JP2021070849A - Cell module for water electrolysis - Google Patents

Abstract

To provide a water electrolysis cell module that makes it easier to replace and maintain the water electrolysis cell by improving the arrangement of the water electrolysis cell, and to extend the life of the water electrolysis cell by improving the use (operation) method and configuration of the water electrolysis cell.SOLUTION: The present invention provides a cell module 10 for water electrolysis and a method for operating the cell module 10 for water electrolysis, in which the cell module 10 for water electrolysis is constituted by three-dimensionally arranging water electrolysis stack cells 9 formed by laminating two or more water electrolysis stack cells when a structure sandwiching both sides of a polymer electrolyte membrane (PEM) 5 by water electrolysis electrodes 2 is used as a single cell 1 for water electrolysis, wherein a pause time for interrupting application voltage for water electrolysis so as not to flow an electrolytic current is provided for each water electrolysis stack cell 9, or for each two-dimensional water electrolysis stack cell group 11 composed of two-dimensional arrangement parts of the water electrolysis stack cells 9, or for each of the entire cell modules 10 for water electrolysis.SELECTED DRAWING: Figure 5

Description

The present invention relates to a cell module for water electrolysis, and more specifically, a cell module for water electrolysis formed by stacking single cells for water electrolysis and arranging stack cells for water electrolysis in two or three dimensions. It also relates to a method of operating the cell module for water electrolysis.

Hydrogen has various uses such as being used as a fuel for fuel cells, and oxygen also has various uses. And they are mostly derived from the electrolysis of water.
A cell having a structure in which both sides of a polymer electrolyte membrane (PEM) are sandwiched between electrodes and used for electrolysis of water (water electrolysis) is known. Water is supplied to the cell, and hydrogen and oxygen can be extracted from the cell by applying a voltage and passing an electric current.

Such water electrolysis cells and devices in which a plurality of the cells are combined or assembled are also known.

Patent Document 1 describes a water electrolysis device including a water supply device, a sensor of a current value supplied to the water electrolysis cell, and a control unit that controls a water supply amount based on an output signal of the sensor. ing.

Further, Patent Document 2 describes a water electrolysis tank, a monitoring device for monitoring the hydrogen concentration or oxygen concentration of the gas on the cathode side, or the amount of power supplied to the water electrolysis tank, a hydrogen supply path, and a flow rate of hydrogen gas. A water electrolysis system with a flow control valve for adjusting the amount of water is described.

Patent Document 3 describes an electrolysis system including a water electrolysis device provided with a water electrolysis cell, a DC power supply, and a relaxation device for alleviating a sudden potential fluctuation or the like in the water electrolysis cell. Has been done.

In Patent Document 4, a water electrolysis stack in which a plurality of water electrolysis cells are laminated on each other and water stored in a gas-liquid separator are supplied into the water electrolysis stack via a water supply path, and unreacted water. Described is a water electrolysis system comprising a circulation pump that circulates water so that the water is discharged to the gas-liquid separator via a water discharge path.

However, none of these techniques has been said to extend the life of the water electrolysis cell itself depending on how the water electrolysis cell is used.
Further, although it is an improvement of the device using the water electrolysis cell, it does not pay attention to the usage method (operation method) of the cell, the ease of maintenance, and the like.
That is, the replacement and maintenance of the water electrolysis cell focused on the modularization of the water electrolysis cell, and the operation method and usage method of the water electrolysis cell were not improved.

In recent years, as the demand for hydrogen has expanded, excellent water electrolysis technology is required. In addition to improving the composition of the water electrolysis cell itself and the chemical materials used, it is used for water electrolysis. The conventional technology is not sufficient for the improvement of the water electrolysis module, which incorporates the improvement of the cell operation (use) method and maintenance (replacement) method, and excellent technology in terms of performance, durability, operation method, etc. is desired. It was.

Japanese Unexamined Patent Publication No. 2018-028134 Japanese Unexamined Patent Publication No. 2018-135580 Japanese Unexamined Patent Publication No. 2019-099905 JP-A-2019-123899

The present invention has been made in view of the above, and the problem is to achieve suitable modularization by improving the assembly and arrangement of single cells for water electrolysis, and to replace and maintain the cells for water electrolysis. It is to provide an easy-to-use cell module for water electrolysis.
Another object of the present invention is to provide a water electrolysis cell module having an extended life of the water electrolysis (single) cell by improving the method and configuration of using (operating) the water electrolysis (single) cell.

As a result of diligent studies to solve the above problems, the present inventor has laminated single cells for water electrolysis to form a stack cell for water electrolysis, and further, the stack cell for water electrolysis is two-dimensional or three-dimensional. After arranging in a dimension to form a cell module for water electrolysis, if the cell is replaced or the cell is maintained for each (partial) unit constituting the cell module for water electrolysis, the cell module for water electrolysis can be obtained. It was found that cell replacement and maintenance can be performed efficiently while ensuring continuous operation.

It has also been found that turning off the applied voltage at regular intervals (regularly) significantly extends the cell life.
Then, the "timing timing" of "the cell replacement and maintenance, etc." and "the periodic shutoff (off)" and "the unit of the stack cell for water electrolysis to be replaced and the off" are unified. As a result, we have found that more efficient operation is possible and have completed the present invention.

That is, in the present invention, when a structure in which both sides of a polymer electrolyte membrane (Polymer Electrolyte Membrane (PEM)) are sandwiched between electrodes for water electrolysis is a single cell for water electrolysis, two or more single cells for water electrolysis are used. A cell module for water electrolysis in which stacked stack cells for water electrolysis are arranged in two dimensions.
Each of the water electrolysis stack cells or the entire water electrolysis cell module is configured to have a pause time in which the applied voltage for water electrolysis is cut off and no electrolysis current flows. It provides a cell module for water electrolysis.
This is an invention of a cell module for water electrolysis in which stack cells for water electrolysis are arranged two-dimensionally.

Further, in the present invention, when a structure in which both sides of a polymer electrolyte membrane (Polymer Electrolyte Membrane (PEM)) are sandwiched between electrodes for water electrolysis is a single cell for water electrolysis, two or more single cells for water electrolysis are used. A cell module for water electrolysis in which stacked stack cells for water electrolysis are arranged in three dimensions.
Water for each stack cell for water electrolysis, or for each stack cell group for two-dimensional water electrolysis consisting of two-dimensional array portions of the stack cell for water electrolysis, or for each cell module for water electrolysis. The present invention provides a cell module for water electrolysis, which is characterized in that it is configured to cut off an applied voltage for electrolysis and provide a pause time in which an electrolysis current does not flow.
This is an invention of a cell module for water electrolysis in which stack cells for water electrolysis are arranged three-dimensionally.

Further, in the present invention, the entire water electrolysis stack cell constituting the two-dimensional water electrolysis stack cell group is mounted on one mounting board and can be moved in units of the mounting boat. The above-mentioned water electrolysis cell module is provided so that the two-dimensional water electrolysis stack cell group can be pulled out from the water electrolysis cell module.
This is an invention in which a three-dimensional water electrolysis cell module can be moved by a mounting boat for each "two-dimensional water electrolysis stack cell group" which is a part of the module.

The present invention also provides the above-mentioned water electrolysis cell module capable of controlling the opening and closing of gas and / or water valves in synchronization with the above-mentioned pause time.

Further, in the present invention, the single cell for water electrolysis has a structure in which both sides of a polymer electrolyte membrane (PEM) are sandwiched between electrodes for water electrolysis.
The electrode for water electrolysis is composed of a porous substrate in which a catalyst is supported from the surface of the porous substrate itself to the inside, and an ionomer fills the porous substrate from the surface to the inside. It provides the above-mentioned cell module for water electrolysis, which is the one that has been used.

Further, the present invention is a method for operating the above-mentioned cell module for water electrolysis.
The rest time is provided for each of the water electrolysis stack cells, or for each of the two-dimensional water electrolysis stack cell groups consisting of the two-dimensional arrangement portion of the water electrolysis stack cell, or the water electrolysis stack cell. Provided is an operation method of a cell module for water electrolysis, which is characterized in that continuous operation is not interrupted by inspecting or replacing the cell module.

If a single cell for water electrolysis having a sufficiently low cell voltage (applied voltage) is used, even if a plurality of single cells for water electrolysis are stacked and combined in series to form a stack cell for water electrolysis, the stack cell has a sufficiently low application. It can be driven by voltage. Therefore, it is possible to control the applied voltage / current, the supplied water, and the generated gas (hydrogen and oxygen) for each stack cell for water electrolysis.
That is, "By using the stack cell for water electrolysis as the unit in which the gas or water pipe and the electric wiring are connected, maintenance such as replacement can be preferably performed.

Hereinafter, "for water electrolysis" is omitted, "single cell for water electrolysis" is referred to as "single cell", "stack cell for water electrolysis" is referred to as "stack cell", and "cell module for water electrolysis" is referred to as "cell". It may be abbreviated as "module".
In addition, "single cell" and "stack cell" may be collectively abbreviated as "cell".

According to the present invention, the above-mentioned problems and the above-mentioned problems are solved, and replacement and maintenance (particularly replacement) are performed for each "stack cell" by using a cell module in which stack cells are arranged two-dimensionally or three-dimensionally. As a result, operations such as cell replacement can be performed efficiently, and continuous operation can be maintained during that time.

Hereinafter, "a cell module formed by arranging stack cells in two dimensions" may be simply abbreviated as "two-dimensional cell module".
Further, the "cell module formed by arranging stack cells in three dimensions" may be simply abbreviated as "three-dimensional cell module".

Further, in the case of "a cell module in which the stack cells are arranged in three dimensions", in particular, for each "two-dimensional stack cell group consisting of a two-dimensional array part of the stack cells" which is a part of the "cell module". If replacement and maintenance (especially replacement) are performed, the work can be performed more efficiently while maintaining continuous operation.

The above-mentioned "two-dimensional stack cell group consisting of a two-dimensional array portion of stack cells" which is a part of the three-dimensional cell module may be abbreviated as "two-dimensional stack cell group".

Further, in the present invention, in addition to improving the mode of the cell itself (layer structure, mode of each layer, (partial) shape of the cell, type of material used therein, etc.), the applied voltage is cut off and the electrolytic current is not passed. It was found that the cell life can be extended by providing a pause time.
Hereinafter, the "pause time in which the applied voltage for water electrolysis is cut off and the electrolysis current is not passed" may be simply abbreviated as "pause time".

Therefore, the cell module of the present invention, which is configured to provide a pause time for each specific unit, can be operated more efficiently.
Specifically, in the cell module of the present invention, especially in the case of a three-dimensional cell module, a pause time is provided for each two-dimensional stack cell group included therein, so that the life of the cell can be extended by the pause time. Efficiency of cell replacement is synergistically achieved.

That is, the "timing timing (time)" and the "unit of the stack cell subject to the replacement and the pause time" of the above-mentioned "cell replacement and maintenance" and the above-mentioned "pause time for extending the life". By unifying, the amount of work and time can be saved, the frequency of ON-OFF operation of large currents can be reduced, and the time when the cell life is reached is unified, and the "stack cell that has not reached the end of its life" will be replaced at the next replacement. Extremely efficient operation such as risk avoidance is possible.

It is a schematic development perspective view of the single cell for water electrolysis. (A) Schematic development perspective view using a catalyst-supported porous substrate (electrode for water electrolysis, gas diffusion layer) (b) Schematic development perspective of a cell for water electrolysis using a membrane electrode assembly (MEA) and a gas diffusion layer Figure It is a schematic development perspective view of the stack cell for water electrolysis which is formed by stacking two single cells for water electrolysis. It is the schematic of the stack cell for water electrolysis. (A) Perspective view of a stack cell in which wiring and piping are connected (b) Schematic cross-sectional view showing a "hydrogen outlet" on the cathode side, a "water inlet" and a "water outlet / oxygen discharge port" on the anode side () c) Perspective view of stack cell without wiring and piping It is a schematic perspective view of the cell module for water electrolysis of this invention which has the stack cell for water electrolysis arranged two-dimensionally. It is a schematic perspective view of the cell module for water electrolysis of this invention which has the stack cell for water electrolysis arranged three-dimensionally. It is a schematic diagram of the system of the cell module of this invention which controls the flow rate of hydrogen, oxygen and water, and the applied voltage (electrolytic voltage) for each stack cell or two-dimensional stack cell group. It is a graph which shows an example of "the operating current control of a stack cell" which provided the pause time. FIG. 1 (a) is a schematic partially enlarged cross-sectional view of a single cell for water electrolysis in which a catalyst-supported porous substrate (which is both an electrode for water electrolysis and a gas diffusion layer) sandwiches a polymer electrolyte membrane (PEM). Single cell aspect). It is a schematic diagram which shows a hydrogen detector, an emergency stop mechanism (the applied voltage and the hydrogen valve shut off), a purge line and the like. Flow of piping discharged to the outside by the purge line (a) In the case of the present invention (b) In the conventional case

Hereinafter, the present invention will be described, but the present invention is not limited to the following specific forms, and can be arbitrarily modified within the scope of the technical idea.

<Cell modules for water electrolysis arranged in two dimensions>
According to the present invention, when a structure in which both sides of a polymer electrolyte membrane (PEM) are sandwiched between electrodes for water electrolysis is a single cell for water electrolysis, two or more single cells for water electrolysis are laminated for water electrolysis. A cell module for water electrolysis in which stack cells are arranged in two dimensions (see, for example, FIG. 4).
Each of the water electrolysis stack cells or the entire water electrolysis cell module is configured to have a pause time in which the applied voltage for water electrolysis is cut off and no electrolysis current flows. It is a cell module for water electrolysis.
That is, in other words, the two-dimensional cell module of the present invention is characterized in that a pause time is provided for each stack cell or for each cell module.

<Cell modules for water electrolysis arranged in three dimensions>
Further, in the present invention, when a structure in which both sides of a polymer electrolyte membrane (PEM) are sandwiched between electrodes for water electrolysis is a single cell for water electrolysis, water formed by laminating two or more single cells for water electrolysis. A cell module for water electrolysis in which electrolysis stack cells are arranged in three dimensions (see, for example, FIG. 5).
For each of the water electrolysis stack cells, or for each "two-dimensional water electrolysis stack cell group consisting of two-dimensional arrangement portions of the water electrolysis stack cells", or for each of the water electrolysis cell modules. The cell module for water electrolysis is characterized in that it has a configuration in which an applied voltage for water electrolysis is cut off and a pause time is provided so that an electrolysis current does not flow.
That is, in other words, the three-dimensional cell module of the present invention is characterized in that a pause time is provided for each stack cell, each two-dimensional stack cell group, or each cell module. And.

<< Single cell for water electrolysis >>
The "stack cell 9 constituting the cell module 10 of the present invention" is formed by stacking two or more single cells. The single cell 1 in the present invention is for electrolysis of water, and for example, as shown in FIG. 1 (a) or FIG. 1 (b), the polymer electrolyte membrane (PEM). There is no particular limitation as long as it has a structure in which both sides of the above are sandwiched between the water electrolysis electrodes 2.
Hereinafter, the "polymer electrolyte membrane (PEM)" may be simply abbreviated as "PEM".

That is, specifically, as shown in FIG. 1A, the single cell 1 in the present invention sandwiches one PEM 5 between the electrode 2 and the catalyst-supporting porous substrate 3 having the functions of a gas diffusion layer. However, it may have a structure, and as shown in FIG. 1 (b), it has a structure in which a membrane electrode assembly (MEA) having a catalyst is sandwiched between gas diffusion layers. It may be a thing.
As shown in FIG. 1 (a) or FIG. 1 (b), the single cell 1 is on the outside of both sides of the "structure in which both sides of the PEM are sandwiched between the electrodes 2", both on the cathode side and the anode side, respectively. It has a gasket, a feeding body 6, a resin tank body 7, and the like.

As described above, the single cell 1 in the present invention is not particularly limited, and examples thereof include those shown in FIGS. 1 (a) and 1 (b). It is preferable from the viewpoints of low voltage applied to a single cell, suppression of catalyst dropout, contactability between constituent materials, magnitude of effect of providing a rest time described later, durability, and the like.

As the basic structure of the single cell 1, among the structures shown in FIG. 1A, for example, a structure having a structure as shown in a schematic cross-sectional enlarged view in FIG. 8 exerts the above effect particularly preferably. Is particularly preferable.
Although the present invention is not particularly limited, as shown in FIG. 8, the single cell 1 has a structure in which both sides of the polymer electrolyte membrane (PEM) 5 are sandwiched between water electrolysis electrodes 2. The water electrolysis electrode 2 is composed of a porous substrate in which a catalyst is supported from the surface of the porous substrate itself to the inside, and an ionomer 4 is provided from the surface of the porous substrate to the inside. It is preferable that the material is filled toward the surface. The present invention preferably is the above-mentioned water electrolysis cell module 10 having such a water electrolysis electrode 2.

That is, there is a porous substrate on which a catalyst is supported across the PEM5, and the porous substrate has a structure in which it comes into contact with the PEM5 to form a cathode or an anode and also functions as a gas diffusion layer. There is. Then, the catalyst is supported on "the side surface of the pores of the porous substrate or the side surface of the fiber forming the porous substrate" and exists from the surface to the inside of the porous substrate itself. ing. The catalyst may be in the form of a film or in the form of particles as shown in FIG.

Then, it is more preferable that the ionomer 4 is filled in contact with the catalyst from the surface of the porous substrate toward the inside while having a concentration gradient in the thickness direction of the porous substrate (FIG. 8). reference).
Further, regarding the concentration gradient of the ionomer 4, it is particularly preferable that the ionomer 4 is thicker at least on the side close to PEM5 and becomes thinner toward the inside (see FIG. 8).
Further, it is also preferable that the side close to PEM 5 is dark and the power feeding body 6 side is also dark (not shown). That is, the ionomer 4 is preferably in a form in which the PEM5 side and the feeding body 6 side are thickened, and the vicinity of the center in the thickness direction of the porous substrate is thinned.
That is, in other words, it is also preferable that the ionomer 4 is filled from both sides of the porous substrate while having a concentration gradient.

Here, the "ionomer" refers to a polymer that is also called a cation exchange polymer, a polymer having a strong acid group in a side chain, a proton conductive polymer, an ion conductive polymer, or the like.

Although not limited, the catalyst-supported porous substrate 3 particularly preferable is a metal on the side surface of the pores of the porous substrate before firing or the side surface of the fiber forming the porous substrate before firing. It is preferable that it is obtained by having a step of attaching a catalyst or a metal catalyst precursor and firing it, in order to exert the above effect particularly favorably (see FIG. 8).
In the catalyst-supported porous substrate 3, the catalyst is not deposited only on the surface of the porous substrate itself as a catalyst layer, but on the side surface of the pores of the porous substrate or the porous substrate. It is preferable that the porous substrate is supported on the side surface of the fiber forming the substrate and exists from the surface to the inside of the porous substrate itself in order to particularly preferably exert the above effect (see FIG. 8).

The catalyst is not limited to one or more, but is selected from the group consisting of platinum (Pt), ruthenium (Ru), iridium (Ir), palladium (Pd), tantalum (Ta), and nickel (Ni). Is preferably a metal or a metal-containing compound.

The material of the porous substrate is not particularly limited as long as it has electron conductivity, but it is a titanium group metal, a titanium group metal alloy, a titanium group metal compound, or carbon (C). Is preferable.

Here, the "titanium group metal" refers to titanium, zirconium or hafnium. That is, examples of the titanium group substrate include a titanium substrate, a zirconium substrate, a hafnium substrate, a titanium alloy substrate, a zirconium alloy substrate, and a hafnium alloy substrate.
Examples of the "titanium group metal compound" include titanium nitride (titanium nitride (TiN)), titanium carbide (titanium carbide (TiC)), titanium boride (titanium diboride (TiB ₂ )), and the like. Can be mentioned.

As the titanium group metal or alloy, titanium or a titanium alloy is more preferable, and titanium is particularly preferable, because the cell voltage is low and the catalyst particles are preferably prevented from desorbing from the electrode base material.
Further, as the carbon (C), one having a graphite structure (graphene structure) is preferable.

The porous substrate is preferably an aggregate of titanium fibers or titanium alloy fibers, or an aggregate of carbon fibers in order to particularly preferably exert the above effect.

<< Stack cell for water electrolysis >>
The "stack cell 9 for water electrolysis" in the present invention is formed by stacking two or more of the above single cells 1 (see FIGS. 3, (a) and (c)).
FIG. 2 shows a stack cell 9 in which two single cells 1 are connected, and one single cell 1 is present on the right side and one on the left side with the bipolar plate 8 interposed therebetween. In FIG. 2, two single cells 1 happen to be stacked, but the stack cell 9 in the present invention is not limited to "a stack of two single cells".
In the stack cell 9 used in the present invention, in addition to the one shown in FIG. 2, the combined use (existence) of other layers and other members / structures is not excluded.

In the present invention, the stack cell 9 is formed by stacking two or more single cells 1, preferably three or more and ten or less, and particularly preferably four or more and six or less.
If the number of layers is too small, the water electrolysis efficiency (hydrogen generation efficiency) may deteriorate, while if the number of layers is too large, the voltage required for water electrolysis may increase.

In particular, when the electrolytic voltage (cell voltage) of the single cell 1 is low (in the case of a single cell that drives even if it is low), even if a plurality of single cells 1 are connected in series, the stack cell 9 The electrolytic voltage applied between the cathode and the anode can be reduced. Therefore, in the particularly preferable mode of the single cell 1 as described above, since the electrolytic voltage (cell voltage) of the single cell 1 is low, the electrolytic voltage (cell voltage) with respect to the stack cell 9 can also be low, and the "stack cell 9" of the present invention can be made low. Is particularly suitable for a cell module 10 "arranged in two or three dimensions.

As shown in FIGS. 3A and 3B, the water electrolysis stack cell 9 of the present invention is further provided with electrical wiring such as cathode wiring and anode wiring; hydrogen discharge piping and the like. preferable. In other words, in the cell module 10 of the present invention, it is preferable that electrical wiring (cathode wiring and anode wiring) and gas piping (hydrogen piping and / or oxygen piping) are installed for each stack cell 9.
The voltage (current), gas (hydrogen and / or oxygen), and water to be electrolyzed are naturally supplied to the single cell 1 and obtained from the single cell 1, but in the present invention, FIG. 3 (a). ), It is preferable to aggregate each stack cell 9 and supply and take out them.

In the cell of the present invention, as shown in FIGS. 3A and 3B, the water used for electrolysis enters from the water inlet of the anode and exits from the water outlet (also the oxygen outlet) of the anode. It has become. Further, the hydrogen obtained by electrolysis goes out from the hydrogen outlet of the cathode, and the oxygen obtained by electrolysis goes out from the oxygen discharge port (also the water outlet) of the cathode.

When a plurality of stack cells 9 are arranged to form a cell module 10, water is branched and supplied to each stack cell 9 from a water tank (“pure water supply source” in FIG. 6) through a supply pipe, and each is supplied. It is preferable that the water discharged from the stack cell 9 is merged and then returned to the water tank.

Further, it is preferable that the pipe for supplying water to each stack cell 9 can be removed with one touch, and the supply pipe is automatically closed after the removal.
The water supplied here (water used) is preferably pure water such as ion-exchanged water. Impurities such as ordinary chlorine-based disinfectants are filtered or removed with a filter, adsorption column, or the like. In particular, when water containing chlorine is electrolyzed, chlorine generated by the decomposition causes corrosion of the electrode material, so it is preferable to remove it.

<< How to operate multiple stack cells >>
The cell module 10 for water electrolysis of the present invention is formed by arranging a plurality of stack cells 9. In this way, cells can be replaced / maintained in units of "plurality of stack cells 9" or in units of "two-dimensional stack cell group 11" in the case of the three-dimensional cell module 10 described later, and the lifespan described later. If the operation is performed by providing a pause for extension, the down period of the entire system can be eliminated.

FIG. 6 shows an operation method of the cell module 10 of the present invention. The cell module 10 of the present invention is characterized in that the system is divided into fixed units.
Further, in FIG. 6, cell replacement and maintenance can be performed according to the shutoff of the valve and the power supply for each unit.
The flow rate of hydrogen, oxygen, or water and the applied voltage are controlled for each stack cell 9 or two-dimensional stack cell group 11, so that continuous operation can be maintained during cell replacement or maintenance (inspection). It has become.

<< Cell module for water electrolysis >>
The cell module 10 of the present invention is a two-dimensional cell module 10 formed by arranging stack cells 9 in two dimensions as shown in FIG. 4, or a stack cell 9 as shown in FIG. 5 in three dimensions. It is a three-dimensional cell module 10 formed by arranging.
The two-dimensional cell module 10 is configured to provide a pause time in which the applied voltage for water electrolysis is cut off and no electrolytic current flows for each of the stack cells 9 or the entire cell module 10 for water electrolysis. ing.

Further, in the three-dimensional cell module 10, each "stack cell 9 described above" or "two-dimensional stack cell group 11 composed of a two-dimensional array portion of the stack cell 9" (two-dimensional stack cell group 11). Each cell or "the entire cell module" is configured to have a pause time in which the applied voltage for water electrolysis is cut off and the electrolysis current is not passed. With such a configuration, the cell life can be extended.

<Pause time>
For example, as shown in FIG. 7, the life of the cell can be extended by cutting off the applied voltage for water electrolysis and providing a pause time in which the electrolysis current does not flow. The present invention has been made by finding the effect and the like.
Then, by setting the unit for setting the pause time (single cell unit, stack cell unit, two-dimensional stack cell group unit, cell module unit) for extending the cell life to an appropriate unit, an excellent cell module described later will be used. We have reached 10 configurations.

FIG. 7 is a graph showing the time change of the preferable current value per single cell.
For example, in the case of a "stack cell in which five single cells are stacked" that generates hydrogen of about 1.25 L / min, the electrolyte membrane of the single cell used gradually deteriorates when continuous operation is performed, and the electrode and the electrode Electrolytic concentration occurs in the part between the electrodes where the electric field is strong, and the operation of the cell tends to be poor.
In the present invention, it has been found that deterioration of the electrolyte membrane can be suppressed by cutting off the current at regular time intervals using a control circuit or the like, that is, by providing a pause time.

It has been confirmed by the present invention that the life of the cell is doubled by providing this rest period. Specifically, for example, it has been confirmed that the cell life can be extended from 1000 hours to 2000 hours.

The above-mentioned "pause time for prolonging life" is not particularly limited, but is preferably provided once every 1 hour or more and 100 hours or less of operation time, and every 2 hours or more and 70 hours or less of operation time. It is more preferably provided once, more preferably once every operation time of 5 hours or more and 50 hours or less, and particularly preferably once every operation time of 10 hours or more and 30 hours or less.
For example, in FIG. 7, a rest time is provided every 24 hours (1 day).

If the frequency of providing the pause time is too short, for example, the burden of cutting off the applied voltage for passing an extremely large current of several hundred A will increase, wasteful work will increase, operating efficiency (hydrogen acquisition efficiency, etc.). In some cases, the cell life may be worsened, or the cell life may not be extended any further.
On the other hand, if the frequency of providing the pause time is too long, the cell life may not be expected to be extended.

The rest time is not particularly limited, but is preferably a continuous time of 1 second or more and 120 minutes or less. That is, one rest time is preferably 1 second or more and 120 minutes or less.
The rest time of one time is more preferably 1 minute or more and 90 minutes or less, and particularly preferably 5 minutes or more and 60 minutes or less.

If one pause time (one continuous time) is too short, the cell life may not be expected to be extended.
On the other hand, if one pause time (one continuous time) is too long, wasteful work time increases, operating efficiency (hydrogen acquisition efficiency, etc.) deteriorates, and further extension of cell life cannot be expected. In some cases.

Usually, the length and frequency of pauses for life extension are shorter or greater than the length and frequency of stack cell replacement and maintenance.
Therefore, as will be described later, when the stack cell is replaced or maintained at the same time as the pause time or by using the pause time, as long as the above-mentioned "length of pause time and its frequency" is preferable. Absent.
That is, the time for replacing or maintaining the stack cell may be longer than the above, and the frequency for that may be less than the above.

Further, according to the present invention, by providing the above-mentioned pause time and further setting the current value to be passed through the cell to about 80% of the maximum possible current value, it is possible to extend the life by three times or more. Specifically, when there is no pause time or suppression of the current value, the cell life of 1000 hours can be extended to 3000 hours or more.
The "% of the current value" is preferably 50% or more and 90% or less, and particularly preferably 60% or more and 80% or less.
If the "% of the current value" is too small (close to 0%), the hydrogen, etc. that can be obtained may decrease, or the operating efficiency may decrease, even though the service life cannot be further extended. is there.
On the other hand, if the "% of the current value" is too large (close to 100%), the cell life may not be extended (the life cannot be extended).

It should be noted that the voltage (current) associated with cell replacement and maintenance (inspection), such as replacement of the stack cell 9, replacement of the two-dimensional stack cell group 11, replacement of the cell module 10, etc., which will be described later. The stop time and the period of one valve opening / closing control may be longer than the (more particularly) preferable one stop time for "extending the cell life" described above.
As a current control method, a control circuit may be used to insert a pause time at regular intervals, but when the cell is not used for replacement or maintenance, the application of voltage is stopped (manually, etc.). You may.

<< Unit for providing pause time, cell module configuration, and its operation method >>
The three-dimensional cell module 10 is preferably configured to provide a pause time for each "stack cell 9" or for each "two-dimensional stack cell group 11", and is particularly preferable. , The pause time is provided for each "two-dimensional stack cell group 11".

Further, it is preferable that the opening / closing control of the gas and / or water valve can be controlled in synchronization with the above-mentioned pause time. The synchronization of the "pause time" and the "open / close control of the gas and / or water valve" may be performed (semi-) manually by the operator (driver) or may be automatically performed.

ON / OFF of an extremely large current of several hundred A is a large-scale operation / operation, so once a pause time is provided to extend the cell life (when the applied voltage is turned OFF), then, When the stack cell 9 has reached the end of its life, it is efficient to replace it with a new one for each mounting board 12 (for each of the nine stack cells in FIG. 5).

In the three-dimensional cell module 10, the most preferable embodiment is to perform ON / OFF control of the electrolytic current (that is, setting of the pause time) and valve open / close control for each of the two-dimensional stack cell group 11.
In the three-dimensional cell module 10, the pause time for increasing the cell life is set for each two-dimensional stack cell group 11, and the opening / closing control of the valve synchronized with the setting is performed, so that the "two-dimensional stack cell group" described later will be described. Power control and valve opening / closing control can be performed for each mounting board 12 on which 11 is mounted, and the life of the stack cells 9 mounted in the same mounting board 12 can be extended (within the range of variation). When the stack cells 9 have reached the end of their useful life, the stack cells 9 may be replaced for each mounting board 12, which makes the replacement extremely simple.

That is, once the entire stack cell 9 mounted in the mounting board 12 is replaced with a new one, all of the stack cells 9 reach the end of their life at about the same time, so that the second replacement is also the mounting board. Since it is sufficient to perform every 12 steps, the replacement work can be facilitated, and the risk of replacing the stack cell 9 having a limited life can be reduced.

Since the set time of the pause time for increasing the cell life is shifted for each mounting board 12 in order to avoid stopping the entire system (preferably shifted), one mounting can be performed as described above. When the stack cell 9 on the mounting board 12 is replaced, it is not necessary to turn off the stack cell 9 on another mounting board 12 for that purpose.

In FIG. 5, only the mounting board 12 of the two-dimensional stack cell group 11 composed of the nine stack cells 9 on the front side is shown, but the two-dimensional stack cell group 11 on the back side is also shown in the same manner. It is preferable that each two-dimensional stack cell group 11 is mounted on one mounting board 12.
In the present invention, the entire water electrolysis stack cell 9 constituting the two-dimensional water electrolysis stack cell group is mounted on one mounting board 12, and can be moved in units of the mounting boat. It is preferable that the above-mentioned water electrolysis cell module 10 is designed so that each of the two-dimensional water electrolysis stack cell groups can be drawn out from the water electrolysis cell module 10.

Further, the present invention is a unit of the above-mentioned two-dimensional water electrolysis stack cell group, and the above-mentioned water electrolysis cell is configured so that all of the water electrolysis stack cells 9 arranged therein can be inspected or replaced. The module 10 is preferable.

When the present invention is a three-dimensional cell module 10, the operation method comprises "the above-mentioned stack cell 9 for water electrolysis" or "a two-dimensional arrangement portion of the stack cell 9 for water electrolysis". It is preferable that the continuous operation is not interrupted by "providing the above-mentioned pause time or inspecting or replacing the stack cell 9 for water electrolysis" for each "two-dimensional water electrolysis stack cell group".

The above assumes the case where the present invention is a three-dimensional cell module 10, but when the present invention is a two-dimensional cell module 10, the operation method is the above-mentioned pause for each of the above-mentioned stack cells 9 for water electrolysis. It is preferable to allow time or to inspect or replace each of the water electrolysis stack cells 9 so as not to interrupt the continuous operation.

That is, in the present invention, regardless of whether the cell module 10 is two-dimensional or three-dimensional, all of the stack cells 9 arranged in two-dimensional units can be inspected or replaced. preferable.
In order to fully utilize such advantages of high efficiency, the cell module 10 of the present invention is a three-dimensional cell module 10, and is placed for each two-dimensional water electrolysis stack cell group (preferably, they are placed). It is preferably mounted on the board 12) so that the stack cell 9 can be replaced and / maintained.

In particular, as shown in FIG. 5, if a rail 13 is provided so that the entire mounting board 12 can move, the two-dimensional stack cell group 11 mounted on the mounting board 12 is provided along the rail 13. Since all of the above can be pulled out, "replacement of the stack cell 9 for each mounting board 12" or "replacement of the mounting board 12 itself on which the stack cell 9 is mounted" becomes easier.
For example, in FIG. 5, in the three-dimensional cell module 10, a rail 13 on which the mounting board 12 on which the stack cells 9 constituting the two-dimensional stack cell group 11 are mounted can be slid is provided.

On the other hand, it is also preferable that the above-mentioned pause time for increasing the cell life is provided for each small unit, that is, for each "stack cell 9", whereby a plurality of stack cells 9 are exchanged at the same time. This can prevent the "risk of replacing the stack cell 9 which still has a limited life".
However, on the other hand, since it becomes necessary to replace the stack cells 9 individually across the plurality of mounting boards 12, the work becomes complicated (or the amount of work increases), and the above-mentioned features of the mounting boards 12 are also exhibited. You may not be able to enjoy it.

On the contrary, if the above-mentioned pause time for increasing the cell life is provided at the same time for each large unit, that is, for each "cell module 10", a preferable embodiment is "all stacks in the cell module 10". The cells 9 are replaced at the same time, and the entire system of the three-dimensional cell module 10 may be stopped. That is, the system may require an operation stop time in order to perform cell exchange, cell operation check, and the like during the pause time.

FIG. 4 is a schematic perspective view of the two-dimensional cell module 10 of the present invention in which the stack cells 9 of FIGS. 3 (a) and 3 (b) are two-dimensionally arranged in three rows horizontally and three rows vertically.
A gap is provided between the stack cell 9 and the stack cell 9, with a gap (1)-(2) in the horizontal direction and a gap (3)-(6) in the vertical direction. In the drawings, the gap numbers are shown in circles.

For a two-dimensional array, the number of stacks in a single cell 1 (configuration of stack cells 9) and the number of vertical and horizontal stack cells 9 can be adjusted according to the required amount of hydrogen generated. preferable.

FIG. 5 shows the three-dimensional cell module 10 of the present invention in which the stack cells 9 of FIGS. 3 (a) and 3 (b) are three-dimensionally arranged in three rows horizontally, three rows vertically, and three rows in the depth direction. It is a schematic perspective view. That is, FIG. 5 is a three-dimensional arrangement of the stack cells of FIGS. 3A and 3B.
Further, when FIG. 4 is viewed as "a two-dimensional stack cell group 11 composed of a two-dimensional array portion of stack cells" (two-dimensional stack cell group 11) in the three-dimensional cell module 10, FIG. 5 is shown in FIG. It can be said that the cell module 10 for three-dimensional water electrolysis of the present invention in which the two-dimensional stack cell group 11 is laminated in the depth direction of the drawing is shown.

The two-dimensional stack cell group 11 is arranged on a mounting board 12 made of a polymer material such as polycarbonate, and has a stack cell 9 on the mounting board 12 in the foreground and a stack cell on the mounting board 12 next to the back. (1)-(1)'between 9 has a larger gap than any of the gaps (1)-(2) and / or the gaps (3)-(6), and is used for wiring and piping. It is preferable that it is easy to remove. In the drawings, the gap numbers are shown in circles.

When a certain stack cell or almost all stack cells in the three-dimensional cell module 10 having a plurality of stack cells 9 fails or reaches the end of its life, the following measures are taken.
When replacing the stack cell 9, the applied voltage is turned off, the valve of the pipe is closed, and hydrogen in the pipe is flowed to the purge line using an inert gas such as nitrogen or argon.
After the stack cell 9 is replaced, the stack cell 9 is replaced by moving the mounting board 12 on which the stack cell 9 is mounted to the position at the time of maintenance or replacement by using, for example, the rail 13 already installed, and after the replacement and / maintenance is completed. , Return the mounting board 12 to the position when it was used, and connect the wiring and piping.

<Hydrogen detector, stop mechanism, alarm alarm mechanism>
The water electrolysis cell module 10 of the present invention, or the entire system having the water electrolysis cell module of the present invention, further includes a hydrogen detector 14, and when the hydrogen detector 14 detects a hydrogen leak, The applied voltage for water electrolysis is cut off and the hydrogen valve provided in the hydrogen pipe is closed for each stack cell 9 or for each of the two-dimensional stack cell group 11 or for the entire cell module 10. It is preferable to have.

FIG. 9 shows a configuration in which a hydrogen detector 14 is provided, and when the hydrogen detector 14 detects a hydrogen leak, the applied voltage is cut off and the hydrogen valve is closed.
The applied voltage and the hydrogen valve may be shut off manually, but it is preferable that the system automatically performs the hydrogen detection signal when the computer system receives the hydrogen detection signal from the hydrogen detector 14. ..

Repair or replacement if the applied voltage for water electrolysis is cut off and the hydrogen valve provided in the hydrogen pipe is closed for each of the stack cells 9 or for each of the two-dimensional stack cell groups 11. Occasionally, it is not necessary to stop the operation of the entire cell module 10, and continuous operation of the system becomes possible.

The entire water electrolysis cell module is surrounded by a housing 15 that does not allow gas to pass through, and the hydrogen detector 14 is provided inside the housing 15 to reliably detect hydrogen when hydrogen leaks. It is preferable that the vessel 14 can detect the leakage of hydrogen.
The presence of the housing 15 has the effect of preventing dangerous hydrogen gas from leaking to the outside and ensuring that the hydrogen detector 14 can detect the leaked hydrogen.

In FIG. 9, hydrogen emitted from the stack cell 9 or the two-dimensional stack cell group 11 is connected to each pipe, and a valve is installed in each pipe. When there are a plurality of "stack cells 9 or two-dimensional stack cell group 11", that is, when there are a plurality of the pipes, the number of valves can be electromagnetically opened and closed.
Then, the merging destination is transported to a tank for storing hydrogen via a valve.

In FIG. 9, the entire cell module 10 or the entire system thereof is surrounded by a housing 15, and hydrogen can be detected in the ceiling portion of the housing 15 at a concentration of, for example, 100 ppm or less in order to detect hydrogen. A hydrogen detector 14 is arranged, and when hydrogen leaks in the system, a hydrogen detection signal is transmitted to the computer system, the applied voltage for water electrolysis is urgently stopped, and a valve (electromagnetic valve) is opened. It is designed to be closed. At that time, it is preferable that an alarm is issued.

Furthermore, in the event of a hydrogen leak (emergency), the valve for supplying hydrogen to the hydrogen tank is closed, and the valve on the inert gas side such as _{nitrogen (N 2) or argon (Ar) is opened.} It is preferable that the residual hydrogen in the pipe can be discharged to the purge line by an inert gas such as nitrogen or argon.
In the purge line, the hydrogen concentration is less than 0.1%, and the piping of the purge line is set so that hydrogen does not explode even if ignited by the ignition source in the presence of an oxidizing gas. It is preferably placed directly in a safe place (Fig. 9).

As shown in FIG. 10A, it is preferable that the flow of the pipe discharged from the system to the outside by the purge line is substantially linear and upward.
In the uneven piping route as shown in FIG. 10 (b), which has been partially performed in the conventional piping, hydrogen tends to stay at the location shown in FIG. 10 (b) (hydrogen pooling is likely to occur).
If a hydrogen pool is formed, there is a danger of explosion if there is an ignition source in the presence of a gas that easily reacts with hydrogen, such as oxygen. Therefore, as shown in FIG. 10 (a), it is directed downstream. It is preferable that there is no bent piping part.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples as long as the gist thereof is not exceeded.
Hereinafter, unless otherwise specified, the values relating to the ratio or% are the mass ratio or the mass%.

Preparation Example 1
<Preparation of single cell>
A single cell 1 having the configuration shown in FIG. 1 (a) was manufactured.
That is, a coating liquid containing a platinum (Pt) catalyst was applied to a porous substrate in which carbon fibers were aggregated by using a spray. At that time, it was confirmed that the coating liquid permeated from the surface of the porous substrate into the inside.
Next, in order to volatilize the solvent of the coating liquid, the porous substrate was heated at 70 ° C. to dry, and then heat-treated at 300 ° C.

When the obtained catalyst-supported porous substrate 3 was observed with a scanning electron microscope (SEM), as shown in FIG. 8, the catalyst particles were supported on the side surface of the carbon fiber forming the porous substrate. Therefore, it existed in the form of particles from the surface to the inside of the porous substrate itself.

A dispersion of ionomer (Nafion (registered trademark)) was applied to the catalyst-supported porous substrate 3. At that time, it was confirmed that the dispersion liquid permeated from the surface of the catalyst-supported porous substrate 3 into the inside.
Then, the dispersion medium of the ionomer dispersion was volatilized and dried.

When the obtained "catalyst-supported porous substrate 3 after ionomer filling" was observed with a scanning electron microscope (SEM), as shown in FIG. 8, the ionomer 4 was porous while being in contact with the catalyst particles. It was confirmed that the substrate was filled from the surface to the inside with a concentration gradient in the thickness direction.

Preparation Example 2
<Preparation of stack cells>
As shown in FIG. 2, the single cell 1 is laminated with the bipolar plate 8 sandwiched therein, and the feeding body 6 and the resin tank body 7 are arranged on the outside thereof. In FIG. 2, the stack cell 9 is composed of two single cells 1, but the stack cell 9 is prepared in the same manner with the five single cells 1.

Next, as shown in FIGS. 3A and 3B, electrical wiring (cathode wiring and anode wiring) was performed, and water piping (inlet and outlet) was performed on the anode side. Further, gas piping (hydrogen on the cathode side and oxygen on the anode side) was performed to obtain one stack cell 9. The water outlet on the anode side and the oxygen outlet are also used.

Preparation Example 3
<Preparation of cell module>
Using the 27 stack cells obtained above, a three-dimensional cell module 10 as shown in FIG. 5 was prepared.
3 vertical × 3 horizontal = 9 stack cells in total are arranged on the front surface to form a two-dimensional stack cell group 11, and nine stack cells of the two-dimensional stack cell group 11 are mounted on one. It was placed on the placement board 12 (FIG. 5). A two-dimensional stack cell group 11 composed of nine stack cells in the back was also mounted on one mounting board 12 (not shown).

The mounting board 12 is placed on the rail 13 in units of the mounting board 12, and the "two-dimensional stack cell group 11 composed of nine stack cells" is moved to the right side in FIG. 5, and the stack cells are moved. It is easier to replace and maintain 9.

In this three-dimensional cell module 10, as shown in FIG. 6, it was possible (possible) to control the valves and electrical wiring attached to the water and hydrogen pipes in fixed unit units.

Evaluation example 1
<Effect of rest time>
Since the single cell obtained in Preparation Example 1 was able to generate hydrogen of 0.25 L / min, the “stack cell 9 in which 5 single cells were stacked” obtained in Preparation Example 2 was 1 It was possible to generate hydrogen of .25 L / min.

As shown in FIG. 7, the cell voltage (voltage applied to the stack cell 9) is cut off for each stack cell 9 every day (24 hours), that is, a pause time is provided, and the cell life is exhausted. I drove to.
For comparison, the stack cell 9 similarly obtained in Preparation Example 2 was used and operated until the cell life was exhausted without any pause time.
Regarding the operating conditions, the electrolytic voltage was adjusted and continuously applied so that the maximum possible current value would flow except during the above-mentioned pause time.

The life of the stack cell 9 with the pause time was 2000 hours, but the life of the stack cell 9 without the pause time was 1000 hours for comparison.
The life of the stack cell 9 was 3000 hours when the electrolytic voltage was adjusted and continuously applied so that 80% of the maximum possible current value would flow after setting the rest time in the same manner.

When continuous operation is performed, the polymer electrolyte membrane (PEM) of the single cell 1 gradually deteriorates, and electrolytic concentration occurs in the portion where the electric field between the electrodes is strong, which causes the life of the single cell (that is, the life of the stack cell 9). Is thought to come.
It is presumed that according to the present invention, the deterioration of the polymer electrolyte membrane (PEM) can be suppressed by providing the rest time, so that the life can be extended.

Evaluation example 2
<Setting of pause time for each 2D stack cell group, effect of stack cell replacement / maintenance, etc.>
The three-dimensional cell module 10 prepared in Preparation Example 3 controls a gas or water valve and a power supply as shown in FIG. 6 for each “two-dimensional water electrolysis stack cell group consisting of nine stack cells”. Therefore, even if the above-mentioned pause time and stack cell replacement time are provided, the operation of the three-dimensional cell module 10 composed of 27 stack cells as a whole did not stop.

Further, as shown in FIG. 5, a "two-dimensional water electrolysis stack cell group in which nine stack cells are arranged" is placed on one mounting board 12 so that the mounting board 12 can be moved by rail. As a result, stack cell replacement and maintenance became easier.

Moreover, by providing a pause time for each "two-dimensional water electrolysis stack cell group in which nine stack cells are arranged", the nine stack cells can be replaced and maintained at the same time by using the pause time. As a result, hydrogen acquisition becomes highly efficient, and the nine stack cells reach the end of their life at almost the same time, so that the next stack cell replacement / maintenance becomes more efficient. That is, there is no risk of replacing a stack cell that has a long life.

Since the cell module for water electrolysis of the present invention is provided with a pause time for cutting off the applied voltage, the cell life can be extended. In addition, since replacement and maintenance can be performed for each "two-dimensional stack cell group" which is a part of the cell module of the present invention, the down time of the entire system can be eliminated. Furthermore, by combining them, for example, by performing them at the same time, highly efficient water electrolysis became possible.
Therefore, the cell module system as a whole can be operated and operated efficiently while maintaining continuous operation, and is widely used in all fields requiring hydrogen and oxygen.

1 Single cell for water electrolysis 2 Electrode for water electrolysis 3 Catalyst-supported porous substrate 4 Ionomer 5 Polymer electrolyte membrane (PEM)
6 Feeding body 7 Resin tank body 8 Bipolar plate 9 Stack cell for water electrolysis 10 Cell module for water electrolysis 11 Two-dimensional stack cell group 12 Mounting board 13 Rail 14 Hydrogen detector 15 Housing

Claims (12)

When a structure in which both sides of a polymer electrolyte membrane (PEM) are sandwiched between electrodes for water electrolysis is a single cell for water electrolysis, a stack cell for water electrolysis formed by stacking two or more single cells for water electrolysis is formed. A cell module for water electrolysis arranged in two dimensions.
Each of the water electrolysis stack cells or the entire water electrolysis cell module is configured to have a pause time in which the applied voltage for water electrolysis is cut off and no electrolysis current flows. Cell module for water electrolysis. When a structure in which both sides of a polymer electrolyte membrane (PEM) are sandwiched between electrodes for water electrolysis is a single cell for water electrolysis, a stack cell for water electrolysis formed by stacking two or more single cells for water electrolysis is formed. A cell module for water electrolysis arranged in three dimensions.
Water for each stack cell for water electrolysis, or for each stack cell group for two-dimensional water electrolysis consisting of two-dimensional array portions of the stack cell for water electrolysis, or for each cell module for water electrolysis. A cell module for water electrolysis characterized in that a pause time is provided in which an applied voltage for electrolysis is cut off and an electrolysis current does not flow. The entire stack cell for water electrolysis constituting the stack cell group for two-dimensional water electrolysis is mounted on one mounting board and can be moved in units of the mounting boat. The water electrolysis cell module according to claim 2, wherein each of the two-dimensional water electrolysis stack cell groups can be drawn out from the water electrolysis cell module. The water electrolysis according to claim 2 or 3, which is a unit of the two-dimensional water electrolysis stack cell group and has a configuration in which all of the water electrolysis stack cells arranged therein can be inspected or replaced. Cell module. The cell module for water electrolysis according to any one of claims 1 to 4, wherein opening / closing control of a gas and / or water valve can be performed in synchronization with the above-mentioned pause time. The cell module for water electrolysis according to any one of claims 1 to 5, wherein the rest time is periodically provided once every operation time of 1 hour or more and 100 hours or less. The cell module for water electrolysis according to any one of claims 1 to 6, wherein the pause time is a continuous time of 1 second or more and 120 minutes or less. The single cell for water electrolysis has a structure in which both sides of a polymer electrolyte membrane (PEM) are sandwiched between electrodes for water electrolysis.
The electrode for water electrolysis is composed of a porous substrate in which a catalyst is supported from the surface of the porous substrate itself to the inside, and an ionomer fills the porous substrate from the surface to the inside. The water electrolysis cell module according to any one of claims 1 to 7, which is the same as that of the cell module for water electrolysis. Further, a hydrogen detector is provided, and when the hydrogen detector detects the leakage of hydrogen, each of the above-mentioned stack cells for water electrolysis, each of the above-mentioned two-dimensional stack cells, or the entire cell module for water electrolysis. The cell module for water electrolysis according to any one of claims 1 to 8, wherein the applied voltage for water electrolysis is cut off and the hydrogen valve provided in the hydrogen pipe is closed. The entire cell module for water electrolysis is surrounded by a housing that does not allow gas to pass through, and the hydrogen detector is provided inside the housing, so that when hydrogen leaks, the hydrogen detector ensures hydrogen. The cell module for water electrolysis according to claim 9, wherein the leakage of hydrogen can be detected. The method for operating a cell module for water electrolysis according to claim 1, or any of claims 5 to 10.
A cell module for water electrolysis, which comprises providing the rest time for each stack cell for water electrolysis, or inspecting or replacing the stack cell for water electrolysis so as not to interrupt continuous operation. how to drive. The method for operating a cell module for water electrolysis according to any one of claims 2 to 10.
The rest time is provided for each of the stack cells for water electrolysis, or for each stack cell group for two-dimensional water electrolysis composed of a two-dimensional array portion of the stack cell for water electrolysis, or a stack cell for water electrolysis. A method of operating a cell module for water electrolysis, which comprises inspecting or replacing the cell module so as not to interrupt the continuous operation.

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