.
  • Several experiments are described below to prove the efficacy of the above exemplary embodiments.
    • Reference Experiment
  • A graphite carbon plate is applied as a bipolar plate, and flow channels are formed on the bipolar plate through mechanical processing. The result is as shown in the SEM picture of FIG. 5A.
    • Experiment 1
  • Experiment 1 is similar to Reference Experiment. Namely, a graphite carbon plate is applied as a bipolar plate, except that after the flow channels are formed, the top surface of the rib is roughened through applying surface polishing and ultrasonic cavitation techniques. The result is as shown in the SEM picture of FIG. 5B. Upon comparison of FIG. 5A and FIG. 5B, it is known that the surface of the rib in contact with the MEA may be roughened through applying the surface treatment technique, and the pore diameter thereof is approximately 20 μm.
    • Experiment 2
  • Experiment 2 is similar to Reference Experiment. Namely, a graphite carbon plate is applied as a bipolar plate except that after the flow channels are formed, the top surface of the rib is roughened through applying an electrical discharge processing technique. The result is as shown in the SEM picture of FIG. 5C. Upon comparison of FIG. 5A and FIG. 5C, it is known that the surface of the rib in contact with the MEA is roughened through applying the surface treatment technique, and the pore diameter thereof is greater than 50 μm.
    • Experiment 3
  • Experiment 3 is similar to Reference Experiment. Namely, a graphite carbon plate is applied as a bipolar plate, except that after the flow channels are formed, the structure of the top portion of the rib is changed to a porous structure through applying a porous material lamination technique. The result of changing the surface portion of the rib is as shown in the SEM picture of FIG. 5D. In view of FIG. 5D, it is known that the porous material structure is composed of conductive carbon powder, carbon fiber, and hydrophobic material. The original porosity of the porous material is approximately 80%, while the hydrophobicity of the porous material is approximately 23%. After forming the fuel cell, the compression degree of the porous material is approximately 50%, while the porosity thereof is approximately 60%.
    • Measurement 1
  • Each “pore area fraction” of the bipolar plates is calculated from the SEM pictures of Reference Experiment and Experiments 1 and 2, and the roughness of the roughened surface of the rib of each of the bipolar plates is measured. The result is shown in TABLE 1 below.
  • TABLE 1
    Reference
    Experiment Experiment
    1 Experiment 2
    Pore area fraction of the 5 63 77
    rib surface (%)
    Average roughness Ra of 0.1~0.2 0.4~0.9 3.5~4.2
    the rib surface (μm)
    • Measurement 2
  • Each of the bipolar plates provided in Reference Experiment and Experiments 1-3 is composed together with a MEA to form single cells, and a performance test is carried out on each of the single cells.
  • FIG. 6 is a polarization curve diagram of the fuel cells respectively using each of the bipolar plates provided in Reference Experiment and the Experiments under a humidified environment, in which the temperature of cell is 66° C., the temperature of anodic humidification is 60° C. and the temperature of cathodic humidification is 55° C. In view of FIG. 6, it is apparent that the performance of the fuel cells in Experiments 1-3 is better than that in Reference Experiment.
  • FIG. 7 is a polarization curve diagram of the fuel cells respectively using each of the bipolar plates provided in Reference Experiment and the Experiments on conditions of fuels with 65% RH and cell temperature at 70° C. It is also apparent that the performance of the fuel cells in Experiments 1-3 is better than that in Reference Experiment.
  • In view of the above, the disclosure utilizes surface structure processing technique to roughen the surface of the rib and to form the porous structure thereof, so as to respectively improve transmission of electrons (by reducing contact resistance) and enhance the fuel supply (lateral diffusion) capacity. As such, the overall performance of the fuel cell may be improved.
  • It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims and their equivalents.

Claims (15)

What is claimed is:
1. A bipolar plate for a fuel cell, the bipolar plate comprising a plurality of flow channels, wherein a rib is defined between neighboring two of the flow channels, and the bipolar plate is characterized in that: a top surface of the rib is a roughened surface and a side surface of the rib is non-porous.
2. The bipolar plate for the fuel cell according to claim 1, wherein the roughened surface of the rib has a pore diameter of approximately 20 μm to 200 μm.
3. The bipolar plate for the fuel cell according to claim 1, wherein the roughened surface of the rib has a pore area fraction of approximately 50% to 90%.
4. The bipolar plate for the fuel cell according to claim 1, wherein the roughened surface of the rib has a roughness of approximately 0.1 μm to 10 μm.
5. The bipolar plate for the fuel cell according to claim 1, wherein a material of the bipolar plate comprises metal, graphite, or a composite material.
6. A bipolar plate for a fuel cell, the bipolar plate comprising a plurality of flow channels, wherein a rib is defined between neighboring two of the flow channels, and the bipolar plate is characterized in that: a top surface of the rib is a roughened surface, wherein the roughened surface of the rib is made through surface polishing and ultrasonic cavitation techniques or an electrical discharge processing technique.
7. The bipolar plate for the fuel cell according to claim 6, wherein the roughened surface of the rib has a pore diameter of approximately 20 μm to 200 μm.
8. The bipolar plate for the fuel cell according to claim 6, wherein the roughened surface of the rib has a pore area fraction of approximately 50% to 90%.
9. The bipolar plate for the fuel cell according to claim 6, wherein the roughened surface of the rib has a roughness of approximately 0.1 μm to 10 μm.
10. The bipolar plate for the fuel cell according to claim 6, wherein a material of the bipolar plate comprises metal, graphite, or a composite material.
11. A fuel cell, comprising:
a plurality of bipolar plates, wherein each of the bipolar plates has a plurality of flow channels, and a rib is defined between neighboring two of the flow channels; and
at least one membrane electrode assembly (MEA), disposed among the bipolar plates, wherein
a top surface of the rib is a roughened surface and a side surface of the rib is non-porous.
12. The fuel cell according to claim 11, wherein the roughened surface of the rib has a pore diameter of approximately 20 μm to 200 μm.
13. The fuel cell according to claim 11, wherein the roughened surface of the rib has a pore area fraction of approximately 50% to 90%.
14. The fuel cell according to claim 11, wherein the roughened surface of the rib has a roughness of approximately 0.1 μm to 10 μm.
15. The fuel cell according to claim 11, wherein a material of the bipolar plate comprises metal, graphite, or a composite material.
US15/339,938 2011-12-20 2016-11-01 Bipolar plate for fuel cell and fuel cell Abandoned US20170047595A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US15/339,938 US20170047595A1 (en) 2011-12-20 2016-11-01 Bipolar plate for fuel cell and fuel cell

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
TW100147421A TWI447995B (en) 2011-12-20 2011-12-20 Bipolar plate and fuel cell
TW100147421 2011-12-20
US13/565,753 US9515326B2 (en) 2011-12-20 2012-08-02 Bipolar plate for fuel cell and fuel cell
US15/339,938 US20170047595A1 (en) 2011-12-20 2016-11-01 Bipolar plate for fuel cell and fuel cell

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US13/565,753 Division US9515326B2 (en) 2011-12-20 2012-08-02 Bipolar plate for fuel cell and fuel cell

Publications (1)

Publication Number Publication Date
US20170047595A1 true US20170047595A1 (en) 2017-02-16

Family

ID=48610444

Family Applications (2)

Application Number Title Priority Date Filing Date
US13/565,753 Active 2034-08-13 US9515326B2 (en) 2011-12-20 2012-08-02 Bipolar plate for fuel cell and fuel cell
US15/339,938 Abandoned US20170047595A1 (en) 2011-12-20 2016-11-01 Bipolar plate for fuel cell and fuel cell

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US13/565,753 Active 2034-08-13 US9515326B2 (en) 2011-12-20 2012-08-02 Bipolar plate for fuel cell and fuel cell

Country Status (3)

Country Link
US (2) US9515326B2 (en)
CN (1) CN103178275B (en)
TW (1) TWI447995B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180277858A1 (en) * 2016-05-30 2018-09-27 Sumitomo Electric Industries, Ltd. Bipolar plate, cell frame, cell stack, and redox flow battery

Families Citing this family (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016012515A (en) * 2014-06-30 2016-01-21 ダイハツ工業株式会社 Fuel battery
CN106033818B (en) * 2015-03-13 2020-04-03 上海恒劲动力科技有限公司 Flow guide plate and fuel cell stack containing same
CN106395997A (en) * 2016-09-21 2017-02-15 见嘉环境科技（苏州）有限公司 Multifunctional flowing type electrochemical reactor
DE102016120535A1 (en) * 2016-10-27 2018-05-03 Audi Ag Fuel cell, fuel cell stack and fuel cell system
US20200075967A1 (en) * 2016-12-06 2020-03-05 Show A Denko K.K. Collector plate and redox flow battery
US11631867B2 (en) 2017-01-19 2023-04-18 Sumitomo Electric Industries, Ltd. Bipolar plate, cell frame, cell stack and redox flow battery
US20210167411A1 (en) * 2017-06-21 2021-06-03 Sumitomo Electric Industries, Ltd. Redox flow battery
CN107394228A (en) * 2017-08-25 2017-11-24 新奥科技发展有限公司 A kind of bipolar plates and preparation method thereof
JP6962264B2 (en) * 2018-04-24 2021-11-05 トヨタ自動車株式会社 Method for manufacturing fuel cells and separators for fuel cells
CN110854402A (en) * 2018-08-21 2020-02-28 上海汽车集团股份有限公司 Gas diffusion layer precursor, preparation method thereof, gas diffusion layer and fuel cell
JP7245036B2 (en) * 2018-11-28 2023-03-23 太陽誘電株式会社 Fuel cell stack and manufacturing method thereof
CN111384414B (en) * 2018-12-28 2022-03-15 财团法人工业技术研究院 Bipolar plate of fuel cell and manufacturing method thereof
CN110010922A (en) * 2019-04-18 2019-07-12 上海治臻新能源装备有限公司 A kind of fuel battery metal pole plate and its production method with hydrophobic structure
CN110323456A (en) * 2019-06-24 2019-10-11 一汽解放汽车有限公司 A kind of preparation method with low contact resistance bipolar plates
DE102021204917A1 (en) 2021-05-14 2022-11-17 Cellcentric Gmbh & Co. Kg flow field and separator plate
DE102021206839A1 (en) * 2021-06-30 2023-01-05 Robert Bosch Gesellschaft mit beschränkter Haftung Hydrophobic bipolar plate

Family Cites Families (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4374906A (en) * 1981-09-29 1983-02-22 United Technologies Corporation Ribbed electrode substrates
DE10043008A1 (en) * 2000-09-01 2002-03-28 Forschungszentrum Juelich Gmbh Bipolar plate
US6706437B2 (en) * 2001-01-10 2004-03-16 Sgl Carbon Ag Bipolar plates for fuel cell stacks
US6733915B2 (en) * 2001-12-27 2004-05-11 E. I. Du Pont De Nemours And Company Gas diffusion backing for fuel cells
DE60333852D1 (en) * 2002-06-28 2010-09-30 Toyota Motor Co Ltd FUEL BATTERY
US6838202B2 (en) 2002-08-19 2005-01-04 General Motors Corporation Fuel cell bipolar plate having a conductive foam as a coolant layer
DE10315804B4 (en) 2003-03-31 2005-09-29 Reinz-Dichtungs-Gmbh & Co. Kg Bipolar plate for fuel cells from a deformed foil with manufacturing process
WO2004100296A1 (en) * 2003-05-08 2004-11-18 Dainippon Ink And Chemicals, Inc. Method for producing separator for fuel cell, separator for fuel cell and fuel cell
FR2858465A1 (en) 2003-07-29 2005-02-04 Commissariat Energie Atomique POROUS STRUCTURES USED AS BIPOLAR PLATES AND METHODS OF PREPARING SUCH POROUS STRUCTURES
TW200518376A (en) 2003-11-18 2005-06-01 Univ Yuan Ze Surface protection film structure of metal electrode plate for fuel battery and surface treatment method
JP2006049226A (en) * 2004-08-09 2006-02-16 Nissan Motor Co Ltd Fuel cell
CN101044651A (en) * 2004-08-19 2007-09-26 通用汽车环球科技运作公司 Surface modifications of fuel cell elements for improved water management
US7700212B2 (en) 2004-10-07 2010-04-20 Gm Global Technology Operations, Inc. Bipolar plate with enhanced stability
TWI246792B (en) 2005-03-28 2006-01-01 Univ Yuan Ze Structure of bipolar plate having micro-channel for fuel cells and a method for producing the same
JP5045867B2 (en) * 2005-05-23 2012-10-10 日清紡ホールディングス株式会社 Fuel cell separator
TW200721583A (en) 2005-08-05 2007-06-01 Mitsubishi Pencil Co Separator for fuel battery and process for producing the same
CN1314152C (en) 2005-08-18 2007-05-02 上海交通大学 Molten carbonate fuel cell (MCFC) double plates
JP4918984B2 (en) 2005-11-15 2012-04-18 日清紡ホールディングス株式会社 Conductive resin composition for porous fuel cell separator and method for producing the same
US7897295B2 (en) 2005-12-20 2011-03-01 GM Global Technology Operations LLC Surface engineering of bipolar plate materials for better water management
WO2007088832A1 (en) 2006-02-02 2007-08-09 Matsushita Electric Industrial Co., Ltd. Separator plate and fuel cell
CN200965892Y (en) * 2006-07-07 2007-10-24 上海攀业氢能源科技有限公司 Fuel battery composite gas-diffusion-layer
JP4257544B2 (en) 2006-08-24 2009-04-22 日清紡績株式会社 Polymer electrolyte fuel cell separator
US7803499B2 (en) * 2006-10-31 2010-09-28 Gm Global Technology Operations, Inc. Super-hydrophobic composite bipolar plate
US7830499B1 (en) 2007-03-29 2010-11-09 Armando Corella Method and apparatus for laser return characterization in a countermeasures system
TW200921975A (en) 2007-11-08 2009-05-16 Univ Nat Central Fuel cell with composite pole plate
TW201101569A (en) * 2009-06-29 2011-01-01 Univ Yuan Ze Fuel cell having ribs and porous material flow-channel structure
JP5011362B2 (en) * 2009-09-30 2012-08-29 株式会社日立製作所 Bipolar plate for fuel cell and fuel cell
JP5682778B2 (en) * 2010-12-27 2015-03-11 日産自動車株式会社 Fuel cell

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180277858A1 (en) * 2016-05-30 2018-09-27 Sumitomo Electric Industries, Ltd. Bipolar plate, cell frame, cell stack, and redox flow battery

Also Published As

Publication number Publication date
CN103178275B (en) 2015-11-25
US9515326B2 (en) 2016-12-06
CN103178275A (en) 2013-06-26
TWI447995B (en) 2014-08-01
TW201328009A (en) 2013-07-01
US20130157166A1 (en) 2013-06-20

Similar Documents

Publication Publication Date Title
US20170047595A1 (en) Bipolar plate for fuel cell and fuel cell
CN1918725B (en) Flow field geometry for improved water management
US20180145341A1 (en) Component for fuel cell including graphene foam and functioning as flow field and gas diffusion layer
US9431665B2 (en) Selectively coated bipolar plates for water management and freeze start in PEM fuel cells
US7572538B2 (en) Fuel cell
US20080187812A1 (en) Fuel cell
JP5230174B2 (en) Fuel cell
US20180145342A1 (en) Flow field for fuel cell including graphene foam
US11552318B2 (en) Method of manufacturing electricity-generating assembly
JP2006164764A (en) Fuel cell
JP2011150853A (en) Solid polymer fuel cell
US20170358805A1 (en) Structure of fuel cell
JP6156317B2 (en) Membrane electrode assembly and fuel cell
US9147890B2 (en) Fuel cell with embedded flow field
KR20220031376A (en) A Fuel cell stack comprising bipolar plate having embossed structure
JP2021113352A (en) Power supply body and cell for water electrolysis having power supply body
JP2010146765A (en) Assembly for fuel cell, fuel cell, and manufacturing method of them
JP2009245632A (en) Flat-plate solid oxide fuel cell
JP2009277465A (en) Polymer electrolyte type fuel cell stack
CN210837968U (en) Membrane electrode structure, membrane electrode, fuel cell monocell and fuel cell stack
JP2024043817A (en) water electrolysis equipment
JP2021180129A (en) Fuel battery cell, fuel battery, and manufacturing method of fuel battery cell
JP2024063300A (en) Water electrolysis cell
JP2024043818A (en) Separator and water electrolyzer
JP2019160542A (en) Fuel cell stack

Legal Events

Date Code Title Description
STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION