DE102014103292A1 - Composite of electrochemical cells - Google Patents

Abstract

The invention relates to a composite (20) of electrochemical cells (26, 26a, 26b), in particular for a redox flow battery, with cells (26, 26a, 26b) connected in series, each having an anodic half-cell (27, 28a, 27b ) and an adjacent cathodic half cell (28, 27a, 28b) interconnected by an ion conducting membrane (22) and electrodes (18, 18a, 18b, 18c) extending in the half cells, the half cells are each enclosed by an electrically insulating cell wall (12) and filled with electrochemically active medium, and wherein selected adjacent half-cells (28, 28a, 27a, 27b) are connected in series with one another by monolithic electrodes (18a, 18b).

Description

The invention relates to a composite of electrochemical cells, in particular for a redox flow battery, with series-connected cells, each having an anodic half-cell and an adjacent cathodic half-cell, which are interconnected by an ion-conducting membrane, and with electrodes which are in the Half cells extend, wherein the half-cells are each enclosed by an electrically insulating cell wall and filled with electrochemically active media.

A redox flow battery (also called "redox flow cell") stores electrical energy in chemical compounds by having the reactants in a solvent in dissolved form. How about from the WO 2010/094657 A1 , of the EP 2 648 257 A1 or the WO 2011/075135 A1 As is known, the two energy-storing electrolytes circulate in two separate circuits, between which the ion exchange in the cell takes place via an ion-conducting membrane. The energy-storing electrolytes are stored outside the cell in separate tanks. Redox flux batteries are based on the principle that two electrolytes flow through the half cells of an electrochemical cell, changing their oxidation state on the surface of the electrodes. The delivered or received in the half-cell reactions electrodes perform work on the external circuit. In the prior art, porous carbon or graphite is mostly used as electrode material, which is flowed through by the electrolyte. The half-cells are usually stacked coplanar (see. EP 2 648 257 A1 ), wherein the flow of electrolyte leads from one end face of the electrode material to the other. The passage of the electrode material in the cell plane causes a high pressure drop and a high difference in the concentration of the reactive species between the inlet and outlet side.

The half cells are separated by a thin, ion-conducting plastic membrane. The cells stacked coplanar are usually electrically connected to each other via bipolar plates made of a carbon-plastic composite, which simultaneously prevent an exchange of electrolytes between two cells. To minimize the contact resistance between the bipolar plates and the porous electrode materials (typically graphite felt), the components are pressed perpendicular to the cell planes. This results in undesirable compression of the porous electrode material, which increases the hydrodynamic flow resistance in the cell and, over time, crumbles the porous electrode material. Furthermore, the functional materials are stacked coplanar. In order to build up the system in a fluid-tight manner, seals are required at the interfaces between the functional materials.

According to the WO 2011/075135 A1 The cells are interconnected via special bipolar plates. This should reduce the flow resistance. However, the arrangement is very complicated. The use of bipolar plates is to be regarded as disadvantageous. The material and assembly costs are high. In addition, seals are required that can leak. In addition, contact resistances to the electrodes result.

The known composites of electrochemical cells, which are used in particular in redox flow batteries, thus have significant disadvantages, in particular a complicated structure, a high internal resistance and a low efficiency of the electrochemical cell assembly.

Against this background, the invention has for its object to provide an improved composite of electrochemical cells in which the cells are connected in series with each other and what with a simplified structure and in particular a reduced internal resistance results.

This object is achieved by a combination of electrochemical cells, in particular for a redox flux battery, with series-connected cells, each having an anodic half-cell and an adjacent cathodic half-cell, which are interconnected by an ion-conducting membrane, and with electrodes, the extend in the half-cells, wherein the half-cells are each enclosed by an electrically insulating cell wall and are filled with electrochemically active media, and wherein selected adjacent half-cells are connected in series by monolithic electrodes.

The object of the invention is completely solved in this way.

By the serial connection of selected adjacent half cells by means of monolithic electrodes can be dispensed with the use of bipolar plates for connecting the cells. In this way, there is a significant simplification of the structure and at the same time a reduction of the internal resistance of the cell assembly.

According to a further embodiment of the invention, the membrane extends in a plane, alternately anodic and cathodic half-cells being arranged adjacent to one another along the membrane on a first membrane side, complementary cathodic and anodic half-cells being arranged adjacent to one another along the membrane on a second membrane side, such that along the membrane a series of contiguous alternating orientation cells is formed, each alternating adjacent half-cells are isolated on a membrane side against each other and the associated half-cells are electrically connected to each other on the other side of the membrane via a monolithic electrode, so that a meandering current path results through the cells.

The meandering current path preferably runs alternately from one half cell on the one membrane side through the membrane into the associated half cell on the other membrane side, from there via a monolithic electrode into the adjacent half cell on the same membrane side, from there through the membrane back to the opposite membrane side in FIG the associated half-cell, from where the current path, depending on the number of half-cells arranged along the membrane, either continues in a corresponding manner or is conducted through an electrode through a cell wall to the outside.

In this way, a compact and simply constructed composite of electrochemical cells is provided, which are connected in series with each other. Since adjacent cells are each interconnected via a monolithic electrode, which engages in an adjacent half-cell, and incidentally, the current path in each case passes from a half-cell on one side of the membrane through the membrane to the other side of the membrane in the associated half-cell, from the In turn, the current path via the monolithic electrode in the adjacent half cell progresses, results in an extremely compact design and low internal resistance of the cell network.

According to a further embodiment of the invention, the half-cells each have inflow openings and outflow openings for the flow through with electrochemically active medium.

In this way, an active exchange of the active medium can be ensured, as required for example in a redox flow cell.

According to a further embodiment of the invention, the cross-sections of the half-cells along the flow direction of the electrochemically active medium are varied in order to counteract a pressure drop along the respective flow path.

Since the pressure along the flow path is reduced, increasing the cross-section in the flow direction can counteract a slowing down of the flow velocity.

According to a further embodiment of the invention, the inflow openings and the outflow openings at the ends of a respective half cell are arranged on opposite sides of the electrode with respect to an electrode extending therein.

In this way, an intensive interaction of the flowing through the half-cell electrochemically active medium is ensured with the electrode.

In an alternative embodiment of the invention, the inflow openings and outflow openings are arranged on the same side of the membrane on opposite end faces of the respective half-cell.

It has been found that in this way too, a particularly intensive flow through the electrode with the electrochemically active medium can be achieved.

According to a further embodiment of the invention, the monolithic electrodes are formed as porous electrodes which are compressed in the region of the passage through the cell wall each with a plastic to a fluid-tight, electrically conductive solid, which is fluid-tightly connected to the cell wall.

In this case, the cell wall is preferably designed as a plastic part, which is in the region of the passage in each case materially connected and preferably positively connected to the electrode.

Further preferably, the cell wall and the respective electrode are formed in the region of the passage as an integral part, preferably as an integral injection-molded part.

Such a configuration of the electrodes in the region of the implementation on the one hand ensures a particularly simple and reliable fluid-tight passage of the electrode through the cell wall and, on the other hand, a particularly simple production.

The electrodes can advantageously consist of an open-pore foam, a felt, a fleece or a fabric.

According to a further embodiment of the invention, the electrodes consist of a carbon modification, in particular graphite or carbon fibers, a metal or a conductive ceramic.

In particular graphite electrodes have proven to be particularly effective in connection with such cell bonds.

According to a further embodiment of the invention, the electrodes are provided with a thermoplastic, in particular polypropylene or polyethylene, or with a thermosetting plastic, in particular a UV-curable plastic or a two-component adhesive, at least compressed in the region of the implementation. Prerequisite for the plastic used is the resistance in the electrolyte, without that harmful substances, such as plasticizers, are washed out.

In this way, a particularly simple production.

According to a further embodiment of the invention, the electrodes are arranged substantially parallel to the membrane.

In a further preferred embodiment of the invention, the electrodes are mat-shaped.

In this way, an advantageous arrangement for the electrodes and a good electrochemical interaction between the electrodes and the flowing through the respective half-cells electrochemically active medium results.

According to a further embodiment of the invention, the cell walls and the electrodes are connected in the region of the passages through the cell walls in a common shaping step, preferably by injection molding.

In this way, a simple and inexpensive production is guaranteed.

According to a further embodiment of the invention, the electrodes of the first and the last connected in series with each other cells are formed as porous electrodes, which are compacted in the region of the respective passage through the cell wall each with a plastic to a fluid-tight, electrically conductive, solid, the fluid-tight connected to the cell wall.

In this way, the contacting of the electrodes outside the cells in a simple and reliable manner can be realized.

According to a further embodiment of the invention, the electrodes are provided outside the cell walls with a coating of an electrically conductive material, preferably of copper or silver, preferably provided with a galvanically applied coating or with a sprayed coating.

In this way results in a simple and effective contacting of the electrodes outside the cells.

According to an alternative embodiment of the invention, the electrodes are provided with contact layers, which are preferably connected via recesses in the contact layers cohesively with the porous electrodes and thus pressed and are guided by the cell walls to the outside.

In this way too, a particularly simple and effective contacting of the electrodes outside the cells can be ensured.

A redox flux battery can be constructed in a simple manner using the composite according to the invention. Here, a storage for a catholyte and an accumulator for anolyte are provided, which are in each case via a pump and associated lines with the cathodic half-cells and the anodic half-cells in communication to flow through them. Externally, the circuit is closed via a load or a voltage source, wherein the connection via associated electrode connections takes place at the first and last cell of the network. All cathodic half-cells and all anodic half-cells are in this case preferably connected in parallel in terms of flow and are coupled via corresponding distributors with the accumulators for the catholyte or the anolyte.

A composite of electrochemical cells according to the invention can be produced in a simple manner by first producing a first half-composite and a second half-composite each having a sequence of half-cells by a shaping process, such as injection molding, from plastic and then bonding them together with the interposition of a membrane, preferably cohesively, for example by spraying or gluing, or positively, for example by riveting or screwing.

In this way, a particularly simple and cost-effective production of the cell composite is ensured.

In a preferred development of this method, the electrodes are produced from a continuous electrode material which is inserted into the associated form and, in the regions in which electrical insulation between adjacent half-cells is desired, by a subtractive processing step, such as stamping, cutting, laser ablation , Spark erosion, is removed.

In this way, a simple and cost-effective integration of the electrodes at the locations where monolithic electrodes are intended to connect adjacent half-cells to one another, and a separation of the electrodes at the locations, where adjacent half-cells are to be electrically isolated from each other.

Alternatively, the electrodes are made of a continuous electrode material which is inserted into the associated mold and in the areas in which an electrical insulation between adjacent half-cells is desired, by a specific shape of the injection mold used and a corresponding local control of the injection pressure locally is separated and isolated by injected plastic.

In this way, a targeted interruption of the electrodes in the desired areas and at the same time provide insulation at these locations.

It is understood that the features of the invention mentioned above and those yet to be explained below can be used not only in the particular combination indicated, but also in other combinations or in isolation, without departing from the scope of the invention.

Further features and advantages of the invention will become apparent from the following description of preferred embodiments with reference to the drawings. Show it:

1 a cross section through a cell with a porous electrode which is compacted and sealed in the region of a passage through the cell wall by means of plastic;

2 a simplified schematic representation of a composite of electrochemical cells according to the invention, which are connected in series with each other;

3 a longitudinal section through one of the half-cells according to 2 , from which the arrangement of inflow openings and outflow openings for the passage through the half-cell with electrochemically active medium can be seen;

4 a cross section through one of the half-cells according to 2 in an enlarged view;

5 a plan view of the electrode according to 3 before the upper part of the cell wall is sprayed on;

6 an alternative embodiment of the composite according to 2 ;

7 a longitudinal section through one of the half-cells according to 6 , from which the arrangement of inflow openings and outflow openings for flowing through the half-cell can be seen with electrochemically active medium, and

8th a schematic representation of a redox flow cell using a composite of cells according to 2 ,

1 shows an electrochemical cell total with the numeral 10 is designated. The cell 10 has a cell wall 12 made of a thermoplastic, such as polypropylene, on, which has a cavity 14 encloses. The cavity 14 is with an electrochemically active medium 16 filled. Inside the cavity 14 there is an electrode 18 that communicate with the medium within the cavity 14 interacts. The electrode 18 is here by the cell wall 12 to the outside in the area of a passage 17 passed through and in this case fluid-tight with the cell wall 12 sealed. The electrode 18 For example, it consists of a graphite felt having a high active surface in order to interact well with the medium 16 inside the cavity 14 to enable.

Outside the cell wall 12 is the electrode 18 for a good contact with a coating 19 made of a highly electrically conductive material, such as copper or silver.

In 2 is an inventive composite of electrochemical cells, which are connected in series with each other, shown schematically and in total with the numeral 20 designated.

The composite 20 has a sequence of juxtaposed cells 26 . 26a . 26b on, each consisting of two half-cells, the both sides of a membrane 22 are arranged. The membrane 22 extends in one plane. The cells 26 . 26a . 26b are now side by side along the membrane 22 arranged such that on the first side of the membrane 22 (upper side) a cathodic half-cell 27 followed by an anodic half-cell 27a the neighboring cell 26a followed again by an anodic half-cell 27b the neighboring cell 26b , are arranged. On the opposite second side (lower side) of the membrane 22 are successively the respective associated half-cells in the form of a cathodic half-cell 28 the first cell 26 followed by an anodic half-cell 28a the second cell 26a followed again by a cathodic half-cell 28b the neighboring cell 26b arranged.

It is understood that other cells can join, as in 2 is indicated.

In the respective half-cells, electrodes extend 18 . 18a . 18b . 18c parallel to the membrane 22 , which are mat-shaped as porous electrodes, such as graphite felt, designed.

The arrangement of the cells 26 . 26a . 26b of the network 20 is now taken so that the polarity of the cells 26 . 26a . 26b is alternating. This results in a meandering flow of current through the cells 26 . 26a . 26b as by the arrows 29 . 30 . 31 . 32 is indicated. Starting from the electrode 18 the anodic half cell 27 the first cell 26 the current flows through the membrane 22 into the associated cathodic half-cell 28 the first cell 26 , This cathodic half cell 28 is now with the adjacent anodic half cell 28a the subsequent cell 26a via a monolithic electrode 18a connected in series, whereby this through a passage 17 in the cell wall 12 between the two half cells 28 . 28a extends.

This approximately consisting of porous graphite felt electrode 18a is as above based on 1 described, with plastic in the field of implementation 17 potted, so that a one-piece training with the cell wall 12 between the two half cells 28 . 28a results. In contrast, the adjacent half cells 27 . 27a on the opposite first side of the membrane through the cell wall 12 electrically isolated from each other. This results in a current flow starting from the electrode 18 the cathodic half cell 27 the first cell 26 through the membrane 22 into the cathodic half cell 28 the first cell 26 , then over the electrode 18a into the adjacent anodic half-cell 28a the subsequent cell 26a , from this again through the membrane 22 into the cathodic half cell 27a the second cell 26a , then turn over a monolithic electrode 18b into the adjacent anodic half-cell 27b the next cell 26b , from this through the membrane 22 into the associated cathodic half-cell 28b the last cell 26b ,

At the first cell 26 and at the last cell 26b are the respective electrodes 18 respectively. 18c through the cell wall 12 passed to the outside, as previously exemplified by 1 was explained.

The individual half-cells are traversed perpendicular to the plane of electrochemically active medium, such as in the first anodic half cell 27 through dashed inflow openings 21 and dashed drainage holes 33 is shown (compare also the cross section through this half cell 27 according to 3 ).

In this case, the arrangement of the inflow openings 21 and the drainage holes 33 preferably so made that the inflow openings 21 on one side of the mat-shaped electrode 18 located and the drainage holes 33 on the opposite second side of the electrode 18 , This causes the electrode 18 is intensively flowed through by the electrically charged electrolyte, whereby the efficiency of the cell improves.

A production of the composite 20 can be done in a simple and cost-effective way, that first a first half 23 of the network 20 by a suitable molding process, such as injection molding, and similarly a second half 24 of the composite is produced in the same way. The two halves 23 . 24 are then with the interposition of the continuous membrane 22 joined. The two half-composites 23 . 24 can be glued or welded together or otherwise sealingly connected to each other, such as by riveting or screwing. In 2 is a circumferential adhesive bead 25 shown by way of example, with the two Halbverbunde 23 . 24 are glued circumferentially.

In the production of the two half-composites 23 . 24 The electrodes are preferably first inserted as a continuous mat over the entire region of the cells in the associated mold cavity of an injection mold and separated at the points where no continuous connection, but an isolation of adjacent half-cells is desired, by a subtractive method, ie as by punching , Cutting, laser ablation, spark erosion.

Since the electrode mat is a fibrous material, such as graphite nonwoven, alternatively, the separation at the respective areas of the electrode mat can also be achieved by a specific shape of the injection mold used and a corresponding local control of the injection pressure during the injection molding process, wherein in the separate area plastic is injected with in order to obtain the desired insulation at the respective location.

Such a configuration leads to a further simplification in the production.

In addition to the material bond produced in this way, it is possible, if necessary, to produce a form-fitting connection, for example by means of suitable undercuts, in order to counteract disintegration in the event of increased flow stress.

Based on 4 and 5 will be briefly explained below, as a contacting of the electrode 18 in the area outside the cell wall 12 can be done.

While according to 1 a contacting by a galvanic coating or by a spraying method (for example thermal spraying) applied coating has been explained in the embodiment according to 4 and 5 a plate-like material made of a good electrically conductive material, such as copper or Silver, on both sides on the ends of the electrode 18 in the area of the cell wall 12 applied and in the production by injection molding in the cell wall 12 cohesive with integrated. For this purpose, each of the contact layers or terminal tongues 34 . 35 a grid of recesses 36 what an improved cohesive integration into the cell wall 12 guaranteed during injection molding.

As already explained above, the electrode becomes 18 in the field of implementation 17 through the cell wall 12 with the plastic together with the rest of the cell wall 12 compacted and overmolded. This results in an intense adhesion and fluid-tight design in the implementation of the electrode 18 ,

Based on 7 and 8th is an alternative embodiment of the composite, the total with 20a is designated, briefly explained. Corresponding reference numerals are used for corresponding parts.

The only difference to the Verbund gemä0 2 and 3 is that the arrangement of the inflow openings 39 and the drainage holes 33 modified. From the section according to 7 it can be seen that the inflow openings 39 in a direction perpendicular to the electrode 18 running channel 38 lead. Starting from this channel 38 becomes the electrode 18 flows through. On the opposite side, the liquid passes through a drainage channel 37 in drain holes. The individual half-cells are supplied in parallel with electrolyte fluid.

In 8th is an example of the use of the composite 20 in a redox flow battery 40 shown.

Redox flux batteries are based on the principle that two electrolytes flow through the half cells of an electrochemical cell, changing their oxidation state on the surface of the electrodes. The electrodes delivered or received during the half-cell reactions perform work (discharge operation) via an external circuit or are charged via the external circuit (charging operation). The circuit is closed by an ion-conductive separating layer or membrane, which ensures the charge balance between the two half-cells.

In 8th is a redox flux battery 40 with the composite 20 shown in simplified form.

For the catholyte (positively charged electrolyte) and the anolyte (negatively charged electrolyte) are separate memory 42 . 44 intended. The cathodic half cells 28 . 28b become from the Katolyt starting from the memory 42 by means of a pump 46 via assigned inflow pipes 48 flows through and over associated drain lines 50 back to the store 42 recycled. Similarly, the anolyte is removed from the reservoir 44 by means of a pump 52 via inflow pipes 54 into the anodic half cells 28a fed and via drain lines 56 discharged again and back into the container 44 directed. All cathodic half-cells and all anodic half-cells are preferably connected in parallel in terms of flow and are via corresponding distributor with the memories 42 respectively. 44 coupled for the catholyte or the anolyte.

For reasons of simplification are in 8th only the half-cells are shown on one side of the membrane. The opposite half-cells on the other side of the membrane are flowed through in a corresponding manner by the catholyte or the anolyte.

The circuit is externally via electrode connections 62 . 64 at the first cell 26 or at the last cell 26b via an external circuit 58 with a consumer 60 closed, provided that the redox flow battery is discharged or is via an external power source 60 closed if the redox flow cell is to be charged. In practice, a charge controller is used to control such as between the consumer 60 or the power source is turned on.

It is understood that, as a rule, more cells are connected serially with the composite 20 are interconnected, so that more half-cells are flowed through by the catholyte or anolyte.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2010/094657 A1 [0002]
• EP 2648257 A1 [0002, 0002]
• WO 2011/075135 A1 [0002, 0004]

Claims (22)

Composite of electrochemical cells, in particular for a redox flow battery, with series-connected cells, each having an anodic half-cell ( 27 . 27b ) and an adjacent cathodic half cell ( 28 . 28b ) through an ion-conducting membrane ( 22 ) and electrodes ( 18 . 18a . 18b . 18c ) extending in the half cells, the half cells each being enclosed by an electrically insulating cell wall and filled with electrochemically active media, and selected adjacent half cells ( 28 . 28a ; 27a . 27b ) by monolithic electrodes ( 18a . 18b ) are connected in series with each other. Composite according to claim 1, in which the membrane ( 22 ) extends in a plane, wherein on a first membrane side alternately anodic and cathodic half-cells ( 27 . 27a . 27b ) adjacent to each other along the membrane ( 22 ) are arranged, wherein on a second membrane side complementary cathodic and anodic half-cells ( 28 . 28a . 28b ) adjacent to each other along the membrane ( 22 ) are arranged so that along the membrane ( 22 ) a series of contiguous cells ( 26 . 26a . 26b ) alternating orientation, wherein alternately adjacent half-cells ( 27 . 28a ) are isolated from each other on a membrane side and the associated half-cells ( 28 . 28a ) on the other side of the membrane via a monolithic electrode ( 18a ) are electrically connected to each other, so that a meandering current path results through the cells. Composite according to claim 2, in which the half-cells ( 27 . 27a . 27b . 28 . 28a . 28b ) each inflow openings ( 21 ) and drainage holes ( 33 ) to flow through with electrochemically active medium. Composite according to Claim 3, in which the inflow openings ( 21 ) and the drainage holes ( 33 ) at the ends of a respective half cell ( 27 ) with respect to an electrode extending therein ( 18 ) on opposite sides of the electrode ( 18 ) are arranged. Composite according to Claim 3, in which the inflow openings ( 39 ) and drainage holes ( 33 ) on the same side of the membrane ( 22 ) on opposite end faces of the respective half-cell ( 27 ) lie. Composite according to Claim 3, 4 or 5, in which the cross-sections of the half-cells ( 27 . 27a . 27b . 28 . 28a . 28b ) are varied along the flow direction of the electrochemically active medium to counteract a pressure drop along the respective flow path. Composite according to one of the preceding claims, in which the monolithic electrodes ( 18 . 18a . 18b . 18c ) are formed as porous electrodes in the region of the implementation ( 17 ) through the cell wall ( 12 ) are each compacted with a plastic to a fluid-tight, electrically conductive solid, the fluid-tight with the cell wall ( 12 ) connected is. An electrochemical cell according to claim 7, wherein the cell wall ( 12 ) is formed as a plastic part, which in the field of implementation ( 17 ) in each case cohesively and preferably positively with the electrode ( 18 . 18a . 18b . 18c ) connected is. An electrochemical cell according to claim 8, wherein the cell wall ( 12 ) and the respective electrode ( 18 . 18a . 18b . 18c ) in the field of implementation ( 17 ) are formed as an integral part, preferably as an integral injection molded part or extrusion part. Electrochemical cell according to one of the preceding claims, in which the electrodes ( 18 . 18a . 18b . 18c ) consist of an open-pored foam, felt, fleece or fabric. Electrochemical cell according to one of the preceding claims, in which the electrodes ( 18 . 18a . 18b . 18c ) consist of a carbon modification, in particular graphite or carbon fibers, a metal or a conductive ceramic. Electrochemical cell according to one of the preceding claims, in which the electrodes ( 18 . 18a . 18b . 18c ) with a thermoplastic, in particular polypropylene or polyethylene, or with a thermosetting plastic, in particular a UV-curable plastic or a two-component adhesive, at least in the area of implementation ( 17 ) are compressed. Composite according to one of the preceding claims, in which the electrodes ( 18 . 18a . 18b . 18c ) substantially parallel to the membrane ( 22 ) are arranged. Composite according to one of the preceding claims, in which the electrodes ( 18 . 18a . 18b . 18c ) are mat-shaped. Composite according to one of the preceding claims, in which the cell walls ( 12 ) and the electrodes ( 18 . 18a . 18b . 18c ) in the area of the bushings ( 17 ) through the cell walls ( 12 ) are connected in a common shaping step, preferably by injection molding or extrusion. Composite according to one of the preceding claims, in which the electrodes ( 18 . 18c ) of the first and the last connected in series Cells ( 26 . 26b ) are formed as porous electrodes in the region of the respective implementation ( 17 ) through the cell wall ( 12 ) are each compacted with a plastic to a fluid-tight, electrically conductive, solid, the fluid-tight with the cell wall ( 12 ) connected is. Composite according to Claim 16, in which the electrodes ( 18 . 18c ) outside the cell walls ( 12 ) with a coating ( 19 ) of an electrically conductive material, preferably of copper or silver, are provided, preferably with a galvanically applied coating ( 19 ) or with a sprayed coating ( 19 ) are provided. Composite according to Claim 16, in which the electrodes ( 18 . 18c ) with contact layers ( 34 . 35 ), which preferably have recesses ( 36 ) in the contact layers ( 34 . 35 ) cohesively with the porous electrodes ( 18 . 18c ) and are thus pressed and by the cell walls ( 12 ) are led to the outside. Redox flux battery with a composite ( 20 ) according to one of the preceding claims, having a memory ( 42 ) for a catholyte, with a reservoir ( 44 ) for an anolyte, each via a pump ( 46 . 52 ) and associated lines ( 48 . 50 ; 54 . 56 ) are in communication with the cathodic half-cells and the anodic half-cells in order to flow through them, and with an external circuit ( 58 ), which is affiliated to the 20 ) via electrode connections ( 62 . 64 ) and a consumer ( 60 ) or a voltage source. Process for producing a composite of electrochemical cells according to one of Claims 1 to 18, in which initially a first semi-composite ( 23 ) and a second half-composite ( 24 ) each with a sequence of half-cells by a molding process, such as injection molding, are made of plastic, and then with the interposition of a membrane ( 22 ), preferably cohesively, for example by spraying or gluing, or positively, for example by riveting or screwing. Method according to Claim 20, in which the electrodes ( 18 . 18a . 18b . 18c ) are made of a continuous electrode material which is inserted into the associated shape and in the areas in which electrical insulation between adjacent half-cells is desired, by a subtractive processing step, such as punching, cutting, laser ablation, spark erosion is removed. Method according to Claim 20, in which the electrodes ( 18 . 18a . 18b . 18c ) are made of a continuous electrode material, which is inserted into the associated shape and in the areas in which an electrical insulation between adjacent half-cells is desired, by a specific shape of the injection mold used and a corresponding local control of the injection pressure is separated locally and by injected plastic is isolated.

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