Interconnector plate for a fuel cell, and fuel cell system for an aircraft

Abstract

An interconnector plate for a fuel cell and a fuel cell system for an aircraft. For better extraction of the energy generated by the fuel cell, an interconnector plate can be attached by form fit to fixing studs of the fuel cell by retaining eyes. The interconnector plate may additionally be secured using glass solder. In preparation for a higher power density, a fuel cell can be produced in ceramic by 3D-printing and has an improved power density because of its helical shape.

Claims

1. An interconnector plate for a fuel cell, the interconnector plate comprising: a strip-like region, which, in an installed state, follows a contour of a fuel cell segment; a connecting region, which is at an end of the strip-like region and is configured for extracting electrical energy from the interconnector plate; at least one retaining eye, which is formed in the strip-like region and by which the interconnector plate can be retained by a form fit engagement with the fuel cell segment by attachment to a retaining device of the fuel cell segment; and at least one contact tongue, which extends from the strip-like region to be insertable within a gas channel of the fuel cell segment.

2. The interconnector plate of claim 1, wherein the interconnector plate is configured as a bent sheet metal part.

3. The interconnector plate of claim 1, wherein the at least one tongue contact is a plurality of contact tongues, which are arranged in a comb-like fashion, such that each of the plurality of contact tongues is insertable within the gas channel of the fuel cell segment.

4. The interconnector plate of claim 1, wherein the interconnector plate has a same expansion coefficient as an expansion coefficient of the gas channel in which it is insertable to prevent delamination of the interconnector plate and the at least one contact tongue.

5. The interconnector plate of claim 1, wherein the at least one retaining eye is a first retaining eye and a second retaining eye, the at least one contact tongue being arranged, along the strip-like section, between the first retaining eye and the second retaining eye.

6. The interconnector plate of claim 1, wherein the at least one retaining eye has a circular or D-shaped form.

7. The interconnector plate of claim 1, wherein the at least one contact tongue extends from the strip-like region such that a direction of insertion of the at least one contact tongue within the gas channel of the fuel cell segment is radially inward.

8. A fuel cell segment for forming a fuel cell, the fuel cell segment comprising: a gas channel; at least one fixing stud; and the interconnector plate of claim 1; wherein the at least one fixing stud engages with the at least one retaining eye to retain the interconnector plate on the fuel cell segment by a form fit engagement therewith.

9. The fuel cell segment of claim 8, wherein the at least one fixing stud is configured as a hemisphere, a quarter sphere, or a hook.

10. The fuel cell segment of claim 8, wherein the fuel cell segment comprises, at an edge of the gas channel, a contact face for the strip-like region of the interconnector plate, so that the strip-like region, in an installed state, follows a contour of the fuel cell segment.

11. A fuel cell or a solid oxide fuel cell for a fuel cell system or for an aircraft, the fuel cell comprising: a plurality of fuel cell segments for forming the fuel cell, each of the plurality of fuel cell segments comprising: a gas channel; at least one fixing stud; and the interconnector plate of claim 1; wherein the at least one fixing stud engages with the at least one retaining eye to retain the interconnector plate on the fuel cell segment by a form fit engagement therewith; and wherein the plurality of fuel cell segments are stacked one on top of another to form the fuel cell or the solid oxide fuel cell.

12. An aircraft comprising the fuel cell or the solid oxide fuel cell of claim 11.

13. A method for manufacturing an interconnector plate for a fuel cell segment, the method comprising: providing a flat metal sheet; cutting out a flat interconnector plate blank; forming, from the flat interconnector plate blank, the interconnector plate, which comprises: a strip-like region, which, in an installed state, follows a contour of the fuel cell segment; at connecting region, which is at an end of the strip-like region and is configured for extracting electrical energy from the interconnector plate; at least one retaining eye, which is formed in the strip-like region and by which the interconnector plate can be retained by a form fit engagement with the fuel cell segment by attachment to a retaining device of the fuel cell segment; and at least one contact tongue, which extends from the strip-like region to be insertable within a gas channel of the fuel cell segment; and bending the interconnector plate blank into a three-dimensional form, which corresponds to the contour of the fuel cell segment such that, in the installed state, the interconnector plate follows the contour of the fuel cell segment.

14. A method of manufacturing a fuel cell, the method comprising: providing a plurality of fuel cell segments, each of which comprises a gas channel delimited by a gas channel wall; stacking the plurality of fuel cell segments one on top of another; forming a plurality of interconnector plates by: providing a flat metal sheet; cutting out a flat interconnector plate blank; forming, from the flat interconnector plate blank, the interconnector plate, which comprises: a strip-like region, which, in an installed state, follows a contour of the fuel cell segment a connecting region, which is at an end of the strip-like region and is configured for extracting electrical energy from the interconnector plate; at least one retaining eye, which is formed in the strip-like region and by which the interconnector plate can be retained by a form fit engagement with the fuel cell segment by attachment to a retaining device of the fuel cell segment; and at least one contact tongue, which extends from the strip-like region to be insertable within a gas channel of the fuel cell segment; and bending the interconnector plate blank into a three-dimensional form, which corresponds to the contour of the fuel cell segment such that, in the installed state, the interconnector plate follows the contour of the fuel cell segment; inserting the at least one contact tongue of each of the plurality of interconnector plates within a gas channel of a corresponding one of the plurality of fuel cell segments; and attaching each of the plurality of the interconnector plates to the gas channel wall of the corresponding one of the plurality of fuel cell segments.

15. The method of claim 14, comprising subsequently coating the gas channel wall of each of the plurality of fuel cell segments with an electrode coating so that each of the plurality of interconnector plates is embedded in the electrode coating.

16. The fuel cell segment of claim 8, wherein the interconnector plate is configured as a bent sheet metal part.

17. The fuel cell segment of claim 8, wherein the at least one tongue contact is a plurality of contact tongues, which are arranged in a comb-like fashion, such that each of the plurality of contact tongues is insertable within the gas channel of the fuel cell segment.

18. The fuel cell segment of claim 8, wherein the interconnector plate has a same expansion coefficient as an expansion coefficient of the gas channel in which it is insertable to prevent delamination of the interconnector plate and the at least one contact tongue.

19. The fuel cell segment of claim 8, wherein the at least one retaining eye is a first retaining eye and a second retaining eye, the at least one contact tongue being arranged, along the strip-like section, between the first retaining eye and the second retaining eye.

20. The fuel cell segment of claim 8, wherein the at least one contact tongue extends from the strip-like region such that a direction of insertion of the at least one contact tongue within the gas channel of the fuel cell segment is radially inward.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Example embodiments of the disclosure herein are described in more detail below with reference to the appended schematic drawings. In the drawings:

(2) FIG. 1 shows an example of a helical fuel cell;

(3) FIG. 2 shows an example of flat fuel cell region;

(4) FIG. 3 shows a plurality of fuel cell regions;

(5) FIG. 4 shows an example of a fuel cell comprising the fuel cell regions in FIG. 2;

(6) FIG. 5 shows a section through the fuel cell from FIG. 4;

(7) FIG. 6 shows a further example of a fuel cell;

(8) FIG. 7 is a schematic view of the gas supply to the fuel cell from FIG. 6;

(9) FIG. 8 through FIG. 12 show an example embodiment of a fuel cell with interconnector plates;

(10) FIG. 13 shows an example of an interconnector plate;

(11) FIG. 14 shows the interconnector plate from FIG. 13 in the installed state;

(12) FIG. 15 through FIG. 17 show example embodiments of the fixing of the interconnector plate;

(13) FIG. 18 and FIG. 19 show an example of manufacture of the interconnector plate from FIG. 13;

(14) FIG. 20 and FIG. 21 each show an example embodiment of the fuel cell system;

(15) FIG. 22 shows an example embodiment of a fuel cell;

(16) FIG. 23 shows a schematic illustration of the supply and discharge of gas in the fuel cell from FIG. 22;

(17) FIG. 24 shows a detail view of a wiring of a fuel cell from FIG. 22;

(18) FIG. 25 shows an example embodiment of an interconnector plate; and

(19) FIG. 26 shows an example of a wiring process of the fuel cell.

DETAILED DESCRIPTION

(20) Reference is firstly made to FIG. 1 which shows an example of a fuel cell 10. The fuel cell 10 has a first fuel cell region 12 and a second fuel cell region 14. Each fuel cell region 12, 14 contains a gas channel 16.

(21) The first fuel cell region 12 comprises a first gas channel 18, for example for an oxidator, and the second fuel cell region 14 comprises a second gas channel 20, for example for fuel.

(22) The first gas channel 18 and the second gas channel 20 extend in a helix in a peripheral direction around a structural axis 22. The structural axis 22 here runs in the center of the helix.

(23) The first gas channel 18 and the second gas channel 20 are connected together along their extension direction by an ion-conductive separating layer 24. Furthermore, an isolating layer 26 is provided to prevent cell conclusion.

(24) Each gas channel 16 may contain an electrode coating 28 for extracting the generated electrical energy from the fuel cell 10.

(25) Reference is made to FIG. 2 through FIG. 4 which show an example of a fuel cell 30. The fuel cell 30 comprises a plurality of fuel cell regions 32. A first fuel cell region 34 and a second fuel cell region 36 may be formed as one piece.

(26) Each fuel cell region 32 comprises a first gas channel 38 and a second gas channel 40. The fuel cell region 32 is configured such that the gas channels 38, 40 run in the peripheral direction around a structural axis 42. The structural axis 42 runs perpendicular to the drawing plane in FIGS. 2 and 3.

(27) Each gas channel 38, 40 has a gas channel curvature region 44 and an adjoining gas channel planar region 46. The gas channel curvature region 44 is preferably curved through 180°. The gas channel planar region 46 is straight with no curvature, giving an elongated oval form of the fuel cell region 32.

(28) The first gas channel 38 and the second gas channel 40 each have a gas inlet region 48. The gas inlet region 48 is evident in the top view of FIGS. 2 and 3 but is not shown in detail in FIG. 4. In FIG. 4, the gas inlet region 48 is oriented upward. The gas inlet region 48 is arranged for example in the middle of the gas channel planar region 46. The gas inlet region 48 is preferably arranged such that, e.g. on arrangement of a further fuel cell region 32 along the structural axis 42, the gas inlet region 48 is fluidically connected to the respective gas channel 38, 40 of the further fuel cell region 32.

(29) The first gas channel 38 and the second gas channel 40 each have a gas outlet region 50. The gas outlet region 50 is below the drawing plane in the top view of FIGS. 2 and 3 and therefore not visible. In FIG. 4, the gas outlet region 50 is oriented downward. The gas outlet region 50 is arranged for example in the middle of the gas channel planar region 46. The gas outlet region 50 is preferably arranged such that, e.g. on arrangement of a further fuel cell region 32 along the structural axis 42, the gas inlet region 48 is fluidically connected to the gas outlet region 50 of the respective gas channel 38, 40 of the further fuel cell region 32.

(30) Each gas channel 38, 40 may contain an electrode coating 52 in order to extract the generated electrical energy from the fuel cell 30.

(31) As a whole, thus a continuous first gas channel 38 and second gas channel 40 may be formed. Thus the effective area is significantly enlarged and the volumetric power density may be increased.

(32) As FIG. 5 shows, the gas channels 38, 40 may be formed at an angle α relative to the horizontal direction. With this design, production by 3-D printing may be simplified because fewer or no support structures are required.

(33) Reference is made to FIG. 6 and FIG. 7 which show an example of a fuel cell 54 in different variants. The fuel cell 54 comprises a plurality of fuel cell regions 32, a first distribution pipe 56 and a second distribution pipe 58. The first distribution pipe 56 may be provided for the fuel, while the second distribution pipe 58 may be provided for the oxidator.

(34) The distribution pipes 56, 58 are arranged in a region which is surrounded by the gas channels 38, 40, or enclosed when viewed in top view. The distribution pipes 56, 58 in the present case run parallel to the structural axis 42.

(35) Each distribution pipe 56, 58 has a gas supply region 60 which may be configured so as to be connectable to a gas reservoir. In the case of the oxidator, the gas supply region 60 may serve for the air supply without a gas reservoir.

(36) Each distribution pipe 56, 58 also has a gas discharge region 62 from which the unused residual gas and reaction product may escape.

(37) In the variant shown in FIG. 6, the first distribution pipe 56 serves for distribution of the fuel, and the second distribution pipe 58 for distribution of the oxidator. In this variant, the first distribution pipe 56 with the first gas channel 38, and the second distribution pipe 58 with the second gas channel 40, form a respective continuous fluid path.

(38) In the variant shown in FIG. 7, the fuel cell 54 is divided for example into three part portions 64. Each part portion 64 is supplied with fuel and oxidator through the distribution pipes 56, 58, independently of the other part portions 64.

(39) Reference is made to FIGS. 8 through 14 which show an example of a fuel cell 66. The fuel cell 66 is configured similarly to the fuel cell 54 and also has a plurality of interconnector plates 68. Each interconnector plate 68 is arranged on a fuel cell region 70 of the fuel cell 64. The generated electrical energy can be extracted by the interconnector plates 68.

(40) The interconnector plate 68 comprises a plurality of contact tongues 71. Each contact tongue 71 protrudes either into the first gas channel 38 or into the second gas channel 40. The contact tongues 71 are attached to the wall of the respective gas channel 38, 40. The electrode coating 52 is preferably arranged such that the contact tongues 71 are embedded in the electrode coating 52.

(41) Each interconnector plate 68 furthermore comprises an electrical connecting region 72. The connecting regions 72 are configured such that they can be electrically connected along a connecting axis 74 by a threaded rod. Each connecting region 72 may have a connecting opening 76 for the threaded rod. In other words, the connecting openings 76 of the connecting regions 72 are aligned.

(42) Each interconnector plate 68 has a strip-like region 78. The strip-like region 78 is adapted to the contour of the fuel cell region 70 such that the strip-like region 78 closely follows the contour of the fuel cell region 70. The strip-like region 78 is preferably C-shaped. A retaining eye 80 is arranged at each of the opposite ends of the strip-like region 78.

(43) The fuel cell region 70 comprises a retaining device 81 adapted to the retaining eyes 80, in order to retain the interconnector plate 68. The retaining device 81 has fixing studs 82 for creating a form-fit connection with the retaining eyes 80.

(44) Each fixing stud 82 is arranged on an outer peripheral face of the fuel cell region 70. The fixing stud 82 is preferably configured so as to be substantially hemispherical. The interconnector plates 68 may be attached to the fuel cell region 70 by glass solder. Here, the glass solder may seal any remaining openings.

(45) The fuel cell region 70 furthermore comprises an opening 84 for each contact tongue 71.

(46) As shown in FIGS. 15 through 17, the retaining eyes 80 and the fixing studs 82 may have different forms. The left-hand part of FIG. 15 shows a hemispherical fixing stud 82 which is associated with a circular retaining eye 80 (FIG. 15, center). The right-hand part of FIG. 15 shows the form-fit connection which prevents the interconnector plate 68 from slipping out of the fuel cell region 70.

(47) A further variant which has a quarter-spherical fixing stud 82 is shown on the left in FIG. 16. This is associated with a D-shaped retaining eye 80 (FIG. 16, center). The steep flank of the fixing stud 82 may better prevent slipping (FIG. 16). It is also possible to hold the interconnector plate 68 under slightly less mechanical stress and thus allow a better contact with the fuel cell region 70.

(48) The form-fit connection may be further improved with the variant shown in FIG. 17. As in FIG. 16, a D-shaped retaining eye 80 is necessary. However, the fixing stud 82 has an acute angle to the horizontal.

(49) The manufacture of an interconnector plate 68 is explained in more detail below with reference to FIGS. 18 and 19. An interconnector plate blank 86 is cut out of an initially provided flat sheet metal material.

(50) The interconnector plate blank 86 already has a plurality of rectangular contact tongues 71, a connecting region 72, a strip-like region 78 and retaining eyes 80.

(51) The interconnector plate blank 86 is formed into the finished interconnector plate 68 by bending. The strip-like region 78 is here bent such that the interconnector plate 68 can closely follow the contour of the fuel cell region 70. The retaining eyes 80 are bent into the positions corresponding to the fixing studs 82. The contact tongues 71 have an angle α which corresponds to the slope of the gas channels 38, 40 relative to the horizontal direction. Finally, the connecting region 72 may be bent into the horizontal.

(52) Reference is now made to FIGS. 20 and 21 which each show an example of the fuel cell system 88. The fuel cell system 88 comprises a plurality of fuel cells 90 which are shown in more detail in FIGS. 22 through 24.

(53) The fuel cells 90 have an approximately hexagonal form in top view. The fuel cells 90, as shown in more detail for example in FIG. 20, are arranged in one plane spaced apart from one another. The fuel cells 90 may also be arranged stacked along their structural axis 22, as shown in more detail in FIG. 21. A combination of the arrangements is also possible in which the fuel cells 90 are arranged one above the other in several levels.

(54) An example of the fuel cell 90 will now be explained in more detail with reference to FIGS. 22 through 24.

(55) The fuel cell 90 has a first fuel cell region 92 and a second fuel cell region 94. Each fuel cell region 92, 94 contains a gas channel. In the present case, the first fuel cell region 92 and the second fuel cell region 94 are configured integrally as a single one-piece element.

(56) The first fuel cell region 92 comprises a first gas channel, for example for oxidator, and the second fuel cell region 94 comprises a second gas channel, for example for fuel.

(57) The first gas channel and the second gas channel extend in the form of a double helix in a peripheral direction around the structural axis 22. The structural axis 22 runs in the center of the fuel cell 90.

(58) The first gas channel and the second gas channel are preferably connected together along their extension direction by an ion-conductive separating layer. Furthermore, an isolating layer may be arranged to prevent cell conclusion.

(59) Each gas channel may contain an electrode coating 96 for extracting the electrical energy generated in the fuel cell 90.

(60) Each gas channel has a plurality of gas channel curvature regions 98 and adjacent gas channel planar regions 100. Each gas channel curvature region 98 is preferably curved through 120°. Each gas channel planar region 100 is straight and has no curvature.

(61) As a whole, in top view, the fuel cell regions 92, 94 have a substantially hexagonal form.

(62) The fuel cell 90 comprises a first distribution pipe 102 and a second distribution pipe 104. The first distribution pipe 102 may be provided for the fuel, while the second distribution pipe 104 may be provided for the oxidator.

(63) The distribution pipes 102, 104 are arranged in a region which is surrounded by the gas channels, or enclosed when viewed in top view. The distribution pipes 102, 104 are preferably arranged in the center of the fuel cell 90 when viewed in top view. The distribution pipes 102, 104 in the present case run parallel to the structural axis 22.

(64) Each distribution pipe 102, 104 has a gas supply region 106 which may be configured so as to be connectable to a gas reservoir. In the case of the oxidator, the gas supply region 106 may serve as an air supply without a gas reservoir.

(65) Each distribution pipe 102, 104 also has a gas discharge region 108 from which unused residual gas and reaction product may escape.

(66) The first distribution pipe 102 may for example be provided for distribution of fuel and form a continuous fluid path together with the first gas channel. In other words, the gas supply region 106 of the first distribution pipe 102 is fluidically connected via the first gas channel to the gas discharge region 108 of the first distribution pipe 102.

(67) The second distribution pipe 104 may serve for distribution of oxidator and form a continuous fluid path together with the second gas channel. In other words, the gas supply region 106 of the second distribution pipe 104 is fluidically connected via the second gas channel to the gas discharge region 108 of the second distribution pipe 104.

(68) The fuel cell 90 may be divided into several part portions which can be supplied with fuel and oxidator through the distribution pipes 102, 104, independently of the other part portions.

(69) The fuel cell 90 also comprises a plurality of openings 110 for interconnector plates. The openings 110 are preferably arranged on the gas channel planar regions 100. The openings 110 may be arranged at the respective ends of the gas channel planar region 100 next to the gas channel curvature regions 98.

(70) The fuel cell 90 comprises a retaining device 112 for interconnector plates. The retaining device 112 is arranged close to or in the openings 110.

(71) The fuel cell 90 also comprises a winding structure 114 for a conductive element 116, for example a wire. The winding structure 114 is provided on the peripheral outer face of the fuel cell 90. The winding structure 114 is configured in helical form. The winding structure 114 preferably comprises a groove 118 which runs such that interconnector plates of the same polarity can be connected together electrically by winding the conductive element 116 around the winding structure 114.

(72) Furthermore, the conductive element 116 may have an isolation which prevents the conductive element 116 from causing a short circuit. The conductive element 116 may also contain several wires which are each assigned to an interconnector polarity and can only come into contact therewith.

(73) The fuel cell 90 furthermore comprises a plurality of interconnector plates 120.

(74) Each interconnector plate 120 comprises a single contact tongue 122. The contact tongue 122 protrudes into the first gas channel or into the second gas channel. The contact tongues 122 are each attached to the wall of the respective gas channel. The electrode coating 96 is preferably arranged such that the contact tongues 122 are embedded in the electrode coating 96.

(75) Each interconnector plate 120 furthermore comprises an electrical connecting region 124 which adjoins the contact tongue 122. The connecting region 124 is configured such that in the installed state of the interconnector plate 120, it is facing radially outward and can be received by a conductive element 116.

(76) Each interconnector plate 120 has a clamping region 126. The clamping region 126 extends substantially parallel to and at a distance from the contact tongue 122. The interconnector plate 120 may thus be inserted in the opening 110 and retained on the fuel cell 90.

(77) Reference is now made to FIG. 26. The fuel cell 90 may be electrically connected as shown, in that firstly the interconnector plates 120 are inserted in the openings 110. Then the conductive element 116 is wound around the peripheral outer face of the fuel cell 90 using the winding structure 114. The conductive element 116 thus comes into contact with the interconnector plates 120, more precisely with the electrical connecting region 124. Any remaining openings may be sealed by glass solder 128. The glass solder may simultaneously serve for securing the interconnector plates 120.

(78) To provide a higher power density, a fuel cell 66 is proposed. The fuel cell 66 may be produced in ceramic by 3-D printing and has an improved power density because of its helical shape. For better extraction of the energy generated by the fuel cell 66, an interconnector plate 68 is proposed which can be attached by form fit to fixing studs 82 of the fuel cell 66 by retaining eyes 80. In addition, the interconnector plate 68 may be secured by glass solder.

(79) While at least one example embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the example embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a”, “an” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.

LIST OF REFERENCE SIGNS

(80) 10 Fuel cell 12 First fuel cell region 14 Second fuel cell region 16 Gas channel 18 First gas channel 20 Second gas channel 22 Structural axis 24 Ion-conductive separating layer 26 Isolating layer 28 Electrode coating 30 Fuel cell 32 Fuel cell region 34 First fuel cell region 36 Second fuel cell region 38 First gas channel 40 Second gas channel 42 Structural axis 44 Gas channel curvature region 46 Gas channel planar region 48 Gas inlet region 50 Gas outlet region 52 Electrode coating 54 Fuel cell 56 First distribution pipe 58 Second distribution pipe 60 Gas supply region 62 Gas discharge region 64 Part portion 66 Fuel cell 68 Interconnector plate 70 Fuel cell region 71 Contact tongue 72 Connecting region 74 Connection axis 76 Connecting opening 78 Strip-like region 80 Retaining eye 81 Retaining device 82 Fixing stud 84 Opening 86 Interconnector plate blank 88 Fuel cell system 90 Fuel cell 92 First fuel cell region 94 Second fuel cell region 96 Electrode coating 98 Gas channel curvature region 100 Gas channel planar region 102 First distribution pipe 104 Second distribution pipe 106 Gas supply region 108 Gas discharge region 110 Opening 112 Retaining device 114 Winding structure 116 Conductive element 118 Groove 120 Interconnector plate 122 Contact tongue 124 Electrical connecting region 126 Clamping region 128 Glass solder