WO2022063610A1 - Elektrochemische zelle, insbesondere einer redox-flow-batterie, sowie entsprechender zellstack - Google Patents
Elektrochemische zelle, insbesondere einer redox-flow-batterie, sowie entsprechender zellstack Download PDFInfo
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- WO2022063610A1 WO2022063610A1 PCT/EP2021/074972 EP2021074972W WO2022063610A1 WO 2022063610 A1 WO2022063610 A1 WO 2022063610A1 EP 2021074972 W EP2021074972 W EP 2021074972W WO 2022063610 A1 WO2022063610 A1 WO 2022063610A1
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- cell
- electrode
- electrolyte
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- porous section
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- 239000003792 electrolyte Substances 0.000 claims abstract description 103
- 238000007599 discharging Methods 0.000 claims abstract description 3
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- 239000003566 sealing material Substances 0.000 description 7
- 239000011148 porous material Substances 0.000 description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
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- 238000006479 redox reaction Methods 0.000 description 3
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- 150000001455 metallic ions Chemical class 0.000 description 2
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- 239000007864 aqueous solution Substances 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- UPHIPHFJVNKLMR-UHFFFAOYSA-N chromium iron Chemical compound [Cr].[Fe] UPHIPHFJVNKLMR-UHFFFAOYSA-N 0.000 description 1
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- 229910052720 vanadium Inorganic materials 0.000 description 1
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 description 1
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
- H01M8/18—Regenerative fuel cells, e.g. redox flow batteries or secondary fuel cells
- H01M8/184—Regeneration by electrochemical means
- H01M8/188—Regeneration by electrochemical means by recharging of redox couples containing fluids; Redox flow type batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
- H01M4/8605—Porous electrodes
- H01M4/8626—Porous electrodes characterised by the form
- H01M4/8631—Bipolar electrodes
-
- 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
- H01M8/0258—Collectors; Separators, e.g. bipolar separators; Interconnectors characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant
-
- 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
- H01M8/0271—Sealing or supporting means around electrodes, matrices or membranes
- H01M8/0273—Sealing or supporting means around electrodes, matrices or membranes with sealing or supporting means in the form of a frame
-
- 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
- H01M8/24—Grouping of fuel cells, e.g. stacking of fuel cells
- H01M8/2459—Comprising electrode layers with interposed electrolyte compartment with possible electrolyte supply or circulation
-
- 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
- H01M8/24—Grouping of fuel cells, e.g. stacking of fuel cells
- H01M8/2465—Details of groupings of fuel cells
- H01M8/2483—Details of groupings of fuel cells characterised by internal manifolds
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
- H01M2004/8678—Inert electrodes with catalytic activity, e.g. for fuel cells characterised by the polarity
- H01M2004/8694—Bipolar electrodes
-
- 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
- Electrochemical cell in particular a redox flow battery, and corresponding cell stack
- the invention relates to an electrochemical cell, in particular a redox flow battery, with at least one cell frame and at least one electrode, the cell frame enclosing a cell interior on the circumference, the cell frame having at least one supply channel for supplying electrolyte into the cell interior and at least one discharge channel for Leading off electrolyte from the cell interior, wherein the at least one cell frame has at least one finger element projecting into the cell interior and the electrode is arranged at least in regions in the cell interior and on opposite sides of the at least one finger element. Furthermore, the invention relates to a cell stack, in particular a redox flow battery, comprising a plurality of corresponding electrochemical cells.
- Electrochemical cells are known in different configurations and are sometimes also referred to as electrochemical reactors, since electrochemical reactions take place in the electrochemical cells.
- the electrochemical cells can, for example, be in the form of galvanic cells in the form of electrochemical current sources which supply usable electrical energy through chemical reactions at the various electrodes.
- the electrochemical cells can also be electrolytic cells, which are used to produce specific products by applying an external voltage.
- Accumulator cells serve alternately as a power source like galvanic cells and also as a power storage device, as in an electrolytic cell.
- the present invention can be used with all types of electrochemical cells.
- the invention is very particularly preferred in connection with accumulator cells and here preferably in connection with redox flow batteries, which themselves have been known for a long time and in various designs. Such designs are described by way of example in EP 0 051 766 A1 and US 2004/0170893 A1.
- An important advantage of the redox flow batteries lies in the flexible scalability of performance and capacity and thus in their suitability for being able to store very large amounts of energy even with a lower selected performance and vice versa.
- the energy is stored in electrolytes that can be kept in external tanks.
- the electrolytes usually have metallic ions of different oxidation states. In order to extract electrical energy from the electrolytes or to recharge them, the electrolytes are pumped through a so-called electrochemical cell.
- the electrochemical cell is generally formed from two half-cells which are separated from one another by a separator in the form of a semi-permeable membrane and each have an electrolyte and an electrode.
- the purpose of the semipermeable membrane is to spatially and electrically separate the cathode and the anode of an electrochemical cell.
- the semi-permeable membrane must therefore be permeable to ions, which convert the stored chemical energy into electrical energy or vice versa.
- Semipermeable membranes can be formed, for example, from microporous plastics and nonwovens made from glass fiber or polyethylene and so-called diaphragms. Redox reactions take place at both electrodes of the electrochemical cell, with the electrolytes releasing electrons at one electrode and accepting electrons at the other electrode.
- the metallic and/or non-metallic ions of the electrolytes form redox pairs and consequently generate a redox potential.
- redox pairs are iron-chromium, polysulfide-bromide or vanadium.
- these or other redox pairs can be present in aqueous or non-aqueous solution.
- the electrodes of a cell between which a potential difference forms as a result of the redox potentials, are outside the cell, e.g. B. via an electrical load, electrically connected to each other. While the electrons pass from one half-cell to the other outside the cell, ions from the electrolyte pass directly from one half-cell to the other half-cell through the semi-permeable membrane.
- a potential difference can be applied to the electrodes of the half-cells instead of the electrical load, for example by means of a charging device, which reverses the redox reactions taking place at the electrodes of the half-cells.
- Cell frames that enclose a cell interior are used, inter alia, to form the cell described.
- the cell frames typically do not enclose the cell interior completely, but only along a peripheral narrow side.
- the cell frame therefore runs around the circumference of the cell interior and separates two opposite, larger-area sides from one another, which in turn are assigned to a semipermeable membrane or an electrode.
- the thickness of the cell frame, which is formed by the edge of the cell frame, is typically significantly less than the width and the height of the cell frame, which define the larger-area opposite sides.
- Each half-cell of the electrochemical cell includes a cell frame of this type, which is produced, for example, from a thermoplastic material by injection molding.
- a semi-permeable membrane is arranged between two cell frames, which separates the electrolytes of the half-cells from one another with regard to a convective exchange of substances, but allows certain ions to diffuse from one half-cell into the other half-cell.
- an electrode is assigned to each of the cell interiors in such a way that they are in contact with the electrolyte flowing through the cell interiors.
- the electrodes can, for example, close off the cell interior of each cell frame on the side facing away from the semipermeable membrane. But he can Cell interior remain essentially free and be filled only by one electrolyte.
- the respective electrode can also be provided at least partially in the cell interior.
- the electrode is then typically designed in such a way that the electrolyte can partially flow through the electrode.
- electrodes with a high specific surface come into consideration here, on which the corresponding electrochemical reactions can take place correspondingly quickly and/or extensively. Ultimately, this leads to a high volume-specific performance of the cell.
- the cell interiors are mostly closed by the electrode on the side facing away from the semipermeable membrane.
- So-called bipolar plates which can be coated, for example, with a catalyst or another substance, can also be used as the non-porous part of the electrodes.
- Each cell frame has openings and channels through which the corresponding electrolyte can flow from a supply line into the respective cell interior and can be withdrawn from there and fed to a disposal line.
- the electrolytes of the half-cells are pumped from a storage tank to a collection tank via the supply line and the disposal line. This allows the electrolytes to be reused, which consequently do not have to be discarded or replaced.
- each cell frame has at least two openings, at least one of which is connected to a supply line, while the at least one other opening is connected to the disposal line.
- each port is connected to a flow channel that opens to the cell interior. This allows electrolyte to be supplied from the supply line to the cell interior via a supply channel and the electrolyte that has flowed through the cell interior to be discharged via a discharge channel.
- the respective supply channel and/or discharge channel between the outer opening and the cell interior i.e. in the area of the frame jacket of the cell frame, can be branched once or several times.
- a series of separate supply channels and/or discharge channels for supplying or removing electrolyte can be provided in the cell frame. In both cases, the electrolyte enters the cell interior distributed as evenly as possible via the outlet openings of the supply channels on one side of the cell frame and exits the cell interior again as evenly distributed as possible via the discharge channels on the other side of the cell frame.
- the feed channels are connected to the supply line via inlet openings.
- the electrolyte can get from the supply line through the at least one feed channel of the cell frame of each half-cell into the corresponding cell interior.
- a plurality of electrochemical cells of the same type are combined in a redox flow battery.
- the cells are usually stacked on top of each other, which is why the entirety of the cells is also referred to as a cell stack or cell stack.
- the electrolytes usually flow through the individual cells parallel to one another, while the cells are usually electrically connected in series.
- the cells are usually connected hydraulically in parallel and electrically in series. In this case, the state of charge of the electrolytes is the same in one of the half-cells of the cell stack.
- half-cells are connected to one another with supply and disposal lines.
- each half-cell or each cell interior of a cell has a different electrolyte flowing through it, the two electrolytes must be separated from one another while passing through the cell stack. Therefore, as a rule, two separate supply lines and two separate disposal lines are provided along the cell stack. Everyone these channels are usually partially formed by the cell frames themselves, which have four openings for this purpose. The openings extend along the cell stack and form the supply and disposal lines, arranged one behind the other and, if necessary, separated from one another by sealing materials.
- the electrodes in at least one of the half-cells reach at least partially into the cell interior, are porous and have the corresponding electrolyte flowing through them.
- the increase in power density is often unsatisfactory. This indicates that the surface area provided by the electrode is not being used fully or as effectively as possible. This can be explained by a non-uniform flow through the electrodes, as can also be observed in the flow through similar porous solids. Even small irregularities in the porosity lead to irregular flows, as the pressure losses depend heavily on the corresponding free flow cross-sections and the volume flow. However, an uneven flow through a cell interior can also occur if no porous section of the electrodes engages in the cell interior.
- cell frames with finger elements or webs have been proposed which extend into the cell interior or through the cell interior.
- Cell chambers are then provided on either side of the finger member or strut.
- struts that extend through the entire cell interior from one side to the opposite side, these can completely separate the cell chambers from one another, through which different proportions of the corresponding electrolyte flow.
- finger elements that have a free end, the cell chambers are connected to one another at least in the area of the free ends of the finger elements.
- a part of an electrode with a porosity for the flow of the electrolyte can be provided.
- the porosity of the electrode enables the electrolyte to flow at least in sections through the electrode from a supply channel to a discharge channel of the same cell frame. Otherwise, the corresponding electrolyte flows along a non-porous surface of the corresponding electrode from a supply channel to a discharge channel of the same cell frame.
- the present invention is therefore based on the object of designing and developing the electrochemical cells and the cell stack of the type mentioned at the beginning and explained in more detail above in such a way that a more expedient flow can be achieved that reliably enables a lower pressure loss and a higher power density.
- a cell stack in particular a redox flow battery, comprising a plurality of electrochemical cells according to one of claims 1 to 14.
- the finger elements of the cell frame can therefore not only be used to divide the cell interior into different cell chambers and for the corresponding flow guidance of the electrolytes in the cell interior.
- Some of the finger elements also accommodate at least one supply channel and/or one discharge channel, so that the electrolyte can enter the cell interior and/or exit from the cell interior via corresponding outlet openings and/or inlet openings. In this way, the flow of the electrolyte can be specified and adjusted much more precisely.
- the flow of the electrolyte is therefore less random and dependent on the unavoidable irregularities of the cell interior, in particular an electrolyte provided in the cell interior.
- the pressure loss can be predicted more reliably.
- the flow of the electrolyte can also be distributed more evenly, with the electrolyte also having to cover shorter distances if necessary. Consequently, the pressure loss of the electrolyte across the cell interior can be reduced by appropriate use of the finger members of the cell frame.
- the cell frame has in particular a plate-like shape in which the cell interior is integrated.
- the cell frame thus has a height or thickness perpendicular to a plane defined by the cell interior or by the cell frame itself, which can be many times smaller than the length or width parallel to the plane defined by the cell interior or by the cell frame itself .
- the cell frame has at least essentially a constant height or thickness all around the cell interior.
- the height or the thickness of the cell interior corresponds, if required, at least essentially to the height or thickness of the cell frame.
- the height of the cell interior can in particular also be somewhat less than the height of the cell frame, because the semipermeable membrane and/or a non-permeable section of the electrode can be provided at least partially in the cell frame.
- the cell frame is made of a plastic, in which case production by means of injection molding is then possible to form the at least one feed channel and/or the at least one discharge channel in a simple manner in the cell frame.
- the electrode in the cell interior has a porosity for the electrolyte to flow through at least partially from the at least one supply channel to the at least one discharge channel. Since the electrolyte can flow through the porous section of the electrode, unlike a preferably provided non-porous section of the electrode, the space occupied by the porous section of the electrode is assigned to the cell interior, which is plausible in particular from a functional point of view.
- the porous section of the electrode can be designed in one piece or in multiple pieces, with a one-piece configuration being possible for the sake of simplicity.
- the electrode can be formed from fibers, in particular like a felt.
- the material for the electrode is graphite, which can be present in the form of graphite fibers.
- the porosity of the electrode provides a significantly larger interface between the electrode and the electrolyte, which favors the processes and reactions taking place in the corresponding interface. In particular, the processes and reactions run faster and/or more extensively.
- a porous portion of the electrode is provided in the cell interior and electrically conductively connected to a non-porous portion of the electrode. Electrolyte cannot pass through the non-porous portion of the electrode, unlike the porous portion of the electrode. This can be used to at least partially close the cell interior. Closing the cell interior is particularly useful on a side of the cell frame that is opposite a semipermeable membrane and can in turn close the cell interior on the corresponding side.
- the cell interior is on the length and width of the cell frame defining Sides closed by the electrode and the semipermeable membrane and at the height or thickness of the cell frame defining narrow sides of the cell frame by the cell frame itself.
- the non-porous section of the electrode can be in the form of a bipolar plate.
- the use of bipolar plates in combination with porous electrodes has already been provided for in a number of known electrochemical cells. For the sake of simplicity, a similar configuration also appears to be advantageous here.
- the electrode can be inadvertently compressed, at least in its porous areas. In this case, however, the electrode can no longer be flown through as desired in these areas, and increased pressure losses result. However, correspondingly increased pressures of the electrolyte are regularly undesirable because this can easily lead to damage and/or leaks in the electrochemical cell or the cell stack. So that the electrode is not excessively compressed and/or so that the electrolyte can flow through the cell interior as evenly as possible, it is expedient if the at least one finger element is designed as an at least essentially continuous strut bridging the cell interior.
- a finger element is basically understood to mean one that can have a free end. The finger element can thus protrude into the cell interior and end with its free end in the cell interior.
- the finger element can also be designed without a free end, in that the finger element is designed in the form of a strut, which is connected at two different points to the area of the cell frame that encloses the cell interior and extends through the cell interior in between, the finger element or the Strut preferably separates two cell chambers from each other. It is further preferred if the strut extends transversely through the cell interior from one side of the cell frame to the opposite side of the cell frame. In addition, for the sake of simplicity, this can be done in a direction parallel to the length or width of the cell frame and/or the cell interior. Alternatively or additionally, for the sake of simplicity, it is also preferred if the finger elements or struts extend in a straight line through the cell interior.
- the pressure loss of the electrolyte across the cell interior can be reduced by the fact that the flow of the electrolyte through the cell interior is more uniform he follows.
- at least one flow channel can be embedded in the electrode.
- the flow channel is characterized in that the free flow cross section in the flow channel is significantly larger, in particular by a multiple, than the average pore diameter of the porous section of the electrode. Electrolyte can then get into the pores of the electrode via the flow channel. Alternatively or additionally, electrolyte escaping from the pores of the electrode can be collected in the flow channel. Against this background, it is also particularly useful if the at least one flow channel is embedded in the porous section of the electrode.
- the at least one flow channel is connected to an inlet opening and/or outlet opening of the at least one finger element. Then the electrolyte to be distributed can be distributed via the flow channel in the porosity of the electrode and/or the electrolyte to be collected can be collected via the flow channel.
- the flow of the electrolyte can be distributed uniformly to the cell interior of the cell frame if the flow channels adjoining at least one inlet opening and the flow channels adjoining at least one outlet opening are alternately provided in at least one direction. In this case, this direction is preferably parallel to a aligned to the plane defined by the cell border.
- a uniform flow of the electrolyte in the cell interior can be supported in that the at least one flow channel of the electrode and the at least one finger element of the cell frame are arranged at least essentially perpendicular to one another. Then the electrolyte can flow in a direction through the finger element in a direction perpendicular thereto through the at least one flow channel of the electrode.
- the advantages associated with the at least one finger element can be used even more extensively if a plurality of finger elements arranged at least essentially parallel to one another are provided. In this way, a uniform flow of the electrolyte through the cell interiors can be achieved even with larger cell interiors.
- a plurality of at least essentially parallel flow channels are provided in the electrode.
- the electrolyte can then be supplied to the cell interior via a supply channel in a finger element and removed via a discharge channel of an adjacent finger element or the peripheral edge of the cell frame.
- the direction of flow of the electrolyte in the cell interior can be specified precisely, namely always from a supply channel to a discharge channel.
- the finger elements do not necessarily have to be straight.
- the finger elements or the struts form a lattice structure.
- the interior of the cell can be divided into individual quadrants, which then form separate cell chambers be able.
- the additional connections can lead to an additional stiffening of the cell frame.
- individual segments of the finger elements or the struts can then be used for a materially or form-fitting connection with adjoining semipermeable membranes or, in particular, non-porous sections of electrodes.
- the at least one supply channel and/or the at least one discharge channel extends in only one direction in a finger element or in a strut. No electrolyte is then conducted in sections of the finger element or the strut that are oriented transversely to the at least one supply channel and/or at least one discharge channel; these sections then serve purposes other than the conduction of the electrolyte.
- the at least one finger element is materially bonded to the semipermeable membrane and/or to, in particular the non-porous section, of the electrode.
- the electrochemical cell becomes more stable and stiff overall.
- the cell frame and thus the electrochemical cell as a whole are therefore less susceptible to undesired deformations or leaks.
- the electrode this applies to a particular degree if the at least one finger element is connected to the bipolar plate, which typically itself already provides high torsional rigidity or a high area moment of inertia.
- adhesive or welded connections are particularly suitable.
- the non-porous section of the electrode which can in particular be designed as a bipolar plate, and the porous section of the electrode do not have to be firmly connected to one another.
- the manufacture of the electrochemical cell can be simplified and damage to the electrode can be avoided.
- the non-porous section the electrode or the bipolar plate and the porous section of the electrode engage in one another in a form-fitting manner. This allows a slight movement of said electrode sections and at the same time it can be ensured that these sections of the electrode remain reliably aligned with one another in a predetermined manner, for example during assembly and operation.
- the non-porous section of the electrode has ribs.
- the ribs of the non-porous section of the electrode or of the bipolar plate can then positively engage in the porous section of the electrode in order to position the different sections of the electrode against one another. If the ribs of the non-porous section of the electrode or the bipolar plate engage in the flow channels of the porous section of the electrode, at least in sections, not only does the structure of the electrode become stiffer overall, but a uniform flow of the electrolyte through the cell interior is also promoted, since the width of the flow channels remains constant due to the positive fit.
- the finger elements are each provided in both half cells of the plurality of electrochemical cells.
- the advantages described above can be used all the more or in both half-cells of the electrochemical cells.
- the finger elements are arranged at least in sections in the stacking direction of the electrochemical cells at least substantially flush with one another, at least in half-cells that are adjacent to one another. In this way, the electrolyte can flow evenly in the cell interiors of the half-cells.
- a positive fit between the cell frame, the semipermeable membranes and, if necessary, the electrodes can be achieved, which allows forces to be dissipated via the finger elements to adjacent finger elements via different half-cells and, if required, via different electrochemical cells.
- a stable and rigid cell stack can be provided which is less inclined to deform in an undesired manner or to leak, for example without the contact pressures between the half-cells and/or the electrochemical cells having to be excessively high.
- the corresponding form fit can be achieved in particular without excessive compression of the electrodes, through which the flow occurs unevenly as a result of such compression, if the height of the respective aligned sections of the finger elements is at least essentially the height of the respective cell interior and/or the respective cell frame in each case Corresponds to the area of the aligned sections of the finger elements.
- the finger elements are then preferably in contact with the semi-permeable membranes and the electrodes, so that the finger elements can transmit forces to adjacent finger elements without any significant deformation of the electrochemical cells or the cell stack being necessary for this. This is particularly true when the aligned sections of the finger elements are in contact with a semipermeable membrane on one side and with a non-porous section of the electrode, in particular the bipolar plate, on the opposite side.
- FIG. 1A-B a first cell stack according to the invention in the form of a redox flow battery in a longitudinal section
- FIG. 2A-D a cell frame of an electrochemical cell according to the invention of the cell stack from FIG. 1 together with an associated electrode in the cell interior of the cell frame in a top view and in opposite sectional views along a sectional plane BB or CC perpendicular to the plane of the cell frame,
- FIG. 3 shows part of the electrode from FIG. 2 in a perspective view and
- FIG. 4 shows a detail of a second cell stack according to the invention in an enlarged view.
- the cell stack 1 comprises three cells 2, each having two half-cells 3 with corresponding electrolytes.
- Each half-cell 3 has a cell frame 4, which includes a cell interior 5, through which an electrolyte stored in a storage container can be passed and into which an electrode 6 engages at least partially, which also closes off and closes the cell interior 5 on one side.
- the electrolytes flowing through the cell interiors 5 differ from one another.
- the respective cell interior 5 is closed on the side facing away from the electrode 6 adjacent to the cell frame 4 of the second half-cell 3 of the same electrochemical cell 2 by a semipermeable membrane 7 provided between the cell frame 4 of the two half-cells 3 .
- a convective transfer of the two different electrolytes of the two half-cells 3 into the cell interior 5 of the cell frame 4 of the other half-cell 3 is thus prevented.
- ions can diffuse from one electrolyte to the other electrolyte via the semipermeable membrane 7, resulting in charge transport. Electrons are either released or absorbed by redox reactions of the redox pairs of the electrolytes at the electrodes 6 of the half-cells 3 of a cell 2 .
- the released electrons can flow from one electrode 6 to the other electrode 6 of a cell 2 via an electrical connection which is provided outside the redox flow battery and, if necessary, has an electrical load. Which reactions take place at which electrode 6 depends on whether the redox flow battery is being charged or discharged.
- the electrodes 6 lie flat on an outside 8 of the cell frame 4 .
- the electrode 6 thus forms a frame surface in the area of contact with the outside 8 of the cell frame 4 , which acts as a sealing surface 9 .
- a sealing material 10 is located between the facing outer sides 8 of the cell frame 4 of a cell 2, in which the membrane 7 is accommodated in a sealing manner.
- the sealing material 10 lies flat against the outer sides 8 of the adjoining cell frames 4 and thus forms frame surfaces that act as sealing surfaces 9 .
- FIG. 1A there is a supply line 11 and a disposal line 12 shown.
- a feed channel 13 branches off from the supply line 11 in one half-cell 3 of each cell 2 , via which feed channel 13 the electrolyte can be fed to the corresponding cell interior 5 of the half-cell 3 .
- a discharge channel 14 is provided on opposite sections of the corresponding cell frames 4 , via which the electrolyte can be discharged from the cell interiors 5 into the disposal line 12 .
- the supply line 11 not shown in FIG. 1A and the disposal line 12 also not shown, enable the second electrolyte to flow through the other cell interiors 5 of the other half-cells 3 via a similar supply channel 13 and a discharge channel 14 .
- FIG. 2A-B shows top views of a cell frame 4 and sectional views along a common sectional plane but in opposite viewing directions.
- the cell frame without an electrode is shown in FIG. 2A and the same cell frame with an inserted electrode is shown in FIG. 2B.
- the electrodes are also shown in place.
- each opening 15 is part of a supply line 11 or a disposal line 12 forms.
- the supply channel 13 and the discharge channel 14 are embedded as depressions or open channels in the illustrated outside 8 of the frame casing 16 of the cell frame 4 running around the cell interior 5 .
- the supply channel 13 and the discharge channel 14 are closed to form lines that are closed on the peripheral side when they are assembled to form a cell stack 1 .
- this is done, for example, and in sections by the sealing materials 10 and the electrodes 6.
- the electrodes 6 could also be spatially separated from the supply lines 11 and the disposal lines 12 by sealing materials 10 and/or the electrical insulation of these materials.
- the sealing material 10 adjacent to the semipermeable membrane 7, the feed channels 13 and the discharge channels 14 could also be dispensed with.
- the supply channel 13 and the discharge channel 14 are branched, so that the electrolyte can be distributed via the supply channel 13 over the cell interior 5 and can be discharged distributed via the discharge channel 14 .
- this is not required. It is also possible to provide supply channels 13 that lead off the supply line 11 separately. Likewise, discharge channels 14 connected separately to a disposal line 12 could also be provided.
- the cell frame 4 that is shown and is preferred in this respect is provided surrounding the cell interior 5 and also has three finger elements 17 designed as struts that extend transversely through the cell interior 5 and thus divide the cell interior 5 into four cell chambers 18, which in the cell frame 4 be completely separated from each other.
- the finger elements 17 also run parallel to the plane of the cell frame 4 and parallel to one another as well as parallel to the longitudinal extent of the cell frame 4. Furthermore, the finger elements 17 are spaced at least essentially the same distance from the adjacent finger element 17 or the lateral edge 19 of the cell interior 5. In this way, cell chambers 18 of the same size are provided.
- the cell frame 4 shown and preferred in this respect has two finger elements 17 each having a part of the feed channel 13 which is also formed as an open channel in the area of the finger elements 17 and is closed by the semipermeable membrane 7 or the electrode 6 .
- the third and middle finger element 17, on the other hand, has part of the discharge channel 14, which is also designed as an open channel, which is closed by the semipermeable membrane 7 or the electrode 6 when the cell 2 is assembled.
- parts of the discharge channel 14 are also provided in the lateral edges 19, into which electrolyte can flow from the cell interior 5.
- parts of the feed channel 13 could also be provided in the sides of the cell frame 4 .
- finger elements 17 with a part of the discharge channel 14 would preferably connect to the inside.
- the electrolyte is conducted from the feed channel 13 to the discharge channel 14 via a cell chamber 18 in each case.
- the electrolyte flows into the cell interior 5 via outlet openings 20 which are distributed along the length of the finger element 17 .
- the electrolyte flows from the cell interior 5 or the cell chambers 18 via inlet openings 21 into the discharge channel 14.
- the inlet openings 21 are provided in the illustrated and to this extent preferred cell frame 4 in the finger element 17 and in the lateral edges 19 of the cell frame 4. If a supply channel 13 should be provided in the lateral edges 19 of the cell frame 4, outlet openings 20 are preferably also provided there in order to allow the electrolyte to flow from there into the cell interior 5.
- the outlet ports 20 and inlet ports 21 are shown in Figures 2C-D. It is also shown that the finger elements 17 extend at least essentially over the entire height of the cell frame 4 . However, part of the height of the cell frame 4 in the area of the finger elements 17 is provided by the electrode 6 . This part of the electrode 6 represents the non-porous section 22 of the electrode 6 in the form of a bipolar plate.
- the porous section 23 of the electrode 6 extends into the cell chambers 18 of the cell interior 5 and is electrically conductive conductive contact to the non-porous portion 22 of the electrode 6 is provided.
- the porous section 23 of the electrode 6 has flow channels 24 which connect at one end to an outlet opening 20 of the supply channel 13 or an inlet opening 21 of the discharge channel 14 .
- the flow channels 24 run parallel to one another and at an at least substantially equal distance from one another. Ribs 26 are provided along the flow channels 24 in the non-porous section 22 of the electrode 6 and engage in the flow channels 24 of the porous section 23 of the electrode 6 in a form-fitting manner.
- the flow channels 24 are provided with a free end 25, so that the flow channels 24 are not in direct contact with one another.
- the flow channels 24 are each spaced apart from one another via porous regions of the electrode 6 .
- the flow channels 24 extend over the majority of the width of the cell chamber 18. The length of the flow channels 24 is approximately the same. It makes no difference here whether the flow channels 24 connect to a supply channel 13 or a discharge channel 14 . In the electrode 6 shown, the flow channels 24 are cut out of the porous material of the electrode 6 .
- the porous material of the electrode 6 is a kind of felt made of graphite fibers.
- the non-porous section 22 of the electrode 6 is in the form of a solid plate made of graphite, from which the ribs 26 for the form fit with the porous section 23 of the electrode 6 protrude.
- the thickness of the porous section 23 of the electrode 6 is significantly greater than the height of the ribs 26. In many cases it is expedient if the thickness of the porous section 23 of the electrode 6 is at least twice the height of the ribs 26 of the not porous section 22 of the electrode 6. In the present case, the thickness of the porous section 23 of the electrode 6 is at least three times the height of the ribs 26.
- each of the half-cells 3 comprises a cell frame 4, with a semipermeable membrane 7 or a non-porous section 22 of the electrode 6 being provided between two cell frames 4 in each case.
- the semi-permeable membrane 7 and the non-porous portion 22 of the electrode 6 are connected to the associated cell frame 4 without a sealant.
- the connection is materially bonded and has been joined by welding the cell frame 4 formed from a thermoplastic material and the semipermeable membranes 7 or electrodes 6, which are also made at least partially from a thermoplastic material.
- the cell stack 1 could basically also be designed in a different way.
- a finger element 17 is provided between a semipermeable membrane 7 and a non-porous section 22 of the electrode 6 in which a supply channel 13 or discharge channel 14 in the form of an open channel closed by the semipermeable membrane 7 is provided.
- the finger elements 17 are connected, in particular welded, to the non-porous sections 22 of the electrodes 6 via material connections 27 .
- the finger elements 17 extend from the porous section 23 of the electrode 6 to the adjacent semipermeable membrane 7, ie over the entire height of the cell interior 5, so that two adjacent cell chambers 18 are separated from one another.
- the corresponding finger elements 17 of the successive half-cells 3 are arranged in alignment with one another in the stacking direction of the half-cells 3 .
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Abstract
Description
Claims
Priority Applications (7)
Application Number | Priority Date | Filing Date | Title |
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JP2023518374A JP2023542948A (ja) | 2020-09-23 | 2021-09-10 | 特にレドックスフロー電池の、電気化学セルおよび対応するセルスタック |
CA3196052A CA3196052A1 (en) | 2020-09-23 | 2021-09-10 | Electrochemical cell, in particular of a redox flow battery, and corresponding cell stack |
IL301508A IL301508A (en) | 2020-09-23 | 2021-09-10 | An electrochemical cell, in particular of a redox current battery and a suitable cell stack |
AU2021348962A AU2021348962A1 (en) | 2020-09-23 | 2021-09-10 | Electrochemical cell, more particularly of a redox flow battery, and corresponding cell stack |
US18/027,779 US20240030475A1 (en) | 2020-09-23 | 2021-09-10 | Electrochemical Cell, More Particularly of a Redox Flow Battery, and Corresponding Cell Stack |
KR1020237012886A KR20230073256A (ko) | 2020-09-23 | 2021-09-10 | 특히 레독스 흐름 배터리의 전기화학 셀 및 대응하는 셀 스택 |
EP21777275.5A EP4218077A1 (de) | 2020-09-23 | 2021-09-10 | Elektrochemische zelle, insbesondere einer redox-flow-batterie, sowie entsprechender zellstack |
Applications Claiming Priority (2)
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DE102020124801.6 | 2020-09-23 | ||
DE102020124801.6A DE102020124801A1 (de) | 2020-09-23 | 2020-09-23 | Elektrochemische Zelle, insbesondere einer Redox-Flow-Batterie, sowie entsprechender Zellstack |
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WO2022063610A1 true WO2022063610A1 (de) | 2022-03-31 |
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PCT/EP2021/074972 WO2022063610A1 (de) | 2020-09-23 | 2021-09-10 | Elektrochemische zelle, insbesondere einer redox-flow-batterie, sowie entsprechender zellstack |
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US (1) | US20240030475A1 (de) |
EP (1) | EP4218077A1 (de) |
JP (1) | JP2023542948A (de) |
KR (1) | KR20230073256A (de) |
AU (1) | AU2021348962A1 (de) |
CA (1) | CA3196052A1 (de) |
DE (1) | DE102020124801A1 (de) |
IL (1) | IL301508A (de) |
WO (1) | WO2022063610A1 (de) |
Cited By (1)
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WO2022268264A1 (de) * | 2021-06-22 | 2022-12-29 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e. V. | Strukturintegrierte elektrochemische zelle und daraus aufgebauter strukturintegrierter stack |
Families Citing this family (2)
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DE102022004497B3 (de) * | 2022-12-01 | 2024-01-11 | Mercedes-Benz Group AG | Batterieeinzelzelle, Befüllvorrichtung und Verfahren zum Befüllen der Batterieeinzelzelle mit Elektrolyt |
DE102023108336B3 (de) | 2023-03-31 | 2024-05-29 | Angela Ludwig | Redoxfluss-Akkumulator und Herstellungsverfahren dafür |
Citations (4)
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EP0051766A1 (de) | 1980-11-07 | 1982-05-19 | Siemens Aktiengesellschaft | Haltevorrichtung für elektrische Geräte, insbesondere für Einbruchdetektoren |
DE69905177T2 (de) * | 1999-07-01 | 2003-06-05 | Squirrel Holdings Ltd | Durch membran getrennter bipolarer mehrzelliger elektrochemischer reaktor |
US20040170893A1 (en) | 2001-06-12 | 2004-09-02 | Hiroyuki Nakaishi | Cell frame for redox flow cell and redox flow cell |
WO2014083387A1 (en) * | 2012-11-30 | 2014-06-05 | Hydraredox Technologies Inc. | Back plate-electrode-membrane assembly for a redox, flow energy storage electrochemical cell |
Family Cites Families (2)
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US20150125768A1 (en) | 2013-11-07 | 2015-05-07 | Enervault Corporation | Cell and Cell Block Configurations for Redox Flow Battery Systems |
PT3378116T (pt) | 2015-11-18 | 2021-09-22 | Invinity Energy Systems Canada Corp | Montagem de elétrodo e bateria de fluxo com melhor distribuição de eletrólito |
-
2020
- 2020-09-23 DE DE102020124801.6A patent/DE102020124801A1/de active Pending
-
2021
- 2021-09-10 AU AU2021348962A patent/AU2021348962A1/en active Pending
- 2021-09-10 CA CA3196052A patent/CA3196052A1/en active Pending
- 2021-09-10 EP EP21777275.5A patent/EP4218077A1/de active Pending
- 2021-09-10 WO PCT/EP2021/074972 patent/WO2022063610A1/de active Application Filing
- 2021-09-10 IL IL301508A patent/IL301508A/en unknown
- 2021-09-10 KR KR1020237012886A patent/KR20230073256A/ko unknown
- 2021-09-10 US US18/027,779 patent/US20240030475A1/en active Pending
- 2021-09-10 JP JP2023518374A patent/JP2023542948A/ja active Pending
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
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EP0051766A1 (de) | 1980-11-07 | 1982-05-19 | Siemens Aktiengesellschaft | Haltevorrichtung für elektrische Geräte, insbesondere für Einbruchdetektoren |
DE69905177T2 (de) * | 1999-07-01 | 2003-06-05 | Squirrel Holdings Ltd | Durch membran getrennter bipolarer mehrzelliger elektrochemischer reaktor |
US20040170893A1 (en) | 2001-06-12 | 2004-09-02 | Hiroyuki Nakaishi | Cell frame for redox flow cell and redox flow cell |
US20080081247A1 (en) * | 2001-06-12 | 2008-04-03 | Sumitomo Electric Industries, Ltd. | Cell frame for redox flow battery, and redox flow battery |
WO2014083387A1 (en) * | 2012-11-30 | 2014-06-05 | Hydraredox Technologies Inc. | Back plate-electrode-membrane assembly for a redox, flow energy storage electrochemical cell |
Cited By (1)
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WO2022268264A1 (de) * | 2021-06-22 | 2022-12-29 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e. V. | Strukturintegrierte elektrochemische zelle und daraus aufgebauter strukturintegrierter stack |
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US20240030475A1 (en) | 2024-01-25 |
JP2023542948A (ja) | 2023-10-12 |
KR20230073256A (ko) | 2023-05-25 |
EP4218077A1 (de) | 2023-08-02 |
CA3196052A1 (en) | 2022-03-31 |
IL301508A (en) | 2023-05-01 |
DE102020124801A1 (de) | 2022-03-24 |
AU2021348962A1 (en) | 2023-05-04 |
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