JP4908958B2 - Manufacturing method and apparatus for electrolyte / electrode assembly - Google Patents

Description

  The present invention relates to an electrolyte / electrode assembly manufacturing method and an apparatus therefor, in which an electrode paste is applied to an electrolyte membrane to provide an electrolyte / electrode assembly for a fuel cell.

  The unit cell constituting the fuel cell has an electrolyte / electrode assembly in which an anode electrode or a cathode electrode is formed on each end face of the electrolyte membrane. That is, a unit cell is configured by interposing this electrolyte / electrode assembly between a pair of separators.

  Examples of the electrolyte membrane include polymer films. In this case, the electrolyte / electrode assembly is manufactured as follows, for example.

  First, one end of a long polymer film wound around a supply roller is pulled out, suspended on a suction roller, and further pulled. As a result, the polymer film is sequentially fed to the suction roller and is attracted to the side peripheral wall of the suction roller by suction performed through the suction roller.

  In the polymer film, an electrode paste is applied to a portion adsorbed on the side peripheral wall of the suction roller. Here, the suction roller is generally provided with a heating means. In this case, the suction roller is preheated under the action of the heating means. Accordingly, the applied electrode paste is quickly dried to become an electrode by the heat transmitted from the suction roller.

  The part provided with the electrode is detached from the suction roller by being pulled by the pulling means. And the site | part which should be apply | coated next in a polymer film is adsorb | sucked by a suction roller.

  By repeating this operation, electrodes are intermittently formed on the polymer film. If the polymer film (electrolyte membrane) is separated between the electrodes, a plurality of electrolyte / electrode assemblies can be obtained.

  Thus, the method of apply | coating an electrode paste, adsorb | sucking an electrolyte membrane on a suction roller is disclosed by patent document 1, 2, for example.

JP 2004-351413 A JP 2001-70863 A

  By the way, when the electrolyte film is adsorbed on the suction roller and the electrode paste is applied as described above, the electrolyte film or the electrode may swell. When such a situation occurs, the current density varies depending on the electrode portion during operation of the fuel cell, which causes variations in the internal resistance of the fuel cell. In some cases, the electrode is cracked, which may cause a short circuit.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a method and an apparatus for manufacturing an electrolyte / electrode assembly that can avoid the occurrence of swelling in the electrolyte / electrode assembly. .

  When the cover is not present, a portion exposed from the electrolyte membrane appears on the side peripheral wall of the suction roller. Of course, the atmosphere is sucked infinitely at this site. That is, it is in a so-called suction leakage state.

  The present inventor has inferred that the suction force of the suction roller with respect to the electrolyte membrane is reduced as a result of such suction leakage, resulting in swelling of the electrolyte / electrode assembly. Therefore, intensive studies were conducted to avoid the occurrence of suction leakage, and the present invention was reached.

That is, the present invention is a method for producing an electrolyte / electrode assembly in which an electrode paste is applied to an electrolyte membrane to provide an electrolyte / electrode assembly for a fuel cell,
While pulling the electrolyte membrane wound around the supply roller, it is adsorbed on the side peripheral wall of the suction roller, and when applying the electrode paste to the portion adsorbed on the side peripheral wall of the electrolyte membrane, the electrolyte membrane on the side peripheral wall and The separated part is covered with a cover, and the air existing between the side peripheral wall and the cover surface of the cover is sucked through the cover with a suction force larger than the suction force through the suction roller. It is characterized by that.

  In the present invention, the side peripheral wall of the suction roller is covered with either the electrolyte membrane or the cover. The suction hole is blocked by the electrolyte membrane at the portion covered with the electrolyte membrane, while the majority of the atmosphere between the cover and the suction roller is sucked toward the cover side at the portion covered with the cover. For this reason, the suction roller does not have a portion capable of sucking air infinitely. In other words, the suction leakage does not occur. As a result, the suction force of the suction roller to the electrolyte membrane is improved.

  When the electrode paste is applied onto the electrolyte membrane in this state, an electrolyte / electrode assembly in which swelling is remarkably suppressed can be obtained.

  The electrode paste applied to the electrolyte film may be dried by heating the suction roller. In this case, it is not necessary to dry the electrode paste as a post process, so that the electrolyte / electrode assembly can be efficiently produced.

Further, the present invention is an electrolyte / electrode assembly manufacturing apparatus for applying an electrode paste to an electrolyte membrane to provide an electrolyte / electrode assembly for a fuel cell,
A supply roller around which an electrolyte membrane is wound;
Pulling means for pulling the electrolyte membrane wound around the supply roller from one end side pulled out of the electrolyte membrane;
A suction roller for adsorbing the electrolyte membrane pulled by the pulling means to a side peripheral wall;
An application means for applying an electrode paste to a portion adsorbed on the side peripheral wall of the electrolyte membrane;
A cover that covers a portion of the side peripheral wall spaced from the electrolyte membrane;
An air intake means capable of sucking the air existing between the side peripheral wall and the cover surface of the cover through the cover with a suction force larger than the suction force through the suction roller;
It is characterized by providing.

  With such a configuration, the electrode paste can be applied in a state where the electrolyte membrane is firmly adsorbed to the suction roller. Therefore, it is possible to obtain an electrolyte / electrode assembly in which swelling is remarkably suppressed.

  Further, by providing a heating means for heating the suction roller, the electrode paste applied to the electrolyte membrane can be efficiently dried to form an electrode, thereby improving the production efficiency of the electrolyte / electrode assembly.

  In the present invention, a portion of the side wall of the suction roller that is separated from the electrolyte membrane is covered with a cover, and the air between the cover and the suction roller is sucked from the cover side. The so-called suction leakage is avoided. For this reason, the electrolyte membrane is firmly adsorbed to the side peripheral wall of the suction roller. When an electrode paste is applied to the electrolyte membrane in this state, an electrolyte / electrode assembly in which swelling is remarkably suppressed is obtained.

  That is, according to the present invention, there is obtained an effect that an electrolyte / electrode assembly in which there is almost no variation in the internal resistance of the fuel cell and the concern of causing a short circuit can be eliminated.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for producing an electrolyte / electrode assembly according to the present invention will be described in detail with reference to the accompanying drawings by giving preferred embodiments in relation to an apparatus for carrying out the method.

  FIG. 1 is a perspective view schematically illustrating a main part of an electrolyte / electrode assembly manufacturing apparatus (hereinafter referred to as an MEA manufacturing apparatus) 10 according to the present embodiment. The MEA manufacturing apparatus 10 includes a supply roller 12, a suction roller 14, a paste applicator 16 attached to the suction roller 14, a cover 18 that covers a part of the suction roller 14, and a not-shown illustration. Traction means.

  A long polymer film 20 is wound around the supply roller 12. One end portion of the polymer film 20 drawn from the supply roller 12 is suspended by the suspension roller 22 and the suction roller 14 and then held by the pulling means.

  The suction roller 14 is a cylindrical body in which a hollow portion is provided inside and a number of suction holes 24 (see FIG. 1) communicating with the hollow portion are formed on the surface. In this case, the installation width of the suction hole 24, that is, the distance from the suction hole 24 located at one end to the suction hole 24 located at the other end is set slightly smaller than the width direction dimension of the polymer film 20. Yes.

  Further, a heat medium circulation passage (not shown) is provided in the vicinity of the surface of the suction roller 14, and the temperature of the suction roller 14 rises when a heat medium such as hot water flows through the heat medium circulation passage. That is, the heat medium circulation passage constitutes a heating means.

  Here, an intake pipe of a first pump (intake means) (not shown) is connected to the hollow portion of the suction roller 14. That is, the air that has entered the hollow portion from the suction hole 24 is sucked through the first pump.

  The paste applicator 16 is an application means for applying the electrode paste P to the polymer film 20 (electrolyte film), and a paste supply pipe 28 having an electromagnetic valve 26 interposed is connected to one end thereof. Yes.

  The electrode paste P in the paste supply pipe 28 is always pressed by a paste pressurizing mechanism (not shown). For this reason, when the electromagnetic valve 26 is opened, the electrode paste P in the paste supply pipe 28 pushes out the electrode paste P in the paste applicator 16, and as a result, the electrode paste P is led out toward the polymer film 20. . On the other hand, when the electromagnetic valve 26 is closed, the pressure applied by the paste pressurizing mechanism is blocked by the electromagnetic valve 26, so that the derivation of the electrode paste P is completed. In other words, application of the electrode paste P to the polymer film 20 is started or stopped as the electromagnetic valve 26 is opened and closed.

  In the paste applicator 16, the application part 29 for leading the electrode paste P is formed with an acute angle at the tip. The application part 29 having such a shape follows the closing of the electromagnetic valve 26, and the derivation of the electrode paste P is immediately terminated.

  As can be understood from FIGS. 1 and 2, the polymer film 20 is wound around the side peripheral wall of the suction roller 14 to about 3/4 of its peripheral length. That is, the side peripheral wall of the suction roller 14 has a portion where the polymer film 20 is exposed without being wound.

  The cover 18 covers the exposed portion on the side peripheral wall of the suction roller 14. That is, the cover 18 has a covering surface 30 that is curved according to the shape of the side peripheral wall of the suction roller 14, and the arc length of the covering surface 30 substantially matches the arc length of the exposed portion. Of course, the distance (height) between the bottom surfaces of the suction roller 14 and the lateral length of the cover 18 are substantially the same.

  An intake passage (not shown) is provided inside the cover 18, and the covering surface 30 is provided with a number of small holes (not shown) communicating with the intake passage. A joint hole 34 is provided on the upper end surface of the cover 18 at a position that does not interfere with the polymer film 20.

  One end of an intake tube 40 is connected to the joint hole 34 via an L-shaped joint 36 and a pipe joint 38. The other end of the intake tube 40 is connected to a second pump (intake means) (not shown). Therefore, the air present in the clearance between the covering surface 30 of the cover 18 and the side peripheral wall of the suction roller 14 is Suction is performed under the action of the second pump.

  The suction force of the second pump can be set larger than that of the first pump. In other words, when the second pump is energized at the same time as the first pump, the second pump sucks a larger amount of air than the first pump.

  The cover 18 can be provided from, for example, polytetrafluoroethylene resin.

  The main part of the MEA manufacturing apparatus 10 according to the present embodiment is basically configured as described above. Next, the function and effect will be described in relation to the method for manufacturing an electrolyte / electrode assembly.

  One end of the polymer film 20 wound around the supply roller 12 is pulled out, suspended on the suspension roller 22 and the suction roller 14, and then held by the traction means (not shown).

  The suction roller 14 is heated in advance when a heat medium such as hot water is circulated through the heat medium circulation passage, and the air present in the vicinity of the surface of the side peripheral wall is energized by the first pump. Is waiting in a state of being sucked through the suction hole 24. For this reason, the polymer film 20 is adsorbed on the side peripheral wall of the suction roller 14, and heat is transmitted from the suction roller 14 at a portion of the polymer film 20 adsorbed on the side peripheral wall of the suction roller 14.

  Further, a portion of the side peripheral wall of the suction roller 14 that is exposed without the polymer film 20 being wound is covered with the covering surface 30 of the cover 18. For this reason, the side peripheral wall of the suction roller 14 is covered with either the polymer film 20 or the cover 18, and the exposed part is not recognized.

  Here, the covering surface 30 of the cover 18 does not airtightly close the side peripheral wall of the suction roller 14, and there is a slight clearance between the covering surface 30 of the cover 18 and the side peripheral wall of the suction roller 14. . Therefore, when the second pump is energized, the atmosphere around the MEA manufacturing apparatus 10 enters between the covering surface 30 of the cover 18 and the side peripheral wall of the suction roller 14 from the clearance, and passes through the intake tube 40. And sucked by the second pump.

  In this state, the traction means starts to pull the polymer film 20. When a predetermined length of the polymer film 20 is sent out, the electromagnetic valve 26 is opened by a command from a control circuit (not shown).

  As described above, since the electrode paste P in the paste supply pipe 28 is pressurized by the paste pressurizing mechanism, the electrode paste P in the paste supply pipe 28 flows as the electromagnetic valve 26 is opened. As a result, the electrode paste P in the paste applicator 16 is pushed out and led out toward the polymer film 20 through the applicator 29. In other words, the electrode paste P is applied to the polymer film 20.

  The applied electrode paste P is extended as the polymer film 20 is delivered. Of course, a new electrode paste P is replenished in the paste applicator 16 by the flow described above.

  When a predetermined amount of electrode paste P is derived, the electromagnetic valve 26 is closed under the control action of the control circuit. Since the application part 29 in the paste applicator 16 is provided with an acute angle shape, the application of the electrode paste P to the polymer film 20 is immediately terminated. For this reason, it is avoided that the lead-out amount of the electrode paste P is gradually reduced and the coating thickness on the polymer film 20 is gradually reduced, and the electrode paste P is extended to a length of a predetermined length or more. Is avoided.

  As described above, the suction roller 14 is heated in advance. For this reason, heat is transmitted from the suction roller 14 to the electrode paste P. As a result, the solvent contained in the electrode paste P is volatilized and removed, and the electrode paste P is cured to form an electrode.

  During this time, suction of air through the cover 18 is continued. The suction force of the second pump is set to be larger than that of the first pump. For this reason, most of the atmosphere that has entered the clearance is sucked by the second pump at the portion where the cover 18 is covered. . In other words, the amount of air sucked toward the suction roller 14 is very small.

  As a result of this suction, the portion of the side peripheral wall of the suction roller 14 that is covered with the cover 18 becomes pseudo airtight. This is because, as described above, the amount of air sucked to the suction roller 14 side is extremely small.

  As described above, the polymer film 20 is adsorbed to other portions of the suction roller 14. Thus, in the site | part which the polymer film 20 adsorb | sucked, the polymer film 20 obstruct | occludes the suction hole 24, Therefore, air | atmosphere is hardly attracted | sucked to the suction roller 14 side.

  As can be understood from the above, the suction roller 14 has no portion capable of sucking the air infinitely through the suction hole 24. In other words, there is no so-called suction leakage. As a result, the suction force of the suction roller 14 to the polymer film 20 is improved.

  Eventually, the polymer film 20 is held more firmly on the suction roller 14 than when the cover 18 is not provided. When the electrode paste P is applied and dried in such a state, an electrolyte / electrode assembly with almost no swelling is obtained.

  That is, according to the present embodiment, a portion of the side peripheral wall of the suction roller 14 that is separated from the polymer film 20 is covered with the cover 18, and the space between the cover surface 30 of the cover 18 and the side peripheral wall of the suction roller 14 is covered. Since the atmosphere is sucked, it is possible to avoid suction leakage from the suction roller 14. For this reason, as a result of improving the suction force of the suction roller 14 to the polymer film 20, an electrolyte / electrode assembly in which swelling is suppressed is obtained.

  In the above-described embodiment, the temperature of the suction roller 14 is increased with a heating medium. However, a heater is embedded in the suction roller 14 and the heater is heated by energization, whereby the suction roller 14 is heated. The temperature may be raised.

  Further, instead of drying the electrode paste P by raising the temperature of the suction roller 14, hot air spraying means is disposed in the vicinity of the suction roller 14, and the electrode paste P applied to the polymer film 20 is applied by the hot air spraying means. You may make it dry.

  Further, the electrolyte membrane is not particularly limited to the polymer film 20 and may be any material as long as it is flexible and can be adsorbed to the suction roller 14. .

It is a principal part schematic structure perspective explanatory drawing of the electrolyte electrode assembly manufacturing apparatus which concerns on this Embodiment. FIG. 2 is a side view of the electrolyte / electrode assembly manufacturing apparatus of FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Electrolyte electrode assembly (MEA) manufacturing apparatus 12 ... Supply roller 14 ... Suction roller 16 ... Paste applicator 18 ... Cover 20 ... Polymer film 22 ... Suspension roller 24 ... Suction hole 26 ... Solenoid valve 30 ... Covering surface 40 … Intake tube P… Electrode paste

Claims (4)

A method for producing an electrolyte / electrode assembly, in which an electrode paste is applied to an electrolyte membrane to provide an electrolyte / electrode assembly for a fuel cell,
While pulling the electrolyte membrane wound around the supply roller, it is adsorbed on the side peripheral wall of the suction roller, and when applying the electrode paste to the portion adsorbed on the side peripheral wall of the electrolyte membrane, the electrolyte membrane on the side peripheral wall and The separated part is covered with a cover, and the air existing between the side peripheral wall and the cover surface of the cover is sucked through the cover with a suction force larger than the suction force through the suction roller. A method for producing an electrolyte / electrode assembly.   2. The method of manufacturing an electrolyte / electrode assembly according to claim 1, wherein the electrode paste applied to the electrolyte membrane is dried by heating the suction roller. An electrolyte / electrode assembly manufacturing apparatus for applying an electrode paste to an electrolyte membrane to provide an electrolyte / electrode assembly for a fuel cell,
A supply roller around which an electrolyte membrane is wound;
Pulling means for pulling the electrolyte membrane wound around the supply roller from one end side pulled out of the electrolyte membrane;
A suction roller for adsorbing the electrolyte membrane pulled by the pulling means to a side peripheral wall;
An application means for applying an electrode paste to a portion adsorbed on the side peripheral wall of the electrolyte membrane;
A cover that covers a portion of the side peripheral wall spaced from the electrolyte membrane;
An air intake means capable of sucking the air existing between the side peripheral wall and the cover surface of the cover through the cover with a suction force larger than the suction force through the suction roller;
An apparatus for producing an electrolyte / electrode assembly, comprising:   4. The manufacturing apparatus according to claim 3, further comprising heating means for heating the suction roller.

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