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
  • H01M8/0258—Collectors; Separators, e.g. bipolar separators; Interconnectors characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant
  • H01M8/0263—Collectors; Separators, e.g. bipolar separators; Interconnectors characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant having meandering or serpentine paths
• • 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
  • H01M8/0267—Collectors; Separators, e.g. bipolar separators; Interconnectors having heating or cooling means, e.g. heaters or coolant flow channels
• • 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
  • H01M8/24—Grouping of fuel cells, e.g. stacking of fuel cells
  • H01M8/2465—Details of groupings of fuel cells
  • H01M8/2483—Details of groupings of fuel cells characterised by internal manifolds
• • 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
• • 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
  • H01M8/0221—Organic resins; Organic polymers
• • 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
  • H01M8/0226—Composites in the form of mixtures
• • 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 invention relates to a cathode plate of a
• a bipolar element comprising a first plate side on which a cathode channel structure for distributing a
• Oxidizing agent is formed, and one of the first
• Cooling channel structure is formed for distributing a coolant.
• the present invention relates to a method for operating a cathode plate of a fuel cell, wherein the cathode plate has a first plate side, on which a
• Cathodic channel structure is formed for distributing an oxidizing agent, and a second plate side facing away from the first plate side, on which a cooling channel structure for
• Distribution of a coolant is formed, and wherein the coolant and the oxidant of the cathode plate are supplied separately.
• the basic structure of a fuel cell and especially a polymer electrolyte membrane fuel cell (PEMFC or PEM fuel cell), as described for example in the document US 2008/0233443 AI, comprises a membrane-electrode assembly (MEA), which in turn consists of one
• Anode a cathode and arranged between the anode and cathode polymer electrolyte membrane (PEM), which is also called ionomer membrane, constructed.
• PEM polymer electrolyte membrane
• MEA membrane-electrode assembly
• Separator plate channels for the distribution of fuel for example, hydrogen
• the other separator plate has channels for the distribution of oxidant (for example, oxygen-enriched air).
• the channels for the distribution of fuel and the channels for the distribution of oxidant are facing the membrane-electrode assembly (MEA), wherein the channels each form a channel structure, which is referred to as a so-called flow field or flow field.
• the electrodes, ie the anode and the cathode, are in this case designed as gas diffusion electrodes (GDE) and have the function of dissipating the current generated in the electrochemical reaction (for example 2H 2 + 0 2 -> 2H 2 O) and the reactants ( Educts and products) to diffuse through.
• GDE gas diffusion electrodes
• Such a fuel cell can produce high power electrical power at relatively low operating temperatures.
• real fuel cells are usually stacked into so-called fuel cell stacks (stacks).
• so-called bipolar elements bipolar
• the monopolar separator plates are also called end plates and can differ structurally significantly from the bipolar elements.
• the bipolar elements mechanically, electrically and thermally connect the anode of one fuel cell to the cathode of another
• the bipolar elements may consist of a single bipolar plate (one-piece) or composed of two partial plates (multi-part). While in a one-piece bipolar element, the bipolar plate on its one plate side, which faces in the installed state of the cathode of a fuel cell, a channel structure for the distribution of a
• Oxidizing agent is on the other side of the plate, which in the installed state of the anode of an adjacent
• the two sub-plates which are also referred to as anode plate and cathode plate, but need not necessarily be mirror images. It is only important that they have at least one common contact surface to which they are connected can be.
• the partial plates have an uneven topography. This results in each of them away from each other
• the channel system for the oxidant is therefore also the channel system for the cooling air at the same time. Accordingly, the supplied air is used both as an oxidizing agent and as a coolant on the side of the cathode, so that a separate cooling channel system is dispensable in the bipolar plates, whereby the space can be minimized.
• volume flow of the oxidizing agent for the cathode and the volume flow of the cooling air can not be regulated separately, which affects the operational management of the fuel cell stack.
• Fuel cell can heat up, but large volume flows of the oxidant, so that at low temperatures numerous accumulating liquid water can be removed,
• the oxidizing agent should be supplied as low as possible, to excessive
• fuel cell stacks are known in which the cathode channel structure is completely separated from the cooling channel structure.
• the different and separate channel structures which provide a separate supply of oxidant and coolant to the various components.
• a respective bipolar element consists of two sub-plates (an anode-facing anode plate and a cathode-facing cathode plate) in which the respective facing surfaces of the partial plates
• the cavity structure arises.
• the cavity structure is in
• a cathode plate facing the sub-plate corresponds to the cathode plate of the type designated input and is disclosed for example in DE 100 15 360 B4, from the addition of a method of the input
• “Closed cathode” has the advantage that the temperature and the cathode supply of the fuel cell stack
• Cathode product is a major part of the product water contained, outside of the fuel cell, the product water flow of the cathode has cooled so far that liquid water is produced. In stationary and mobile applications of such
• Fuel cell stack must be integrated with a solution for the disposal of the liquid water, which is especially at
• the invention is therefore an object of the invention to provide a solution in a structurally simple way
• Fuel cell stack is provided, which is a cooling of stacked fuel cells without the above
• the object is achieved in that at least one from the first plate side to the second
• Plate side extending passage is formed through the cathode plate, which connects the cathode channel structure and the cooling channel structure.
• the object is achieved in a method of the type called input, that after the
• Bipolarelement provided, which is characterized by a functional design and has a simple and inexpensive construction. The two concepts are combined in an inventive way. At this
• Electrochemical reaction resulting cathode products are still transferred according to the invention in the fuel cell stack in the flow of the coolant.
• combined media management means that
• Cathode is also the case, wherein the exhaust air flow of the products of the cathode and the cooling is carried out together as in the concept of" open cathode ".
• the transfer of the cathode products into the cooling channel structure is still suitable within the fuel cell stack
• the dew point of the combined mixture of cathode product and coolant can be lowered so that the product water in gaseous form from the system or the
• Fuel cell stack can be performed. Further is
• the amount of oxidant supplied regardless of the amount of coolant supplied, so that both quantities or volume flows are independently controllable and a fuel cell or a fuel cell stack can be started easily, especially at low temperatures, quickly. Since the volume flow of
• Oxidizing agent for the cathode many times less than is the volume flow of the coolant, it can be in the combined media management a filtering of the air as
• Oxidizing agent for the cathode can be realized with little effort.
• the combined media guide also has the advantage that due to the separate supply or supply of
• Oxidizing agent and coolant the individual media streams can be controlled individually and separately from each other, which in particular the cold start behavior of a
• Fuel cell stack improved. Furthermore, the as
• Oxidizing agent used air can be targeted and costly filtered, so that the fuel cell stack with the
• the invention provides, in an embodiment of the cathode plate, that the cathode channel structure has at least one channel end on the first plate side, which is flow-connected via the at least one passage to the cooling channel structure formed on the second plate side.
• the cathode channel structure has at least one channel whose channel end opens into the passage, so that at the end of the channel of the cathode channel structure, the cathode product is supplied via the passage to the coolant flow.
• a single passage may also divert the cathode product of multiple channel ends, and then a type of collection zone may be formed between the passage and the channel ends, which collects the cathode product from the channel ends and passes them to one passageway. Since the volume flow of the coolant is drier than the volume flow of the cathode product or the
• Oxidizing agent a "dilution" of the cathode Product, when this is transferred into the coolant flow, whereby the risk of condensate formation is significantly reduced.
• the cathode products are first supplied to the heated coolant, since so condensation by cooling the cathode products can be avoided, is in
• Cooling channel structure having an inlet portion and a downstream of the inlet portion formed outlet region for the coolant, wherein the at least one passage which extends from the first plate side to the second plate side, upstream of the outlet region opens into the cooling channel structure.
• Cooling are formed by depressions or recesses on the two sides of the plate, using known methods, whereby the manufacturing cost of a cathode plate according to the invention can be kept low.
• Canals are discontinuously formed by hollow embossing, hydroforming, high-speed forming,
• the cathode channel structure as at least one formed in the first plate side
• Recess is formed and / or that the cooling channel structure is formed as at least one formed in the second plate side recess.
• Cathode plate provided that a respective recess in the cathode channel structure is associated with a passage through which the respective recess with the cooling channel structure
• the invention provides that the cathode channel structure comprises a plurality of recesses and at least two recesses of the cathode channel structure are associated with a passage through which the respective recess is fluidly connected to the cooling channel structure.
• Cathode channel structure formed recesses to the number of the cathode channel structure with the cooling channel structure
• Flow connecting passages is at least one and at most six. Consequently, six channels of the
• Cathode channel structure associated with a single passage to the cathode product in the flow of coolant
• the invention provides that all recesses formed in the cathode channel structure by a passage with the
• Cooling channel structure are flow connecting.
• all the channels of the cathode channel structure may be associated with a single passageway to transfer the cathode product into the flow of the cathode
• the flow field ie the contact area between the cathode plate and the membrane-electrode assembly (MEA)
• MEA membrane-electrode assembly
• the invention provides in an embodiment that the
• the channels of the cathode channel structure are L-shaped, U-shaped or parallel, rectilinear design.
• the cathode plate consists of electrically conductive materials such as metals, electrically conductive plastics or compounds.
• electrically conductive materials such as metals, electrically conductive plastics or compounds.
• polymer-bound, highly filled graphite-based compound materials have proven to be alternative
• structured bipolar subplates or one-piece bipolar plates can be polymer-bound
• Figure 1 is a perspective plan view of a first
• FIG. 2 a shows a detailed view of the inflow region of the cathode channel structure shown in FIG. 1,
• FIG. 2b shows a detailed view of the outflow region of the cathode channel structure shown in FIG. 1, which according to the invention connects the cathode channel structure to the cooling channel structure.
• FIG. 3 is a perspective plan view of a second plate side with a cooling channel structure of the cathode plate shown in FIG. 1,
• FIG. 4 a shows a detailed view of a longitudinal end of the cooling channel structure shown in FIG. 3,
• FIG. 4b shows a detail view of the other longitudinal end of the cooling channel structure shown in FIG. 3,
• Figure 5 is an enlarged sectional view of a supply line of oxidant to the cathode channel structure in
• Figure 6 is an enlarged sectional view in the
• Invention connect the cathode channel structure with the cooling channel structure
• FIG. 7 shows a cathode plate with an alternative
• FIG. 8 is a side sectional view of the cathode plate shown in FIG.
• FIGS. 1 to 6 show different views of a cathode plate 1 according to the invention according to a first embodiment
• the cathode plate 1, 1 corresponds to a partial plate, which forms a bipolar element for an air-cooled fuel cell stack together with an anode plate not shown in greater detail in the figures.
• a fuel cell stack has a plurality of such bipolar elements, between which a respective membrane electrode assembly (MEA) is arranged and which limit the individual fuel cells.
• MEA membrane electrode assembly
• a cathode channel structure 3 which serves to distribute an oxidant over the first plate side 2.
• the oxidizing agent is passed to the cathode plate 1 via a gas guide hole 4 and passes from the gas guide hole 4 via a between the cathode channel structure 3 and the
• Gas guide hole 4 formed line system 5 (see, for example, Figure 5) to the cathode channel structure 3.
• Embodiment a plurality of recesses 6, which the
• Recesses 6 are formed by webs 30 (see for example FIGS. 3 and 4a) and lead the oxidizing agent to one
• the cathode channel structure 3 has several
• Recesses 8 (in total, it is in the illustrated
• Embodiment six recesses which are formed in the first plate side 2, which faces in the installed state of the cathode.
• the recesses 8 represent individual channels 9, which are traversed by the oxidizing agent from the passage openings 7 from.
• Cathode channel structure 3 also alternative of corresponding
• the passage openings 7 are formed at a first longitudinal end 10 of the cathode plate 1, wherein the gas guide hole 4 is arranged between the first longitudinal end 10 and the passage openings 7. From the first
• Cathode channel system 3 are at least one passage 14th flow-connected, so that the oxidizing agent or after the electrochemical reaction at a respective channel end 12 present cathode product can be removed via a corresponding passage 14 of the cathode channel system 3.
• FIG. 2 b which shows an enlarged detail view of FIG. 1, a plurality of recesses 8 and / or channels 9 are assigned to a passage 14, with the respective channel ends 12 opening into a sort of collecting zone and collecting there the cathode product to be taken off.
• a respective passage 14 of the cathode plate 1 extends from the first plate side 2 to a second plate side 15 (see, for example, Figure 3 or 4b), which faces away from the first plate side 2.
• a second plate side 15 see, for example, Figure 3 or 4b
• Plate side 15 is a cooling channel structure 16 for distributing a coolant formed to the fuel cell of the
• the channel ends 12 of the recesses 8 or channels 9 formed on the first plate side 2 are flow-connected to the cooling channel structure 16 on the second plate side 15, so that the cathode product is conducted via the passages 14 into the cooling channel structure 16 and there together with the Coolant is directed away from the fuel cell or the cathode plate 1.
• the coolant channel structure 16 is rectilinear
• Plate side 2 which flows substantially from the first longitudinal end 10 to the second longitudinal end 11 of the first plate side 2, as can be seen for example in FIG. It could, of course, for the coolant passage structure 16, a single recess as sufficient, but causes the
• the cooling passage structure 16 of the cathode plate 1 for the coolant has an inlet portion 18 formed along a first longitudinal side 19 of the cathode plate 1 and an outlet portion 20 formed downstream of the inlet portion 18, which is on one of the first
• the cathode product is supplied to the coolant, so that they together on
• Outlet area 20 are led away from the cathode plate 1.
• Cooling channel structure 16 is directed away from the cathode plate 1, which is shown by the arrows K + P in Figures 1 and 3. As can be seen, for example, from FIG. 2 b or FIG. 6, at least one recess 8 of the cathode channel structure 3 is assigned to a passage 14. As already explained above, a respective recess 8 of the cathode channel structure 3 is flow-connected to the cooling channel structure 16 via an associated passage 14.
• FIGS. 7 and 8 show a cathode plate 1 'according to a second embodiment of the invention.
• the cathode channel structure 3 is formed with channels 9 'running parallel to one another on the first plate side 2.
• Cooling passage structure 16 flow connecting passages 14 at least one and at most six. Ultimately, however, the upper limit of six is not fixed because, for a real ratio, it is rather due to the resulting degree of
• Coolant flow arrives for a certain operating point.
• the cathode plate 1, 1 'described in detail above is used in a fuel cell stack, resulting in a method for operating the cathode plate 1, 1', in which the coolant and the oxidant of the cathode plate 1, 1 'are supplied separately. It will be after the
• a cathode plate 1, 1 ' according to the invention is described above, which is used in an air-cooled fuel cell and in which the cathode products are transferred into the air flow of cooling, so that the cathode product and the cooling air flow together from the cathode plate 1, 1 'be forwarded.
• the cathode reactants and the air flow of the cooling separately from the fuel cell or the
• the invention includes all transfers of the cathode products in the air flow of the cooling within the
• the invention also includes
• Fuel cell stack is a failure of the product water can be avoided under suitable operating conditions.
• the dew point of the combined volume flow can be lowered so that the product water can be led out of the system in gaseous form.
• the cathode is independent of the air cooling regulated and the stack can be started easily, especially at low temperatures, quickly.
• the volume flow of the cathode supply is many times lower than that
• Media management is a separate supply to the cathode and ventilation, so that the media streams can be controlled individually, which improves the cold start behavior of the fuel cell stack. Furthermore, the air supply to the cathode can be selectively filtered, so that the fuel cell stack with the cathode plate according to the invention for the operation

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• 2015
  • 2015-01-19 DE DE102015100704.5A patent/DE102015100704B3/de active Active
• 2016
  • 2016-01-15 CN CN201680006354.4A patent/CN107592945B/zh active Active
  • 2016-01-15 WO PCT/EP2016/050833 patent/WO2016116381A1/de active Application Filing

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