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
  • H01M8/24—Grouping of fuel cells, e.g. stacking of fuel cells
  • H01M8/2465—Details of groupings of fuel cells
  • H01M8/247—Arrangements for tightening a stack, for accommodation of a stack in a tank or for assembling different tanks
• • 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
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M2300/00—Electrolytes
  • H01M2300/0017—Non-aqueous electrolytes
  • H01M2300/0065—Solid electrolytes
  • H01M2300/0082—Organic polymers
• • 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

• Fuel cell stack method for assembling and using such a fuel cell stack
• the invention relates to a fuel cell stack, method for assembling the fuel cell stack and use of such a fuel cell stack.
• EP 0 795 205 B1 is a fuel cell and a
• Fuel cell stack is known, in which the fuel cell units are mechanically stacked and held together by end plates with the aid of screw bolts. Sealing lips serve as sealing material on the individual bushings with a support ring as a mechanical abutment.
• System-related to the design is that there is direct contact between the pole plates designed as bipolar plates and the membrane, which can lead to corrosion problems.
• the object of the invention is to create a fuel cell stack which is suitable for all types of a PEM fuel cell and which at the same time overcomes the disadvantages of the prior art.
• a method for assembling such a fuel cell stack is the subject of claim 11, a preferred use is specified in claim 14.
• the invention relates to a fuel cell stack with at least two stacked fuel cell units and at least one end plate and / or a housing and / or an outermost pole plate or bipolar plate, the fuel cell units being connected to one another with a material with sealing and fixing properties.
• the invention also relates to a method for assembling a fuel cell stack, in which at least two fuel cell units are connected to form a stack via a material with sealing and fixing properties, and the use of such a fuel cell stack in a fuel cell system with HT-PEM fuel cells.
• the material also has adhesive properties, so that the fuel cell units connected via the material are bonded to one another and connected in a sealing manner. This means that either no further or only a slight sealing pressure is required due to end plates with a tensioning device.
• the material is elastic, so that thermally induced volume changes in the non-elastic structural parts of the stack, such as in particular the bipolar plate, the electrode, the membrane and / or matrix, can be compensated for by the elasticity of the connecting material.
• the mate ⁇ rial is periodic in part elastic. This is understood to mean that the material in successive areas is not continuously elastic, but alternately elastic and elastic, ie mechanically rigid, so that it also gives the stack mechanical strength.
• the fibers can be made of metal, carbon, glass fibers or the like, that is to say those fibers which can absorb tensile forces in connection with the base material.
• reinforced plastics refer to the glass-fiber ⁇ which can also be used.
• cross-link materials in a targeted, localized manner, for example by so-called beam cross-linking. It can periodically or the same material. have elastic or non-elastic properties in sections. The non-elastic partial areas are preferably located on the outside of the stack.
• the elements of the fuel cell unit - such as the membrane electrode unit and the pole plates - are likewise connected to one another via a material with sealing and fixing properties.
• This connection is preferably designed such that there is no direct contact between a bipolar plate and the membrane and / or matrix, because there is a risk that the acid located on the membrane or matrix attacks the material and / or the surface coating of the pole plate.
• the material is preferably a plastic that is stable up to approx. 300 ° C.
• a polymer material that is made up of identical or different monomer units is suitable for this.
• various monomeric units and additives occur in the plastic.
• an elastomer is used as the material taken, preferably an adhesive elastomer and particularly preferably an adhesive elastomer with non-elastic partial areas and / or with periodically partially elastic areas.
• the plastic forms a frame element that encloses the stack.
• the plastic forms support rings and / or sealing rings that seal the fuel cell units to one another at the bushings of the axial channels and / or so-called manifolds.
• the pole plates of neighboring cells are glued to one another by the material.
• the support and / or sealing rings made of plastic are, as mentioned, reinforced with metal or glass fibers according to one embodiment.
• the stack is accommodated in a pressure-carrying outer housing, so that no internal manifold is required, at least for a process gas and / or the cooling medium.
• the fuel cell stack preferably forms a closed design.
• an open stack design can also be realized if the fuel cell units are only partially sealed to one another.
• open ⁇ stack design with Wasserstoffruckbuchung and reformer operation is because of inevitable impurities membrane a Gasremists-, for example, m the gas supply line is attached, is advantageous.
• the stack in the open design is advantageously arranged with vertically oriented active cell areas so that the water drips out of the active cell areas.
• the stack is additionally held together by tie rods and screw bolts on the end plates, it being possible for at least one tie rod to be guided through an axial supply channel, for example.
• FIG. 1 shows a section through a fuel cell stack which is part of a fuel cell system
• FIG. 2 shows a detail from FIG. 1 in the edge area
• Figures 3 and 4 two alternative arrangements as a partial section before assembly
• Figure 5 shows a sealing element that is alternately fixed and / or sealed.
• a stack is a stack of at least two fuel cell units with the associated lines and at least part of the cooling system.
• the entire fuel cell system that has one or more subsystems is referred to as a fuel cell system.
• Each subsystem has at least one fuel cell unit, the corresponding supply lines, i.e. the process gas supply and discharge ducts, end plates and / or a housing and / or an outermost pole plate, a cooling system with cooling medium and cooling lines and a “fuel cell stack peripheral X.
• This periphery includes, for example a reformer, compressor, blower and / or heating for process gas preheating, as well as other modules if necessary.
• a fuel cell stack is denoted by 10 in FIG.
• the stack consists of a large number of individual ones
• MEA Membrane Electrode Assembly
• the entire arrangement is held together by means of end plates 12 and 13 and a plurality of tie rods, of which the tie rods 14 and 15 can be seen in the figure.
• the material formation 20 can be designed to be elastic in the area 21 in order to absorb temperature-related stresses, while in the areas 22 the material is elastic and serves, as it were, as a rigid frame.
• Each fuel cell unit 11 comprises at least one membrane 110 and / or matrix with a chemical one and / or physically bound electrolytes and two electrodes 111 and 112, which are located on opposite sides of the membrane and / or matrix.
• a reaction chamber 113, 114 borders on at least one electrode 111, 112, each of which has a pole plate or for two
• the design of the sealing means 20 can be seen in detail from FIG. 2 in particular: there is a seal 21 in the inner region which is elastically sealing and is deformed in the process. In the outer area there is a seal 22 which has fixing properties and is not deformed. With this construction, in particular through the fixing seals 22, a stability of the arrangement is achieved.
• a closed design of the fuel cell stack is realized.
• corresponding openings are to be provided in the lower region in the case of a vertical arrangement of the individual fuel cell units 11, 11 of the fuel cell stack 10.
• seals 20 made of the material with deformable areas 21 and non-deformable areas 22 are applied, for example vulcanized, to the bipolar plates 115.
• the actual MEA is inserted between two such arrangements of bipolar plates 115 with the seals 21.
• a force is required for sealing, which deforms the elastic regions 21 of the seals 20 until the non-elastic regions 22 lie on one another. The sum of the distances fixed in this way gives the total height of the stack.
• a sealing element 40 can have alternating fixing and sealing properties.
• the element 40 has an outer region 41, which is preformed, for example, in a bead-like manner and has natural inherent shadows and is suitable for compressing the MEA from the membrane 110 and electrodes 111, 112.
• the area 42 aligned with the pole plate has fixing properties. These properties can be achieved, for example, by incorporating fibers made of other materials, for example metallic materials, or, in the case of certain polymers, by means of beam crosslinking.
• the MEA can be sealed on the one hand in areas with elastic properties and likewise fixed in a support ring with non-elastic properties, so that the cell-internal force absorption is possible and the overall requirements for the end plates and their bracing become lower. This is possible because the plastic material used provides support functions at certain points.
• a single or double-walled container can serve as the housing.
• a possibility of insulation can play a role here, so that in the double-walled embodiment, for example, the cavity is filled with a latent heat storage material, preferably with paraffin.
• the housing With an open stack design with housing and pressurization in the housing, the housing must be pressure-stable.
• the invention improves the thermostability of the known stack structure, and allows an increase in the operation ⁇ temperature up to 300 ° C.
• HT-PEM fuel cells which are operated in a specific manner at such working temperatures and are referred to as HT-PEM fuel cells.
• HT-PEM fuel cells have operating temperatures between 80 and 300 ° C.
• the use of corrosive phosphoric acid in such PEM fuel cells means that the selection of materials is of particular importance.

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)

Applications Claiming Priority (3)

Publications (1)

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ID=7934279

Family Applications (1)

Country Status (7)

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Family Cites Families (16)

• 1999
  • 1999-12-23 DE DE19962682A patent/DE19962682A1/de not_active Ceased
• 2000
  • 2000-12-22 JP JP2001548462A patent/JP2003529186A/ja not_active Withdrawn
  • 2000-12-22 CN CN00818676A patent/CN1460302A/zh active Pending
  • 2000-12-22 CA CA002395503A patent/CA2395503A1/en not_active Abandoned
  • 2000-12-22 WO PCT/DE2000/004593 patent/WO2001048845A2/de not_active Application Discontinuation
  • 2000-12-22 EP EP00991114A patent/EP1285473A2/de not_active Withdrawn
• 2002
  • 2002-06-24 US US10/178,647 patent/US20030027031A1/en not_active Abandoned

Non-Patent Citations (1)

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