DE102019212014A1 - Process for the production of a layer system of a battery cell - Google Patents

Abstract

The invention relates to a method for producing a layer system (2) of a battery cell (4), in which a porous layer material (14) with an open pore structure (16, 16 ') is produced, in which a gas scavenger material (24) for binding cell gases is introduced into the pore structure (16, 16 '), and in which the layer material (14) is treated in such a way that the pores (18, 20) of the pore structure (16, 16') are partially closed.

Description

The invention relates to a method for producing a layer system of a battery cell. The invention further relates to such a layer system and the use of such a layer system as well as a battery cell with a corresponding layer system.

Motor vehicles driven or drivable by electric or electric motors, such as for example electric or hybrid vehicles, generally comprise an electric motor with which one or both vehicle axles can be driven. To supply electrical energy, the electric motor is usually connected to a (high-voltage) battery inside the vehicle as an electrical energy store.

An electrochemical battery, in particular, is to be understood here and below as a so-called secondary battery (secondary battery) of the motor vehicle. In the case of such a (secondary) vehicle battery, the chemical energy used can be restored by means of an electrical (charging) process. Such vehicle batteries are designed, for example, as electrochemical accumulators, in particular as lithium-ion accumulators. In order to generate or provide a sufficiently high operating voltage, such vehicle batteries typically have at least one battery module in which several individual battery cells are connected in a modular manner.

The battery cells are designed, for example, as electrochemical (thin) layer cells. The thin-film cells have a layered structure with a cathode layer (cathode) and with an anode layer (anode) and with a separator layer (separator) introduced in between. These components are penetrated by a liquid electrolyte (liquid electrolyte), for example, which creates an ionic compound of the components or a charge balance. The ionic conduction is based on conductive salts of the battery cell, which are usually lithium ions.

During the transport through the electrolyte, the lithium ions are surrounded by a so-called solvation shell, which is made up of the organic molecules of the electrolyte and the ions of the conductive salt. The spatial dimension of the solvation shell (solvation shell) can be characterized by the Stokes radius, which, depending on the solvent used, is between approximately 0.2 nm and 1 nm. This corresponds approximately to a diameter between 0.4 nm and 2 nm.

The separator layer is usually a porous membrane composed of polymers or ceramics. In other words, the layer system of the separator is provided with a pore structure. The separator layer electrically separates the anode and the cathode from one another and thus prevents a short circuit in the battery cell.

A pore structure is to be understood here and below in particular as a spatial arrangement or distribution of a multiplicity of pores in a layer material forming the layer system. In this context, a pore is understood to mean, in particular, a hole-like opening or recess or depression, in particular a cavity or a cavity, in the layer material. According to IUPAC, such pores are differentiated according to their (pore) diameter. So-called macroscopic pores (macropores) have average pore diameters greater than 50 nm (nanometers), mesoscopic pores (mesopores) having average pore diameters between 2 nm and 50 nm, and microscopic pores (micropores) having average pore diameters less than 2 nm. Correspondingly, the porosity of the layer material is referred to as macroporous, mesoporous, or microporous.

The pore size and pore distribution of the separator or of the layer system of the separator is typically in a range that allows lithium ions to easily pass through in the electrolyte solution. Macroporous separators with an average pore size of less than 1 µm (micrometer) are usually used.

During the operation of lithium-ion cells, decomposition reactions occur within the battery cell, which outgas, i.e. generate a gaseous reaction or formation product. This generation or evolution of gas occurs increasingly during a charging process, in particular during a first charging step. These (cell) gases depend on the electrolyte material, with essentially oxygen (O ₂ ) and carbon dioxide (CO ₂ ) being formed as a rule. Such cell gases are typically electrically neutral, that is to say, in contrast to the ions of the conductive salt, not electrically charged, so that cell gases essentially have no solvation shell in the electrolyte. As a result, these gases usually have comparatively small Stokes radii.

The resulting gases accumulate inside the battery cell and cause an increase in volume or volume expansion of the battery cell and / or other undesirable side reactions.

Battery cells are usually arranged within a cell housing to protect against external influences. Frequently, several battery cells are stacked to form a cell stack and held by means of a tensioning system and accommodated in a common cell housing. The gas-related increase in volume of the or each battery cell can lead to damage (cracks) or complete destruction of the battery or the cell housing, or can open a burst membrane provided in the cell housing.

In this case it is possible, for example, to design the installation space available in the cell housing with regard to such a volume-enlarged battery cell, whereby the installation space requirement of the battery cell is increased and its energy density is reduced. Additionally or alternatively, it is also possible, for example, to provide an additional pressure relief valve on the cell housing, which is intended to prevent the cell housing from bursting open. Such overpressure valves prevent the cell housing from bursting, but still lead to failure of the battery cell when triggered.

The formation of cell gases typically cannot be prevented. However, it is possible, for example, to bind such cell gases by means of a gas trap in order to largely avoid or at least reduce harmful influences of the cell gases, such as a pressure build-up inside the battery cell. A “gas scavenger” or a “gas scavenger material” is to be understood here and in the following in particular as a material which absorbs and / or adsorbs occurring cell gases, that is to say binds physically and / or chemically to itself. In other words, a gas scavenger can absorb or adsorb the cell gases that occur or also convert them chemically in a reaction and thus bind them.

From the KR 2015 0014668 A a battery cell is known in which gas-absorbing substances are introduced as gas traps. The gas traps are arranged in a mesoporous to macroporous carrier matrix with an average pore size between 0.01 µm and 5000 µm

In the KR 10 1625820 B1 describes a cell housing for a battery cell, in which the inner wall of the cell housing is provided with an oxygen scavenger, and in which an additional pocket-like or chamber-like cavity is provided in the cell housing for receiving the cell gases.

Disadvantageously, such gas trap concepts require the introduction of additional carrier systems for the gas trap materials into the battery cell or into the cell housing. Such carrier systems require additional installation space in the battery cell or in the cell housing, as a result of which the installation space requirement of the battery cell itself is increased and its energy density is disadvantageously reduced.

From the JP 2007 242454 A a battery cell with a mesoporous separator layer is known, which is provided with an amine as a gas scavenger.

The JP 2008 146963 A describes a layer system for a separator of a solid-state battery cell, in which a gas trap is mixed into the separator material.

Disadvantageously, due to the mesoscopic or markoscopic pore size of the layer system, the introduced gas trap is accessible both to the cell gases and to the conductive salts and the electrolytes. As a result, reaction or decay products of the gas scavenger can get back into the cell interior, for example into the electrolyte, which can cause undesired side reactions.

The invention is based on the object of specifying a particularly suitable method for producing a layer system of a battery cell. In particular, with such a layer system, escape of reaction products from gas traps into the battery cell should be reliably and simply prevented. The invention is also based on the object of specifying a particularly suitable layer system and a particularly suitable use of such a layer system as well as a particularly suitable battery cell.

With regard to the method, the object is achieved according to the invention with the features of claim 1 and with regard to the layer system with the features of claim 7 and with regard to the use with the features of claim 9 and with regard to the battery cell with the features of claim 10. Advantageous refinements and developments are the subject of the respective subclaims. The advantages and configurations cited with regard to the method can also be applied analogously to the layer system and / or the use and / or the battery cell and vice versa. The conjunction “and / or” is to be understood here and below in such a way that the features linked by means of this conjunction can be designed both together and as alternatives to one another.

The method according to the invention is suitable and designed for producing a layer system of a battery cell. Here, a porous layer material with an open pore structure, that is to say with a large number of pores, is produced. Then a gas scavenger material is used to bind im Cell gases occurring during operation of the battery cell are introduced into the pore structure. According to the method, it is provided that the layer material is treated in such a way that the pores of the pore structure are partially closed. The pores are therefore not completely closed, but only partially, which means that a respective pore opening remains. A particularly suitable production method for a layer system of a battery cell is thereby implemented.

The remaining pore openings here preferably have a diameter which is approximately equal to a micro- or sub-micropore.

The resulting average pore openings are preferably dimensioned large enough with regard to the Stokes radii on the one hand so that the (uncharged) cell gases, in particular oxygen and / or carbon dioxide, can penetrate into the pores. On the other hand, the pore openings are preferably dimensioned small enough so that conductive salts with a solvation shell, such as lithium ions, cannot penetrate the interior of the pores without stripping off their solvation shell. Stripping off the solvation shell is energetically unfavorable for the conductive salts, so that penetration of the conductive salts into the pores is prevented. In particular, the pore openings are dimensioned small enough that reaction and / or decomposition products of the gas scavenger material do not escape from the interior of the pores. This means that the gas trapping material binds the cell gases in the partially closed pores without reaction and / or decay products being able to get into the cell interior.

According to the invention, it is thus provided that pore openings of the pore structure are created which on the one hand are dimensioned large enough for the penetration of cell gases or gas molecules of these cell gases into the pores, and on the other hand are dimensioned small enough that conductive salts of the battery cell and / or reaction and / or decomposition products of the gas trapping material cannot flow into or out of the pores. In other words, the invention provides a precisely defined size of the pore openings, which is specifically dimensioned for the cell gases produced in the battery cell, so that other cell components cannot easily penetrate the pores and by-products from the pore cannot get back into the cell.

In contrast to the prior art, the gas trap material is not simply mixed with or mixed into the layer material. The introduction of the gas trap material into the pore structure and the subsequent partial closure of the pores essentially prevents direct contact between the gas trap material and a (liquid) electrolyte (liquid electrolyte) of the battery cell. As a result of the reduction in the pore openings, the pores and thus the gas trapping material are essentially inaccessible to the electrolyte. According to the invention, the pore openings are dimensioned with regard to the gas molecules of the cell gases occurring, so that only these gas molecules can penetrate into the pores. As a result, the gas trapping material is not in direct contact with the electrolyte but only with the cell gases of the battery cell. In this case, the decomposition and / or reaction products suitably do not fit through the pore openings and thus cannot escape from the pore structure.

The layer system is preferably a cell component of the battery cell, that is to say an electrode or separator layer. This means that the cell component itself is designed as a carrier system for the gas trap material, so that no additional carrier systems with additional space requirements in the battery cell or a cell housing are necessary.

In particular, a separator material is used as the layer material. This means that the layer system is designed in particular as a separator layer or as a separator of the battery cell.

In the case of a liquid battery cell, that is to say a battery cell with a liquid electrolyte, the layer material or separator material is, for example, a polymer or ceramic material. In the case of a solid-state battery cell, the layer material is, for example, the material of the solid-state electrolyte, which acts as a separator in solid-state battery cells. In solid-state battery cells, thermal events on the cathode side in particular are responsible as the main cause for the formation of oxygen as cell gas, with the pore structure on the cathode side in particular being expediently provided with an oxygen gas scavenger material.

The pore openings are preferably reduced in such a way that the size of the pore entrance is smaller than the diameter of the conductive salts in the electrolyte of the battery cell, which is determined by the Stokes radius. Since the Stokes radius is solvent-dependent, the pore openings are preferably dimensioned specifically for the solvent. In a particularly preferred embodiment of the method, the pore openings are reduced in such a way that the remaining average pore opening is smaller than 0.5 nm. In other words, the pores finally have, on average, a through opening with a diameter of less than 0.5 nm. A particularly suitable production method for a layer system of a battery cell is thereby implemented. This ensures that only Cell gases or cell gas molecules can pass through the pore opening.

The pores here preferably have a meso- or macroscopic diameter, with only the pore entrance or the pore opening being reduced to the diameter of a micro- or sub-micropore.

In order to produce the particularly open pore structure, that is to say an open porosity of the layer material, it is possible, for example, to chemically etch the layer material or to treat it by means of electrolysis. An open porosity is to be understood here in particular as a pore structure in which the pores at least partially merge or open into one another. The generated, preferably mesoscopic or markoscopic, pores are then provided with the gas trapping material. The pores are then partially closed.

To close the pores, it is provided in an advantageous embodiment that the layer material is thermally treated. A particularly simple and reliable reduction of the pore opening to preferably less than 0.5 nm is thereby possible.

The (treatment) temperature of the thermal treatment is essentially dependent on the layer material used. In the case of a polyethylene (PE) or other polymer material, for example, a thermal treatment of about 100 ° C. to 150 ° C. is sufficient to cause shrinkage phenomena in the pore openings and to reduce the porosity of the layer material. In the case of a ceramic layer material or a solid electrolyte material, it is necessary that the temperature of the thermal treatment is in the sintering range of the materials or ceramics, for example between 700 ° C and 1200 ° C.

In a preferred embodiment of the method, a hierarchical pore structure of the layer material is generated. A hierarchical pore structure is understood here to mean in particular a pore structure which has a plurality of first pores with a comparatively large pore diameter and a plurality of second pores with a comparatively small pore diameter, the second pores being arranged in particular on a wall or on a circumference of the first pores are. This means that the generated open pore structure of the layer material essentially forms a system of pores opening into one another, with smaller pores opening into these, in particular on the outer circumference of larger pores. The smaller, second pores thus increase the inner surface of the pore structure or of the layer material.

The larger first pores are designed, for example, as macro or mesopores, the second pores opening hierarchically into them being designed in particular as mesopores or micropores. The gas trapping material is introduced into the second pores in particular, the pore opening of the second pores then being reduced to an average diameter of less than 0.5 nm in the larger first pores. This results in a particularly suitable pore structure of the layer material. The larger (first) pores ensure that the electrolyte transport of the conductive salts is as unimpeded as possible, with the (second) smaller pores having the gas trapping material at the edges of the larger pores, and the resulting increased pore surface binding cell gases particularly reliably and safely.

The gas trapping material is suitable and designed, for example, for trapping or binding carbon dioxide. As gas scavenger material for such a carbon dioxide scavenger, for example, lime, amino-modified zeolites, Li-silica monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), N-methyldiethanolamine (MDEA), 2- (2-amino-ethody) ethanol ( DGA), 2-amino-2-methyl-propanol (AMP), epoxy compounds and amine compounds can be used.

The gas scavenger material can alternatively be suitable and designed, for example, for trapping or binding oxygen. As gas scavenger material for such an oxygen scavenger, for example, ascorbic acid, iso-ascorbic acid, gallic acid and their salts, tocopherol, hydroquinones, catechols, di-butyl-hydroxitoloul, die-butyl-hydroxianisole, pyrogallol, sorbose, glucose, lignin, iron-based materials, hemoglobin , Thiosulphates, redox-active resins or the group of zeolites are possible.

In a particularly advantageous embodiment of the method, a phosphine is used as a gas scavenger material, in particular as an oxygen scavenger. Phosphines are typically not used in battery cells to bind oxygen because the resulting reaction products are viscous oils. Due to the small pore entrance according to the invention or due to the pore openings of less than 0.5 nm, however, such oils that arise are reliably held within the pores. This makes it possible to use a phosphine or a phosphine compound as a gas scavenger or oxygen scavenger material. This creates new freedoms in the production of layer systems integrated gas trap materials realized, which enables a particularly flexible process.

In a conceivable embodiment, activated carbon particles mixed with the gas scavenger material are introduced into the pore structure. In other words, the gas scavenger material is introduced indirectly into the pore structure. This means that the activated carbon particles are impregnated with the gas-trapping material, for example, and then introduced into the pore structure or the pore structure of the layer material. Activated carbon has a porosity in the meso or microscopic range. The pores of the activated carbon particles are suitably partially closed, so that the remaining average pore opening is less than 0.5 nm. The pores of the pore structure of the layer material are preferably only partially closed to such an extent that the activated carbon particles cannot slide or escape from the open pore structure of the layer material. The activated carbon particles suitably do not form a percolating network within the layer material, so that the electrically insulating properties of the layer material are not adversely affected.

The layer system according to the invention is suitable and set up for a battery cell. The layer system is arranged in particular as a separator layer between a cathode and an anode of the battery cell and has a porous layer material with a pore structure and at least one gas scavenger material introduced or integrated into the pore structure. The average pore openings of the pores of the pore structure are here smaller than 0.5 nm. This results in a particularly suitable layer system of a battery cell. The diameter of the pore openings is dimensioned with regard to the gas molecules of the occurring cell gases, so that only these gas molecules can penetrate through the pore openings. The layer system is produced in particular by means of a method described above.

In an expedient embodiment, the battery cell is a lithium-ion battery cell, preferably with a liquid electrolyte.

In a preferred use, the layer system described above is used as a separator in a battery cell. This enables a battery cell with a particularly compact installation space and improved performance. In particular, no additional support structures or functional structures of the cell housing, such as an overpressure valve, are necessary in such a battery cell.

A battery cell according to the invention has a cathode and an anode and an above-described layer system arranged between them as a separator. The battery cell according to the invention is particularly compact in terms of installation space and has a particularly high energy density for a given size. The battery cell is preferably part of a vehicle battery of an electrically powered or drivable motor vehicle, in particular an electric or hybrid vehicle. As a result, a vehicle battery with a particularly compact installation space and improved performance is implemented. This necessitates a reduction in the installation weight of the vehicle battery, which is advantageously carried over to the range of the motor vehicle.

• 1 ein Flussdiagramm eines erfindungsgemäßen Herstellungsverfahrens eines Schichtsystems,
• 2 eine Batteriezelle mit einem als Separator ausgeführten Schichtsystem,
• 3 ausschnittsweise das Schichtsystem mit einer Porenstruktur in einer ersten Ausführungsform,
• 4 ausschnittsweise eine hierarchische Pore der Porenstruktur gem. 3,
• 5 ausschnittsweise das Schichtsystem mit einer Porenstruktur in einer zweiten Ausführungsform mit einer Vielzahl von Aktivkohlepartikeln, und
• 6 ausschnittsweise eine Pore eines Aktivkohlepartikels gem. 5.

Exemplary embodiments of the invention are explained in more detail below with reference to a drawing. It shows in schematic and simplified representations:

• 1 a flow diagram of a production method according to the invention of a layer system,
• 2 a battery cell with a layer system designed as a separator,
• 3 a section of the layer system with a pore structure in a first embodiment,
• 4th a hierarchical pore of the pore structure according to FIG. 3 ,
• 5 a section of the layer system with a pore structure in a second embodiment with a large number of activated carbon particles, and
• 6th section of a pore of an activated carbon particle according to. 5 .

Corresponding parts and sizes are always provided with the same reference symbols in all figures.

The 1 shows a schematic and simplified representation of a flowchart of a production method according to the invention for a layer system 2 one in the 2 battery cell shown 4th . The battery cell 4th has a layered structure with two electrode layers, one cathode layer (cathode) 6th and an anode layer (anode) 8th , as well as with a separator layer arranged in between in the form of the layer system (separator) 2 on. The cathode 6th and the anode 8th are each with an arrester 10 electrically conductive coupled.

To produce the layer system 2 is in accordance with the method in a first method step 12 a layer material 14th with a pore structure 16 Mistake ( 3 to 6th ). For this purpose, a large number of pores are created for example by means of chemical etching or by means of electrolysis 18th , 20th into the layer material 14th introduced, which has an open pore structure 16 form. The pores 18th , 20th are in particular mesopores or micropores.

In the in the 3 and in the 4th The embodiment shown schematically and in simplified form is the pore structure 16 here hierarchically, this means that the pore structure 16 superior pores 18th with larger pore diameter, and subordinate pores 20th with a smaller pore diameter. The 3 shows a section A of the layer system 2 according to 2 , where the 4th a section B of a pore 18th according to 3 shows.

The pores 18th are dimensioned here large enough that the electrolyte salts of the battery cell 4th simply through the shift system 2 can flow through. The pores 20th are in particular in the outer circumference or on the edge of the larger pores 18th brought in. The pores 18th are in the 3 provided with reference symbols only as an example.

In a second process step 22nd becomes a gas scavenger material 24 ( 4th , 6th ) into the layer material 14th or in the pore structure 16 brought in. The gas trap material 24 is for example an oxygen scavenger, preferably a phosphine.

In a third process step 26th becomes the layer material 14th thermally treated in such a way that the pore openings of the open pore structure 16 be scaled down or reduced. The pore openings between the pores 18th and the pore openings 28 between the pores 18th and pores 20th are partially closed. The pore openings 28 are reduced in such a way that the remaining average pore opening 28 is smaller than 0.5 nm. In other words, the pores point 20th after the process step 26th on average a through opening with a diameter of less than 0.5 nm. In other words, the pore openings have 28 a diameter which corresponds approximately to the size of a micro- or sub-micropore.

The following is based on the 1 , 5 and 6th a second embodiment of the invention explained in more detail. The 5 shows section A of the layer system 2 according to 2 , where the 6th a section C of a pore 18th according to 5 shows.

In this embodiment, the pore structure 16 ' only the pores 18th on. The gas trap material 24 is here in the process step 22nd indirectly by means of activated carbon particles 30th into the pore structure 16 ' brought in. For this purpose, meso- or microporous activated carbon particles are used 30th in one process step 32 generated. This means that the activated carbon particles 30th with pores 20 ' be provided. The activated carbon particles 30th are in the 5 provided with reference symbols only as an example.

The porous activated carbon particles 30th are then in one process step 34 with the gas trap material 24 soaked and then in the process step 22nd into the framework of the pore structure 16 ' introduced in such a way that the activated carbon particles 30th do not form a percolated network.

In the process step 26th this is done with activated carbon particles 30th provided layer material 14th so thermally treated. On the one hand, the thermal treatment opens the pore openings 28 ' the pores 20 ' the activated carbon particles 30th partially closed so that the resulting pore openings 28 ' have a diameter of less than 0.5 nm. On the other hand, the pore openings between the pores 18th partially closed so that the activated carbon particles 30th not out of the pores 18th the pore structure 16 ' can slide out.

According to the invention, the method creates pore openings 28 , 28 ' the pore structure 16 or the activated carbon particles 30th causes which, on the one hand, are large enough for cell gases or gas molecules of these cell gases to penetrate into the pores 20th , 20 ' are dimensioned, and on the other hand are dimensioned small enough that conductive salts of the battery cell 4th and / or reaction and / or decomposition products of the gas scavenger material 24 not in the pores 20th , 20 ' can flow in or out. In other words, according to the invention, the size of the pore openings is precisely defined 28 , 28 ' provided which are specific to those in the battery cell 4th The resulting cell gases are dimensioned so that other cell components cannot easily enter the pores 20th , 20 ' penetrate and by-products from the pores 20th , 20 ' not in the battery cell 4th can get back.

The claimed invention is not restricted to the exemplary embodiments described above. Rather, other variants of the invention can also be derived therefrom by the person skilled in the art within the scope of the disclosed claims without departing from the subject matter of the claimed invention. In particular, all the individual features described in connection with the various exemplary embodiments can also be combined in other ways within the scope of the disclosed claims without departing from the subject matter of the claimed invention.

List of reference symbols

2

Shift system

4th

Battery cell

6

cathode

8th

anode

10

Arrester

12

Process step

14th

Layer material

16, 16 '

Pore structure

18th

pore

20, 20 '

pore

22nd

Process step

24

Gas trap material

26th

Process step

28, 28 '

Pore opening

30th

Activated carbon particles

32, 34

Process step

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was 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.

Patent literature cited

• KR 20150014668 A [0014]
• KR 101625820 B1 [0015]
• JP 2007242454 A [0017]
• JP 2008146963 A [0018]

Claims (10)

Method for producing a layer system (2) of a battery cell (4), - in which a porous layer material (14) with an open pore structure (16, 16 ') is produced, - in which a gas trapping material (24) for binding cell gases is introduced into the pore structure (16, 16 '), and - in which the layer material (14) is treated in such a way that the pores (18, 20) of the pore structure (16, 16 ') are partially closed. Procedure according to Claim 1 , characterized in that the pores (20) of the pore structure (16) are partially closed in such a way that the remaining average pore openings (28) are smaller than 0.5 nm. Procedure according to Claim 1 or 2 , characterized in that the layer material (14) is thermally treated to close the pores (18, 20). Method according to one of the Claims 1 to 3 , characterized in that a hierarchical pore structure (16) of the layer material (14) is generated. Method according to one of the Claims 1 to 4th , characterized in that a phosphane is used as gas scavenger material (24). Method according to one of the Claims 1 to 5 , characterized in that activated carbon particles (30) mixed with the gas scavenger material (24) are introduced into the pore structure (16 '). Layer system (2) for a battery cell (4), comprising a porous layer material (14) and at least one gas scavenger material (24), - wherein the gas trapping material (24) is introduced into a pore structure (16, 16 ') of the layer material (14), and - The pores (18, 20) having a pore opening (28) smaller than 0.5 nm. Layer system (2) Claim 7 , characterized in that the battery cell (4) is a lithium-ion battery cell. Use of the shift system (2) after Claim 7 or 8th as a separator in a battery cell (4). Battery cell (4) with a cathode (6) and with an anode (8) and with a layer system (2) arranged in between Claim 7 or 8th as a separator.

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