DE102024201239A1 - Electrolysis cell with optimized contacting of a catalyst layer - Google Patents

Abstract

The invention relates to an electrolysis cell (01) for the electrolysis of CO2. This cell (01) comprises, in direct or indirect sequence, a cathode end plate (04), a gas chamber (06), a gas diffusion layer (08), a catalyst layer (09), a water chamber (07), and an anode end plate (05). It is provided that the gas diffusion layer (08) comprises an electrically non-conductive base body (12) and an electrically conductive grid (13), wherein the grid (13) is arranged at least predominantly within the base body (12). Contacting of the catalyst layer (09) is effected via a plurality of grid contact points (14).

Description

TECHNICAL FIELD

The invention relates to an electrolysis cell for the electrolysis of CO2. This cell comprises a gas chamber containing CO2 and a water chamber containing an electrolyte, which are separated from each other by a gas diffusion layer and a catalyst layer. Contacting of the catalyst layer is required.

BACKGROUND

Renewable electricity, such as solar and wind power, can be provided in some locations in quantities that exceed local demand. The effective use of available electricity is problematic in this case. One possibility is the electrolysis of water to produce hydrogen and oxygen. However, the storage and transport of hydrogen are problematic. Furthermore, it is known that available renewable electricity can be utilized through the electrochemical conversion of CO2, capturing the greenhouse gas CO2 as a product. The electrochemical reduction reaction of carbon dioxide (CO2) to hydrocarbons through CO2 electrolysis represents a promising alternative to other energy storage strategies.

Electrolysis cells are used to reduce CO2. On one side is an anode, separated from a liquid electrolyte by a membrane. Inside the electrolysis cell is the cathode, which is in contact with the CO2 to be reduced. When the appropriate voltage is applied between the anode and cathode, electrolysis of the CO2 takes place. For this purpose, in the electrolysis cell used regularly, a cavity for holding the electrolyte is arranged adjacent to the cathode on the side facing the anode. Opposite is a cavity for holding the CO2, with the cavities separated from each other by a gas diffusion electrode.

The general functioning of an electrolysis cell for the electrolysis of CO2 is well known to those skilled in the art. This is described, for example, in WO2023/217624A1 or the WO2019/096985A1 described.

It has proven advantageous if the gas diffusion electrode is formed by a non-conductive gas diffusion layer and a conductive catalyst layer. This requires contact between the catalyst layer.

Contact with the catalyst layer is usually made along the surrounding edge of the catalyst layer, for example, by applying copper strips. Provided the electrolysis cell is small, a sufficiently uniform voltage distribution across the surface of the catalyst layer can be achieved.

The problem is the limited conductivity of the catalyst layer and the thin layer thicknesses typically used for the catalyst layer. Combined with the need to provide a sufficient surface area for practical application, a sufficient and, in particular, uniform voltage between the catalyst layer and the anode cannot be easily guaranteed.

To solve the problem, known designs propose arranging a conductive grid, for example made of copper, on the catalyst layer opposite the gas diffusion layer, i.e. on the anode side in the electrolyte.

However, this arrangement has several disadvantages. Firstly, the arrangement of the conductive grid in the electrolyte can have a detrimental effect on the electrochemical process. Another disadvantage is the smaller distance between the anode and the conductive grid compared to the distance between the anode and the catalyst layer. Furthermore, the effective area of the catalyst layer is reduced by the grid.

SUMMARY OF THE INVENTION

The object of the present invention is to provide the most uniform voltage possible across the surface of the catalyst layer. The effective available area of the catalyst layer should be as large as possible.

The object is achieved by an embodiment of the invention according to the teaching of claim 1. Advantageous embodiments are the subject of the dependent claims.

An electrolysis cell for the electrolysis of CO2 comprises, in direct or indirect sequence, a cathode end plate, a gas chamber, a gas diffusion layer, a catalyst layer, a water chamber and an anode end plate.

According to the invention, the gas diffusion layer comprises an electrically non-conductive base body and an electrically conductive grid, wherein the grid is arranged at least predominantly within the base body. The catalyst layer is contacted via a large number of lattice contact points.

DESCRIPTION OF THE INVENTION

• - eine Kathodenendplatte,
• - eine Gaskammer,
• - eine Gasdiffusionsschicht,
• - eine Katalysatorschicht,
• - eine Wasserkammer, und
• - eine Anodenendplatte.

The generic electrolysis cell is intended for the electrolysis of CO2 and includes, as a direct or indirect consequence,

• - a cathode end plate,
• - a gas chamber,
• - a gas diffusion layer,
• - a catalyst layer,
• - a water chamber, and
• - an anode end plate.

For the remainder of the description, reference is made to a left side, where the anode end plate is located, and an opposite right side. The terms "left side" and "right side" are chosen arbitrarily in this regard; however, in the following, they should always be understood that the left side refers to the side where the anode end plate is located, with the right side correspondingly being the opposite side of the electrolysis cell.

The cathode end plate and the anode end plate are the geometric ends of the respective electrolysis cell. In an arrangement of multiple electrolysis cells, a cathode end plate of one electrolysis cell can also form the anode end plate of the following electrolysis cell.

The gas chamber is a cavity in the electrolysis cell to which CO2 is supplied during operation. The water chamber is another cavity that contains an electrolyte during operation.

The gas diffusion layer, together with the catalyst layer, forms a gas diffusion electrode. This separates the gas chamber from the water chamber. For functional reasons, it is necessary that the gas diffusion layer is permeable to CO2, but that the passage of liquid through the gas diffusion electrode is prevented.

First, the invention is based on the assumption that the gas diffusion layer is an electrically non-conductive layer. For this purpose, it has a base body made of an electrically non-conductive material as its essential element.

In contrast, the catalyst layer is particularly advantageously electrically conductive. To this end, it consists of an electrically conductive material or at least has an electrically conductive coating.

The catalyst layer forms the cathode of the electrolysis cell.

Furthermore, it is possible to construct the catalyst layer or the gas diffusion layer in multiple layers. For possible and advantageous layer structures, reference is made to the known state of the art.

It is obvious that the gas chamber, the gas diffusion layer, the catalyst layer, and the water chamber must be sealed all the way around to enable the gas chamber and the water chamber to be realized as cavities. Furthermore, it is obvious that appropriate connections are required for the introduction and discharge of fluids into and from the gas chamber and water chamber, respectively.

In a simple and advantageous manner, the gas chamber is directly adjacent to the cathode end plate.

It is particularly advantageous if the gas diffusion layer is directly adjacent to the gas chamber.

Effective CO2 electrolysis can be achieved if the catalyst layer is directly adjacent to the gas diffusion layer.

It is particularly advantageous if the water chamber is directly adjacent to the catalyst layer.

In any case, an anode is required. In one embodiment, the anode end plate may also serve as the anode of the electrolysis cell. In an alternative embodiment, an anode is arranged indirectly or, preferably, directly adjacent to the anode end plate.

It is particularly advantageous if the water chamber is separated from the anode by an anode membrane and the anode membrane is therefore directly adjacent to the water chamber.

An anode chamber may be arranged between the anode membrane and the anode. However, direct contact of the anode membrane with the anode is preferred.

For functional reasons, it is necessary that a voltage can be applied to the electrolysis cell. It is particularly advantageous if the power connection to the electrolysis cell is made on the left side at the anode end plate and on the opposite right side at the cathode end plate.

Alternatively, it can also be provided that the anode and/or the catalyst layer as a cathode are contacted to the outside separately from the anode end plate or cathode end plate.

To achieve the most uniform voltage distribution possible across the catalyst layer, electrical contact is established at a number of locations. However, the conventional arrangement of an electrically conductive grid in the water chamber is omitted.

In contrast, the invention provides for an electrically conductive grid to be arranged within the gas diffusion layer. However, it should be noted that the gas diffusion layer must initially be electrically non-conductive. Thus, it is necessary to form the gas diffusion layer from an electrically non-conductive base body, with an electrically conductive grid being arranged at least predominantly within the base body.

The thickness and distribution of the grid can be chosen differently. At a minimum, the grid should make up a smaller portion of the gas diffusion layer's volume than the base body. This way, the diffusion of CO2 is not unnecessarily impeded. It is important to ensure that the grid has the necessary electrical conductivity.

The gas diffusion layer thus preferably comprises an electrically non-conductive base body and an electrically conductive grid, wherein the volume of the grid is a maximum of 0.25 times the volume of the base body. Particularly preferably, the volume of the grid is less than 0.15 times the volume of the base body.

Furthermore, according to the invention, the grid on the left side adjacent to the catalyst layer extends to the surface of the gas diffusion layer at a plurality of points, allowing contact with the catalyst layer at a plurality of grid contact points. This means that an electrically conductive connection to the catalyst layer is established via the grid contact points.

The shape of the lattice can also be varied. It is not necessary for the lattice to be completely contained within the base body. It is assumed that at least half of the lattice (or its volume) is contained within the base body.

However, it is advantageous if at least two-thirds of the grid's volume is arranged within the base body. Particularly advantageous is the grid being arranged essentially entirely within the base body, whereby the grid must be exposed at the grid contact points and at other locations for indirect contact with a cathode terminal, i.e., not enclosed by the base body.

The inventive design distributes the current flow to the catalyst layer across multiple grid contact points, thus allowing the current supply to the surface of the catalyst layer to be extended beyond the connection at the outer edge of the catalyst layer. This allows for flexible dimensioning of the electrolysis cell and eliminates the limitation to small sizes.

By arranging the electrically conductive grid in the gas diffusion layer, there is no need to arrange a conductive grid in the water chamber and thus in the electrolyte.

It is obvious and advantageous that the peripheral edge of the catalyst layer can be electrically contacted without any reduction, so that the edge region of the catalyst layer is supplied with voltage.

The electrically conductive connection of the grid arranged within the gas diffusion electrode to a cathode terminal is preferably made on the circumferential outer circumference of the gas diffusion electrode via a plurality of connection points, i.e. at respective individual free ends of the grid.

The connection points can be arranged outside the base body, distributed around the outer circumference. It can also be provided that the base body is removed in sections to expose the connection points.

In a second contacting variant, a plurality of edge contact points are used on the grid. The edge contact points are designed to coincide with the grid contact points, i.e., they are also arranged on the left side of the surface of the base body, facing the catalyst layer. For contacting, a conductive layer—for example, a copper strip—can be applied to the surrounding edge of the gas diffusion layer, so that a contact tacting at the edge contact points is possible.

In a third contacting variant, the grid is provided with a plurality of connection points. These can be designed analogously to the grid contact points, but are arranged opposite each other on the side facing the gas chamber. Thus, the grid can be contacted via the plurality of connection points, and the current can be transferred to the catalyst layer in a distributed manner across the numerous grid contact points.

It is obviously possible to combine the three different types of contact.

The grating can be designed as a cast component, for example, in the form of a grating. However, the small dimensions, especially the material thicknesses, can be problematic.

Furthermore, it is possible to produce the grid using an additive manufacturing process. This allows the grid to be optimally adapted to the locally required cross-section for current conduction, the optimal distribution within the gas diffusion electrode, and the optimal contacting of the catalyst layer. However, the disadvantage is the high cost of producing the grid.

Alternatively, the grid may be made from a plurality of intersecting metal wires, wherein the intersecting metal wires are spot-welded for stabilization, similar to a mesh fence.

In principle, it is sufficient to guide a plurality of metal threads through the base body to form the grid, essentially parallel to one another, along only one direction. In this context, "essentially" refers to the metal threads running through the base body along a common direction, but can be shaped differently transversely to the common direction, particularly for the realization of the grid contact points.

In addition, a further advantageous embodiment for forming the electrically conductive grid can be selected, in which a plurality of first metal threads are guided through the base body along a first direction, with a plurality of second metal threads traversing the base body along a second direction, e.g., transverse to the first direction, essentially parallel to one another. In this case, it is not initially intended that the first metal threads and the second metal threads be woven, interwoven, or otherwise connected to one another.

However, the grid is particularly preferably formed in the form of a net. The grid comprises a plurality of metal wires, which are woven or braided together to form the grid.

When designed in a mesh-like manner or using metal threads to create the grid, it is advantageous to combine the metal wires of the grid with non-conductive plastic threads, creating a more stable mesh with an integrated grid. The density and distribution of the metal wires and non-conductive plastic threads can be advantageously determined based on the required cross-sections and the selected manufacturing process.

Alternatively, it can also be provided that the grid comprises a plurality of metal threads, analogous to the previous variant, but these are sewn into the base body.

It is also possible to manufacture the base body in the form of a multi-layer mesh. In this case, the electrically conductive mesh can be arranged as a single layer between other non-conductive layers of the base body. In the variant with metal threads sewn into the mesh, for example, the metal threads can be sewn onto a left-hand layer of the base body from the right side, and then, for example, a right-hand layer can be sewn onto the right side to complete the base body.

Likewise, a combined mesh comprising the electrically conductive grid and non-conductive plastic threads can preferably be combined with additional non-conductive layers. In this case, the metal threads of the grid are advantageously incorporated directly into the mesh or into the multiple meshes of the multi-layer base body, i.e., woven or braided.

In any case, it is preferred if the grid is embedded integrally in the gas diffusion layer. This means that the grid is inseparably fixed in the main body of the gas diffusion layer.

This is made possible, on the one hand, by incorporating the grid directly into a mesh-like base body. Alternatively, the grid can be cast or foamed into the base body. This allows for particularly easy handling of the gas diffusion layer.

In any case, it is necessary that the grid is installed in a number of places up to the surface on the left side, thus creating the lattice contact points. This enables contacting of the catalyst layer at the lattice contact points.

If, due to the design and/or the manufacturing process, no grid contact points are directly present, it can advantageously be provided that the gas diffusion layer on the left side is machined, for example ground, so that contact at the grid contact points can be ensured.

To ensure long-term stability without compromising electrolysis, it may be advantageous to coat the grid with a non-conductive coating. Obviously, the grid contact points and connection points for contacting must be exposed.

To prevent the adhesion of any substances or molecules in the gas diffusion layer, it is particularly advantageous if the electrically conductive grid is provided with a hydrophobic coating. This prevents particles from adhering to the inherently conductive grid, which usually has hydrophilic properties – regardless of whether they occur during production/assembly or during operation or downtime – and thus reducing the free passage of CO2.

The number of grid contact points per surface area of the catalyst layer can be varied. The larger the number, the more uniform the voltage distribution will be across the surface of the catalyst layer. However, the problem to consider is that with an increasing number of grid contact points, the effort required to produce the gas diffusion layer with the electrically conductive grid increases.

An advantage over state-of-the-art solutions is achieved by having at least one grid contact point per 500 mm2. However, to avoid unnecessarily restricting the effective area of the catalyst layer, the density of grid contact points should not exceed one grid contact point per 1 mm2.

It has proven advantageous to provide at least one grid contact point per 100 mm² of the catalyst layer area. Particularly preferred is a maximum of one grid contact point per 50 mm² of the catalyst layer area.

In contrast, the number of grid contact points should preferably not exceed one grid contact point per 2 mm2. It is considered particularly preferable to have a maximum of one grid contact point per 4 mm2.

To ensure a defined distance between the cathode end plate and the gas diffusion layer, especially to secure the position of the gas diffusion layer and the width of the gas chamber, it is particularly advantageous to insert at least one cathode-side spacer on the right side of the gas diffusion layer. This requires a defined position of the cathode-side spacer between the cathode end plate and the gas diffusion layer.

The cathode-side spacer is designed to rest against the cathode end plate and, opposite, against the gas diffusion layer. It is obvious that the cathode-side spacer is located within the gas chamber or penetrates it. The cathode-side spacer is thus intended to ensure that the distance between the cathode end plate and the gas diffusion layer does not change due to deformation of the gas diffusion layer.

Furthermore, depending on the dimensions of the electrolysis cell and the stiffness of the gas diffusion layer and the catalyst layer, it may be advantageous to arrange at least one anode-side spacer in the water chamber. This requires a defined position of the anode-side spacer between the anode end plate and the catalyst layer.

The anode-side spacer is intended to ensure that the distance between the anode end plate and the catalyst layer does not change due to deformation of the catalyst layer.

In conjunction with the cathode-side spacer, the anode-side spacer can reliably determine the position of the catalyst layer and the gas diffusion layer. This ensures the flat adhesion of the catalyst layer to the gas diffusion layer.

In a first option, several cathode-side spacers can be arranged in the gas chamber, or several anode-side spacers in the water chamber. In this case, the cathode-side spacers are to be firmly connected to the cathode end plate, or the anode-side spacers are to be firmly connected to the anode end plate, so that their position is fixed.

In the case of anode-side spacers firmly connected to the anode end plate, the anode must be designed to surround the spacers. It can be provided that the anode membrane also surrounds the spacers. If the shape of the anode membrane allows it, the anode and the spacers are preferably covered by the anode membrane.

In a second option, it can be provided that a one-piece cathode-side spacer is inserted between the cathode end plate and the gas diffusion layer or a one-piece anode-side spacer is inserted between the anode end plate and the catalyst layer in the water chamber.

The preferred design utilizes integral cathode-side spacers attached to the cathode endplate and a one-piece, mounted anode-side spacer located within the water chamber. Thus, there are no restrictions or overhead on the design of the anode and anode membrane.

To ensure the most unobstructed flow in the gas chamber or water chamber, a one-piece mounted spacer must be designed in a grid-like manner. The covered area of the gas diffusion layer or catalyst layer should be as small as possible, and the grid-like spacer should otherwise be spaced apart from the cathode end plate or anode end plate, and especially from the gas diffusion layer or catalyst layer.

BRIEF DESCRIPTION OF THE DRAWINGS

• 1 shows schematically in section a first embodiment of the structure of an electrolysis cell according to the invention with an electrically conductive grid arranged within the non-conductive gas diffusion layer.
• 2 shows schematically in section a second embodiment of the construction of an electrolysis cell according to the invention analogous to the first embodiment, wherein the position of the gas diffusion electrode is fixed by spacers.
• 3 shows schematically the possible shape of a grid that can be embedded in the gas diffusion layer.
• 4 shows schematically a gas diffusion view with integrated conductive grid.

DESCRIPTION OF THE EMBODIMENTS

In the 1 A first exemplary embodiment of an electrolysis cell 01 according to the invention is outlined. This simplified sketch shows the structure of the electrolysis cell 01 in the sequence from the right side 02 to the left side 03.

On the right side 02 is the cathode end plate 04. The cathode-side power connection is usually made at the cathode end plate 04. Adjacent to the cathode end plate 04 is the gas chamber 06. During operation of the electrolysis cell 01, the carbon dioxide (CO2) to be converted is fed to the gas chamber.

The anode end plate 05 is located on the left side 03. The anode-side power connection is intended to be made on the left side, preferably at the anode end plate 05. In the figure, the water chamber 07 is sketched adjacent to the anode end plate 05. During implementation, it must be taken into account that the anode is located at, or forms, the anode end plate 05. To create the electrolysis cell, the anode must in turn be separated from the water chamber 07 by an anode membrane. During operation of the electrolysis cell 01, the electrolyte for enabling electrolysis is located in the water chamber 07.

The gas chamber 06 is separated from the water chamber 07 by a gas diffusion electrode. This consists of a gas diffusion layer 08 and a catalyst layer 09. The gas diffusion layer 08 is electrically non-conductive, while the catalyst layer 09 is electrically conductive.

To enable CO2 electrolysis, the catalyst layer 09 must be electrically connected to a cathode terminal. This is preferably done via the connection to the cathode end plate 04, to which the cathode terminal is connected.

For this purpose, the invention provides that an electrically conductive grid 13 is arranged within the gas diffusion layer 08. This grid 13 extends over the entire extent of the gas diffusion layer 08 and can be circumferentially connected to a plurality of free connection points 15 (see 4 ) with a cathode terminal or indirectly with the cathode end plate 04. Furthermore, the grid 13 extends at a plurality of locations to the catalyst layer 09, so that an electrically conductive connection to the catalyst layer 09 is established via a plurality of grid contact points 14.

In the 2 The structure of a second embodiment of an electrolytic cell 11 according to the invention is schematically outlined. This essentially corresponds to the first embodiment of 1 , so only the additions will be discussed.

To fix the position of the gas diffusion electrode formed from the gas diffusion layer 08 and the catalyst layer 09, this example provides for the use of spacers 24, 25. Cathode-side spacers 24, integrally connected to the cathode end plate 14, are inserted in contact with the gas diffusion layer 08. Opposite, anode-side spacers 25, integrally connected to the anode end plate 15, are inserted. To prevent contact through the anode-side spacers 25, these 25 are provided with a non-conductive coating 28.

Not sketched is the necessary anode and the anode membrane for separating the anode from the water chamber 07.

In the 3 A grid 13 is schematically depicted, which is woven into a mesh. For example, the grid 13 can be formed by alternating metal wires 16 and plastic wires 17.

The shape for the grid contact points 14 is not directly shown. For this purpose, the metal wires 16 must be bent at appropriate points before being embedded in the base body 12 of the gas diffusion layer 08, so that the grid 13 extends locally to the surface on the left side 03 at a plurality of points.

In the 4 The gas diffusion layer 08 is schematically outlined. This 08 essentially consists of the electrically non-conductive base body 12. Within the gas diffusion layer 08 is the integrally embedded electrically conductive grid 13. This 13 extends along the outer circumference of the gas diffusion layer 08 beyond the base body 12, so that a plurality of connection points 15 are available. On the left side 03 of the gas diffusion layer 08, the grid contact points 14 of the grid 13 are freely accessible, enabling contact with the catalyst layer 09.

QUOTES CONTAINED IN THE DESCRIPTION

This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This 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 2023/217624A1 [0004]
• WO 2019/096985A1 [0004]

Claims (15)

Electrolysis cell (01, 11) for the electrolysis of CO2 with a cathode side (02) and an anode side (03), comprising in direct or indirect sequence - a cathode end plate (04, 14), - a gas chamber (06), - a gas diffusion layer (08), - a catalyst layer (09), - a water chamber (07), and - an anode end plate (05, 25); characterized in that the gas diffusion layer (08) comprises an electrically non-conductive base body (12) and an electrically conductive grid (13), wherein the grid (13) is arranged at least predominantly within the base body (12) and comprises a plurality of grid contact points (14) which are electrically conductively connected to the catalyst layer (09). Electrolysis cell (01,11) according to Claim 1 , wherein the grid (13) is electrically conductively connected to a cathode terminal via a plurality of connection points (15) arranged on the outer circumference of the gas diffusion layer (08) as free ends of the grid. Electrolysis cell (01,11) according to Claim 1 or 2 , wherein the grid (13) is electrically conductively connected to a cathode terminal via a plurality of edge contact points which are designed analogously to the grid contact points (14) and are arranged near the ends of the grid. Electrolysis cell (01,11) according to one of the Claims 1 until 3 , wherein the grid (13) is electrically conductively connected to a cathode terminal via a plurality of connection points which are designed analogously to the grid contact points (14) and are arranged on the side opposite the cathode end plate (04,14). Electrolysis cell (01,11) according to one of the Claims 1 until 4 , wherein the grid (13) comprises a plurality of metal wires (16) running substantially parallel through the base body. Electrolysis cell (01,11) according to one of the Claims 1 until 4 , wherein the grid (13) comprises a plurality of metal wires (16) woven and/or braided into a net. Electrolysis cell (01,11) according to one of the Claims 1 until 4 , wherein the grid (13) comprises a plurality of metal wires (16) sewn into the base body. Electrolysis cell (01,11) according to Claim 5 , wherein the base body (12) is at least partially designed in the manner of a woven and/or braided net and the metal wires of the grid (13) are woven or braided into the net of the base body (12). Electrolysis cell (01,11) according to one of the Claims 1 until 8 , wherein the grid (13) is integrally embedded in the gas diffusion layer (08), in particular cast or foamed. Electrolysis cell (01,11) according to one of the Claims 1 until 9 , wherein the grid (13) has a non-conductive coating with the exception of the grid contact points (14) and with the exception of connection points (15). Electrolysis cell (01,11) according to one of the Claims 1 until 10 , wherein the grid (13) has a hydrophobic coating with the exception of the grid contact points (14) and with the exception of connection points (15). Electrolysis cell (01,11) according to one of the Claims 1 until 11 , wherein, based on the area of the catalyst layer (09), at least one lattice contact point (14) is present per 500 mm2; and/or wherein, based on the area of the catalyst layer (09), a maximum of one lattice contact point (14) is present per 1 mm2. Electrolysis cell (01,11) according to one of the Claims 1 until 12 , wherein, based on the area of the catalyst layer (09), at least one grid contact point (14) is present every 100 mm2, in particular every 50 mm2; and/or wherein, based on the area of the catalyst layer (09), a maximum of one grid contact point (14) is present every 2 mm2, in particular every 4 mm2. Electrolysis cell (11) according to one of the Claims 1 until 13 , characterized by at least one cathode-side spacer (24) which is fixed between the cathode-side cathode end plate (14) and the gas diffusion layer (08) in the gas chamber (06); and/or characterized by at least one anode-side spacer (25) which is fixed between the anode-side anode end plate (15) and the catalyst layer (09) in the water chamber (07). Gas diffusion electrode for use in an electrolysis cell (11) according to one of the preceding claims, comprising a catalyst layer (09) and a gas diffusion layer (08), which (08) comprises an electrically non-conductive base body (12) and an electrically conductive grid (13), wherein the grid (13) is arranged at least predominantly within the base body (12) and comprises a plurality of grid contact points (14) which are electrically conductively connected to the catalyst layer (09).