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
  • H01M8/0247—Collectors; Separators, e.g. bipolar separators; Interconnectors characterised by the form
• • 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 bipolar plate for a fuel cell consisting of two plate halves, which are in particular glued together, according to the type defined in more detail in the preamble of claim 1.
• the bipolar plate consists of two halves or layers which are materially connected to one another, for example welded in the case of metallic bipolar plates, as are described in the cited German patent application.
• the bipolar plate in the case of the bipolar plate according to the invention, it is provided, comparable to the generic prior art, that it is made up of two plate halves.
• the two plate halves have, at least on their mutually facing surfaces, alignment elements in the area of the surface, which consist of elevations with a height and corresponding depressions with a depth.
• all elevations and corresponding depressions have a greater extent in a first longitudinal direction than in a second transverse direction, with the longitudinal direction and the transverse direction being perpendicular to one another and lying in the same plane.
• Four of the alignment features are now located on each of the surfaces. Two of the alignment elements each lie on a common straight line and have the same orientation.
• the longitudinal direction of the two alignment elements lying on a common straight line is aligned in the same way, for example with respect to the outer edge of the half of the plate or a central line of symmetry of the half of the plate, while the other two alignment elements, which lie on a second straight line preferably intersecting the first line, are also aligned have the same orientation.
• the orientations are therefore the same in pairs, but preferably different between the pairs.
• the longitudinal direction of the two alignment elements runs with the same orientation along the straight line.
• the longitudinal direction is therefore arranged along or aligned with the straight line connecting the two respective alignment elements, so that an adjustment of the position along this straight line and along the longitudinal direction is still possible to a certain extent, which is due to the unavoidable minimal size difference between the depression on the one hand and the one corresponding to it Survey on the other hand, which is very small in practice, since only tolerances in the range of a few tenths of a millimeter have to be compensated for here.
• At least one of the straight lines does not coincide with a line of symmetry between the outer dimensions of the plate half.
• two of the alignment elements could be positioned on one and the same straight line in the middle of the corresponding half of the plate.
• the straight line runs off-center and deviates from such a line of symmetry in the middle of the structure.
• it can run at an angle to it, so that the alignment elements arranged with the same orientation are arranged, for example, in diagonally opposite corners of the respective half of the plate.
• the straight line which deviates from the line of symmetry is aligned parallel to it and deviates parallel from this line of symmetry by less than twice the dimension of the longitudinal direction.
• the straight line is only shifted “a little” in relation to the line of symmetry in order to efficiently counteract a potential twisting of the half-plates in relation to one another before the alignment and gluing. This makes production very error-resistant.
• the elevations and corresponding depressions have the same shape, with the elevations in the longitudinal direction, the transverse direction and their height being smaller than the depressions in the longitudinal direction, the transverse direction and their depth are trained.
• the same shape and the only minimally smaller design of the elevations in all three spatial directions compared to the depressions allows efficient absorption of the respective elevation by the respective depression in order to achieve a safe and reliable alignment, which aligns the two plate halves with very little Allows tolerances to each other and at the same time can efficiently compensate for the minimal manufacturing tolerances in the panels.
• the plate halves are formed from a plastic matrix with carbon-containing material distributed therein.
• Such bipolar plates which are often also referred to as graphite plates or carbon composite bipolar plates, are typically made in appropriate molds. They are therefore subject to comparatively low manufacturing tolerances, since the shape allows a forced shaping with low tolerances to be implemented. The same shape of the elevations and the corresponding depressions can thus be ideally used to optimally connect this type of panel to one another.
• the metallic bipolar plates described in the prior art described at the outset which expand accordingly during welding and therefore make the same shape of elevations and corresponding depressions virtually impossible.
• Another very advantageous embodiment also provides that the surfaces of the elevations running transversely to the surface are arranged at the same angle to the surface as the corresponding surfaces of the depressions. It is therefore particularly favorable if, within the alignment elements, both the elevations and the depressions have the same angle in their region running transversely to the surface. This angle can be, for example, about 5 to 15° and thus allows the two plate halves to be reliably immersed in one another in the area of their alignment elements with simultaneous alignment of the position of one plate half relative to the other plate half for gluing the two plate halves.
• the extent of the alignment elements in the transverse direction can be less than a third of the extent in the longitudinal direction in order to reliably define a targeted preferred direction, with the height and depth being less than half the extent in the transverse direction. This reliably prevents the elevations from resting on the bottom of the depressions, so that the contact and sealing is achieved by gluing between the actual plate halves and their surfaces in the areas provided for this purpose.
• the longitudinal direction can have an extent of, for example, 2 to 10 mm, preferably 5 to 7 mm.
• Such a structure is small enough to be placed between the flow-guiding regions and the outer edge of the plate half, and at the same time large enough to allow reliable positioning of the plate halves against one another.
• no additional elements such as projections or ears are then necessary in order to position the elements accordingly for alignment, which then take up unnecessary space in later use take up and bring an unnecessary weight with them or have to be removed from the finished bipolar plates in a correspondingly complex manner.
• FIG. 1 is a schematic exploded view of a prior art bipolar plate
• FIG. 2 shows a plan view of a first possible embodiment of a plate half of a bipolar plate according to the invention
• FIG. 3 shows a plan view of a second possible embodiment of a plate half of a bipolar plate according to the invention
• Figure 4 shows a longitudinal section and a cross section through a recess of the alignment element
• FIG. 5 shows a plan view of the recess according to FIG. 4
• FIG. 6 shows a cross-section and a longitudinal section through an elevation of an alignment element according to the invention
• FIG. 7 shows a plan view of the elevation according to FIG. 6;
• FIG. 8 shows a plan view of a third possible embodiment of a plate half of a bipolar plate according to the invention.
• FIG. 9 shows a plan view of a fourth possible embodiment of a plate half of a bipolar plate according to the invention
• a diagrammatically indicated bipolar plate 1 can be seen in an exploded view in FIG. 1 . It consists of two plate halves 2, 3, which are connected to each other via a sealing and adhesive compound 4 in the embodiment shown here.
• a flow field 5 for one of the educts of a fuel cell constructed with such bipolar plates 1, in particular atmospheric oxygen or hydrogen, is provided in the surface shown at the top.
• a coolant flow field is typically enclosed between the two plate halves 2, 3, of which only one of the halves, namely the half located in the lower plate half 3, can be seen. This is denoted by the reference number 6 . Otherwise 1 openings 7 are provided for the supply and removal of media in the bipolar plate, which in a conventional manner are executed.
• FIG. 2 the view, for example, of the lower plate half 3 and its corresponding flow field 6 for the cooling medium is shown again.
• the flow field 6 is located together with the openings 7 already mentioned within an outer border 8 of the respective plate halves 2, 3 and the later bipolar plate 1 formed from these plate halves 2, 3 by gluing.
• Each of the plate halves 2, 3 comes from a press mold and consists of a mixture of a carbonaceous material, such as graphite, and a corresponding plastic matrix.
• the finished plate halves 2, 3 are largely identical over the entire stack of the fuel cell.
• alignment elements 9 are now provided on the mutually facing surfaces of the plate halves 2, 3, each consisting of an elevation or elevation 14 (see FIG. 6) in one of the plate halves 2, 3 and a corresponding depression 12 (cf. FIG. 4) are formed in the same area of the respective other plate half 3, 2.
• two alignment elements 9 are formed approximately in the center in relation to the flow field 6 and here transversely to the main direction of the channels through which flow occurs.
• they are designed in the form of two rectangles with rounded edges, which are arranged in such a way that they are connected to one another by a straight line that is drawn in dashed lines and is labeled 10 .
• Another pair of alignment elements 9 is also located between the outer border 8 and the openings 7 and can be connected to one another via a further straight line 11.
• These two pairs of alignment elements 9 are each arranged in the same orientation, which in the exemplary embodiment shown in Fig. 2 is aligned with a longitudinal direction of the respective alignment elements 9, which will be explained in the following Figures 4 et seq., or along the straight line 11 and 10 respectively.
• the straights 10, 11 intersect approximately at a right angle, so that the longitudinal directions of the alignment elements 9, which each belong together in pairs, are correspondingly at right angles to one another.
• At least one of the straight lines is offset parallel to a line of symmetry S of the plate half 3 in order to reliably prevent the plate halves 2, 3 from being assembled in a twisted manner.
• the offset between the line of symmetry S and the straight line 11 is smaller than twice the extent of the alignment elements 9 in the longitudinal direction, i.e. comparatively small in relation to the dimensions of the entire plate half 3 or bipolar plate 1.
• FIG. 3 An alternative arrangement of the individual alignment elements 9 is shown in FIG. 3 .
• the straight lines 10 and 11 run diagonally from one corner to the other and intersect approximately in the center of the plate half 3.
• the two alignment elements 9 connected to one another via the respective straight line 10 or 11 are again in the same alignment formed, which, however, does not have to be aligned with the respective straight line 10, 11, as can be seen in the representation of FIG.
• the alignments of the orientation of the respective pairs of alignment elements 9, which are connected to each other via the respective straight line 10, 11, can be formed, for example, at a greater angle than the angle of intersection between the two straight lines 10, 11, so that the orientations are, for example, in an angular range between 80 and 100° to each other.
• FIG. 4 An enlarged representation of a possible configuration of the depressions 12 and elevations 14 of the alignment elements 9 can now be seen in the representation of FIG. 4 et seq.
• the plate half 2 is shown here, which in the illustration of FIG. 1 corresponds to the upper half of the plate and, purely by way of example, to the anode plate.
• the indentation 12 can be seen in a longitudinal section along the longitudinal direction L, in the cross section shown to the right along the transverse direction Q.
• the indentation 12 points along the longitudinal direction L, for example in the area which faces the plate half 2 on the surface 13 , a first extent L1 in the longitudinal direction L and a first extent Q1 in the transverse direction Q.
• the depth between the surface 13 and the deepest point of the depression 12 is T.
• the depression 12 can have the shape of a rectangle with rounded edges or two semicircles connected by straight edges, as shown in FIG. 5 in a viewing direction according to the arrow V in FIG.
• the elevation 14 corresponding to the depression 12 in the representation of FIG. 4 is now shown, wherein the longitudinal section can also be seen here on the left and the cross section on the right.
• the increase 14 protrudes over the surface 15 of the second plate half 3 accordingly.
• L In the longitudinal direction L, it again has a dimension L2 in the area of the intersection lines with the surface 15 and in the transverse direction Q a dimension of Q2. It has a height H from the surface 15 .
• the height H is also correspondingly smaller than the depth T in order to achieve centering without impairing the contact of the surfaces 13, 15 against one another or against the adhesive and sealing compound 4 arranged between them.
• the depth T can have, for example, the 0.5 mm already mentioned above, while the height H is only 0.45 mm.
• the depth T should be smaller than a third of the thickness of the entire plate half 2, 3 in order to prevent an unnecessary reduction in the stability of the plate half 2.
• Figure 8 shows a variant of the embodiment according to figure 2.
• the arrangement of the alignment elements 9 according to figure 2 could be described as being in the shape of a cross.
• the arrangement of the alignment elements 9 according to FIG. 8 could similarly also be described as being in the shape of a cross, the cross in FIG. 8 being tilted to the side or rotated by 45° in comparison to FIG. 2 .
• Fig. 9 combines design elements of the embodiment of Fig. 3, where the arrangement of the alignment elements 9 could be described as circular, and the embodiment of Fig. 8:
• the two Alignment elements 9 left below and right above are arranged as in Fig. 3; the two alignment elements 9 top left and bottom right as in Fig. 9.
• each pair of alignment elements 9 could thus comprise, for example, a depression 12 and a ridge 14 on the respective plate half 2,3.
• a different design of the pairs to one another would also be conceivable.

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• 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)

Applications Claiming Priority (2)

Publications (1)

Family

ID=82940040

Family Applications (1)

Country Status (8)

Family Cites Families (4)

• 2021
  • 2021-07-22 DE DE102021207840.0A patent/DE102021207840A1/de active Pending
• 2022
  • 2022-07-07 TW TW111125523A patent/TW202312546A/zh unknown
  • 2022-07-20 WO PCT/EP2022/070298 patent/WO2023001870A1/de active Application Filing
  • 2022-07-20 CN CN202280036997.9A patent/CN117378067A/zh active Pending
  • 2022-07-20 EP EP22755084.5A patent/EP4374439A1/de active Pending
  • 2022-07-20 JP JP2024502531A patent/JP2024527415A/ja active Pending
  • 2022-07-20 KR KR1020237043135A patent/KR20240008904A/ko active Search and Examination
  • 2022-07-20 CA CA3220513A patent/CA3220513A1/en active Pending

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