JP4451954B2 - Separator and electrolytic cell structure using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a separator used in a solid polymer water electrolysis (SPWE) apparatus.
[0002]
[Prior art]
For example, it is well known that solid polymer membrane water electrolysis (apparatus) is used in the production of hydrogen as fuel for a solid electrolyte fuel cell. The basic structure of this solid polymer membrane water electrolysis is shown in FIGS.
[0003]
As shown in FIG. 9, the electrolyte membrane 1 made of a hydrogen ion permeable solid polymer membrane has an anode-side power feeding body 2 made of a titanium (Ti) sintered body and a cathode made of a stainless steel (SUS) sintered body or the like. A metal separator 5 having a large number of grooves 4 for holding pure water to be electrolyzed passes between the power feeding bodies 2 and 3 and is disposed outside the power feeding bodies 2 and 3. A stack 6 is formed.
[0004]
As shown in FIG. 8, the separator 5 supplies water to the supply hole 7a for electrolysis, and is discharged with hydrogen or oxygen generated from the discharge hole 7b provided at the opposite position. In the figure, reference numeral 8 denotes a passage that communicates the groove 5 with the holes 7a and 7b.
[0005]
When water (pure water) is caused to flow through the groove 4 of the stack 6 and a direct current is applied between the power feeding bodies 2 and 3, oxygen gas is generated on the anode side and hydrogen gas is generated on the cathode side. Water containing these gases is separated into air and water while flowing through a circulating water tank and a drain tank (not shown), and oxygen gas and hydrogen gas are respectively taken out of the system and water is again subjected to electrolysis.
[0006]
[Problems to be solved by the invention]
By the way, in the solid polymer membrane water electrolysis (apparatus), in order to perform electrolysis with high efficiency, the separator 5 and the electrolyte membrane 1 are in close contact with each other at high surface pressure through both the power feeders 2 and 3. It is necessary to reduce the contact resistance.
[0007]
Therefore, conventionally, as shown in FIGS. 6 and 7, electrolysis was performed using a separator 5 having a large number of grooves 4 in a thick metal plate. However, since the separator 5 has the grooves 4 formed by machining the holes 7a and 7b and the passage 8 for supplying water and machining by cutting, it is necessary to increase the thickness of the metal plate to some extent. There was a problem that the processing cost was very expensive.
In particular, when a material such as titanium is used because of resistance to generated gases such as hydrogen and oxygen, and corrosion resistance to an electrolyte, there is a problem that processing of the separator and material costs increase due to processing from the titanium stripping material. .
In addition, since a thick separator is used, there is a problem that the volume of the cell stack increases.
[0008]
In view of the above problems, an object of the present invention is to provide a separator having a thin separator structure and being easy to process and having high sealing properties, and an electrolytic cell structure using the separator.
[0009]
[Means for Solving the Problems]
The invention of [Claim 1] that solves the above-mentioned problems is as follows.
A separator having a large number of grooves for supplying water for electrolysis provided on the outside of a power supply body sandwiching a solid electrolyte membrane,
Water supply / discharge holes at the four corners of the separator body,
A plurality of corrugated supply grooves for circulating water supplied from the water supply holes;
A support portion for supporting the feeder body on both sides, Ri Na formed integrally with the press type,
The support portion of the power feeding body is an uneven portion formed on the outer periphery of the supply groove and alternately formed on each side of the hexagon .
[0011]
The invention of [Claim 2]
In claim 1,
A concavo- convex part is formed in a region surrounded by the two-side concavo-convex part constituting the hexagon and the supply groove, and the power feeding body is supported.
[0012]
The invention of [Claim 3 ]
In claim 1,
The separator body is a titanium alloy thin film.
[0013]
The invention of [Claim 4]
In claim 1,
A rugged portion is formed between the concavo-convex portion of one side constituting the hexagon adjacent to the water supply / discharge hole and the water supply / discharge hole, and a rigid header portion is provided between the concavo-convex portion and the solid electrolyte membrane. It is characterized by interposing.
[0014]
The invention of the electrolytic cell structure of [Claim 5 ]
An electrolyte membrane composed of a solid polymer membrane permeable to hydrogen ions;
An anode-side feeder and a cathode-side feeder disposed on both sides of the electrolyte membrane;
It consists of the separator of any one of Claims 1 thru | or 4 which has many groove | channels for the pure water to electrolyze to the outer side of these electric power feeding bodies.
[0015]
The invention of the hydrogen production apparatus of [Claim 6 ]
Water is supplied to the front surface side and the back surface side of the separator according to any one of claims 1 to 4 to supply water for electrolysis to the anode side power supply body and the cathode side power supply body,
A direct current is applied between both power feeding bodies, and hydrogen gas is extracted to the cathode side.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below, but the present invention is not limited to these embodiments.
[0017]
An embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a perspective view of a separator according to the present embodiment. 2A is a cross-sectional view taken along the line AA, and FIG. 2B is a cross-sectional view taken along the line BB.
FIG. 4 is a schematic view of the electrolytic cell structure according to the present embodiment.
As shown in FIG. 4, the separator of the solid polymer membrane water electrolysis apparatus according to the present embodiment is provided on the outer side of the power feeding bodies 12 and 13 formed by holding the solid electrolyte membrane 11, and electrolyzed water 14 is supplied. A separator 16 to be supplied, which is supplied from supply holes 18a and 18b for supplying water provided at the four corners of the thin separator main body, discharge holes 19a and 19b for discharging water, and the water supply holes 18a and 18b. A plurality of corrugated supply grooves 20 that circulate the water 14 and convex portions (support portions) 21 that alternately support the power feeding bodies 12 and 13 on both surfaces are integrally formed by a press die.
In addition, what is shown to FIG. 4 (A) is what provided the electrode 11a and the electrode 11b on both surfaces of the solid electrolyte membrane 11, as shown to FIG. 4 (B) which is the X partial enlarged view, The present invention is not limited to this. For example, as shown in FIG. 4C, electrodes 12a and 13b may be provided on the side of the solid electrolyte membrane 11 of the power feeders 12 and 13, respectively.
[0018]
As shown in FIG. 1, the separator 16 according to the present embodiment has water supply 18a, 18b and discharge holes 19a, 19b formed at the four corners of the separator body, and the water supplied from the supply hole 18a on the surface side. Is discharged from the discharge hole 19a, while the water supplied from the supply hole 18b on the back side is discharged from the discharge hole 19b. The discharged water is discharged as water accompanied by hydrogen and oxygen generated by electrolysis (water 14A containing O ₂ and water 14B containing H ₂ ), respectively.
The water 14 supplied from the water supply holes 18a and 18b flows through a plurality of corrugated supply grooves 20 formed integrally by a press.
[0019]
The material of the separator body is not particularly limited, and stainless steel, titanium, or the like can be used. However, it is preferable to use a titanium-based material from the viewpoint of resistance to generated gases such as hydrogen and oxygen and corrosion resistance to the electrolyte. .
[0020]
Further, the thickness is not particularly limited, and may be a thickness that can be integrally formed by a press and a thickness that can maintain strength when integrated, and a thickness of 8 mm or less is appropriately used.
[0021]
Further, the convex portions 21 and the concave portions 22 alternately formed in the hexagonal shape of the separator main body support the hexagonal power feeding body 12 in FIG. 4 at the convex portion 21 on the front surface side, and the concave portions 22 on the back surface side. 4 is supported by a completely reversible structure that supports the hexagonal power feeding body 13 in FIG.
Further, the power feeders 12 and 13 are supported also at the groove top portion 20 a, and are also supported by the convex portions 25 of the uneven portions formed in the inlet water chamber 23 and the outlet water chamber 24.
[0022]
FIG. 3 shows the flow of water (O ₂ side) to be supplied.
As shown in FIG. 3, the water 14 </ b> A supplied from the supply hole 18 a of the separator 16 flows from the recess 22-1, is dispersed in the inlet water chamber 23, and flows toward the formed grooves 20. The generated oxygen is collected in the outlet water chamber 24, flows out from the recess 22-3, and is discharged from the discharge hole 19a.
Further, the power feeding body on the front surface side is supported by the convex portions 21-1 to 21-4, and the power feeding body on the back surface side is supported by them because the back surface side of the concave portions 22-1 to 22-4 becomes a convex portion on the contrary. Yes. Similarly, on the back surface side, water supplied from the supply hole 18b flows from the recess 22-1, is dispersed in the inlet water chamber 23, flows toward the formed grooves 20, and is accompanied by hydrogen generated in the grooves 20. Are collected in the outlet water chamber 24, flow out of the recess 22-3, and are discharged from the discharge hole 19b.
When the separators 16 are stacked, packing (not shown) is provided and sealed around the supply holes 18a and 18b and the discharge holes 19a and 19b.
[0023]
By using the separator 16 to form a stack by laminating the anode-side power feeder and the cathode-side power feeder provided on both surfaces of the electrolyte membrane made of the hydrogen ion permeable solid polymer membrane 11, compared to the conventional case. The volume is small.
In addition, the separator is integrated so that water can be supplied to the supply grooves 20 formed on both sides, and the water flow is uniform, the water supply is stabilized, and the progress of electrolysis can be performed stably.
[0024]
Also, using the separator as described above, water is supplied to the front side and the back side of the separator body, water for electrolysis is supplied to the anode side power supply body and the cathode side power supply body, and direct current is supplied between both power supply bodies. Hydrogen can be stably produced by applying an electric current and extracting hydrogen gas to the cathode side.
[0025]
FIG. 5 is a schematic view of a separator structure according to another embodiment of the present invention. FIG. 6 is a configuration diagram of the header portion, and FIG. 7 is a cross-sectional view of a state in which the separator and the header portion are stacked.
[0026]
As shown in these drawings, the present embodiment has a configuration similar to that of the separator shown in FIG. 1, and is formed by forming convex portions 25 in the vicinity of the water supply hole 18a and the discharge hole 19a.
A rigid header portion 31 is interposed between the apex of the convex portion 25 and the solid polymer film 11, and the solid polymer film 11 closes the concave portion of the concavo-convex portion, and the flow of water. To prevent it.
The header portion 31 is formed with a hole 32 for supplying or discharging water, and a notch portion 33 which is a space portion in contact with the apex of the convex portion 25 is formed.
The header portion 31 is made of a material such as titanium or polytetrafluoroethylene (PTFE) having high rigidity.
[0027]
By laminating the solid polymer film 11 and the separator 16 using the header portion 31, as shown in FIG. 7, the apex portion of the convex portion 25 and the inner surface of the notched portion 33 of the header portion 31 are in contact with each other. The polymer film 11 does not enter the recess, and the flow path of the water 14 is prevented from being blocked.
As a result, the gas-liquid flow path is prevented from being blocked by the solid polymer film 11, the unbalance in the supply of the water 14 to the supply groove 20 is eliminated, and the uniform supply of water 14 becomes possible.
Further, since the header portion 31 is rigid, the gas-liquid sealing property is improved and the reliability of the fuel cell operation is also improved.
In the figure, reference numerals 34 and 35 denote seal members, respectively.
[0028]
In the present embodiment, since the convex portion 25 is formed in the vicinity of the periphery of the holes 18a and 19a for supplying or discharging the water of the separator 16, the shape of the header member 31 is a right triangle shape. For example, as shown in FIG. It is only necessary to provide an isosceles triangle-shaped header member at the location where the concavo-convex portions are formed so as to form an isosceles triangle shape at both ends of the supply groove 20.
[0029]
【The invention's effect】
As described above, according to the invention of [Claim 1], the separator is provided on the outer side of the power feeding body sandwiching the solid electrolyte membrane, and has a plurality of grooves for supplying water for electrolysis. A water supply / discharge hole provided at the four corners of the separator body, a plurality of corrugated supply grooves for circulating the water supplied from the water supply hole, and a support portion for supporting the power supply body on both sides. Since the power supply body can be satisfactorily supported by the support portion, water can be supplied to the grooves formed on both sides, the water flow is uniform, the water supply is stabilized, and Can be carried out stably. Further, since it is integrally molded, members such as a conventional water supply / discharge header are not required, and the size is reduced and the manufacturing cost is reduced.
Since the support portion of the power supply body is an uneven portion formed on the outer periphery of the supply groove and alternately formed on each side of the hexagonal shape, the support structure of the power supply body has a completely reversible structure, and the supply water The flow should be even better and the progress of electrolysis should be stable.
Can do.
[0031]
According to the invention of [Claim 2], an uneven portion is formed in the vicinity of the water supply / discharge hole in the region surrounded by the uneven portion of two sides constituting the hexagon and the supply groove, and the power supply body is supported. Thus, the support of the supply body is further improved.
[0032]
According to the invention of [Claim 3 ], since the separator body is a titanium alloy thin film in Claim 1, resistance to hydrogen and oxygen, which are generated gases, and corrosion resistance to the electrolyte are improved.
[0033]
According to the invention of [Claim 4], in Claim 1, an uneven part is formed between the uneven part on one side constituting the hexagon adjacent to the water supply / discharge hole and the water supply / discharge hole. Since the rigid header portion is interposed between the concavo-convex portion and the solid electrolyte membrane, the solid polymer membrane is prevented from sticking to the concave portion, the water supply is improved, and the water to the supply groove is improved. The supply is uniform and the sealing performance is improved.
[0034]
According to the invention of the electrolytic cell structure of [Claim 5 ], an electrolyte membrane made of a hydrogen ion permeable solid polymer membrane, an anode side feeder and a cathode side feeder disposed on both sides of the electrolyte membrane, Since the separator according to any one of claims 1 to 4 having a large number of grooves through which pure water to be electrolyzed passes outside the power feeder, the electrolytic cell structure is made compact and good electrolysis is achieved. Is possible.
[0035]
According to the invention of the hydrogen production apparatus of [Claim 6 ], water is supplied to the front surface side and the back surface side of the separator according to any one of Claims 1 to 4, so that the anode side power supply body and the cathode side power supply body are supplied. In addition, since water for electrolysis is supplied, a direct current is applied between both power feeding bodies, and hydrogen gas is taken out to the cathode side, hydrogen can be stably obtained with a compact structure.
[Brief description of the drawings]
FIG. 1 is a schematic view of a separator according to an embodiment.
2A is a cross-sectional view taken along line AA in FIG. 1, and FIG. 2B is a cross-sectional view taken along line BB in FIG.
FIG. 3 is a plan view of a separator body according to the present embodiment.
FIG. 4 is a schematic view of an electrolytic cell structure according to the present embodiment.
FIG. 5 is a schematic view of a separator structure according to another embodiment.
FIG. 6 is a configuration diagram of a header part;
FIG. 7 is a cross-sectional view of a state in which a separator and a header portion are stacked.
FIG. 8 is a perspective view of a separator according to a conventional technique.
FIG. 9 is a structural diagram of an electrolysis cell according to the prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Solid electrolyte membrane 12, 13 Feed body 14 Water 16 Separator 18a, 18b Supply hole 19a, 19b Discharge hole 20 Supply groove 21 Convex part (support part)
22 Concave portion 23 Inlet water chamber 24 Outlet water chamber 25 Convex portion

Claims (6)

A separator having a large number of grooves provided on the outside of a power supply body sandwiching a solid electrolyte membrane and supplying water for electrolysis;
Water supply / discharge holes at the four corners of the separator body,
A plurality of corrugated supply grooves for circulating water supplied from the water supply holes;
A support part that supports the power feeding body on both sides is formed integrally with a press die,
The separator, wherein the power supply support portion is an uneven portion formed on the outer periphery of the supply groove and alternately formed on each side of the hexagon. In claim 1,
The separator characterized by forming an uneven | corrugated | grooved part in the area | region enclosed by the uneven | corrugated | grooved part of two sides and the supply groove | channel which comprise the said hexagon, and supporting the said electric power feeding body. In claim 1,
A separator characterized in that the separator body is a titanium alloy thin film. In claim 1,
A concave and convex portion is formed between the concave and convex portion on one side constituting the hexagon adjacent to the water supply and discharge hole and the water supply and discharge hole, and a rigid header portion is provided between the concave and convex portion and the solid electrolyte membrane. A separator characterized by comprising an interferometer. An electrolyte membrane composed of a solid polymer membrane permeable to hydrogen ions;
An anode-side feeder and a cathode-side feeder disposed on both sides of the electrolyte membrane;
An electrolytic cell structure comprising the separator according to any one of claims 1 to 4, having a plurality of grooves through which pure water to be electrolyzed passes outside of the power supply body. Water is supplied to the front surface side and the back surface side of the separator according to any one of claims 1 to 4, and water for electrolysis is supplied to the anode side power supply body and the cathode side power supply body,
A hydrogen production apparatus, wherein a direct current is applied between both power feeding bodies and hydrogen gas is taken out to a cathode side.

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