WO2023006724A2

WO2023006724A2 - Electrolytic cell having a temperature-control device, electrolyzer stack having a temperature-control device, electrolysis system having the electrolyzer stack, and method for the temperature control of an electrolyzer stack

Info

Publication number: WO2023006724A2
Application number: PCT/EP2022/070906
Authority: WO
Inventors: Jan Andreas
Original assignee: Argo Gmbh
Priority date: 2021-07-28
Filing date: 2022-07-26
Publication date: 2023-02-02
Also published as: DE102021208137A1; CN216712260U; CN115679354A; WO2023006724A3

Abstract

The present invention relates to an electrolytic cell (100), more particularly a polymer membrane electrolytic cell or an alkaline solid polymer-electrolyte-membrane electrolytic cell, which is designed to produce hydrogen and oxygen from water, comprising: - two electrodes, an anode (103) and a cathode (104); - a proton-conducting membrane (101) as an electrolyte, the membrane being located between the two electrodes (103, 104); - two flow field plates (106), which are designed for the electrical contacting of the electrolytic cell (100); and - a media supply (102) for water; wherein the electrolytic cell (100) is also designed to be temperature-controlled by means of a temperature-control device (110, 330), and the temperature control is accomplished by means of a temperature-control portion (111) and/or temperature-control plate (112) located next to the anode (103) and/or the cathode (104), preferably next to the anode (103). The present invention also relates to an electrolyzer stack (300) having an electrolytic cell (100) according to the invention and to an electrolysis system having at least one electrolyzer stack (300) according to the invention. The present invention further relates to a method for the temperature control of an electrolyzer stack.

Description

ELECTROLYSIS CELL WITH TEMPERATURE CONTROL DEVICE, ELECTROLYZER STACK HAVING A TEMPERATURE CONTROL DEVICE, ELECTROLYSIS SYSTEM HAVING THE ELECTROLYSER STACK AND METHOD FOR TEMPERATURE CONTROL OF AN ELECTROLYSER STACK

technical field

The present invention relates to an electrolytic cell, in particular a polymer membrane electrolytic cell (PEM) or alkaline solid polymer electrolyte membrane electrolytic cell, which is used for the production (electrolysis) of hydrogen and oxygen from water and is equipped with a temperature control device, an electrolyzer stack having the temperature control device according to the invention, and an electrolysis system having at least one electrolyzer stack according to the invention. Furthermore, the present invention relates to a method for controlling the temperature of an electrolyzer stack, in particular an electrolyzer stack according to the present invention.

State of the art

Polymer membrane electrolytic cells or . Protone exchange membrane electrolytic cells, so-called PEM electrolytic cells, have been known and proven for a long time, for example DE 697 00 772 T2 describes a conventional fuel cell, which usually consists of a number of individual cells combined to form a so-called stack (membrane electrode unit; MEA = membrane Electrode Assembly), each of which has two electrodes (anode and cathode). The respective electrode is adjoined by a cathode space and an anode space, these spaces being closed off on the side facing away from the polymer membrane in each case from a polar plate to the next fuel cell. Polar plates come in the form of monopolar plates or bipolar plates. Monopolar plates are understood to be plates that have channel or groove-shaped depressions on only one side that form a flow field and with the help of which gas or oxidant or the reaction product can be transported to or from the membrane. In the case of bipolar plates, such channels or grooves are formed on both sides of the plate.

The spatial separation of the reaction partners hydrogen and oxygen is ensured by an electrolyte in such a way that the electron exchange that takes place during the chemical reaction between hydrogen and oxygen does not take place locally but via an external circuit. During the operation of fuel cells (cell stacks or electrolyser stacks), electricity and heat are generated due to the process. For safe operation of the fuel cell or electrolyzer stack, the heat generated must be continuously and specifically dissipated. In a PEM fuel cell, the chemical process takes place at an operating temperature of around 50°C to 90°C. As a rule, for example, with 100 watts of useful electrical power per individual cell, there is also 100 watts of heat that has to be dissipated. For this reason, stacks, in particular stacks of electrolytic cells for generating electricity, have appropriately designed cooling devices.

Fuel cell stacks or electrolyzer stacks made of graphite, for example, have a harmonious heat dissipation characteristic due to the thermal properties of the material graphite, but the respective fuel cell or electrolyzer stack is relatively large and heavy due to the thickness of the material.

In order to make the entire structure of fuel cell or electrolyzer stacks much more compact, recently made of metal foils. However, due to the thermal properties, ie the good thermal conductivity of the metal material, a significantly more sensitive heating and cooling characteristic is created. In addition, the useful electrical output of the fuel cell or electrolytic cell is directly dependent on the local, thermal cooling or heating in each cell, which can lead to local overheating or undercooling.

In order for hydrogen to be produced in a climate-neutral manner using electrolysers with green electricity, which is provided, for example, by wind and solar energy systems, it is also necessary to absorb the volatile and fluctuating power output or power generation associated with renewable energy sources and the associated load fluctuations on the electrolysers.

State-of-the-art commercial PEM electrolyzers or PEM electrolysis systems achieve power densities of up to 4.4 W/cm ² . Furthermore, the efficiency of PEM electrolyzers is usually between 40 and 70 percent based on the lower calorific value of hydrogen. This range results from the dependency of the system efficiency on the operating parameters and the design of the electrolyser. It has been shown that the efficiency of a PEM electrolyser depends in particular on the working pressure present, the temperature in the stack and an even temperature distribution over the entire stack. In order to take account of the problems mentioned, it is proposed in the prior art to run scalable electrolysis systems, in particular in the range of several megawatts, and to switch individual electrolysers (with an output of 1 or 2 megawatts, for example) on or off in accordance with the load fluctuations the power capacity of the electrolysis system (which, for example, has a total power of 10 megawatts) to adapt to the volatile and fluctuating power output of the renewable energy source. On the one hand, however, this leads to a great deal of control effort and, on the other hand, to a reduction in the service life of the individual components of the electrolyzers or of the electrolyzer system due to the clocked operation of the electrolyzers. Furthermore, the adjustment to the power output of the renewable energy source can only take place in stages, for example in steps of 1 or 2 megawatts (switching on and off individual electrolyzers), which does not allow optimal utilization of the electrolyzers and thus reduces the overall efficiency of the system.

There is therefore a great need for inexpensive electrolysers that can be installed decentrally without great effort on the one hand, and on the other hand offer the possibility of achieving constant and high efficiency in hydrogen production even with load fluctuations or fluctuations in the power fed in (amount of electricity).

Presentation of the invention

Against the background of the need described above, one object of the present invention is to provide an electrolytic cell, in particular a polymer membrane electrolytic cell or alkaline solid polymer electrolyte membrane electrolytic cell, which is set up for the production (electrolysis) of hydrogen and oxygen from water and is equipped with a temperature control device is to provide an electrolyzer stack for generating hydrogen and oxygen from water, an electrolysis system having an electrolyzer stack according to the invention, and a method for controlling the temperature of an electrolyzer stack, in particular the electrolyzer stack according to the invention, which are capable, even in the case of a volatile and fluctuating supply of electrical power or electric current as constant and high an efficiency as possible of the electrolytic cell used, in particular of the electrolytic stack used, to realize the structure of the electrolytic cell being simple and inexpensive to implement. In addition, they should be able to produce hydrogen with constant purity, in particular constant relative humidity.

The stated object is achieved by an electrolytic cell according to claim 1, an electrolyzer stack according to claim 11, an electrolytic system according to claim 16, a method for temperature control of an electrolyzer stack according to claim 17. Preferred developments of the invention are specified in the dependent claims, the subject matter of the Electrolytic cell related claims can be used in the context of the electrolytic stack, the electrolytic system and the method for tempering an electrolytic stack and vice versa.

One of the basic ideas of the present invention is to provide a temperature control device for an electrolytic cell, which is designed to close the electrolytic cell by means of a temperature control section and/or a temperature control plate, which is/are arranged next to the anode and/or the cathode of the electrolytic cell temperature control, in particular to heat and cool.

In the context of the present invention, the term "next to" in relation to "next to the anode and/or cathode" includes that the tempering section and/or the tempering plate is/are arranged within the electrolytic cell or at the edge of the electrolytic cell, the latter being in particular in the With regard to the stacked arrangement of the electrolysis cells within an electrolyzer stack. According to one aspect of the present invention, an electrolytic cell, particularly polymer membrane electrolytic cell or alkaline solid polymer electrolyte membrane electrolytic cell, configured to produce hydrogen and oxygen from water has: two electrodes, an anode and a cathode, one between the two electrodes arranged proton-conducting membrane as an electrolyte, two bipolar plates, which are set up for electrical contacting of the electrolytic cell, and a media supply for water, wherein the electrolytic cell is also set up to be temperature-controlled by means of a temperature control device, and the temperature control using at least one next to the anode and/or the cathode, preferably next to the anode, arranged temperature control section and/or temperature control plate, wherein the temperature control preferably takes place by cooling or heating the temperature control section and/or the temperature control plate. In this case, the electrolytic cell can preferably have the temperature control device according to the invention.

According to one embodiment of the present invention, the at least one temperature control section and/or the at least one temperature control plate can be provided with at least one flow channel, which is designed for a temperature control fluid, in particular water, to flow through, the at least one flow channel preferably being at least partially transverse to an axial extension of the electrolytic cell, in particular through the tempering section and/or the tempering plate.

Furthermore, it is advantageous that the flow channel in the temperature control section and/or the temperature control plate runs in a meandering, bifilar or helical or modular manner.

According to a further embodiment of the present invention, it can be advantageous that the tempering section and/or the tempering plate is/are arranged between the anode and the anode-side bipolar plate, and/or is/are arranged between the cathode and the cathode-side bipolar plate, and/or on an outside of the anode-side bipolar plate, which faces away from the anode, and /or is/are arranged on an outside of the cathode-side bipolar plate, which faces away from the cathode.

Furthermore, the electrolytic cell can also have at least one anode-side current collector (current collector plate) which is arranged between the anode and the anode-side bipolar plate, with the tempering section preferably being part of the anode-side current collector.

According to a further embodiment of the present invention, the electrolytic cell can also have at least one anode-side current collector (current collector plate) arranged between the anode and the anode-side bipolar plate, the tempering section preferably being part of the anode-side current collector.

Furthermore, it is advantageous that the tempering section is part of the anode-side bipolar plate and/or the cathode-side bipolar plate. In other words, the tempering section is integrated into the anode-side and/or cathode-side bipolar plate.

According to a further configuration, the anode-side bipolar plate can have at least one first channel structure, which is part of the media supply and is used for collecting and removing the oxygen that has been split off.

Furthermore, it is preferred that the anode-side bipolar plate has a second channel structure, which is part of the media supply and is used to supply the proton-conducting membrane with water. Furthermore, it is advantageous that the cathode-side bipolar plate has at least a first channel structure, which is part of the media supply and is used to collect and discharge the hydrogen obtained, wherein the cathode-side bipolar plate can be provided in particular with a second channel structure, which is part of the media supply and serves to supply the proton-conducting membrane with water.

The second channel structure for supplying water is optional. Since it is known that the proton-conducting membrane transports water diffusively, it can be sufficient if the water provided for decomposition is fed exclusively to the cathode side or the cathode space of the electrolytic cell.

According to a further embodiment, the electrolytic cell can also have a heating element, in particular an electrical heating element (heating resistor), which is arranged in the tempering section and/or the tempering plate.

The present invention also relates to an electrolyzer stack for generating hydrogen and oxygen from water, comprising: at least two, preferably a large number of, electrolytic cells, in particular the electrolytic cell according to the invention described above, two end plates which are designed to supply the at least two electrolytic cells with water supply and discharge the generated hydrogen and oxygen as well as being able to introduce the necessary energy, in particular the necessary electricity, and a temperature control device, in particular the temperature control device according to the invention, which is set up to control the temperature of the at least two electrolysis cells, the temperature control using a temperature control section and/or or a temperature control plate, which takes place between an anode and an anode-side bipolar plate at least one of the electrolytic cells is/are arranged, and/or at least one of the electrolytic cells is/are arranged between a cathode and a cathode-side bipolar plate, and/or between the at least two electrolytic cells, preferably between the anode-side bipolar plate of one electrolytic cell and the cathode-side bipolar plate of the other electrolytic cell , is/are arranged.

According to a further embodiment of the present invention, the at least two electrolytic cells, in particular polymer membrane electrolytic cells or alkaline solid polymer electrolyte membrane electrolytic cells, which are set up to produce hydrogen and oxygen from water, have: two electrodes, an anode and a cathode, one between the proton-conducting membrane arranged at both electrodes as electrolyte, the two bipolar plates, which are set up for electrical contacting of the electrolytic cell, and a media supply for water.

It is advantageous here if the electrolyzer stack also has at least one temperature sensor, which is preferably integrated or installed in the temperature control section and/or the temperature control plate and/or a temperature control fluid discharge line and is set up to increase the temperature of the temperature control section or the temperature control plate or the temperature control fluid capture.

Furthermore, the electrolyzer stack can also have at least one humidity sensor, which is preferably integrated or installed in a hydrogen discharge line and is set up to detect humidity or humidity, in particular the relative humidity, of the hydrogen produced.

In this case, the electrolyzer stack can also have a pressure control valve in an advantageous manner Hydrogen discharge line is integrated or installed and is adapted to control and / or regulate the outlet pressure of the hydrogen produced.

Furthermore, the present invention relates to an electrolysis system for generating hydrogen and oxygen from water, comprising: at least one electrolyzer stack according to the invention as described above, a rectifier unit comprising a transformer and a rectifier, a temperature control device comprising a circulation pump, a cooler and a heater, and a Gas management device comprising a pressure regulator for hydrogen and oxygen, a gas separation device and a gas cooler.

Furthermore, the present invention relates to a method for temperature control of an electrolyzer stack, in particular the electrolyzer stack according to the invention described above, comprising: detecting at least one temperature of a temperature control section and/or a temperature control plate of one of the at least two electrolysis cells and/or a temperature control fluid used for temperature control, in particular after exiting the electrolytic cell, and controlling and/or regulating a temperature control device which is set up to control the temperature of the at least two electrolytic cells by heating or cooling the temperature control section and/or the temperature control plate, based on the detected at least one temperature.

According to a further embodiment of the present invention, the method can include: detecting further control and/or regulation parameters selected from the group comprising: a large number of temperatures measured in different tempering sections and/or tempering plates of the electrolyzer stack, outlet pressure of the hydrogen produced, outlet pressure of the produced hydrogen oxygen, inlet pressure of the introduced water,

Moisture or humidity, in particular relative humidity, of the hydrogen produced and input power (introduced into the electrolyzer amount of electricity), and controlling the temperature of the electrolyzer stack, in particular the heating or cooling of the to be tempered

Tempering section and / or to be tempered

Tempering plate based on at least one of the other detected control and / or regulation parameters and / or control and / or controlled variable.

Furthermore, it is advantageous that the method also has: if it is detected that the energy introduced into the electrolyzer stack, in particular the amount of electricity, is decreasing, it is checked whether the temperature of the electrolyzer stack is decreasing within a predetermined time (triggered by reduction of the reaction waste heat), in particular falls below a preset limit value, and/or it is checked whether the relative humidity of the hydrogen produced increases within a predetermined time (triggered by reduction of the reaction waste heat), and if one of the two limit values is exceeded, one of the control and/or regulation parameters , in particular the temperature of the tempering section to be tempered and/or the to be tempered

Tempering plate, is adjusted.

Brief description of the figures

Further features and advantages of a device, a use and/or a method result from the following description of embodiments with reference to the attached figures. From these figures shows:

1 schematically shows the structure of a known PEM electrolysis cell according to the prior art, FIG. 2 schematic spatial representation of a PEM stack according to the prior art, FIG. 3 schematic spatial representation of a PEM electrolysis system according to an embodiment of the present invention,

4 shows schematically the structure of the PEM electrolysis system according to the invention shown in FIG. 3, FIG.

6 shows a schematic diagram of the relative humidity in the hydrogen produced as a function of temperature and pressure,

7 schematically shows the structure of a PEM electrolytic cell with temperature control according to a first embodiment of the present invention,

8 schematically shows the structure of a PEM electrolytic cell with temperature control according to a second embodiment of the present invention, and

Fig. 9 schematically shows three different ones

Embodiments for the design of

Flow channel within a tempering plate. Description of Embodiments

The same reference symbols that are listed in different figures designate identical, corresponding, or functionally similar elements.

Figure 1 shows schematically the structure of a known PEM electrolytic cell 200. The central element of the PEM electrolytic cell 200 is the polymeric membrane 201. The proton conductivity is generally achieved by sulfonated side groups of a tetrafluoroethylene-based polymer (PTFE), also known as an inomer . The ions are transported via the Grotthus mechanism along water-filled channels 202. The membrane used is generally between 150 and 250 μm thick.

Electrolysis takes place on the surfaces of the catalysts used in the anode 203 and cathode 204. The protons and electrons involved in the reaction must therefore be transported through the electrode layer. Platinum has hitherto been used as the catalyst material, with the platinum being applied to carbon particles in order to reduce the platinum loading. The electrode layers are electrically contacted by current collectors 205. Due to the significantly higher potential of the oxygen evolution reaction of >1.4 V compared to the slightly negative potential of the hydrogen evolution reaction, noble metals such as titanium must be used for the anode-side current collectors. Due to the low potentials of the hydrogen evolution reaction, carbon-based materials can be used on the cathode side. Furthermore, the supply of water and the removal of the product gases takes place via the current collectors 205 . The current collectors 205 are therefore typically made of porous materials. For the anode side titanium-based current collectors 205AN are commonly used Sintered materials or expanded metals used. The current collectors 205KA on the cathode side are designed as carbon fiber fleece.

After exiting the current collectors 205 , the product gases generated (hydrogen and oxygen) are introduced into channel structures 202 and discharged from the electrolytic cell 200 . For a stack construction, bipolar plates are used in a known manner, which use the rear side of the channel structure for the neighboring cell. The components with the introduced channel structure, in other words the bipolar plates, are also subject to high requirements in terms of stability and electrical conductivity; these properties can be provided by precious metals such as titanium or gold. In order to reduce the amount of material used, carrier materials with coatings made of the noble metals mentioned are usually used.

FIG. 2 shows a schematic three-dimensional representation of a PEM stack according to the prior art. As can be seen from FIG. 2, an electrolyzer stack 320 for generating hydrogen and oxygen from water has a multiplicity of electrolytic cells which are arranged one behind the other in the longitudinal direction of the electrolyzer stack 320 . The electrolyzer stack 320 also has two end plates 321, which are arranged at both ends of the electrolytic cells stacked on top of one another and serve to supply the at least two electrolytic cells with water and to discharge the hydrogen and oxygen produced as well as the necessary energy, in particular the necessary electricity. to be able to inject into the stack.

FIG. 3 shows a schematic spatial representation of a PEM electrolysis system 300 according to an embodiment of the present invention. The system has a rectifier unit 310 having a transformer 311 and a rectifier 312, an electrolyzer stack 320 and a temperature control device 330 having a circulating pump 331, a cooler 332 and a heater 333. The PEM electrolysis system 300 shown also has product gas lines 333 which carry the product gases (hydrogen and oxygen) to a gas management device 340 having a pressure regulator 341 for hydrogen and oxygen, a gas separator 342 and a gas cooler 343 directs. Furthermore, the system has a feed water supply device 350 which supplies the electrolyzer stack 320 with purified water. Finally, the system 300 has a control device 360, a gas freezer 365 and a dry cooler/media connection 370.

Furthermore, FIG. 4 schematically shows the structure of the PEM electrolysis system 300 according to the invention shown in FIG. The process steps and the associated system components are shown schematically in FIG. As already mentioned above, the electrolyzer 320 or the electrolyzer stack is the central system component for the production of hydrogen. The energy fed in from the electrical grid or the renewable energy source (wind turbine, photovoltaic system and the like) is adapted to the requirements of the electrolyzer 320 using power electronics (rectifier unit 310). The product gases leave the electrolyser with a water vapor content which, as already mentioned above, is largely determined by the saturation vapor pressure of the water at the respective operating parameters (working pressure and working temperature of the electrolyser stack). Gas drying in the gas management device 340 reduces the water content for the further process steps reduced. Finally, the hydrogen produced can be mechanically compressed by means of a compression device 380 for storage in order to be able to store it in a space-saving manner in downstream high-pressure accumulators 385.

Furthermore, FIG. 5 schematically shows a procedural hydraulic diagram of a PEM electrolyser according to a first embodiment. The main component of the electrolyser is the Stack 320, in which individual cells (electrolytic cell 200) are combined into one unit using a stacking technique. The series connection of individual cells increases the active cell area of the overall system and thus the maximum power consumption or . Generation capacity of hydrogen (kg/h). Through the stacking technique, the channel structures 202 of adjacent electrolytic cells 200 can be combined in one component. The mentioned structure with bipolar plates reduces the number of necessary components and thus the cell width. A decisive factor in the design of the so-called Bipolar plates is the pressure loss that occurs as the flow passes through the channel structure 202, which leads to an increased pump output.

As already mentioned above, the electrolyzer system 300 also has at least one temperature control device 330, which serves on the one hand to supply the individual electrolytic cell 200 or the electrolyzer stack 320 with reaction water, which is provided in particular by the feed water supply device 350, and on the other hand to supply the individual electrolytic cell 200 or to bring the electrolyzer stack 320 to the desired working temperature or to keep it there. For this purpose, as shown in FIG. 5, the PEM electrolysis system can be equipped with two temperature control devices 330, one for temperature control of the anode and the other temperature control device 330 for temperature control of the cathode. The two temperature control devices 330 shown each have a circulation pump 331, a heater 333 and a cooler 332 . The heater 333 and the cooler 332 can also be realized by a heat exchanger. Alternatively, there is also the possibility of designing the cooler 332 as a heat exchanger with a radiator and the heater 333 as an electric heater.

FIG. 6 schematically shows a diagram of the relative humidity in the hydrogen produced as a function of the temperature and the pressure. As briefly mentioned above, the product gases leave the electrolyser fully saturated with water vapour. The amount of water vapor results from the saturation vapor pressure of water in hydrogen or oxygen. This depends on the state variables pressure and temperature of the product gas. FIG. 6 shows the relative humidity of hydrogen as a function of the pressure for different temperatures. The isotherms shown clearly show the strong temperature and pressure dependency of the water vapor content.

FIG. 7 schematically shows the structure of a PEM electrolytic cell with temperature control according to a first embodiment of the present invention. As can be seen from FIG. 7, a PEM electrolytic cell according to the illustrated embodiment has two electrodes, an anode 103 and a cathode 104, a proton-conducting membrane 101 arranged between the two electrodes 103, 104 as the electrolyte, two bipolar plates 106AN, 106KA, which are set up for electrical contacting of the electrolytic cell 100, and a media supply 102 for water. As can also be seen from FIG. 7, the electrolytic cell 100 shown also has a temperature control device 110, 330, which is designed to control the temperature of the electrolytic cell 100, in particular to cool or heat it according to the requirements, the temperature control being based on an adjacent temperature control section 111 arranged on the anode 103, which in of this embodiment is integrated into the anode-side current collector 105 AN. In the illustrated embodiment, the electrolytic cell 100 is further provided with a temperature control plate 112, which is arranged on the right side of the electrolytic cell on the outside of the anode-side bipolar plate 106AN. As a rule, however, it will be sufficient to provide only one tempering section 111 or one tempering plate 112 per electrolytic cell.

FIG. 8 schematically shows the structure of a PEM electrolytic cell with temperature control according to a second embodiment of the present invention. In the embodiment shown here, temperature control of the temperature control section 111 and/or the temperature control plate 112 by means of a temperature control fluid, such as water, is dispensed with, and only in the temperature control section 111 and/or the temperature control plate 112, which in this case is on the left-hand side of the electrolytic cell 100 is arranged on the outside of the cathode-side bipolar plate 106KA, a heating element 117, in particular a heating resistor, is provided.

FIG. 9 schematically shows three different embodiments for designing the flow channel within a tempering plate. As can be seen from FIG. 9, it is conceivable to provide the flow channel in the tempering plate 112 in a meandering, bifilar or helical or modular manner. The same applies if the flow channel is provided in the temperature control section 111 . Reference List

100 electrolytic cell

101 proton conducting membrane

102 channel structure(s)

103 anode

104 cathode

105 current collector(s)

105AN Anode side current collector. 105KA Cathode side current collector

106 bipolar plate(s)

106A Anode side bipolar plate. 106K Cathode side bipolar plate

110 temperature control device

111 tempering section

112 tempering plate

113 first channel structure (anode side bipolar plate)

114 second channel structure (anode side bipolar plate)

115 first channel structure (cathode side bipolar plate)

116 second channel structure (cathode side bipolar plate)

117 heating element

200 electrolytic cell (state of the art)

201 polymeric membrane

202 channel structure(s) (media supply)

203 anode

204 cathode

205 current collector(s)

205AN Anode side current collector. 205KA Cathode side current collector

206 bipolar plate(s)

300 PEM electrolysis system

310 rectifier unit

311 transformer

312 rectifier

320 electrolyser stack 321 end plate(s)

322 temperature sensor

323 humidity sensor

324 Temperature control fluid discharge line

325 hydrogen exhaust line

326 pressure control valve

330 temperature control device

331 circulation pump

332 cooler

333 heating

334 product gas lines

340 gas management device

341 pressure regulator

342 gas separation device

343 gas cooler

350 feed water supply device

360 controller

365 gas freezer

370 dry cooler / media connection

380 compression device (gas compressor)

385 high pressure accumulator

Claims

EXPECTATIONS

1. Electrolytic cell (100), in particular polymer membrane

Electrolytic Cell or Alkaline Solid

Polymer electrolyte membrane electrolytic cell set up to generate hydrogen and oxygen from water, comprising: two electrodes, an anode (103) and a cathode (104), a proton-conducting membrane (101) arranged between the two electrodes (103, 104) as an electrolyte, two bipolar plates (106AN, 106KA) used for electrical

Contacting the electrolytic cell (100) are set up, and a media supply (102) for water, wherein the electrolytic cell (100) is also set up to be temperature controlled by means of a temperature control device (110, 330), and the temperature control using a / one next to the anode (103) and/or the cathode (104), preferably next to the anode (103), arranged tempering section (111) and/or

Tempering plate (112) takes place.

2. The electrolytic cell (100) according to claim 1, in which the temperature control section (111) and/or the temperature control plate (112) is/are provided with at least one flow channel through which a temperature control fluid, in particular water, flows at least one flow channel preferably runs at least partially transversely to an axial extent of the electrolytic cell (100), in particular through the temperature control section (111) and/or the temperature control plate (112).

3. Electrolytic cell (100) according to claim 2, in which the flow channel in the tempering section (111) and/or the tempering plate (112) runs in a meandering, bifilar or helical or modular manner.

4. Electrolytic cell (100) according to one of the preceding claims, in which the tempering section (111) and/or the tempering plate (112) is/are arranged between the anode (103) and the anode-side bipolar plate (106AN), and/or between the Cathode (104) and the cathode-side bipolar plate (106KN) is/are arranged, and/or is/are arranged on an outside of the anode-side bipolar plate (106AN) and/or on an outside of the cathode-side bipolar plate (106KA).

5. Electrolytic cell (100) according to one of the preceding claims, further comprising at least one anode-side current collector (105AN) (current collector plate) which is arranged between the anode (103) and the anode-side bipolar plate (106AN), the temperature control section (111) preferably being a part of the anode side current collector (105AN).

6. Electrolytic cell (100) according to one of the preceding claims 1 to 4, wherein the tempering section (111) is part of the anode-side bipolar plate (106AN) and/or the cathode-side bipolar plate (106KA).

7. Electrolytic cell (100) according to one of the preceding claims, in which the anode-side bipolar plate (106AN) has at least one first channel structure (113) which is part of the media supply (102) and is used to collect and remove the separated oxygen.

8. Electrolytic cell (100) according to claim 7, in which the anode-side bipolar plate (106AN) has a second channel structure (114) which is part of the media supply (102) and is used to supply the proton-conducting membrane (101) with water.

9. Electrolytic cell (100) according to one of the preceding claims, in which the cathode-side bipolar plate (106KA) has at least one first channel structure (115) which is part of the media supply (102) and is used to collect and discharge the hydrogen obtained, the cathode-side bipolar plates (106KA) being provided in particular with a second channel structure (116) which is part of the media supply ( 102) and serves to supply the proton-conducting membrane (101) with water.

10. Electrolytic cell (100) according to any one of the preceding claims, further comprising a heating element (117), in particular an electrical heating element, which is arranged in the tempering section (111) and/or the tempering plate (112).

11. Electrolyzer stack (320) for generating hydrogen and oxygen from water, comprising: at least two, preferably a large number of, electrolysis cells (100), in particular according to one of the preceding claims, two end plates (321) which are designed to have at least to supply two electrolysis cells (100) with water and to discharge the hydrogen and oxygen produced and to be able to introduce the necessary energy, in particular the necessary electricity, and a temperature control device (110, 330) which is set up to heat the at least two electrolysis cells (100) temperature control, wherein the temperature control takes place using a temperature control section (111) and/or a temperature control plate (112), which: is/are arranged between an anode (103) and an anode-side bipolar plate (106AN) of at least one of the electrolysis cells (100), and /or arranged between a cathode (104) and a cathode-side bipolar plate (106KN) of at least one of the electrolysis cells (100). is/are, and/or between the at least two electrolytic cells (100), preferably between the anode-side bipolar plate (106AN) the one electrolytic cell (100) and the cathode-side bipolar plate (106KA) of the other electrolytic cell (100) is/are arranged.

12. Electrolyzer stack (320) according to claim 11, in which the at least two electrolytic cells (100), in particular polymer membrane electrolytic cell or alkaline solid polymer electrolyte membrane electrolytic cell, which are set up to generate hydrogen and oxygen from water, comprise: two electrodes, an anode (103) and a cathode (104), a proton-conducting membrane (101) arranged between the two electrodes (103, 104) as the electrolyte, the two bipolar plates (106AN, 106KA) which are set up for making electrical contact with the electrolytic cell (100). , and a media supply (102) for water.

13. Electrolyzer stack (320) according to claim 11 or 12, further comprising at least one temperature sensor (322), which is preferably in the tempering section (111) and / or the tempering plate (112) and / or

Temperature-controlled fluid discharge line (324) is integrated or installed and is set up to reduce the temperature of

To detect tempering section (111) or the tempering plate (112) or the tempering fluid.

14. Electrolyzer stack (320) according to one of the preceding

Claims 11 to 13, further comprising at least one humidity sensor (323), which is preferably integrated or installed in a hydrogen discharge line (325) and is adapted to a humidity or

Humidity, in particular the relative humidity to detect the hydrogen produced.

15. electrolyzer stack (320) according to any one of the preceding claims 12 to 14, further comprising a pressure control valve (326) integrated or installed in the hydrogen discharge line (325) and adapted to control and/or regulate the outlet pressure of the hydrogen produced.

16. Electrolysis system (300) for generating hydrogen and oxygen from water, comprising: at least one electrolyzer stack (320) according to one of the preceding claims 12 to 15, a rectifier unit (310) having a transformer (311) and a rectifier (312), a temperature control device (330) having a circulation pump (331), a cooler (332) and a heater (333), and a gas management device (340) having a pressure regulator (341) for hydrogen and oxygen, a gas separation device (342) and a gas cooler (343).

17. Method for temperature control of an electrolyzer stack, in particular the electrolyzer stack (320) according to one of the preceding claims 12 to 15, comprising:

detecting at least one temperature of a temperature control section (111) and/or a temperature control plate (112) of one of the at least two electrolytic cells and/or a temperature control fluid used for temperature control, in particular after exiting the electrolytic cell, and

Controlling and/or regulating a temperature control device (110, 330), which is set up to control the temperature of the at least two electrolytic cells (100) by heating or cooling the temperature control section (111) and/or the temperature control plate (112), based on the detected at least a temperature .

18. The method of claim 17, further comprising:

Detecting further control and/or regulation parameters selected from the group comprising: a large number of Temperatures measured in different

Temperature control sections (111) and/or temperature control plates (112) of the electrolyzer stack, outlet pressure of the hydrogen produced, outlet pressure of the oxygen produced, inlet pressure of the water introduced, humidity or humidity, in particular relative humidity, of the hydrogen produced and input power (amount of electricity introduced into the electrolyzer stack), and

Controlling the temperature of the electrolyzer stack, in particular the heating or cooling of the temperature-controlled section (111) and/or the temperature-controlled plate (112) based on at least one of the detected further control and/or regulation parameters.

19. The method according to claim 17 or 18, further comprising: if it is detected that the energy introduced into the electrolyzer stack, in particular the amount of electricity, is decreasing, it is checked whether the temperature of the electrolyzer stack is decreasing within a predetermined time (triggered by reduction of the reaction waste heat), in particular falls below a preset limit value, and/or it is checked whether the relative humidity of the hydrogen produced increases within a predetermined time (triggered by reduction of the reaction waste heat), and if one of the two limit values is exceeded, one of the control and/or regulation parameters , in particular the temperature of the tempering section (111) to be tempered and/or the tempering plate (112) to be tempered is adjusted.