BIPOLAR PLATE FOR AN ELECTROCHEMICAL CELL, METHOD FOR MANUFACTURING SAID BIPOLAR PLATE, ARRANGEMENT OF ELECTROCHEMICAL CELLS, AND METHOD FOR OPERATING SAID ARRANGEMENT OF ELECTROCHEMICAL CELLS

Abstract

The invention relates to a bipolar plate (7) for an electrochemical cell (1), said bipolar plate comprising at least one first monopolar plate (13) having a first bead (15) and a second monopolar plate (17) having a second bead (19), the first bead (15) and the second bead (19) being arranged opposite one another and forming a channel (21), the first bead (15) and the second bead (19) each comprising a central base surface (23) and at least two inclined surfaces (24), and the first bead (15) and/or the second bead (19) comprising at least one outer base surface (25). At least one opening element (111) for the passage of at least one medium (29) between one of the at least two inclined surfaces (24) and the at least one outer base surface (25) is located on the first bead (15) and/or the second bead (19), said at least one opening element (111) comprising a lateral surface (121), a first open side surface (113), a second open side surface (115), and a top surface (140) having an opening (27), said first open side surface (113) being located in the at least one outer base surface (25), and said second open side surface (115) being located in one of the at least two inclined surfaces (24). The invention also relates to a method for manufacturing the bipolar plate (7), to an arrangement (69) of electrochemical cells (1), and to a method for operating said arrangement (69) of electrochemical cells (1).

Claims

1. A bipolar plate (7) for an electrochemical cell (1), the bipolar plate comprising at least one first monopolar plate (13) having a first bead (15), and a second monopolar plate (17) having a second bead (19), wherein the first bead (15) and the second bead (19) are arranged opposite one another and form a channel (21), wherein the first bead (15) and the second bead (19) each comprise a central base surface (23) and at least two inclined surfaces (24) and the first bead (15) and/or the second bead (19) comprise at least one outer base surface (25), and wherein at least one opening element (111) for the passage of at least one medium (29) between one of the at least two inclined surfaces (24) and the at least one outer base surface (25) is located on the first bead (15) and/or the second bead (19), said at least one opening element (111) comprising a lateral surface (121), a first open side surface (113), a second open side surface (115), and a top surface (140) having an opening (27), said first open side surface (113) being located in the at least one outer base surface (25), and said second open side surface (115) being located in one of the at least two inclined surfaces (24).

2. The bipolar plate (7) according to claim 1, wherein the top surface (140) is arranged substantially parallel to the at least one outer base surface (25).

3. The bipolar plate (7) according to claim 1, wherein the top surface (140) has a rectangular shape or is at least partially circular in shape.

4. The bipolar plate (7) according to claim 1, wherein the lateral surface (121) is bordered by the top surface (140), the at least one outer base surface (25), and one of the at least two inclined surfaces (24).

5. The bipolar plate (7) according to claim 1, wherein the opening (27) has a circular cross-section.

6. The bipolar plate (7) according to claim 1, wherein the opening (27) forms a third side surface of the opening element (111).

7. The bipolar plate (7) according to claim 1, wherein the first bead (15) and/or the second bead (19) each comprise at least three inclined surfaces (24), wherein the at least one outer base surface (25) is arranged between two of the at least three inclined surfaces (24) and forms a step (31).

8. A method for manufacturing a bipolar plate (7) according to claim 1, wherein the first bead (15) and/or the second bead (19) and the at least one opening element (111) are manufactured by embossing from a base plate (123) of the first monopolar plate (13) and the second monopolar plate (17), respectively.

9. An arrangement (69) of electrochemical cells (1) comprising at least one bipolar plate (7) according to claim 1 and at least one membrane-electrode assembly (4), wherein the at least one opening element (111) is arranged on the at least one bipolar plate (7) such that the opening (27) faces the at least one membrane-electrode assembly (4).

10. A method for operating an arrangement (69) of electrochemical cells (1) according to claim 9, wherein the at least one medium (29) is passed from the channel (21) through the at least one opening element (111) to the at least one membrane-electrode assembly (4), wherein the at least one medium (29) enters the at least one opening element (111) through the second open side surface (115) and/or through the first open side surface (113) and exits the at least one opening element (111) through the opening (27).

11. The bipolar plate (7) according to claim 2, wherein the top surface (140) has a rectangular shape or is at least partially circular in shape.

12. The bipolar plate (7) according to claim 11, wherein the lateral surface (121) is bordered by the top surface (140), the at least one outer base surface (25), and one of the at least two inclined surfaces (24).

13. The bipolar plate (7) according to claim 12, wherein the opening (27) has a circular cross-section.

14. The bipolar plate (7) according to claim 13, wherein the opening (27) forms a third side surface of the opening element (111).

15. The bipolar plate (7) according to claim 14, wherein the first bead (15) and/or the second bead (19) each comprise at least three inclined surfaces (24), wherein the at least one outer base surface (25) is arranged between two of the at least three inclined surfaces (24) and forms a step (31).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Embodiments of the invention are explained in greater detail with reference to the drawings and the following description.

[0042] Shown are:

[0043] FIG. 1 a schematic view of an electrochemical cell,

[0044] FIG. 2 an exploded view of an arrangement of electrochemical cells,

[0045] FIG. 3 a perspective view of a bead arrangement according to the prior art,

[0046] FIG. 4 a perspective view of a first monopolar plate with opening elements, and

[0047] FIG. 5 a cross-sectional view of a bead arrangement with a step.

DETAILED DESCRIPTION

[0048] In the following description of the embodiments of the invention, identical or similar elements are denoted by identical reference signs, whereby repeated description of these elements is omitted in individual cases. The drawings illustrate the subject matter of the invention merely schematically.

[0049] FIG. 1 schematically shows an electrochemical cell 1 in the form of a fuel cell. The electrochemical cell 1 has a membrane 2 in the form of electrolytes. The membrane 2 separates a cathode space 6 from an anode space 8.

[0050] A respective electrode layer 3, a gas diffusion layer 5, and a distributor plate 7 are arranged on the membrane 2 in the cathode space 6 and anode space 8. The connection of the membrane 2 and the electrode layer 3 can also be referred to as a membrane-electrode assembly 4.

[0051] Media 29 are supplied in the bipolar plates 7. Through the bipolar plate 7 in the cathode space 6, oxygen 9 reaches the gas diffusion layer 5, and through the bipolar plate 7 of the anode space 8, hydrogen 11 reaches the corresponding gas diffusion layer 5.

[0052] FIG. 2 shows an exploded view of an arrangement 69 of electrochemical cells 1 constituting a fuel cell stack. The arrangement 69 comprises individual electrochemical cells 1 strained between current collectors 33 and end plates 35 with straining elements 37.

[0053] FIG. 3 shows a perspective view of a section of a bipolar plate 7 with a bead arrangement 57. The bipolar plate 7 comprises a first monopolar plate 13 having a first bead 15 and a second monopolar plate 17 having a second bead 19, each according to the prior art.

[0054] The first bead 15 and the second bead 19 are arranged opposite one another and form a channel 21. The first bead 15 and the second bead 19 each comprise a central base surface 23 and two inclined surfaces 24, the inclined surfaces 24 comprising openings 27 through which a medium 29 can be guided.

[0055] FIG. 4 shows a perspective view of a section of a first monopolar plate 13 with a first bead 15. The first monopolar plate 13 comprises a central base surface 23, two inclined surfaces 24, and an outer base surface 25. Arranged on the first bead 15, between one of the inclined surfaces 24 and the outer base surface 25, are two opening elements 111 for the passage of the medium 29. The opening elements 111 each comprise a lateral surface 121, a first open side surface 113, a second open side surface 115, and a top surface 140. The top surfaces 140 each comprise an opening 27. Furthermore, the respective first open side surface 113 lies within the outer base surface 25, and the respective second open side surface 115 lies within the inclined surface 24.

[0056] The medium 29 enters the opening element 111 through the first open side surface 113 and the second open side surface 115, respectively, and exits said opening element through the opening 27 in the top surface 140.

[0057] A first opening element 141 is shown, the top surface 140 being partially circular. In a second opening element 143, the top surface 140 has a rectangular shape.

[0058] The central base surface 23 of the first bead 15 is arranged at a first height 59, whereas the top surfaces 140 are arranged at a second height 61, each in relation to a base plate 123 of the first monopolar plate 13.

[0059] FIG. 5 shows a cross-sectional view of a further embodiment of a bead arrangement 57 of a bipolar plate 7. The first bead 15 in this case comprises four inclined surfaces 24, in which case an outer base surface 25 is arranged between two of the four inclined surfaces 24 and forms a step 31. Accordingly, the opening element 111 is arranged on the step 31. The step 31 is arranged at a third height 63 with respect to ground plane 123 of first monopolar plate 13. The central base surfaces 23 further comprise a seal 47.

[0060] The invention is not limited to the exemplary embodiments described herein and the aspects highlighted thereby. Rather, within the range specified by the claims, a large number of modifications are possible which lie within the abilities of a skilled person.