JP2003147564A - Stack structure in water electrolysis apparatus using solid polymer membrane, and solid polymer film used for the apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stack structure in a water electrolysis apparatus using a solid polymer membrane which can prevent any leakage of an electrolyte solution when sealing the periphery of a solid polymer membrane held by a pair of power feeders 2 and 3 of an anode and a cathode with a separator 5 via a sealing member and which maintains high sealability. SOLUTION: In the stack structure in the water electrolysis apparatus using the solid polymer membrane in which the periphery of the solid polymer membrane held by the pair of power feeders 2 and 3 of the anode and the cathode is sealed with the separator 5 via the sealing member, a soft member 12 which has lower hardness than the sealing member or an adhesive liquid-like member 13 is interposed between the sealing member and the solid polymer membrane, or the outer edge of the solid polymer film surface-fitted with the separator 5 via the sealing member is extended outward of the outer edge of the separator 5, and a shape holding frame 15 is fixed to an expanded edge 14 which is not surface-fitted with the separator 5.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a stack structure in a solid polymer water electrolysis (SPWE) device and a solid polymer film used in the device.

[0002]

2. Description of the Related Art It has been well known that a solid polymer membrane water electrolyzer is used for producing hydrogen as a fuel for a solid oxide fuel cell, for example. The basic structure of the solid polymer membrane water electrolysis stack used in this solid polymer membrane water electrolysis apparatus is shown in FIG.

As shown in FIG. 5, a solid polymer film 1 made of a hydrogen ion permeable solid polymer film is used as an anode-side power feeder 2 made of titanium (Ti) fiber sintered body or the like and stainless steel (S).
US) A metal separator 5 having a large number of grooves 4 sandwiched between a cathode-side power feeding body 3 made of a fiber sintered body and the like, and having pure water for electrolysis passing therethrough is arranged on the outside of these power feeding bodies 2, 3. Thus, the stack 6 of the solid polymer membrane water electrolysis device is formed.

The separator 5 supplies water from a supply hole provided in the separator 5 for electrolysis, and discharges it together with hydrogen or oxygen generated from a discharge hole provided at an opposite position.

Then, when water (pure water) is caused to flow in the groove 4 of the separator 5 and a direct current is applied between the power supply members 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 steam and water while flowing through a circulating water tank and a drain tank (not shown), oxygen gas and hydrogen gas are taken out of the system, respectively, and water is again subjected to electrolysis. It should be noted that the power feeding members 2 and 3 are made of a material such as a porous metal having high porosity and high power feeding performance in order to pass gas and liquid, and the separator 5 is a good electric conductor having a groove 4 which is a gas and liquid flow path. , For example, made of titanium material.

[0006]

By the way, the solid polymer membrane 1 used in the apparatus constructed as described above is about 0.1
A thin film having a thickness of about 0.2 mm (for example, 178 μm), carrying (joining) electrodes 8 and 9 by a plating method, and sandwiched between a pair of anode and cathode power supply members 2 and 3 via a separator 5. A solid polymer membrane water electrolysis device comprising a multilayer stack is formed by sequentially stacking layers in water, and the electrodes 8 and 9 bonded to the solid polymer membrane 1 face the power supply members 2 and 3. Since the solid polymer film 1 is formed in the central region of the solid polymer film 1, the solid polymer film 1 at the outer peripheral edge of the solid polymer film 1 is deformed like a wave when the electrodes 8 and 9 are joined. Even if the separator 5 is face-attached through the seal and the seal is laminated, the wavy deformation portion remains as a wrinkle at the time of sealing, and electrolytic water leaks from the wrinkle portion sandwiched by the seal rubber. I was afraid to end up.

By the way, in the solid polymer membrane water electrolysis (apparatus), in order to carry out electrolysis with high efficiency, the separator 5 and the electrolyte membrane 1 are uniformly and appropriately provided via both power feeding members 2 and 3. It is necessary to reduce the contact resistance by bringing them into close contact with each other with surface pressure.

In view of the above problems, the applicant of the present invention has filed Japanese Patent Application Laid-Open No.
No. 01-81589 proposes a technique for providing a separator structure which is thin and easy to process and has a high sealing property, and an electrolytic cell structure using the separator.

FIG. 7 is a schematic view of the separator according to the present embodiment. As shown in FIG. 7, the separator 50 according to the present embodiment has water supply holes 6 at the four corners of the separator body.
8a, 68b and discharge holes 69a, 69b are formed, and the water supplied from the front surface side supply hole 68a is discharged through the discharge hole 6a.
9a, while the water supplied from the rear surface side supply hole 68b is discharged from the discharge hole 69b. The discharged water is discharged as water (hydrogen containing O2 and water containing H2) accompanied by hydrogen and oxygen generated by electrolysis. The water supplied from the water supply holes 68a and 68b flows through a plurality of corrugated supply grooves 64 integrally formed by a press.

FIG. 6 is a schematic view of a prior art electrolytic cell structure including a one-part comparative example (unknown) using such a separator. The separator 50 according to the conventional technique is provided outside the power feeding bodies 2 and 3 that sandwich the solid electrolyte membrane 1.
A separator 50 for supplying water for electrolysis, which is water supply holes 68a and 68b for supplying water provided at four corners of a thin separator 50 as shown in FIG. 7, and a discharge hole 6 for discharging water.
9a and 69b, a plurality of corrugated supply grooves 64 that circulate the water supplied from the water supply holes 68a and 68b, and a convex portion (support portion) 21 that alternately supports the power feeding bodies 2 and 3 on both sides. Is integrally formed by a press die.

However, in such a conventional technique, not only the solid electrolyte membrane but also the separator is thin, so that it is necessary to devise a seal at both ends and a space keeping.

In view of the above problems, the present invention eliminates the risk of leakage of electrolyzed water when sealing the periphery of a solid polymer film sandwiched by a pair of power supply members of an anode and a cathode with a separator via a seal member. An object of the present invention is to provide a stack structure in a solid polymer membrane water electrolysis device that can maintain high sealing properties.

Another object of the present invention is to form an electrode on a solid polymer membrane, which can smoothly seal even when wrinkles are formed outside the position where the electrode is formed, and which can maintain a high sealing property. It is to provide a stack structure in a membrane water electrolysis device. Another object of the present invention is to provide a solid polymer membrane water capable of smoothly sealing even when an electrode is formed on the solid polymer membrane without forming wrinkles outside the electrode formation position and maintaining high sealing property. It is intended to provide a stack structure in an electrolysis device and a solid polymer membrane used in the device. Another object of the present invention is to provide a multi-layer stack structure in a solid polymer membrane water electrolysis device capable of smoothly maintaining a high sealing property with a seal around both ends thereof and a space keeping even when a thin separator is used. is there.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention according to claim 1 relates to a periphery of a solid polymer film 1 sandwiched between a pair of power supply members 2 and 3 of an anode and a cathode. In a stack structure in a solid polymer membrane water electrolysis device in which is sealed with a separator 5 through a seal member,
A stack structure is characterized in that a soft member 12 having a hardness lower than that of the seal member 11 or a liquid member 13 having an adhesive property is interposed between the seal member 11 and the solid polymer film 1. It is preferable to use silicone or soft fluororubber for the soft member 12, and the liquid member 13 having adhesiveness is preferably liquid rubber. In this case, the liquid rubber is applied to the seal member 11 such as a seal rubber. It is good to seal it.

According to the present invention, the electrodes 8 and 9 are formed on the side of the solid polymer membrane 1 facing the power feeders 2 and 3, and the liquid rubber is formed even when wrinkles are formed outside the electrode formation position. Can be smoothly sealed with or soft rubber and can maintain high sealing performance.

The second invention is a solid polymer membrane water electrolysis in which the periphery of a solid polymer membrane 1 sandwiched between a pair of power supply members 2 and 3 of an anode and a cathode is sealed with a separator 5 via a seal member 11. In the stack structure of the apparatus, the outer edge of the solid polymer film 1 that faces the separator 5 via the seal member 11 is further outwardly extended from the outer edge of the separator 5, more specifically, the seal position located at the outer edge of the separator. The shape-holding frame 15 is fixed to at least the expanded edge 14 which is not faced by the separator 5 at the time of assembling. In other words, in the solid polymer membrane used in the solid polymer membrane water electrolysis device, The outer shape of the solid polymer membrane 1 is expanded so as to be larger than the sealing position of the separator 5, and the shape holding frame 15 is fixed to the expanded edge 14 at least at the time of assembly. It is characterized in.

According to the present invention, even when the electrodes 8 and 9 are formed on the side of the solid polymer film 1 facing the power feeding members 2 and 3, wrinkles are not formed outside the positions where the electrodes are formed smoothly. Can seal and maintain high sealing performance.

The third aspect of the invention is a stack 6 in which a solid polymer film 1 is sandwiched between a pair of power supply members 2 and 3 of an anode and a cathode.
Intermediate separators 50 located on both the upper and lower sides of the (electrolysis cell)
In addition to using a thin plate separator by press molding,
The end-side separators 51 located at both upper and lower ends are characterized in that a groove is provided on the side facing the electrolytic cell, and a thick plate separator through which electrolytic water can flow is used in the groove.

According to this invention, since the press-molded separator is used in the intermediate portion sandwiched between the electrolytic cells, the end side separators located at the upper and lower ends face the electrolytic cell while maintaining the merit of low weight and low cost. A groove is provided on the side, and the groove can be used as a separator of a thick plate through which electrolytic water can flow, so that the separator and the flange can be shared, the spacer can be omitted, and the deformation of the end side separators at both ends can be easily prevented. When using the separator of
The seal around the both ends can be smoothly maintained with high sealing property.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the embodiments shown in the drawings. However, unless otherwise specified, the dimensions, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto, but are merely illustrative examples. FIG. 1 is a main part configuration diagram of a stack structure in a solid polymer membrane water electrolysis apparatus according to a first embodiment of the present invention, in which an electrolyte membrane 1 composed of a hydrogen ion permeable solid polymer membrane 1 is a titanium (Ti) fiber. Anode-side power supply 2 made of a sintered body or the like and stainless steel (S
US) A metal separator 5 having a large number of grooves 4 sandwiched between a cathode-side power feeding body 3 made of a fiber sintered body and the like, and having pure water for electrolysis passing therethrough is arranged on the outside of these power feeding bodies 2, 3. Thus, the stack 6 for solid polymer membrane water electrolysis is formed.

A pair of power feeding members 2 of the anode and the cathode,
The solid polymer membrane 1 sandwiched between 3 is sequentially laminated in water through a separator 5 in a multilayer to form a solid polymer membrane water electrolysis device composed of a multilayer stack 6. A space between the outer periphery of the solid polymer film 1 and the outer periphery of the separator 5 is sealed by an endless seal rubber provided in a seal groove 7 having a U-shaped cross section provided so as to surround the outer periphery of the separator 5. There is. The seal rubber has a hardness (JIS A) set to 50 to 80 by increasing the number of carbon parts per 100 parts of rubber. As the material of the rubber, ethylene propylene rubber, fluororubber, nitrile rubber or the like is used in consideration of water resistance and weather resistance.

The solid polymer film 1 is, for example, about 0.1 to 0.2 m.
m (eg 178 μm) thin film 500 × 1000 mm
It has a rectangular shape having a certain size, and square electrodes 8 and 9 are carried (bonded) by a plating method in the central regions of both surfaces of the anode and the cathode that face the respective power supply bodies 2 and 3.

In the above structure, as described above, the solid polymer film 1 is deformed so as to undulate outside when the electrodes 8 and 9 are joined as shown in FIG. 2 (A). And the seal rubber 11 has a hardness (JIS
Since A) is as hard as 50 to 80, the seal rubber 1
2 (B) when the wavy deformation portion is a seal even when the separator 5 is face-attached to the separator 5 and the seal is laminated.
As shown in (C), wrinkles 17 remain, and there is a risk that electrolyzed water inside will leak from that portion.

On the other hand, the stack 6 (electrolysis cell) in which the solid polymer membrane 1 is sandwiched between the pair of current feed members 2 and 3 of the anode and the cathode of the solid polymer membrane water electrolyzer is placed under water through the separator 5. In order to suppress the increase of internal resistance due to stacking,
Although it is necessary to press the laminated body with a predetermined pressure to improve the contact property and keep the contact resistance low, when the seal rubber 11 itself is made soft, the tightening causes the separator 5
I can't keep the interval between them, and it collapses.

Therefore, in the present embodiment, the seal rubber 11 having a hardness (JIS A) of 50 to 80 is used, and as shown in FIG.
A telechelic liquid rubber 13 is applied to the contact surface with the polymer film 1 on the surface. The telechelic liquid rubber 13 may be any of polydiene-based, polyether-based, and polysulfide-based, but has a coatable viscosity and the wrinkle 1
It is necessary to have a viscosity capable of closing the voids of No. 7, and it is preferable to use the one having the viscosity P adjusted to 50 to 1000 at room temperature for adjusting the functional group at the living polymerization end.

Further, as described above, without using the liquid rubber 13,
As shown in FIG. 2B, a soft rubber layer 12 may be bonded to the contact surface of the hard seal rubber surface with the polymer film 1. For such a soft rubber layer, for example, a latex having a hardness (JIS A) of 10 to 30 may be used, or ethylene propylene rubber, fluororubber, or nitrile rubber of the same material as the seal rubber 11 may be used to obtain the degree of vulcanization. May be lowered and hardness (JIS A) may be set to 10-30.

According to this embodiment, in the case where the electrodes 8 and 9 are formed on both the front and back sides facing the power supply members 2 and 3, and the wrinkles 17 are formed on the solid polymer film 1 outside the electrode formation position. However, it is possible to smoothly seal with the liquid rubber 13 and the soft rubber 12, and to maintain a high sealing property, and since the sealing rubber itself is hard, the gap between the separators 5 is maintained even if the laminated body is pressed with a predetermined pressure. Is easy.

FIG. 3 is a schematic view of a main part of a stack structure in a solid polymer membrane water electrolysis apparatus according to a second embodiment of the present invention, in which a solid polymer sandwiched between a pair of anode and cathode power supply members 2 and 3. A stack structure in a solid polymer membrane water electrolysis device in which the periphery of the membrane is sealed with a separator 5 via a seal member 11, wherein the outer edge of the solid polymer membrane 1 is surface-attached to the separator 5 via the seal member 11. 14 is further expanded outward from the seal position 1a on the outer edge of the separator 5,
The shape retaining frame 15 is fixed to the enlarged edge 14 that is not surface-mounted by the separator 5. That is, in this embodiment, the outer shape of the solid polymer membrane used in the solid polymer membrane water electrolyzer is expanded so as to be larger than the outer shape of the separator 5, and first, the shape holding frame 15 is fixed to the enlarged edge 14. After that, the rectangular electrodes 8 and 9 are formed by plating in the central region of both surfaces of the solid polymer film 1 facing the power feeding members 2 and 3.

As a result, when the electrode is formed, the central region of the polymer film 1 is pulled by the electrode bonding and is held by the shape holding frame 15 even if a pulling force acts outside the electrode forming position. 17 is not formed.

The shape-holding frame 15 may be provided after the electrodes 8 and 9 are joined together, whereby the wrinkles 17 formed on the outer peripheral edge side of the electrode forming position can be extended by joining the electrodes.
The shape holding frame 15 is not particularly limited as long as a tensile force acts on the outer peripheral side, but may be formed of a hard rubber having a hardness (JIS A) similar to that of seal rubber of about 50 to 80, or You may form with resin, such as PE (polyethylene) and PP (polypropylene).

FIG. 6 is a comparative example of a solid polymer membrane water electrolysis apparatus using the thin plate separator shown in FIG. 8, in which the solid polymer membrane 1 is sandwiched between a pair of anode and cathode power supply members 2 and 3. The stacked stack 6 (electrolytic cell) is the separator 5 described above.
In order to suppress the increase in internal resistance due to the lamination, the multilayer stack structure 06 has flanges on both upper and lower sides, Utilizing the tightening force of the flange to press the electrolytic cell laminate at a predetermined pressure to improve contact,
Keeps contact resistance low. Further, a thick hard seal rubber 11 is interposed to hold the electrolyzed water in the stack. However, in such a configuration, the spacer 53 must be interposed between the thin plate separators located above and below the multilayer stack structure 06 (electrolytic cell stack) and the flange 70. In particular, the press-molded separator has the advantage of being lightweight and low cost, but since the electrolytic cells exist on the upper and lower sides and the groove is formed on both sides, the spacers on the upper and lower ends are spacers so as not to be deformed by the tightening force. Is mandatory.

Therefore, in the third embodiment of the present invention, as shown in FIG. 8, a stack 6 (electrolytic cell) in which a solid polymer film 1 is sandwiched between a pair of power supply members 2 and 3 of an anode and a cathode. Press-formed thin plate separators are used for the intermediate separators 50 located on the upper and lower sides, and the end side separators 51 located on the upper and lower ends are provided with grooves 4 on the sides facing the electrolysis cells, and the electrolyzed water can flow through the grooves 4. Thick plate separator 5
If it is 1, the separator and the flange can be shared, and the spacer can be omitted. That is, if the end side separators 51 at both ends are machined from a titanium thick plate, the spacers and the flanges at both ends can be omitted, and the end side separators 51 at both ends can be omitted.
Can be easily prevented from being deformed.

[0033]

As described above, according to the first invention, the electrodes 8 and 9 are formed on the side facing the power feeding bodies 2 and 3, and wrinkles are formed on the solid polymer film outside the electrode formation position. Even if there is, you can smoothly seal with the liquid rubber or soft rubber,
In addition, high sealability can be maintained.

According to the second aspect of the invention, even when the electrodes 8 and 9 are formed on the side of the solid polymer membrane which faces the power feeding members 2 and 3, wrinkles are not formed outside the positions where the electrodes are formed. Can be sealed and high sealing performance can be maintained.

Further, according to the third invention, since the press-deformed thin plate separator is used for the intermediate portion sandwiched between the electrolytic cells, the merit of light weight and low cost is maintained,
The end-side separators located at the upper and lower ends are provided with grooves on the side facing the electrolytic cell, and the groove and the separator can be shared by the separator of a thick plate through which electrolytic water can flow, and the spacer can be omitted. The deformation of the end side separators at both ends can be easily prevented, and the seal around the both ends can be smoothly maintained with high sealing performance.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a main part of a stack structure in a solid polymer membrane water electrolysis device according to a first embodiment of the present invention.

2A is a plan view of the solid polymer membrane used in FIG. 1, and FIGS. 2B and 2C are cross-sectional views of the seal rubber used in FIG.

FIG. 3 is a configuration diagram of a main part of a stack structure in a solid polymer membrane water electrolysis device according to a second embodiment of the present invention.

FIG. 4 is a plan view of the solid polymer membrane used in FIG.

FIG. 5 is a schematic configuration diagram of a stack structure in a solid polymer membrane water electrolysis device according to a conventional technique.

FIG. 6 is a schematic view of a laminated stack structure of an electrolytic cell according to a comparative example of the present third invention.

FIG. 7 is a schematic view of a conventional thin plate separator used in FIG.

FIG. 8 is a schematic view of a laminated stack structure of an electrolytic cell according to an example of the present third invention.

[Explanation of symbols]

1 Solid polymer membrane 1a Seal position A few feeds 5 separator 6 stack structure 8, 9 electrodes 11 Seal member 12 Soft member with lower hardness than the seal member 13 Liquid component material with adhesiveness 14 Enlarged edge of solid polymer membrane 15 Shape retention frame 50 thin plate intermediate separator 51 Edge separator

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Mitsufumi Goto             5-717-1, Fukahori-cho, Nagasaki-shi Mitsubishi Heavy Industries             Business Nagasaki Institute (72) Inventor Masayuki Fukagawa             5-717-1, Fukahori-cho, Nagasaki-shi Mitsubishi Heavy Industries             Business Nagasaki Institute (72) Inventor Hashi ▲ Saki ▼ Katsuo             1-1 Nagano-shi Atsunoura-cho Mitsubishi Heavy Industries Ltd.             Company Nagasaki Shipyard (72) Inventor Katsutoshi Shimizu             1-1 Nagano-shi Atsunoura-cho Mitsubishi Heavy Industries Ltd.             Company Nagasaki Shipyard (72) Inventor Tsukasa Yamane             1-1 Nagano-shi Atsunoura-cho Mitsubishi Heavy Industries Ltd.             Company Nagasaki Shipyard F-term (reference) 4K021 AA01 BA02 CA01 CA04 DB04                       DB12 DB31 DB43 DB48 DB50                       DB53 DC01 DC03                 5H027 AA06 BA11

Claims (5)

[Claims] 1. A stack structure in a solid polymer membrane water electrolysis device, wherein a periphery of a solid polymer membrane sandwiched between a pair of an anode and a cathode power feeding body is sealed with a separator via a seal member, in the stack structure. A stack structure in which a soft member having a hardness lower than that of the seal member or a liquid member having an adhesive property is interposed between the solid polymer film and the solid polymer film. 2. The stack structure according to claim 1, wherein the liquid member having adhesiveness is liquid rubber. 3. A stack structure in a solid polymer membrane water electrolysis device, wherein a periphery of a solid polymer membrane sandwiched between a pair of an anode and a cathode power supply body is sealed with a separator via a seal member, wherein the seal member is The outer edge of the solid polymer film that faces the separator via the outer edge is expanded further outward than the sealing position of the outer edge of the separator, and the shape retaining frame is fixed to the expanded edge that is not faced by the separator at least during assembly. A stack structure that is characterized by 4. A solid polymer membrane for use in a solid polymer membrane water electrolysis device, wherein a solid polymer membrane sandwiched between a pair of an anode and a cathode power feeding body is sealed with a separator via a sealing member, A solid polymer membrane, wherein the outer shape of the solid polymer membrane is expanded so as to be larger than the sealing position of the outer edge of the separator, and the shape holding frame is fixed to the expanded position at least during assembly. 5. A thin plate separator formed by press molding is used as an intermediate separator located on both upper and lower sides of a stack (electrolytic cell) in which a solid polymer film is sandwiched between a pair of an anode and a cathode power feeding body, and both upper and lower end sides are used. A multilayer stack structure characterized in that a groove is provided on the end side separator located on the side facing the electrolytic cell, and a thick plate separator through which electrolytic water can flow is used.