COMPONENT FOR AN ELECTGROCHEMICAL CELL AND REDOX-FLOW CELL, FUEL CELL AND ELECTROLYZER

Abstract

A component for an electrochemical cell, wherein the component is present in the form of an electrode for a redox-flow cell or in the form of a bipolar plate for a fuel cell or an electrolyzer or in the form of a fluid diffusion layer for an electrolyzer, including a substrate which is formed from a material in the form of a metal sheet and/or an expanded metal grille, wherein the material is formed from a tin-nickel alloy or a tin-silver alloy or a tin-zinc alloy or a tin-bismuth alloy or a tin-antimony alloy. A redox-flow cell, a fuel cell and an electrolyzer are also provided.

Claims

1. A component for an electrochemical cell, the component comprising: an electrode for a redox-flow cell or a bipolar plate for a fuel cell or an electrolyzer or a fluid diffusion layer for an electrolyzer, comprising a substrate formed from a material comprising at least one of a metal sheet or an expanded metal grille; and the material is formed from a tin-nickel alloy or a tin-silver alloy or a tin-zinc alloy or a tin-bismuth alloy or a tin antimony alloy.

2. The component according to claim 1, wherein the at least one of the metal sheet or the expanded metal grille are each designed with a maximum thickness of 5 mm.

3. The component according to claim 1, wherein the at least one of the metal sheet or the expanded metal grille has a three-dimensional profile at least in regions.

4. The component according to claim 1, further comprising a coating which is applied to the substrate, the coating is either a) carbon or a noble metal or a noble metal alloy or a metal nitride or at least one material from the group consisting of hafnium, niobium, tantalum, bismuth, nickel, tin, tin-nickel alloy, or b) a homogeneous or heterogeneous solid solution or compound from at least one of the material combinations from the group consisting of: IrC, IrRuC, RuC, AgC, WC, CuC, MoC, CrC, MgC, PtC, TaC, NbC, wherein a proportion of carbon in the coating is in a range from 35 to 99.99 at. %, or c) a coating selected to be different from a material composition of the substrate that is made from a copper-tin alloy or a tin-nickel alloy or a tin-silver alloy or a tin-zinc alloy or a tin-bismuth alloy or a tin-antimony alloy.

5. The component according to claim 4, wherein the coating has a layer thickness in a range of 2 to 500 nm.

6. The component according to claim 5, wherein the component is the electrode for the redox flow cell, and the coating covers the substrate at least in a contact region to an electrolyte of the redox flow cell.

7. A redox flow cell, comprising: at least one electrode comprising a substrate formed from a material comprising at least one of a metal sheet or an expanded metal grille in which the material is formed from a tin-nickel alloy or a tin-silver alloy or a tin-zinc alloy or a tin-bismuth alloy or a tin antimony alloy, and at least one electrolyte with a pH in a range from 7 to 14.

8. The redox flow cell according to claim 7, wherein the at least one electrode comprises at least two electrodes, a first reaction chamber and a second reaction chamber, wherein each of the reaction chambers is in contact with one of the electrodes and the reaction chambers are separated from each other by an ion exchange membrane.

9. A fuel cell comprising: at least one bipolar plate comprising a substrate formed from a material comprising at least one of a metal sheet or an expanded metal grille in which the material is formed from a tin-nickel alloy or a tin-silver alloy or a tin-zinc alloy or a tin-bismuth alloy or a tin antimony alloy, and at least one polymer electrolyte membrane.

10. An electrolyzer comprising: at least one bipolar plate or a fluid diffusion layer comprising a substrate formed from a material comprising at least one of a metal sheet or an expanded metal grille in which the material is formed from a tin-nickel alloy or a tin-silver alloy or a tin-zinc alloy or a tin-bismuth alloy or a tin antimony alloy, and at least one polymer electrolyte membrane.

11. The redox flow cell according to claim 7, wherein the at least one of the metal sheet or the expanded metal grille are each designed with a maximum thickness of 5 mm.

12. The redox flow cell according to claim 7, wherein the at least one of the metal sheet or the expanded metal grille has a three-dimensional profile at least in regions.

13. The redox flow cell according to claim 7, further comprising a coating which is applied to the substrate, the coating is either a) carbon or a noble metal or a noble metal alloy or a metal nitride or at least one material from the group consisting of hafnium, niobium, tantalum, bismuth, nickel, tin, tin-nickel alloy, or b) a homogeneous or heterogeneous solid solution or compound from at least one of the material combinations from the group consisting of: IrC, IrRuC, RuC, AgC, WC, CuC, MoC, CrC, MgC, PtC, TaC, NbC, wherein a proportion of carbon in the coating is in a range from 35 to 99.99 at. %, or c) a coating selected to be different from a material composition of the substrate that is made from a copper-tin alloy or a tin-nickel alloy or a tin-silver alloy or a tin-zinc alloy or a tin-bismuth alloy or a tin-antimony alloy.

14. The redox flow cell according to claim 13, wherein the coating has a layer thickness in a range of 2 to 500 nm.

15. The fuel cell according to claim 9, wherein the at least one of the metal sheet or the expanded metal grille are each designed with a maximum thickness of 5 mm.

16. The fuel cell according to claim 9, wherein the at least one of the metal sheet or the expanded metal grille has a three-dimensional profile at least in regions.

17. The fuel cell according to claim 9, further comprising a coating which is applied to the substrate, the coating is either a) carbon or a noble metal or a noble metal alloy or a metal nitride or at least one material from the group consisting of hafnium, niobium, tantalum, bismuth, nickel, tin, tin-nickel alloy, or b) a homogeneous or heterogeneous solid solution or compound from at least one of the material combinations from the group consisting of: IrC, IrRuC, RuC, AgC, WC, CuC, MoC, CrC, MgC, PtC, TaC, NbC, wherein a proportion of carbon in the coating is in a range from 35 to 99.99 at. %, or c) a coating selected to be different from a material composition of the substrate that is made from a copper-tin alloy or a tin-nickel alloy or a tin-silver alloy or a tin-zinc alloy or a tin-bismuth alloy or a tin-antimony alloy.

18. The fuel cell according to claim 17, wherein the coating has a layer thickness in a range of 2 to 500 nm.

19. The electrolyzer according to claim 10, wherein the coating has a layer thickness in a range of 2 to 500 nm.

20. The electrolyzer according to claim 10, wherein the at least one of the metal sheet or the expanded metal grille are each designed with a maximum thickness of 5 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0045] FIGS. 1 through 6 show examples of components in the form of electrodes according to the disclosure and a redox flow cell or a redox flow battery. FIGS. 7 and 8 show an example of a fuel cell and an electrolysis cell of an electrolyzer. In the figures:

[0046] FIG. 1 shows an electrode comprising a substrate in a plan view of the substrate plane,

[0047] FIG. 2 shows a cross-section through an electrode comprising a coating,

[0048] FIG. 3 shows a cross-section through an electrode with a profile,

[0049] FIG. 4 shows a cross-section through an electrode comprising a substrate made of a metal sheet and an expanded metal grille,

[0050] FIG. 5 shows an electrode with a flux field,

[0051] FIG. 6 shows a redox flow cell or a redox flow battery having a redox flow cell,

[0052] FIG. 7 shows an electrolyzer in a sectional view, and

[0053] FIG. 8 shows a fuel cell stack in a three-dimensional view.

DETAILED DESCRIPTION

[0054] FIG. 1 shows a component 1 in the form of an electrode comprising a substrate 2 in a plan view of the substrate plane. The substrate 2 is formed here from a metal sheet 2a with a thickness of less than 0.5 mm. The metal sheet 2a is made of a tin-silver alloy.

[0055] FIG. 2 shows a cross-section through a component 1 in the form of an electrode, comprising a substrate 2 in the form of a metal sheet 2a made of a tin-antimony alloy, which has a coating 3 on both sides. However, the coating 3 can also only be applied to one side of the metal sheet 2a, wherein the coating 3 is intended to cover the substrate 2 at least in a contact region with an electrolyte of a redox flow cell 8 (cf. FIG. 6).

[0056] FIG. 3 shows a cross-section through a component 1 in the form of an electrode comprising a substrate 2 in the form of a metal sheet 2a made of tin-bismuth alloy. The metal sheet 2a has a three-dimensional profile 4, which increases the later contact surface of the metal sheet 2a to an electrolyte of a redox flow cell 8.

[0057] FIG. 4 shows a cross-section through a component 1 in the form of an electrode comprising a substrate 2 which comprises a metal sheet 2a and an expanded metal grille 2b. The metal sheet 2a and the expanded metal grille 2b are formed from a tin-silver alloy.

[0058] FIG. 5 shows a three-dimensional view of a component 1 in the form of an electrode, comprising a substrate 2 in the form of a metal sheet 2a made of a tin-silver alloy with a profile 4, which forms a flux field 7. In the substrate 2 there is a profile 4 on both sides for forming a flow field 7 in each case, resulting in a three-dimensional structuring of the surface of the electrode against which an electrolyte is to flow in a redox flow cell 8.

[0059] FIG. 6 shows a redox flow cell 8 or a redox flow battery, respectively, having a redox flow cell 8. The redox flow cell 8 comprises two components 1a, 1b in the form of electrodes, a first reaction chamber 10a and a second reaction chamber 10b, wherein each reaction chamber 10a, 10b is in contact with one of the electrodes. The reaction chambers 10a, 10b are separated from one another by an ion exchange membrane 9a. A liquid anolyte 11a is pumped from a tank 13a into the first reaction chamber 10a via a pump 12a and is fed through between the component 1a and the ion exchange membrane 9a. A liquid catholyte 11b is pumped from a tank 13b into the second reaction chamber 10b via a pump 12b and is fed through between the component 1b and the ion exchange membrane 9a. Ion exchange occurs across the ion exchange membrane 9a, wherein electrical energy is released due to the redox reaction at the electrodes.

[0060] FIG. 7 shows an electrolysis cell 20 of an electrolyzer comprising a polymer electrolyte membrane 9 which separates an anode side A and a cathode side K from one another. A catalyst layer 21a, 21b, each comprising a catalyst material and a fluid diffusion layer 22a, 22b, is arranged adjacent to the catalyst layer 21a, 21b on both sides of the polymer electrolyte membrane 9. The fluid diffusion layers 22a, 22b are each arranged adjacent to an electrically conductive plate 24a, 24b, wherein the fluid diffusion layers 22a and 22b are formed from an expanded metal 2b, 2b made of a tin-silver alloy. The plates 24a, 24b each have flow channels 23a, 23b on the sides thereof facing the fluid diffusion layers 22a, 22b to improve the supply of reaction medium (water) and a removal of reaction products (water, hydrogen, oxygen).

[0061] FIG. 8 schematically shows a fuel cell stack 100 comprising multiple fuel cells 90. Each fuel cell 90 comprises a polymer electrolyte membrane 9 adjacent to both sides of components 1c, 1din the form of bipolar plates. Each bipolar plate has a tin-silver alloy substrate. The bipolar plate has an inflow region with openings 80a and an outlet region with further openings 80b, which are used to supply a fuel cell (90) with process gases and coolant and to remove reaction products from the fuel cell (90) and coolant. The bipolar plate also has a gas distribution structure 7 on each side, which is provided for contact with the polymer electrolyte membrane 9.

LIST OF REFERENCE SYMBOLS

[0062] 1, 1, 1a, 1b, 1c, 1d Component [0063] 2 Substrate [0064] 2a Sheet metal [0065] 2b, 2b Expanded metal grille [0066] 3 Coating [0067] 4 Profile [0068] 7 Flux field [0069] 7 Gas distribution structure [0070] 8 Redox flow cell or redox flow battery [0071] 9 Polymer electrolyte membrane [0072] 9a Ion exchange membrane [0073] 10a First reaction chamber [0074] 10b Second reaction chamber [0075] 11a Anolyte [0076] 11b Catholyte [0077] 12a, 12b Pump [0078] 13a, 13b, 13c Tank [0079] 20 Electrolysis cell of an electrolyzer [0080] 21a, 21b Catalyst material [0081] 22a, 22b Fluid diffusion layer [0082] 23a, 23b Flow channels [0083] 24a, 24b Electrically conductive plate [0084] 80a, 80b Openings [0085] 90 Fuel cell [0086] 100 Fuel cell stack [0087] A Anode side [0088] K Cathode side [0089] d Thickness of sheet metal or expanded metal [0090] D Thickness of the coating