ELECTROLYSIS STACK

Abstract

Electrolysis stack, including multiple layers that are stacked along a stacking direction, wherein each of the layers includes an anode space with an anode, a cathode space with a cathode and a membrane that separates the anode space and the cathode space from each other, wherein the anode space, the membrane and the cathode space are arranged adjacent to each other in the stated order along the stacking direction, and wherein each of the layers further includes a respective electrically insulating shell that surrounds the anode space and the cathode space so as to enclose the anode space and the cathode space radially with respect to the stacking direction, wherein the shell includes a groove on at least one of its end faces in the stacking direction, wherein the groove surrounds the anode space and the cathode space at least partially.

Claims

1. An electrolysis stack comprising multiple layers that are stacked along a stacking direction, wherein each of the layers comprises an anode space with an anode, a cathode space with a cathode and a membrane that separates the anode space and the cathode space from each other, wherein the anode space, the membrane and the cathode space are arranged adjacent to each other in the stated order along the stacking direction, and wherein each of the layers further comprises a respective electrically insulating shell that surrounds the anode space and the cathode space so as to enclose the anode space and the cathode space radially with respect to the stacking direction, wherein the shell comprises a groove on at least one of its end faces in the stacking direction, wherein the groove surrounds the anode space and the cathode space at least partially.

2. The electrolysis stack according to claim 1, wherein the groove forms a respective first drainage path between adjacent layers.

3. The electrolysis stack according to claim 2, wherein the first drainage paths are connected to each other by a second drainage path.

4. The electrolysis stack according to claim 3, wherein the second drainage path is formed within the shells.

5. The electrolysis stack according to claim 3, wherein the second drainage path is inclined by less than 20° with respect to the stacking direction.

6. The electrolysis stack according to claim 2, wherein a third drainage path is connected with its first end to one of the first drainage paths and/or to the second drainage path and forms with its second end an opening in the shell.

7. The electrolysis stack according to claim 1, wherein the groove fully surrounds the anode space and the cathode space.

8. The electrolysis stack according to claim 1, wherein the groove is shaped to contribute to a positive or frictional connection between adjacent layers,

9. The electrolysis stack according to claim 4, wherein the first drainage paths) have a diameter that increases towards the second drainage path.

10. The electrolysis stack according to claim 1, further comprising a first electrode connected to the anode of the layer that is the first in the stacking direction, wherein the first electrode passes through the shell of this layer, and/or further comprising a second electrode connected to the cathode of the layer that is the last in the stacking direction, wherein the second electrode passes through the shell of this layer.

11. The electrolysis stack according to claim 1, wherein for at least one of the layers the respective anode space comprises a gas diffusion region that is arranged between the membrane and the anode of the respective layer, and/or wherein for at least one of the layers the cathode space comprises a gas diffusion region that is arranged between the membrane and the cathode of the respective layer.

12. The electrolysis stack according to claim 1, wherein at least one of the anodes forms a bipolar plate together with the cathode of one of the neighboring layers.

13. The electrolysis stack according to claim 1, wherein an electrolyte supply conduit and/or an electrolyte drain conduit passes through the shell of at least one of the layers.

14. The electrolysis stack according to claim 1, wherein for at least one of the layers the respective membrane is an anion exchange membrane.

15. A method for performing water electrolysis using an electrolysis stack according to claim 1, wherein for each of the layers a respective electrical voltage is applied between the anode and the cathode.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In the following the invention will be described with respect to the figures. The figures show a preferred embodiment, to which the invention is not limited. The figures and the dimensions shown therein are only schematic. The figures show:

[0049] FIG. 1 illustrates a sectional side view of the device according to the invention; and

[0050] FIG. 2 illustrates a sectional plan view of the device according to the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0051] FIG. 1 shows an electrolysis stack 1, comprising multiple layers 2 that are stacked along a stacking direction d. The layers 2 each comprise an anode space 3 with an anode 5, a cathode space 4 with a cathode 6 and a membrane 7 that separates the anode space 3 and the cathode space 4 from each other and that is an anion exchange membrane 7. To perform the electrolysis, for each of the layers 2 a respective electrical voltage is applied between the anode 5 and the cathode 6, wherein in this case the electrolysis is an anion exchange membrane water electrolysis, AEMWE.

[0052] The anode space 3, the membrane 7 and the cathode space 4 are arranged adjacent to each other in the stated order along the stacking direction d and are held in this order by a pair of clamping plates 20. One of the clamping plates 20 is located above the first layer 2 in the stacking direction d, while the bottom clamping plate 20 is located below the last layer 2 in the stacking direction d. The clamping plates 20 are connected to each other by threaded bolts, not shown in the figures.

[0053] Further, each of the layers 2 comprises a respective electrically insulating shell 8 that surrounds the anode space 3 and the cathode space 4 so as to enclose the anode space 3 and the cathode space 4 radially with respect to the stacking direction d. Furthermore, the shells 8 comprise a respective groove 16 on at least one of their end faces 17, 18 in the stacking direction d, wherein the grooves 16 each surround the respective anode space 3 and cathode space 4 at least partially.

[0054] The grooves 16 are shaped to form a respective first drainage path 16a between adjacent layers 2. If fluid leaks from the layers 2, the fluid can be drained via the first drainage paths 16a. In other words, the groove 16 of a first layer 2 is closed by a second layer 2 that is immediately adjacent to the first layer 2 in the stacking direction d, thus forming a first drainage path 16a. As shown in FIG. 1, both layers 2 have a groove 16 in their end faces 17, 18 towards each other, so that both groves 16, adjacent to each other form the first drainage path 16a between the adjacent layers 2. If a leakage between two adjacent layers 2 occurs, the leaking fluid is collected in the first drainage path 16a formed by the opposing grooves 16.

[0055] The first layer 2 in the stacking direction d and the layer 2 that is the last in the stacking direction d have a groove 16 only on one of their end faces 17, 18 . The layers 2 between the first and the last layer 2 in the stacking direction d respectively comprise a groove 16 on both their end faces 17, 18.

[0056] To remove leaking fluid from the layers 2, the first drainage paths 16a are connected to each other by a second drainage path 16b. Further, a third drainage path 16c is connected with its first end to the second drainage path 16b and forms with its second end an opening 19 in the shell 8. Thus, fluid leaking from the anode spaces 3 and cathode spaces 4 can be led out of the electrolysis stack 1 via the first, second and third drainage paths 16a, 16b, 16c.

[0057] Even if not shown in the figures, to improve the drainage of the liquid, the drainage paths 16a, 16b, 16c can have a diameter that increases towards the opening 19. With other words, the diameter of the first drainage path 16a can increases towards the intersection area of the first drainage path 16a with the vertically running second drainage path 16b. The second and third drainage paths 16b, 16c can also have a diameter that increases towards the opening 19.

[0058] To provide the electrolysis stack 1 with electrical energy, a first electrode 9 is connected to the anode 5 of the layer 2 that is the first in the stacking direction d, wherein the first electrode 9 passes through the shell 8 of this layer 2. A second electrode 10 is connected to the cathode 6 of the layer 2 that is the last in the stacking direction d, wherein the second electrode 10 passes through the shell 8 of this layer 2. The first electrode 9 and the second electrode 10 are connected to a voltage source 15.

[0059] The anode spaces 3 comprise a respective gas diffusion region 11 that is arranged between the membrane 7 and the anode 5 of the respective layer 2, wherein the cathode spaces 4 comprise a respective gas diffusion region 11 that is arranged between the membrane 7 and the cathode 6 of the respective layer 2. With other words, the gas diffusion regions 11 of the anode spaces 3 are designed to remove the oxygen generated during electrolysis. In addition, the gas diffusion regions 11 of the cathode spaces 4 are designed to remove the hydrogen produced simultaneously. To continuously supply the layers 2 with the appropriate electrolyte, an electrolyte supply conduit 13 and an electrolyte drain conduit 14 passes through the shell 8 of each layer 2.

[0060] To reduce the layer 2 thickness and thus increase the efficiency per volume, the anodes 5 form a respective bipolar plate 12 together with the cathode 6 of one of the neighboring layers 2.

[0061] FIG. 2 shows a top view of one of the layers 2. It can be seen that the groove 16 fully surrounds the anode space 3 and the cathode space 4. To better arrange the layers 2 in the stacking direction d, the groove 16 is shaped to contribute to a positive or frictional connection between adjacent layers 2. Thus, the grooves 16 also improve the structural integrity of the electrolysis stack 1. This can be enhanced, for example, by a groove 16 of a first layer 2 having a shape complementary to that of the adjacent second layer 2 or complementary to a groove 16 of the second layer 2. These complementary shapes can be realized, for example, in an interlocking manner.

LIST OF REFERENCE NUMERALS

[0062] 1 electrolysis stack

[0063] 2 layer

[0064] 3 anode space

[0065] 4 cathode space

[0066] 5 anode

[0067] 6 cathode

[0068] 7 membrane

[0069] 8 shell

[0070] 9 first electrode

[0071] 10 second electrode

[0072] 11 gas diffusion region

[0073] 12 bipolar plate

[0074] 13 electrolyte supply conduit

[0075] 14 electrolyte drain conduit

[0076] 15 voltage source

[0077] 16 groove

[0078] 16a first drainage path

[0079] 16b second drainage path

[0080] 16c third drainage path

[0081] 17 end face

[0082] 18 end face

[0083] 19 opening

[0084] 20 clamping plates

[0085] d stacking direction