DE102004023161A1 - Electrolysis cell with multilayer expanded metal cathodes - Google Patents

Abstract

The subject of the invention is a divided electrolytic cell which has at least one electrode with a large specific surface, which is flowed through optimally by the electrolyte. DOLLAR A The electrolytic cell according to the invention consists of sheet-like anodes and cathodes, which are separated by separators and monopolar or bipolar, wherein the cathodes and / or anodes are formed as multilayer expanded metal electrodes, which consists of at least two together and with the edge electrode internal resistance sections contacted expanded metal layers with possibly porous intermediate layers exist, which are flowed through by the electrolyte solution at a speed of at least 0.1 m / s in the longitudinal direction. DOLLAR A The electrolysis cell according to the invention is suitable for metal recovery and for the partial and complete electrochemical reduction or oxidation of organic or inorganic compounds, in particular of natural or synthetic dyes with or without the addition of redox mediators.

Description

The The present invention relates to an electrolytic cell for electrolytic Treatment of process solutions and wastewater. Preferred applications are cathodic reductions and anodic reductions Oxidations of inorganic and organic compounds as well the cathodic deposition of metals at low residual levels. The new electrolysis cell has a size specific electrode surface, which is optimally flown to achieve a good mass transfer. she is therefore particularly suitable for the effective implementation such cathodic and / or anodic electrochemical processes, the material transport is controlled and for the high specific electrode surfaces and Good mass transport conditions are important prerequisites for high current yields at low specific electrical energy consumption.

to preferably complete and economically effective implementation of such material transport controlled cathodic and / or anodic electrochemical processes it is both necessary to provide a sufficiently large electrochemically effective electrode surface, as well as favorable hydrodynamic Conditions for to realize an optimal mass transport from or to the electrode surface. Often leads but an enlargement of the available specific surface not at the same time to improve the mass transport, mostly caused by a poorer flow of the enlarged electrode surface areas. The is often in the so-called three-dimensional electrodes of the Case, especially for fixed-bed particle fillings and single-sided streamed by the electrolyte porous Electrodes with large, on the surface projection referenced, specific surface.

Next possibly insufficient hydrodynamic flow of the electrode surfaces is usually an unfavorable Potential distribution in three-dimensional electrodes responsible for that the available electrode area only partially electrochemical can be used. Often it comes already in a thin, the counter electrode facing surface layer to such a strong Current density drop, that the more distant surface areas can no longer participate in the electrolysis process.

In order to avoid such a decrease in current density with increasing distance from the counter electrode, have been in the DE 36 40 020 Divided electrolytic cells having an anode and a plurality of planar liquid-permeable and electrically insulated from each other arranged cathodes, said increasing with increasing distance from the anode ohmic resistances are compensated by higher applied cell voltages so that the current evenly distributed to the individual cathodes. In the DE 40 07 297 the same principle of action is proposed, but with a cathode and several liquid-permeable anode plates with separate power supply. In these electrolysis cells, the cathodes or anodes formed as liquid-permeable multiple electrodes are flowed through by the electrolyte perpendicularly to its longitudinal extent.

With Although these multi-electrode electrolysis cells, the desired magnification of indeed electrochemically active surface with even current distribution reached on the individual electrodes, but this is also with connected to a number of disadvantages. So is the to be operated apparative effort for the separate power supply to the individual electrodes and for an adapted current distribution relatively large. The separate power supply requires either several controllable rectifiers, or at only a rectifier, the interposition of different external resistors for regulating the electrolysis currents for the individual electrodes the multi-electrode electrolysis cell.

in the Fall of the current adjustment by different resistances is also the required Elektrolysestromverbrauch larger because a portion of the applied DC outside of the cell is converted into heat becomes.

But Also, the electrolysis cells are quite expensive in terms of apparatus. So are the individual or grouped together electrodes, preferably consisting of metal wire nets, electrically isolated from each other to arrange and to provide with separate power connections.

Also the conditions for a cheap substance transport to and from the electrodes are by no means in these multi-electrode cells to be considered optimal. Because the electrodes are transverse to their longitudinal extent flows through the electrolyte become big flowed through Cross-sections. Therefore, very high electrolyte circulation rates are required, a sufficiently large one flow rate along the transversely flowed electrode surfaces achieve and only at extremely low Contact times between the electrolyte flow and the electrode surface.

Finally, in such cells with multiple electrodes due to the required power supply to the individual electrodes is practically impossible, by a bipolar electric scarf tion of several individual cells to a technical electrolyzer with high power capacity to combine. In order to realize such technical electrolysis cells of large current capacity on the basis of the multi-electrode cell, only the apparatus of very complex and therefore economically often unacceptable coupling of a large number of monopolar single cells to be switched electrically parallel with separate power supply remains.

The The present invention relates to a divided electrolytic cell, the above a multi-electrode cells comparable high electrode surface has, the is flown optimally and with the illustrated disadvantages of the known cell designs with big Electrode surfaces, in particular the multi-electrode cells are largely avoided can.

The electrolysis cell according to the invention consists of flat Anodes and cathodes separated by separators are and which strained in a cell trough or in several Electrode frame arranged and electrically monopolar or bipolar are interconnected. It is characterized according to the claims in that the cathodes and / or anodes are in the form of multilayer expanded metal electrodes accomplished are made up of at least two interconnected internal resistance paths contacted expanded metal layers composed of the electrolyte solutions with a speed of at least 0.1 m / s in the longitudinal direction flows through become. Preferably, 4 to 12 expanded metal layers become one Multi-layer expanded metal electrode via internal resistance paths contacted with each other and with an electrode base plate. there can also liners made of a porous Electrode material disposed between at least two expanded metal layers become.

As a result in its longitudinal direction flowed through by the electrolyte Expanded metal layers are ideal conditions for one good substance transport created. For this purpose, flow rates are preferred from 0.3 to 0.8 m / s, based on the mean free cross section which flowed through Expanded metal layers, adjusted. Due to the constant flow deflection during the passage through the expanded metal layers, combined with an alternating narrowing and extension of the flowed through Cross-section, it comes to microturbulence, which is a very favorable Mass transfer of the electrolyte solution to the electrode surface and conversely. In gas-developing electrodes, it also leads to a rapid gas bubble removal, so that only low steady gas loads occur in the interdental spaces. The electrical resistance and thus the cell voltage increase only minimal.

at a preferred expanded metal thickness of 1.5 to 3 mm already result in relatively large distances between the electrode base plate and the furthest from this removed expanded metal layer of for example, 30 mm at 10 to 12 layers. Depending on the electrical conductivity the electrolyte solutions used Does it then already lead to voltage differences in the electrolyte between 0.5 and 2 V. That leads to a decrease in the current density with increasing distance from the Counter electrode. According to the invention this Current density drop compensated or at least buffered by internal Resistance distances between the individual layers, so that too one corresponding voltage difference between that with the power supply connected electrode base plate and the adjacent expanded metal layers is trained.

at the optional use of intermediate layers of porous electrode materials can be the number of layers to achieve a desired surface factor and thus the overall strength the multilayer electrode can be significantly reduced. Such porous liners, preferably consisting of metal foams, metal wire knit or carbon fiber webs at a strength from 1 to 2 mm and a targeted high void volume of at least 70% already over a relatively large one inner surface. The surface factor (OF) as the ratio the geometric surface to the surface the respective expanded metal or intermediate layers is in the expanded metal layers in the range of 1.5 to 4 and in the porous interlayer between 10 to 20. For both Layers is a high volume of voids of at least 70%, preferably 80 to 90%, an important prerequisite with regard to a good permeability for the Electrolysis current and the electrolyte flow.

Of the surface factor achievable by the multilayer expanded metal electrode should preferably be in the range between 5 and 100. Let it go itself the surface factors in the upper area practically only by using porous liners realize.

The influence of the porous intermediate layers will be explained using the example of a multilayer expanded metal electrode consisting of 9 expanded metal layers with a surface factor of 2 each. For the 9 plies, the surface factor of the entire multilayer expanded metal electrode, including the electrode base plate, is 9 × 2 + 1 = 19, with a total expanded metal package thickness of about 18 mm. With only one porous intermediate layer with OF = 14 and 2 expanded metal layers on one electrode Base plate results with OF = 2 + 14 + 2 + 1 = 19 a comparable surface factor at a much lower total thickness of only about 6 mm.

By the two sides to the porous Liner arranged longitudinally perfused Expanded metal layers becomes the porous one Intermediate layer flowed on both sides with high flow velocity. at Use thinner porous Intermediate layers with a maximum thickness of 2 mm are transported on the on the inner surface the porous one Linings to be transposed connections from both sides on one short way from a maximum of 1 mm. This makes it possible for this relatively large inner Surfaces such Liners for make maximum use of the electrolysis process. The transport of the To be converted compounds and the removal of the electrolysis products take place with the electrolyte flow through the adjacent Expanded metal layers.

The to be provided according to the invention for compensation or buffering of the current density decrease internal resistance paths can through the contact resistance formed between the individual expanded metal or porous intermediate layers become. The individual layers are only by pressure means, z. B. plastic webs or plastic screws against each other and pressed against the electrode base plate. Especially when Current transfer from an expanded metal layer to a porous intermediate layer are through the measured contact resistances internal Resistance distances built up to voltage differences of 0.1 lead to 0.5V can. Between two expanded metal layers, the contact resistances are usually lower. If necessary, the contact resistance can be reduced by reducing the contact surface by partial coverage with non-conductive materials, eg. B. thin Fabric inserts can be increased according to the requirements.

To Another feature of the invention is the internal resistance paths formed by one or more expanded metal and / or Liners by spacers made of electrically non-conductive material be separated from each other. Electricity transport from location to location over preferably laterally or upwardly and downwardly arranged contact surfaces. internal Resistance paths are built up by the fact that the electrolysis current the individual expanded metal layers pass in their longitudinal or transverse direction got to. The electrolysis current thus flows through the multilayer expanded metal electrode meandering, wherein the current strength from layer to layer according to the effective surface and the real current density decreases. In this case, the respective expanded metal layers At the contact points are welded together to a good and also long-term stable To reach contact. It is also possible to make a substantial adjustment to make the voltage drop in the electrolyte by that a different number of short-circuited expanded metal layers is electrically connected in series and thereby the voltage drops of Able to be adjusted so that the decreasing amperage within the multilayer expanded metal electrode by increasing resistance is compensated.

A such as possible full Compensation of the current density gradient but is mandatory only in such applications, where in the interest of a high current efficiency, a specific Redox potential is not exceeded or may fall below. For most application methods is there a larger current density range, in which there is no unreasonably large power loss comes.

According to a further feature of the invention, a current density gradient present within the multilayer expanded metal cathode can even be exploited purposefully for achieving high current and conversion yields. For this purpose, within an electrolytic cell several expanded metal segments separated by porous intermediate layers with different current density are provided by separate supply and discharge lines for the electrolyte solutions. In this case, the hydrodynamic circuit is carried out in such a way that the next to the counter electrode segment with the higher current density is flowed through first and the counterelectroder farther segment with the lower current density of the electrolysis solution thereafter. As a result, the main reaction in which the starting materials are still present in a higher concentration is carried out in the expanded metal segment with the higher current density. Then, if the starting materials are present only in low concentration, the reaction in the expanded metal segment with the low current density is completed. This has the same effect as with a cascade of several electrolysis cells with different current density, in which the main reaction takes place in the electrolysis cell with high current density, while the post-reaction is carried out in the electrolysis cell with lower current density. Only in the implementation according to the invention there is the great advantage that no second electrolysis cell is required for the after-reaction. The achievable space-time yield is therefore also much higher. In addition, there is the advantage that the hydrodynamic coupling of the two electrolyte streams can take place in that the electrolyte solution can be converted by an adjustable pressure difference from the segment of high current density through the porous intermediate layer into the segment of low current density. As a result, at the same time the flow through the porous Zwi further improved.

The Expanded metal layers to be used according to the invention are preferably made of stainless steel, nickel, copper or by means Precious metals, precious metal oxides or doped diamond coated Valve metals. The expanded metals come from coated Valve metals mainly for anodic Oxidation processes for use. So can look at expanded metals Niobium, coated on both sides with doped diamond, also on the aimed at relatively low current densities very high anode potentials be achieved, as z. For example an effective oxidative degradation of pollutants are needed.

Instead of single or all expanded metal layers can also be layers of metal wire mesh be used. However, expanded metals are therefore preferred because they are for the flow longitudinal usually have a more favorable opening ratio and also about a larger mechanical stability feature.

Especially with large required power capacities in the kA range, bipolar cells with multilayer expanded metal cathodes are preferred. An advantageous variant of such a bipolar cell construction is in 1 shown schematically. The 1a shows three bipolar cell units with section through the electrochemically active areas. The 1b shows a cross section through these three bipolar single cells, just in case in the electrochemically active area. The anode plates 1 and the cathode base plates 2 are on both sides of the bipolar electrode body 3 made of plastic. Integrated into the electrode body are the cooling channels 5 as well as the inlets and outlets for anolyte 6 . 7 , Catholyte 8th . 9 and the cooling medium 10 . 11 , In the case shown, the cooling channel is located on the anode side, whereby the anode plate resting there is cooled directly. Cooling on the cathode side as well as cooling on both sides are also possible in principle. On the cathode base plates resting and electrically connected to this are the multi-layer expanded metal cathodes. Illustrated are each four expanded metal layers 12 and a porous liner with a large inner surface 13 , The multilayer expanded metal cathodes are laterally delimited by a cathode frame 4 made of plastic, which also ensures a lateral pressure of the expanded metal layers to the cathode base plates. Arranged on the anode plates are the anode sealing frames 14 which limit and seal the anode compartments to the outside. Clamped between the anode sealing frames and the cathode frames of the adjacent bipolar units are the ion exchange membranes 15 which separate the anode compartments from the cathode compartments. The centering and mounting of the ion exchange membranes serve the Anodenspacer 16 and cathode spacer 17 made of plastic. The contacting between the cathode base plate and the anode plate of a bipolar unit is carried out in this cell variant arranged on both sides outside the main electrode body contact rails 18 ,

In the 2 to 5 are several variants for the bipolar electrode plates, again in section through the electrochemically active areas represented.

The 2 and 3 schematically show the sectional views of two bipolar units with multilayer expanded metal cathodes for a catholyte circuit. The corresponding in 2 illustrated variant except for the arrangement of the inlet and outlet nozzles and an additional cooling channel on the cathode side in principle the in 1 illustrated cell variant. In the 4 and 5 The same bipolar units are shown but with separate expanded metal cathode segments for two separate catholyte circuits. In all cases, the multi-layer expanded metal cathode consists of two segments, each with two expanded metal layers and an intermediate layer of a porous electrode material with a large inner surface.

Both 2 and 3 all four expanded metal layers are flowed through in parallel. The porous intermediate layer is flown on from both sides, so that the mass transfer has only a short distance of a maximum of half the thickness of the intermediate layer to its inside to cover.

Both 3 and 5 At the same time, the intermediate layer forms the separating layer between the anode-near expanded metal segment with high current density and the electrode-distal segment with lower current density.

Both 2 and 4 the cathode base plate as the anode plate is solid, broken only with the passage openings for the supply and discharge of the electrolyte solutions. Thus, it is also possible for both electrodes to use the electrode back spaces for the arrangement of cooling channels for internal heat dissipation. Both 3 and 5 If the cathode base plate provided with the power supply is already provided with an expanded metal layer, the cathode back space is filled here with the catholyte. Therefore, only the anode back space can be used for the arrangement of a cooling channel.

The 2 to 5 it is not apparent in what way the anode plate is contacted with the cathode plate of the respective bipolar unit. This can be like in 1 represented by contact bars mounted on both sides outside the electrode main body. But even within the body contact elements can be attached, which allow contact with both electrode plates by the pressure during assembly.

The 6 shows the process scheme of an electrolysis plant with an electrolytic cell analogous to 4 with two separately flowed expanded metal cathode segments. Both separated by a pörose intermediate layer of low permeability cathode segments are integrated into separate Katholytkreislaufe with integrated gas separation. In the first cycle B, consisting of a circulation pump and a circulation vessel with gas separator, the electrolysis is carried out at the higher current density. In the analogously constructed second cycle C, the reaction is completed with a lower current density. Both circulatory systems are coupled hydrodynamically in such a way that the metered addition takes place in the circuit of higher current density (dosing station D) and the Elektrolytabfüh tion is made from the circuit lower current density E. The passage through the porous intermediate layer is characterized by adjusting itself between the two circuits Controlled pressure difference. The anolyte is conveyed by means of the metering station G through the anode chambers. In the gas separator H, the gas leaving at J is separated off, the anolyte leaves at I.

at smaller and medium power capacities are preferred for the electrolysis cell according to the invention a monopolar electrical circuit of the multilayer expanded metal electrodes into consideration, wherein the expanded metal layers or the porous intermediate layers planar or can also be arranged cylindrical. At the cylindrical Arrangement is according to a further feature of the invention, a continuous Expanded metal layer spirally wound and the beginning of the spiral electrically conductive with the provided with the power supply outside or Inner tube of the cylindrical cell connected. An internal resistance path can be constructed in a simple manner, that a location made of insulating spacer material also spirally together with the expanded metal layer is wound, whereby the individual expanded metal layers from each other be electrically isolated. This forces the electrolysis current the longer one To take a path along the spiral, so that between the different Expanded metal layers form tension differences.

at the planar arrangement can the electrodes and separation systems either in a cell trough or arranged in a plurality of clamped electrode frame become.

The 7 shows by way of example a preferred embodiment of such a monopolar electrolysis cell with planar electrodes, which are arranged in mutually braced electrode frame. It shows the cross section through the electrochemically active region of a monopolar electrolysis cell, each with two electrically parallel connected multilayer expanded metal cathodes and two separated by cation exchange membranes plate anodes, which are arranged in three braced plastic frame (the clamping frame is not shown in the picture). The two anode plates 1 and the two cathode base plates 2 are provided with power supply and electrically connected in parallel. The anode plates are made of titanium and are provided in the electrochemically active region with an active layer, for. B. with Ir-Ti mixed oxide. The multilayer expanded metal cathodes, each in a cathode frame, are contacted with the cathode base plates made of stainless steel 4 are arranged. The multilayer expanded metal cathodes each consist of 10 Expanded metal sheets 12 grouped individually or in groups and by cathode spacer 17 made of plastic are separated from each other. The various expanded metal layers separated by spacers are laterally contacted with one another in such a way that the electrolysis current flows through the multilayer expanded metal cathode in a meandering manner. As the electrolysis current decreases from layer to layer, the resistance of the interconnected expanded metal layers towards the anode increases to four times (the number of interconnected expanded metal layers decreases from four to one). The cathode frames contain the inflows and outflows for the catholyte 8th . 9 , The expanded metal and spacer layers are flowed through from bottom to top in the longitudinal direction of the catholyte. The centrally arranged Elekrodengrundkörper 3 contains the entrances and exits for the anolyte 6 . 7 , Through overflow openings of the anolyte enters through the sealing frame and the anode plates in the anode chambers below and above together with the anode gases formed again. These anode spaces are defined by the anode sealing frames 14 educated. Inserted are anodic spacers 16 made of plastic, on which the ion exchange membranes 15 are positioned.

From such monopolar cell units may have multiple within one Tenter be arranged. With required large power capacity exists the great Advantage of the electrolysis cells according to the invention in that even a bipolar circuit has several single cells in a tenter possible is. Then only two edge electrodes with power supply needed between any one, only by the available DC voltage limited, number of bipolar single cells can be arranged.

In the 1 to 7 only some of the particularly advantageous variants of the electrolysis cell according to the invention and their interconnection are shown, they make no claim to completeness.

The in the present invention described electrolysis cell with multilayer expanded metal electrodes according to claims 1 to 13 is for the following special application methods are particularly suitable.

Preferably comes the new electrolytic cell with a multilayer expanded metal cathodes for use for the complete or partial cathodic reduction of organic or inorganic compounds. It can be electrolysed both galvanostatically, and potentiostatically become. Can be reduced organic compounds which are functional groups C-C double and Triple bonds, aromatic C-C linkages, carbonyl groups, heterocarbonyl groups, aromatic CN linkages, Nitro and nitroso groups, C-halogen single bonds, S-S bonds, N-N single bonds and multiple bonds and other heteroatom-heroatom bonds. Such reactions can both in protic solvents, such as As water, alcohols, amines, carboxylic acids, as well as in a mixture with aprotic polar solvents, z. B. tetrahydrofuran be performed. If organic compounds are used which in o. G. solvents not soluble are, can however, they can also be easily replaced by surface-active substances, e.g. higher Alcohols as solvents or solvent additives are dissolved. Furthermore, the electrolysis of suspensions is possible.

In general, the electrolysis according to the invention is carried out in the presence of an auxiliary electrolyte (mediator), as for example in US Pat EP 0808 920 B1 described. Here, too, there are advantages due to the high specific surface area of the multilayer expanded metal cathode, since it is often possible to achieve the same results with a lower mediator addition.

Especially suitable are the new electrolysis cells with multilayer expanded metal cathodes to the full or partial reduction of natural and synthetic dyes such as. Carotenoids, quinone dyes, e.g. Carminic acid and 1,8-dihydroxyanthraquinone, Madder dyes, indigoid dyes, e.g. Indigo, indigotin and 6,6'-dibromoindigo, vat dyes and sulfur dyes as well as to reduce the nitro functionalities. Equally are the new cells are suitable for decolorization of dyeing process solutions and -Abwässern.

The reduction of indigoid and vat dyes can be used both as indirect electrolysis, as in the writings DE 195 13 839 A1 and DE 100 10 060 A1 described as performed without Mediatorzusatz. In the reduction of sulfur dyes such. B. sulfur black 1 for korrospondierenden leuco sulfur black 1 compound both complete and partial reduction can be made as in EP 101 222 10 B1 described. Here, the cathodic reduction is preferably carried out in an alkaline medium (pH 9 to 14).

Fitted With multi-layer expanded metal anodes, the new electrolysis cells also to the complete or partial anodic oxidation of organic and / or inorganic Connections are used. In particular, they are for the oxidative Pollutant degradation in process solutions and wastewater suitable. Particularly advantageous are multilayer expanded metal anodes, consisting of niobium expanded metals coated on both sides with doped diamond. Here again, both a direct electrochemical reaction be realized as well as indirect through mediators or by the anodic formation of oxidizing agents, e.g. peroxodisulfate, Hypochlorite or radical anions, which in a post-reaction the desired Complete the removal of pollutants. But also with platinum-plated expanded metals from titanium can at such oxidation reactions often required for the degradation process high anode potentials can be achieved.

Finally are Cells with multilayer expanded metal cathodes also in metal deposition especially from very diluted Solutions advantageous used. It can Electrodes from the to be recovered Metal used after appropriate metal loading be replaced. In this case, the use of a trough cell with hinged, easily replaceable multilayer expanded metal cathodes advantageous. Around small amounts of metals z. B. from wastewater, can also to work with inert cathode materials making up the deposited metals periodically with a suitable solvent leached become. Therefor are particularly porous Liner large inner surface, with which very low residual metal contents can be achieved.

1

anode plate

2

Cathode base plate

3

Electrode body

4

cathode frame

5

cooling channels

6

entry anolyte

7

exit anolyte

8th

entry catholyte

9

exit catholyte

10

entry cooling medium

11

exit cooling medium

12

Expanded metal sheets

13

porous liners

14

Anode sealing frames

15

ion exchange membranes

16

Anodenspacer

17

Kathodenspacer

18

contact bars

19

Cathode base plate with expanded metal insert

20

anode chamber

21

entry separate catholyte

22

exit separate catholyte

A

electrolysis cell with two separate expanded metal segments

B

catholyte 1 by segment higher current density

C

catholyte 2 by segment lower current density

D

dosing catholyte

e

Katholytaustritt

F

gas outlet (Catholyte)

G

dosing anolyte

H

gas separator anolyte

I

Anolytaustritt

J

gas outlet (Anolyte)

Claims (20)

The invention relates to an electrolytic cell for the electrolytic treatment of process solutions and waste water, consisting of flat anodes and cathodes, which are separated by separators and which are arranged in a cell trough or in a plurality clamped together electrode frame and electrically monopolar or bipolar interconnected, characterized in that the cathodes and / or anodes are designed as multilayer expanded metal electrodes, which consist of at least two expanded metal layers which are in contact with one another via internal resistance paths and through which the electrolyte solutions flow in the longitudinal direction at a speed of at least 0.1 m / s. Electrolysis cell according to claim 1, characterized that one or more intermediate layers of a porous electrode material between at least two of the longitudinally flowed through expanded metal layers arranged and contacted with these. Electrolysis cell according to claims 1 and 2, characterized that made up of several expanded metal layers and possibly made up of porous liners existing multilayer expanded metal electrode compared to a Plate electrode over a 5 to 100 times larger specific electrode surface features. Electrolysis cell according to claims 1 to 3, characterized that the internal resistance paths due to the contact resistance between the expanded metal layers and / or between the expanded metal and the porous Liners are formed. Electrolysis cell according to claims 1 to 3, characterized that for the formation of internal resistance paths single or several expanded metal and / or Liners by spacers made of electrically non-conductive material separated from each other and only over laterally arranged contact surfaces are electrically connected to each other, wherein the current Multi-layer expanded metal electrode flows through meandering. Electrolysis cells according to claims 1 to 5, characterized that the multilayer expanded metal electrode package, optionally with Liners from the porous Material, by pressure means to a connected to the power supply Electrode base plate is pressed and thereby the individual Expanded metal layers with each other and with the electrode base plate be contacted. Electrolysis cell according to claims 1 to 6, characterized that several through porous Liners separated expanded metal segments with different Current density equipped by separate supply and discharge lines for the electrolyte solutions and that is the segment closest to the counter electrode with the higher current density first and the lower current density segment farther away from the counter electrode then from the electrolyte solution flows through becomes. Electrolysis cell according to claim 7, characterized in that that the electrolyte flows in the separated expanded metal segments via the porous intermediate layer with each other hydrodynamically coupled. Electrolysis cell according to claims 1 to 8, characterized that the expanded metal layers of stainless steel, nickel, copper or by means Precious metals, precious metal oxides or doped diamond coated Valve metals exist. Electrolysis cell according to claims 1 to 9, characterized that the individual expanded metal layers, the plastic spacers and optionally the intermediate layers of the porous electrode material a Strength from 1 to 5 mm and a void volume of at least 70%. Electrolysis cell according to claims 1 to 10, characterized that the porous ones Intermediate layers of metal wire mesh, of metal foams or Carbon fiber fleeces exist. Electrolysis cell according to claims 1 to 11, characterized that the multilayer expanded metal electrode from a spirally wound Expanded metal sheet is formed, which is provided with a power supply Outside- or inner tube of a cylindrical electrolytic cell contacted is. Electrolysis cell according to claims 1 to 12, characterized in that instead of single or multiple expanded metal layers such metal wire mesh fabrics are used. Application of the electrolysis cell according to claims 1 to 13 with multilayer expanded metal cathodes for the full or partial cathodic reduction of organic and / or inorganic compounds. Application of the electrolysis cell according to claims 1 to 13 for the cathodic reduction of organic compounds according to claim 14, which as functional groups C-C double and triple bonds, aromatic C-C linkages, Carbonyl groups, heterocarbonyl groups, aromatic CN linkages, Nitro and nitroso groups, C-halogen single bonds, S-S bonds, N-N single bonds and multiple bonds and other heteroatom-heroatom bonds include: Application of the electrolysis cell according to claims 1 to 13 for the cathodic reduction of organic compounds according to the claims 14 and 15 for the reduction of dyeing and dyeing solutions and / or for the decolorization of Dyeing wastewater. Application of the electrolysis cell according to claims 1 to 13 with multilayer expanded metal anodes to the full or partial anodic oxidation of organic and / or inorganic Links. Application of the electrolysis cell according to claims 1 to 13 for anodic oxidation according to claim 17 for the oxidative pollutant degradation in process solutions and wastewater. Application of the electrolysis cell according to claims 1 to 13 to the full or partial cathodic reduction and / or anodic oxidation according to the claims 14 to 18 with the addition of redox mediators. Application of the electrolysis cell according to claims 1 to 13 with multilayer expanded metal cathodes for the Removal of metals from process solutions and wastewater.