JP2014067650A - Dye-sensitized solar cell manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost dye-sensitized solar cell manufacturing method which achieves excellent productivity without complication of a process and which can easily increase an effective power generation area.SOLUTION: A dye-sensitized solar cell manufacturing method comprises: (1) arranging a closed-frame-like seal member on one surface of a conductive substrate; (2) filling a metal oxide-containing paste in the frame of the seal member arranged on the one surface of the conductive substrate; (3) heating the metal oxide-containing paste filled in the frame of the seal member to form a metal oxide film in the frame of the seal member on the surface of the conductive substrate; and (4) obtaining a combined object of an anode, a cathode, the seal member of an anode composite arranged between the anode and the cathode and a dye-containing electrolyte. In the process (4), the electrolyte and a dye solution are individually thrown on the metal oxide film in the frame of the seal member of the anode composite.

Description

  The present invention relates to a method for producing a dye-sensitized solar cell.

  Conventionally, as a photoelectric conversion element, a negative electrode having a conductive substrate and a metal oxide film formed on the surface thereof; a positive electrode; an electrolyte disposed between the negative electrode and the positive electrode; and disposed between the negative electrode and the positive electrode In addition, a dye-sensitized solar cell including a closed frame-shaped sealing member surrounding the metal oxide film and the electrolyte is known (for example, Patent Document 1).

  Specifically, a conventional method for producing a dye-sensitized solar cell includes a step of pasting a mask film on a surface of a conductive substrate, and a paste containing a metal oxide in a predetermined region of the conductive substrate by a squeegee method using the mask film. And a step of heating to obtain a metal oxide film. Further, the method includes forming a metal oxide film over the entire surface of the conductive substrate without using a mask film, and then removing the metal oxide film formed in a region other than the predetermined region.

JP 2005-228594 A

  However, in the above manufacturing method, it is necessary to separately provide a step of attaching or removing the mask film, or a step of removing the metal oxide film formed in a region other than the predetermined region. Productivity decreases. Since it is necessary to prepare a mask film separately or to remove an unnecessary metal oxide film, it is disadvantageous in terms of cost.

  Further, when the manufacturing method includes a step of arranging a closed frame-shaped seal member around the metal oxide film, in consideration of alignment accuracy, mechanical accuracy, yield, and the like for the arrangement of the seal member, It was necessary to provide a certain gap between the seal member and the metal oxide film. That is, it is necessary to make the area of the surface facing the positive electrode in the metal oxide film slightly smaller than the area of the surface facing the positive electrode in the region surrounded by the seal member. Therefore, it has been difficult to increase the size of the surface of the metal oxide film facing the positive electrode to a region surrounded by the seal member without impairing productivity.

  Further, in the case where the above manufacturing method includes a step in which a dye previously dissolved in an electrolyte is added onto the metal oxide film in the frame of the seal member of the negative electrode composite, a plurality of different types of dyes are added. When used in combination, it is necessary to prepare electrolytes as many as the required number of dyes and dissolve the dyes in the electrolyte for each dye. Therefore, there is a problem that the more the number of dyes used, the more complicated the process, the lower the productivity, and the higher the cost.

  Accordingly, an object of the present invention is to provide a method for producing a low-cost dye-sensitized solar cell that is excellent in productivity and can easily increase the effective power generation area without complicating the process. To do.

The first method for producing a dye-sensitized solar cell of the present invention is as follows.
(1) a step of disposing a closed frame-shaped sealing member on one surface of the conductive substrate;
(2) filling a paste containing a metal oxide into a frame of a sealing member disposed on one surface of the conductive substrate;
(3) The paste containing the metal oxide filled in the frame of the seal member is heated to form a metal oxide film in the frame of the seal member on the surface of the conductive substrate, and the conductive substrate as the negative electrode and Obtaining a negative electrode composite having a metal oxide film and a sealing member;
(4) a step of obtaining an integrated product of the negative electrode, the positive electrode, and the electrolyte containing the seal member and the pigment of the negative electrode composite disposed between the negative electrode and the positive electrode;
Including
In the step (4), an electrolyte and a dye solution are individually charged on the metal oxide film in the frame of the seal member of the negative electrode composite.

Moreover, the second method for producing a dye-sensitized solar cell of the present invention is as follows.
(I) a step of disposing a closed frame-shaped sealing member made of a resin curable by heat on one surface of the conductive substrate;
(II) A negative electrode having a conductive substrate and paste as a negative electrode precursor, and a sealing member filled with a paste containing a metal oxide in a frame of a sealing member disposed on one surface of the conductive substrate Obtaining a composite precursor;
(III) After superposing the negative electrode composite precursor and the positive electrode having holes for individually injecting the liquid electrolyte and the dye solution so that the seal member is disposed between the negative electrode precursor and the positive electrode The metal oxide-containing paste and the sealing member are simultaneously heated to form a metal oxide film to obtain a negative electrode composed of a conductive substrate and a metal oxide film, and the sealing member is cured to obtain a negative electrode and a positive electrode. A step of integrating the sealing member;
(IV) a step of closing the hole after individually injecting the liquid electrolyte and the dye solution on the metal oxide film in the frame of the seal member from the hole;
It is characterized by including.

  An object of the present invention is to provide a method for producing a low-cost dye-sensitized solar cell that is excellent in productivity and can easily increase the effective power generation area without complicating the process. To do.

It is the schematic which shows the filling process (2) of the paste containing the metal oxide in the manufacturing method of the dye-sensitized solar cell of this invention. It is principal part sectional drawing which shows the state immediately after implementation of the process (4a) in the manufacturing method of the dye-sensitized solar cell of this invention. It is principal part sectional drawing which shows an example of the dye-sensitized solar cell module obtained by the manufacturing method of this invention. It is principal part sectional drawing which shows an example of the dye-sensitized solar cell module obtained by the conventional manufacturing method. It is the schematic which shows the process in which the photosensitizing dye in electrolyte is adsorb | sucked with respect to a metal oxide film in the manufacturing method of this invention.

  The present invention relates to a conductive substrate and a negative electrode having a dye-adsorbed metal oxide film formed on one surface of the conductive substrate; a positive electrode; an electrolyte disposed between the negative electrode and the positive electrode; And a closed frame-shaped sealing member that is disposed between the electrode and the positive electrode and surrounds the metal oxide film and the electrolyte.

The present invention uses a frame-shaped sealing member, which is a constituent member of a battery, as a filling frame of a metal oxide paste, and a solution of an electrolyte and a photosensitizing dye on a metal oxide film in the frame of the sealing member. Are separately added, and the dye is included in the electrolyte in the battery.
More specifically, the first method for producing a dye-sensitized solar cell of the present invention includes the following steps (1) to (4).
Step (1): A closed frame-shaped sealing member is disposed on one surface of the conductive substrate.
Step (2): The paste containing the metal oxide is filled in the frame of the sealing member disposed on one surface of the conductive substrate.
Step (3): The paste containing the metal oxide filled in the frame of the seal member is heated to form a metal oxide film in the frame of the seal member on the surface of the conductive substrate, and the conductivity as the negative electrode A negative electrode composite having a substrate, a metal oxide film, and a seal member is obtained.
Step (4): An integrated product of the negative electrode, the positive electrode, the negative electrode composite seal member disposed between the negative electrode and the positive electrode, and an electrolyte containing a pigment is obtained.
Then, in the process of obtaining the integrated product in the step (4), the electrolyte and the dye solution are individually put on the metal oxide film in the frame of the seal member of the negative electrode composite.

  The sealing member is used for the purpose of preventing the electrolyte from leaking out of the battery by integrating the positive electrode and the negative electrode apart from each other. Moreover, when a dye-sensitized solar cell is comprised with a some single cell, it is used also for the purpose of partitioning between the mutually adjacent single cells. In the present invention, this seal member is used not only for the above-mentioned purpose but also as a frame material for forming a metal oxide film on a predetermined region (for example, the surface of a conductive film described later) on the conductive substrate. Is. That is, the sealing member of the present invention is used as one of the constituent members of the battery after being used as a frame material for forming the metal oxide film in a predetermined region.

Therefore, in the manufacturing method of the present invention, unlike the conventional manufacturing method, there is no need to separately provide a step of attaching or removing the mask film and a step of removing the metal oxide film formed in a region other than the predetermined region. . As a result, in the present invention, the metal oxide film can be reliably and easily formed in a predetermined region without complicating the process, and excellent productivity can be obtained. The present invention is a manufacturing method suitable for a roll-to-roll system.
Further, since it is not necessary to prepare a mask film separately or to remove an unnecessary metal oxide film, the present invention is advantageous in terms of cost.

In the conventional manufacturing method in which a closed frame-shaped seal member is arranged around the metal oxide film after forming the metal oxide film, the alignment accuracy, mechanical accuracy, and yield with respect to the arrangement of the seal member are taken into consideration. It is necessary to provide a certain gap between the seal member and the metal oxide film. That is, it is necessary to make the area of the metal oxide film (the size of the surface facing the positive electrode) slightly smaller than the area of the region surrounded by the seal member.
On the other hand, in the manufacturing method of the present invention including the step (2), the seal member is disposed before the metal oxide film is formed in the step (1). For this reason, it is not necessary to consider alignment accuracy as described above, and the metal oxide film can be formed without providing a gap between the seal member and the metal oxide film. As a result, the size of the surface of the metal oxide film facing the positive electrode can be increased over the entire region surrounded by the seal member. That is, the effective power generation area of the battery can be increased.

Here, FIG. 1 is a schematic view schematically showing an example of the step (2).
As shown in FIG. 1, the conductive substrate 1 has a transparent substrate and a plurality of conductive films (not shown) formed on the one surface of the transparent substrate at a constant interval. Such a conductive film is formed, for example, by patterning with a laser or the like. More specifically, in FIG. 1, 12 conductive films are arranged in 6 × 2 rows so that two cell groups in which six single cells are connected in series can be connected in parallel. Yes. The closed frame-shaped seal member 2 is disposed so as to surround the peripheral end portion of the conductive film. The frame 3 of the sealing member 2 disposed on the surface of the conductive substrate 1 is filled with a paste 3 containing a metal oxide using a nozzle 4. Most of the conductive film is covered with a paste 3 containing a metal oxide.
In this way, the paste 3 containing the metal oxide is applied to a predetermined region (region where the conductive film is formed) by using the sealing member 2 used for the purpose of sealing the battery or partitioning between adjacent single cells. ) Easily and reliably.

As the conductive substrate on the negative electrode side used in the step (1), for example, a transparent substrate having a conductive film formed on one surface or a substrate made of a conductive material such as metal is used.
Examples of the transparent substrate include a synthetic resin plate and a glass plate. From the viewpoint of lightness and safety (hardness to break), the synthetic resin plate is preferably a thermoplastic resin film. Examples of the thermoplastic resin include polyester resin, polycarbonate resin, and polyolefin resin. Examples of the polyester resin include polyethylene naphthalate (PEN) and polyethylene terephthalate (PET).
Examples of the conductive film include metal oxides such as tin-added indium oxide (ITO), fluorine-added tin oxide (FTO), tin oxide (SnO ₂ ), indium zinc oxide (IZO), and zinc oxide (ZnO). The thin film containing is mentioned. From the viewpoint of conductivity, the conductive film is preferably an ITO film. A conventionally known method may be appropriately used as a method for forming the conductive film.

For the paste containing the metal oxide used in the step (2), for example, a liquid in which fine metal oxide is dispersed is used. For example, water or an organic dispersion medium is used as the dispersion medium. For example, alcohol, acetone, or hexane is used as the organic dispersion medium.
Examples of the metal oxide include titanium oxide (TiO ₂ ), tin oxide (SnO ₂ ), tungsten oxide (WO ₃ ), zinc oxide (ZnO), and niobium oxide (Nb ₂ O ₅ ).
The particle size of the fine metal oxide is, for example, 5 to 100 nm.

  The step (3) of heating the paste containing the metal oxide is a step of removing the dispersion medium in the paste and firing the metal oxide. By firing the metal oxide, a metal oxide film is formed in a region within the frame of the seal member on the surface of the conductive substrate.

What is necessary is just to determine the heating temperature of a process (3) suitably according to the material etc. of an electroconductive board | substrate and a sealing member.
When a thermoplastic resin film is used for the transparent substrate, the heating temperature in the step (3) is preferably a relatively low temperature region of 120 to 150 ° C. When the heating temperature in step (3) is 120 ° C. or higher, a metal oxide film can be formed. If the thermoplastic resin film and the conductive film are not damaged by heat, the heating temperature in the step (3) can be increased to about 150 ° C.
The heating time may be appropriately determined according to the thickness of the metal oxide film. When heating in the relatively low temperature region, the heating time is preferably 5 to 30 minutes. When the heating time is 5 minutes or longer, a metal oxide film can be formed. When the heating time is 30 minutes or less, productivity is not impaired.

When using the material excellent in heat resistance like a glass plate for a transparent substrate, it is preferable that the heating temperature of a process (3) is a relatively high temperature area | region of 450-600 degreeC. When a plurality of metal oxides containing a polymer compound are applied and then heated at 450 ° C. or higher, the polymer compound contained in the metal oxide is removed, so that a porous metal oxide film can be formed. . If the conductive film formed on the glass plate is not damaged by heat, the heating temperature is more preferably 550 ° C. or higher.
When heating in the above relatively high temperature region, the heating time is preferably 30 to 150 minutes. When the heating time is 30 minutes or more, a porous metal oxide film can be formed by removing the polymer compound contained in the metal oxide. When the heating time is 150 minutes or less, productivity is not impaired.
When heating in the above relatively high temperature region, it is preferable to use an FTO film as the conductive film from the viewpoint of heat resistance.

When the heating temperature in the step (3) is set to the above-described relatively low temperature or relatively high temperature region, the seal member does not decompose (deteriorate) and harden in the above relatively low temperature or relatively high temperature region, for example. A thermosetting resin or an ultraviolet curable resin is used. In addition to the curable resin, a resin material or a rubber material having excellent adhesion, sealing properties, and heat resistance may be used.
Among these, in the step (4), the sealing member is cured by irradiation with ultraviolet rays, and the negative electrode, the positive electrode, and the sealing member can be easily and surely integrated. It is preferable to use a functional resin.

  In the method for producing a dye-sensitized solar cell of the present invention, in step (4), the electrolyte and the dye solution are separately added. Thereby, the pigment | dye in electrolyte can be easily adsorb | sucked to a metal oxide film in the below-mentioned process (5). By adding the electrolyte and the dye solution separately, it is not necessary to prepare as many electrolytes as the required number of dyes, even when using a combination of different types of dyes, and the dyes are dissolved in the electrolyte for each dye. There is no need. When the number of dyes used is large, the process can be simplified, and a low-cost method for producing a dye-sensitized solar cell excellent in productivity can be provided. As a result, a battery rich in design can be easily manufactured by a simple process.

Specifically, a plurality of dye solutions and one type of electrolyte may be prepared. When a liquid electrolyte is used, it is not necessary to replace the syringe for injecting the liquid electrolyte in the step of injecting the liquid electrolyte.
The electrolyte usually needs to be prepared by blending many chemicals, and it is necessary to prevent moisture from entering. On the other hand, the dye solution can be prepared simply by dissolving the dye in a solvent such as about 1 to 3 kinds of alcohol.
Although the process of adding the dye solution increases, the workload can be greatly reduced and the production time can be greatly reduced as compared with the case of producing a plurality of electrolytes.
It is sufficient that the electrolyte is sufficiently mixed with the dye solution at the time of carrying out the step (5) described later, and it is not necessary to completely dissolve the dye in the solvent at the stage of preparing the dye solution. It does not take time.

  In order to adsorb the dye to the metal oxide film in the step (5) described later, in the electrolyte containing the dye obtained in the step (4), the dye needs to be dissolved in a solvent such as acetonitrile or ethanol. is there. This solvent may be a solvent derived from an electrolyte or a solvent derived from a dye solution.

  The dye solution is preferably adjusted to a predetermined color by mixing a plurality of different kinds of dyes. When preparing a plurality of colors, a new color can be produced by mixing a plurality of pigments. Therefore, the number of dye solutions to be prepared can be reduced as compared with the conventional case of preparing a plurality of electrolytes containing dyes in advance.

As the electrolyte, for example, a liquid electrolyte, a solid electrolyte, or a gel electrolyte is used.
Examples of the liquid electrolyte include iodine-based liquid electrolytes. The iodine-based liquid electrolyte includes, for example, an organic solvent and an iodine-based electrolyte component that dissolves in the organic solvent. Examples of the iodine-based electrolyte component include a combination of iodine, iodide, and tertiary butyl pyridine. Examples of the organic solvent include acetonitrile, ethanol, propanol, t-butanol, ethylene carbonate, and methoxyacetonitrile. Examples of the electrolyte include a liquid electrolyte using a cobalt complex in addition to the iodine-based liquid electrolyte.

Examples of the gel electrolyte and the solid electrolyte include a combination of iodine and iodide and a combination of bromine and bromide.
Examples of the iodide include dimethylpropylimidazolium iodide (DMPImI), metal iodide, and iodine salt of a quaternary ammonium compound. Examples of the metal iodide include lithium iodide, sodium iodide, potassium iodide, cesium iodide, and calcium iodide. Examples of iodine salts of quaternary ammonium compounds include tetraalkylammonium iodide.
Examples of bromides include metal bromides and bromine salts of quaternary ammonium compounds. Examples of bromine salts of quaternary ammonium compounds include tetraalkylammonium bromide.

The order in which the electrolyte and the dye solution are charged is not particularly limited, but it is preferable that the electrolyte is charged after the dye solution is charged. Since it is colored depending on the type of the electrolyte, it is easier to confirm that a predetermined color is arranged in a predetermined region when the dye solution is added before the electrolyte.
Since the liquid electrolyte has a certain degree of viscosity, it is easier for the dye solution to enter the metal oxide film when the dye solution is added before the electrolyte.

When the liquid electrolyte is likely to be mixed with the dye solution, the liquid electrolyte and the dye solution can be mixed by, for example, standing for about several minutes to several hours. When the liquid electrolyte is difficult to mix with the dye solution, the liquid electrolyte and the dye solution may be stirred using a method such as applying vibration to the liquid electrolyte and the dye solution.
The mixing of the solid electrolyte or gel electrolyte and the dye can be performed, for example, by impregnating the dye solution into the solid electrolyte or the gel electrolyte.

Examples of the dye include a ruthenium complex having a ligand including a pyridine structure or a terpyridine structure; an iron complex having a ligand including a pyridine structure or a terpyridine structure; a porphyrin-based or phthalocyanine-based metal complex; eosin, rhodamine , Organic pigments such as coumarin, merocyanine and indoline.
From the viewpoint of the solubility of the dye in the electrolyte, the dye is preferably a ruthenium complex or an organic dye, and among the organic dyes, coumarin, merocyanine, and indoline are more preferable.

The solvent in which the dye in the dye solution dissolves is preferably one that can be used as an electrolyte solvent. After the electrolyte and the dye solution are separately added, the solvent in which the dye in the dye solution dissolves is used as it is as the solvent for the electrolyte.
In the case of using a liquid electrolyte, the solvent of the dye solution is preferably the same type as the solvent of the liquid electrolyte from the viewpoint of easy work and easy mixing of the dye solution and the liquid electrolyte.

  The concentration of the dye in the electrolyte is preferably 0.1 to 1 mM, more preferably 0.2 to 0.6 mM. When the concentration of the dye in the electrolyte is 0.1 mM or more, a sufficient amount of the dye can be adsorbed to the metal oxide. When the concentration of the dye in the electrolyte is 1.0 mM or less, all of the dye is dissolved in the electrolyte and uniformly dispersed, so that adsorption unevenness does not occur. Further, the excessive presence of the dye does not cause a problem that the flow of electrons from the dye to the metal oxide is inhibited.

The positive electrode used in the step (4) has, for example, a conductive substrate and a catalyst layer formed in a predetermined region (a region facing the metal oxide film of the negative electrode) on one surface of the conductive substrate. For example, a platinum layer is used as the catalyst layer.
When such a positive electrode is used, the negative electrode composite and the positive electrode are overlapped so that the catalyst layer of the positive electrode and the metal oxide film of the negative electrode face each other.

As the conductive substrate on the positive electrode side, for example, a transparent substrate having a conductive film formed on one surface or a substrate made of a conductive material such as a metal such as aluminum, copper, or tin is used.
When forming a conductive film on one surface of the transparent substrate, the catalyst layer is formed on the surface of the conductive film.

  In addition to the above, a positive electrode may be used in which a solid electrolyte is held on a mesh electrode made of metal such as aluminum, copper, or tin, or carbon. The positive electrode is obtained by forming a conductive adhesive layer on one surface of a transparent substrate and then transferring brush-like carbon nanotubes separately formed on the surface of the conductive adhesive layer to the transparent substrate. Alternatively, an electrode may be used.

  On one surface of the transparent substrate, for example, a plurality of conductive films corresponding to a plurality of single cells are arranged at regular intervals. Such a plurality of conductive films can be obtained, for example, by patterning an ITO film using a laser or the like. Further, a silver paste may be applied to one surface of the substrate using a screen printer or the like to form a current collecting layer having a thickness of about several μm.

Preferable specific embodiments of the step (4) include the following steps (4a) and (4b).
Step (4a): An electrolyte and a dye solution are individually charged onto the metal oxide film in the frame of the seal member.
Step (4b): The negative electrode composite and the positive electrode are overlapped so that the seal member, the electrolyte, and the dye solution are disposed between the negative electrode and the positive electrode, and the negative electrode, the positive electrode, and the seal member are integrated.

Here, FIG. 2 shows a cross-sectional view of relevant parts showing an example of a state immediately after the execution of the step (4a). FIG. 2 shows a state immediately after injecting the liquid electrolyte 15a after injecting the dye solution 15b onto the metal oxide film 19 ′ in the frame of the seal member 13 in the negative electrode composite obtained in the step (3). Indicates. The negative electrode composite includes a negative electrode having a conductive substrate having a conductive film 18 formed on one surface of a transparent substrate 17 and a metal oxide film 19 ′ formed on the surface of the conductive film 18, and a conductive substrate. A closed frame-like seal member 13 disposed on one surface and surrounding the metal oxide film 19 ′.
As shown in FIG. 2, by injecting the dye solution 15b before the liquid electrolyte 15a, the dye can be easily adsorbed to the metal oxide film 19 ′ in the step (5). When the liquid electrolyte 15a has a certain degree of viscosity, after the dye solution 15b is injected, the liquid electrolyte 15a is separated into two phases of the liquid electrolyte 15a and the dye solution 15b for a while immediately after the liquid electrolyte 15a is injected, as shown in FIG. It will be in the state. When both are easy to mix to some extent, mixing of the liquid electrolyte 15a and the dye solution 15b can be performed only by leaving still for several hours to several days. When it is difficult to mix the two, a uniform phase may be obtained by stirring using a predetermined apparatus. As a stirring method, for example, rotating for 10 minutes at 10 to 200 rpm using a shaker can be mentioned.

Further, as another specific aspect of the step (4), holes for individually injecting the liquid electrolyte and the dye solution are provided in the positive electrode, and the following steps (4a ′) and (4b ′) are performed. Also good.
Step (4a ′): The negative electrode composite and the positive electrode having holes for individually injecting the liquid electrolyte and the dye solution are overlapped so that the seal member is disposed between the negative electrode and the positive electrode, The positive electrode and the seal member are integrated.
Step (4b ′): After the liquid electrolyte and the dye solution are individually injected from the positive electrode hole in the integrated structure of the positive electrode, the negative electrode, and the seal member, the hole is closed.
As the positive electrode having holes for individually injecting the liquid electrolyte and the dye solution, the positive electrode used in the second production method described later may be used. As a method for closing the hole, a method used in a second manufacturing method described later may be used.

  Specific methods for integrating the positive electrode, the negative electrode, and the seal member include a method of curing a resin, a laser welding method when the transparent substrate for positive and negative electrodes is a thermoplastic resin film, and a transparent substrate for positive and negative electrodes When is a glass substrate, a method using a glass frit or the like is used.

The 2nd manufacturing method of this invention is a manufacturing method using resin hardened | cured by the heat applied in order to form a metal oxide film for a sealing member. Specifically, the following (I) to (IV) are included.
(I) A closed frame-shaped sealing member made of a thermosetting resin is disposed on the surface of the conductive substrate.
(II) A negative electrode composite precursor in which a paste containing a metal oxide is filled in a frame of a seal member arranged on the surface of a conductive substrate, and the conductive substrate and paste as a negative electrode precursor and a seal member are included. Get.
(III) After superposing the negative electrode composite precursor and the positive electrode having holes for individually injecting the liquid electrolyte and the dye solution so that the seal member is disposed between the negative electrode precursor and the positive electrode The metal oxide-containing paste and the sealing member are simultaneously heated to form a metal oxide film to obtain a negative electrode composed of a conductive substrate and a metal oxide film, and the sealing member is cured to obtain a negative electrode and a positive electrode. The seal member is integrated.
(IV) After individually injecting the liquid electrolyte and the dye solution onto the metal oxide film in the frame of the seal member from the hole, the hole is closed.

In the second manufacturing method, in the step (II), as in the first manufacturing method, the paste containing the metal oxide is filled in the frame of the sealing member disposed on the surface of the conductive substrate. Therefore, in the second manufacturing method, the same effect as in the first manufacturing method can be obtained in that the paste containing the metal oxide is filled in the frame of the sealing member disposed on the surface of the conductive substrate.
In the second production method, in step (IV), the liquid electrolyte and the dye solution are individually injected in the same manner as in the first production method. Therefore, in the second manufacturing method, the same effect as in the first manufacturing method can be obtained in that the electrolyte and the dye solution are individually injected.
Furthermore, in the second manufacturing method, in the step (III), the heating for forming the metal oxide film and the heating for curing the thermosetting resin used for the sealing member are simultaneously performed. The cost required for heating can be reduced.

As the positive electrode in the step (III), a positive electrode provided with holes for individually injecting the liquid electrolyte and the dye solution at a predetermined position of the positive electrode is used.
What is necessary is just to determine the heating temperature of process (III) suitably according to the material etc. of an electroconductive board | substrate and a sealing member. When using a thermoplastic resin film for the transparent substrate, the heating temperature in the step (III) is preferably in a relatively low temperature region of 120 to 150 ° C. When the heating temperature is 120 ° C. or higher, a metal oxide film can be formed. If the thermoplastic film and the conductive film are not damaged by heat, the heating temperature in step (3) can be increased to about 150 ° C.

  The heating time may be appropriately determined according to the thickness of the metal oxide film. When heating in the relatively low temperature region, the heating time is preferably 5 to 30 minutes. When the heating time is 5 minutes or longer, a metal oxide film can be formed. When the heating time is 30 minutes or less, productivity is not impaired.

  When the heating temperature in the step (III) is set to the above relatively low temperature region, for example, a resin that cures without being decomposed (deteriorated) in the above relatively low temperature region is used for the seal member.

When a material having excellent heat resistance such as a glass plate is used for the transparent substrate, the heating temperature in the step (III) is preferably a relatively high temperature region of 450 to 600 ° C. When a plurality of metal oxides containing a polymer compound are applied and then heated at 450 ° C. or higher, the polymer compound contained in the metal oxide is removed, so that a porous metal oxide film can be formed. . If the conductive film formed on the glass plate is not damaged by heat, the heating temperature is more preferably 550 ° C. or higher.
When heating in the above relatively high temperature region, the heating time is preferably 30 to 150 minutes. When the heating time is 30 minutes or more, a porous metal oxide film can be formed by removing the polymer compound contained in the metal oxide. When the heating time is 150 minutes or less, productivity is not impaired.
When heating in the above relatively high temperature region, it is preferable to use an FTO film as the conductive film from the viewpoint of heat resistance.

  When the heating temperature in step (III) is set to the above-described relatively high temperature region, for example, a resin that cures without being decomposed (deteriorated) in the above-described relatively high temperature region is used for the seal member. Examples of such a resin include thermosetting polyimide.

The liquid electrolyte used in the first manufacturing method may be used as the liquid electrolyte injected in step (IV).
The holes for injecting the liquid electrolyte and the dye solution preferably have a diameter of 0.3 to 2.0 mm. When the hole diameter is 0.3 mm or more, the electrolyte and the dye solution can be reliably and promptly injected without impairing the productivity. When the hole diameter is 2.0 mm or less, there is no influence on battery characteristics such as the amount of power generated by providing the hole in the positive electrode.

  In order to quickly and reliably inject the liquid electrolyte and the dye solution into the single cell, apart from the holes for injecting the liquid electrolyte and the dye solution, air corresponding to the amount of the liquid electrolyte and the dye solution injected is supplied to the single cell. It is preferable that a second hole for discharging from the inside to the outside is further provided in the positive electrode. The second hole for exhaust may have the same size and shape as the hole for injecting the electrolyte and the dye solution.

  Examples of the method of closing the hole in the step (IV) include a method of closing the hole with a seal member. For the sealing member, for example, a thermosetting resin or an ultraviolet curable resin excellent in electrolyte resistance and sealing performance is used.

For example, a dye-sensitized solar cell includes a negative electrode conductive film, a metal oxide film, an electrolyte, a catalyst layer, and a positive electrode conductive film between a rectangular negative electrode transparent substrate and a rectangular positive electrode transparent substrate. And a seal member that surrounds the power generation unit.
The dye-sensitized solar cell is configured, for example, by electrically connecting a plurality of single cells including the power generation unit described above in series or in parallel. The power generation units of the single cells adjacent to each other are partitioned by a seal member. In the case where a plurality of single cells are electrically connected in series, a connecting portion that connects the positive electrode of one single cell and the negative electrode of the other single cell in adjacent single cells is disposed. The connecting portion is disposed in a space formed between a seal member constituting one unit cell and the seal member constituting the other unit cell in the unit cells adjacent to each other. When a plurality of single cells are electrically connected in parallel, the adjacent single cells may be partitioned by a seal member without providing a space for arranging the connecting portion.

Here, FIG. 3 is a cross-sectional view of an essential part showing an example of the dye-sensitized solar cell module obtained by the production method of the present invention. FIG. 3 shows a dye-sensitized solar cell module in which the step (4) or the step (IV) is performed and the electrolyte and the dye solution are mixed and the dye is included in the electrolyte.
The dye-sensitized solar cell in FIG. 3 is composed of a plurality of single cells. The single cell includes a conductive substrate having a conductive film 12 formed on one surface of a transparent substrate 14 and a positive electrode having a catalyst layer 11 formed on the surface of the conductive film 12; A negative electrode having a conductive substrate on which the conductive film 18 is formed and a metal oxide film 19 ′ formed on the surface of the conductive film 18; an electrolyte 15 disposed between the positive electrode and the negative electrode and containing a dye; A closed frame-shaped sealing member 13 is provided between the negative electrode and surrounding the electrolyte 15 and the metal oxide film 19 ′. The positive electrode and the negative electrode are arranged so that the catalyst layer 11 and the metal oxide film 19 ′ face each other. The electrolyte 15 is disposed in a space surrounded by the positive electrode, the negative electrode, and the seal member 13. Between adjacent single cells, a gap is provided between the seal member 13 of one single cell and the seal member 13 of the other single cell, and a positive electrode of one single cell and a negative electrode of the other single cell are formed in the gap. The connection part 16 which electrically connects is provided. Thereby, the several single cell is connected in series.

  Conventionally, after forming a metal oxide film, a closed frame-shaped sealing member is arranged around the metal oxide film. For this reason, as shown in FIG. 4, from the viewpoint of productivity, in consideration of alignment accuracy with respect to the arrangement of the seal member, mechanical accuracy, yield, and the like, a certain amount is provided between the seal member 13 and the metal oxide film 19. It was necessary to provide the gap 10. That is, it is necessary to make the area of the surface facing the positive electrode in the metal oxide film 19 slightly smaller than the area of the surface facing the positive electrode in the region surrounded by the seal member 13.

On the other hand, in this invention, after arrange | positioning the sealing member 13, after filling the paste of a metal oxide in the frame of the sealing member 13, it heats and metal oxide film 19 'is formed.
Further, in the present invention, since the seal member 13 is arranged before the metal oxide film 19 ′ is formed, the alignment accuracy is considered with respect to the arrangement of the seal member 13 as in the prior art, as shown in FIG. As shown, there is no need to provide a gap 10 between the seal member 13 and the metal oxide film 19.
Therefore, the metal oxide film 19 ′ is formed so that the entire surface facing the seal member is in contact with the seal member 13, and the entire region within the frame of the seal member 13 has a surface facing the positive electrode (catalyst layer 11). obtain. In this way, the size of the surface of the metal oxide film 19 ′ facing the positive electrode can be increased to the entire region within the frame of the seal member 13. As a result, the metal oxide film 19 ′ of the dye-sensitized solar cell shown in FIG. 3 of the present invention has a large effective power generation area (as compared with the metal oxide film 19 of the dye-sensitized solar cell shown in FIG. 4). The size of the surface facing the positive electrode) is obtained.

  The production method of the present invention further includes connecting a resistor between the positive electrode and the negative electrode while irradiating light to the dye-sensitized solar cell module obtained in the step (4) or the step (IV), or light. It is preferable to include a step (5) or a step (V) in which a voltage is applied between the positive electrode and the negative electrode while irradiating and adsorbing the dye in the electrolyte to the metal oxide film.

Conventionally, the dye is adsorbed on the metal oxide by immersing the metal oxide film in the dye solution for several tens of minutes to several tens of hours. In particular, when the conductive film is an ITO film, it is necessary to cover the periphery of the metal oxide film with a mask film in order to prevent dye adsorption to the conductive film.
Further, even when a mask film is attached to the conductive substrate, the dye may enter from the end of the mask film, and the dye may adhere to the conductive substrate. For this reason, after removing the mask film, it is necessary to separately provide a cleaning process for removing the dye attached to the conductive substrate.
On the other hand, in the present invention, a dye is included in the electrolyte injected into the dye-sensitized solar cell, and a mask film or a colored paper solution is separately used or cleaned by performing the step (5) or the step (V). Without providing a separate process, the dye can be easily adsorbed to the metal oxide film in a short time in a state where the battery module is assembled. Therefore, the manufacturing process can be greatly simplified, and the productivity can be greatly increased. The process of adsorbing the conventional dye can be omitted, and it can be produced by a roll-to-roll method.
In the present invention, the manufacturing process can be greatly simplified through the steps (1) to (5) or the steps (I) to (V), and the roll-to-roll method can be used. Can be greatly increased.

Here, FIG. 5 is a schematic view showing a process in which the photosensitizing dye in the electrolyte is adsorbed to the metal oxide film in the production method of the present invention.
As shown in FIG. 5, the photosensitizing dye 25 in the electrolyte 21 emits electrons 24 and has a positive charge. Light emitted from sunlight or an artificial light source is irradiated between the positive electrode 29 having the conductive substrate 22 and the catalyst layer 23 containing platinum and the negative electrode 20 having the conductive substrate 27 and the metal oxide film 26. By connecting a resistance between the positive electrode 29 and the negative electrode 20 or applying a voltage between the positive electrode 29 and the negative electrode 20 while irradiating light, positive charges are applied to the metal oxide film. The sensitized dye 25 is adsorbed. Thereby, in the state which assembled the obtained dye-sensitized solar cell module, a pigment | dye can be easily adsorbed to a metal oxide film in a short time.

  For example, when a xenon lamp or a metal halide lamp is used as the light source, light of 10,000 to 100,000 lux may be irradiated. For example, a known resistor such as a light bulb or a light emitting diode may be used as the resistor. The voltage applied between the negative electrode and the positive electrode may be appropriately determined according to the distance between the two electrodes and the type of the dye, but from the viewpoint of protecting the positive and negative electrode conductive films, the voltage is 0.5 to 100V. preferable.

Examples of the present invention will be specifically described below, but the present invention is not limited to these examples.
[Evaluation]
A standard light source is irradiated to a dye-sensitized solar cell (size: 100 mm × 100 mm) under conditions of amplitude modulation of 1.5 and power density of 100 mW / cm ² to measure current density, open-circuit voltage, fill factor, and conversion efficiency. did.

Example 1
[Step (1)]
As shown in FIG. 1, a closed frame-shaped sealing member 2 is disposed on one surface of the conductive substrate 1. As the conductive substrate 1, a transparent substrate having a conductive film formed in a predetermined region on one surface was used. In each conductive film, a frame-shaped seal member 2 surrounding the peripheral end portion was disposed. A PEN resin film (thickness: 200 μm) was used for the transparent substrate. An ITO film (thickness 1500 mm) was used as the conductive film. For the seal member 2, an ultraviolet curable resin (manufactured by Three Bond Co., Ltd.) was used. Using a commercially available dispenser, an ultraviolet curable resin was applied so as to surround the peripheral edge of the conductive film.

[Step (2)]
As shown in FIG. 1, a predetermined amount of paste 3 containing a metal oxide was discharged from a nozzle 4 into a frame of a seal member 2 disposed on the surface of a conductive substrate. For paste 3, titanium oxide fine particles (manufactured by Nippon Aerosil Co., Ltd., P-25, particle size 20 nm) dispersed in propanol were used. The content of fine titanium oxide particles in the paste was 10% by weight. Furthermore, 1% by weight of titanium (IV) isopropoxide was added to the paste as a photocatalyst precursor.

[Step (3)]
The paste 3 filled in the frame of the seal member 2 is heated, and a metal oxide film (thickness at the time of application 50 μm, thickness after drying) is formed on the surface of the conductive substrate 1 in the frame of the seal member 2. 2-3 μm) was formed. More specifically, after the paste containing the metal oxide is dried at about room temperature and about 30% humidity for about 10 minutes (the dispersion medium is removed), the metal oxide is heated (fired) at 150 ° C. for about 10 minutes. . Thus, the negative electrode composite which has the electroconductive board | substrate and metal oxide film as a negative electrode, and a sealing member was obtained.

Using the negative electrode composite obtained above, the Z-type dye-sensitized solar cell module shown in FIG.
[Step (4a)]
As shown in FIG. 2, after the dye solution 15b was injected onto the metal oxide film 19 ′ in the frame of the seal member 13 under reduced pressure, the liquid electrolyte 15a was injected.
As the dye solution 15b, a solution obtained by dissolving N719 dye made of a ruthenium complex in acetonitrile was used.
The liquid electrolyte 15a was prepared by dissolving iodine, lithium iodide, DMPImI, and 4-tert-butylpyridine in acetonitrile.
In the mixed solution of the liquid electrolyte 15a and the dye solution 15b, the concentrations of N719, iodine, lithium iodide, DMPImI, and 4-tert-butylpyridine are 0.3 mM, 0.05 M, 0.1 M, 0.06 mM, and 0.5M.

[Step (4b)]
A transparent substrate 14 (manufactured by Pexel Technologies Co., Ltd.) having a conductive film 12 formed on one surface is prepared, and platinum as a catalyst layer 11 is formed on the surface of the conductive film 12 by immersion in a platinum nanocolloid solution. A layer (thickness 5 nm) was formed to obtain a positive electrode. A PEN resin film (thickness 200 μm) was used for the transparent substrate 14. As the conductive film 12, an ITO film (thickness 1500 mm) was used.
The negative electrode composite obtained in the above and the positive electrode are formed such that the metal oxide film 19 ′ of the negative electrode and the catalyst layer 11 of the positive electrode face each other, and the seal member 13, the liquid electrolyte 15a, and the dye solution are interposed between the negative electrode and the positive electrode. Overlapping was performed so that 15b was arranged. Then, the negative electrode and the positive electrode, and the seal member 13 were integrated by curing the seal member by irradiation with ultraviolet rays. At this time, the connecting portion 16 that connects the positive electrode of one single cell and the negative electrode of the other single cell in adjacent single cells is connected to the seal member 13 of one single cell and the seal member of the other single cell. It arrange | positioned in the clearance gap provided in between. In this way, a dye-sensitized solar cell module was obtained.

  The dye-sensitized solar cell module was placed on a commercially available shaker and rotated at 30 rpm, whereby the liquid electrolyte 15a and the dye solution 15b were stirred for 10 minutes.

[Step (5)]
Using a solar simulator manufactured by Pexel Technologies, a voltage of 5 V was applied between the positive electrode and the negative electrode while irradiating the dye-sensitized solar cell module with light of 1 sun or 100,000 lux. This state was maintained for 6 hours to obtain a dye-sensitized solar cell.
In the dye-sensitized solar cell of Example 1, the current density was 0.95 mA / cm ² , the open circuit voltage was 4.28 V, the fill factor was 0.53, and the conversion efficiency was 2.12%.

Example 2
[Steps (I) and (II)]
The sealing member is disposed on the surface of the conductive substrate in the same manner as in steps (1) and (2) except that a thermosetting resin (manufactured by Three Bond Co., Ltd.) is used instead of the ultraviolet curable resin. The paste containing the metal oxide was filled in the frame of the sealed member. Thus, a negative electrode composite precursor having a conductive substrate and a paste containing a metal oxide as a negative electrode precursor and a sealing member was obtained.

[Step (III)]
The negative electrode composite precursor and the positive electrode having holes for individually injecting the liquid electrolyte and the dye solution were overlapped so that the seal member was disposed between the negative electrode precursor and the positive electrode. As the positive electrode, the same positive electrode as in Example 1 was used, and a hole having a diameter of 1 mm was provided at a predetermined position of the positive electrode.
Then, after superposing | stacking what overlapped the negative electrode precursor and the positive electrode at about normal temperature and about 30% of humidity for about 10 minutes (after drying a paste), it heated at 150 degreeC for about 10 minutes. At this time, the paste containing the metal oxide and the seal member were simultaneously heated.
By heating the paste containing the metal oxide, the dispersion medium was removed from the paste, and the metal oxide was baked to form a metal oxide film. The volatilized dispersion medium was discharged outside through the holes. For this reason, the gas component of the dispersion medium does not stay inside, and there is no problem that the battery is deformed by the staying of the gas.
The thermosetting resin was cured by heating the sealing member, and the negative electrode and the positive electrode were integrated with the sealing member. At this time, the connection part which connects the positive electrode of one single cell and the negative electrode of the other single cell in adjacent single cells was arrange | positioned in the clearance gap provided between adjacent seal members.

[Step (IV)]
Under reduced pressure, the dye solution was injected from the hole onto the metal oxide film in the frame of the seal member, and then the liquid electrolyte was injected.
As the dye solution, a solution obtained by dissolving MK-2 dye made of coumarin dye in ethanol was used.
As the liquid electrolyte, an iodine, lithium iodide, DMPImI, and 4-tert-butylpyridine dissolved in ethanol was used.
The concentrations of MK-2 dye, iodine, lithium iodide, DMPImI, and 4-tert-butylpyridine in the dye solution and the liquid electrolyte mixed solution were 0.1 mM, 0.05 M, 0.1 M, and 0.06 mM, respectively. , And 0.5M.
After injecting the dye solution and the liquid electrolyte, the hole was closed with a seal member. The same thermosetting resin as described above was used for the sealing member for closing the hole.
In this way, a dye-sensitized solar cell module was obtained.
This dye-sensitized solar cell module was placed on a commercially available shaker and rotated at 30 rpm, whereby the liquid electrolyte and the dye solution were stirred for 10 minutes.

[Step (V)]
Using a solar simulator manufactured by Pexel Technologies, a voltage of 5 V was applied between the positive electrode and the negative electrode while irradiating the dye-sensitized solar cell module with light of 1 sun or 100,000 lux. This state was maintained for 6 hours to obtain a dye-sensitized solar cell.
In the dye-sensitized solar cell of Example 2, the current density was 0.81 mA / cm ² , the open circuit voltage was 4.27 V, the fill factor was 0.56, and the conversion efficiency was 1.91%.

  In the examples of the present invention, since the thermoplastic resin film was used for the transparent substrate constituting the positive electrode and the negative electrode, the metal oxide was baked at a relatively low temperature of about 150 ° C., but a glass plate or the like was used for the transparent substrate. Even when the metal oxide is fired at a high temperature of about 500 ° C., the production method of the present invention can be used. In the case of firing at a high temperature, it is preferable to use fluorine-added tin oxide that has better heat resistance than tin-added indium oxide for the conductive film. In the dye adsorption step on the metal oxide film, the voltage applied between the positive electrode and the negative electrode can be further increased, and the adsorption of the dye can be promoted more effectively.

1, 22 and 27 Conductive substrates 2 and 13 Seal member 3 Paste 4 containing metal oxide Nozzle 10 Gaps 11 and 23 between seal member and metal oxide film Catalyst layers 12 and 18 Conductive films 14 and 17 Transparent Substrates 15 and 21 Electrolyte 15a containing dye 15a Liquid electrolyte 15b Dye solution 16 Connection portion 19 and 26 Metal oxide film 20 Negative electrode 24 Electron 25 Photosensitizing dye 28 Light irradiation 29 Positive electrode

Claims (9)

(1) a step of disposing a closed frame-shaped sealing member on one surface of the conductive substrate;
(2) filling a paste containing a metal oxide into a frame of a sealing member disposed on one surface of the conductive substrate;
(3) The paste containing the metal oxide filled in the frame of the seal member is heated to form a metal oxide film in the frame of the seal member on the surface of the conductive substrate, and the conductive substrate as the negative electrode and Obtaining a negative electrode composite having a metal oxide film and a sealing member;
(4) a step of obtaining an integrated product of the negative electrode, the positive electrode, and the electrolyte containing the seal member and the pigment of the negative electrode composite disposed between the negative electrode and the positive electrode;
Including
In the step (4), a method for producing a dye-sensitized solar cell, comprising separately supplying an electrolyte and a dye solution onto the metal oxide film in the frame of the seal member of the negative electrode composite. The electrolyte is a liquid electrolyte,
The method for producing a dye-sensitized solar cell according to claim 1, wherein in step (4), the liquid electrolyte is injected after injecting the dye solution.   The method for producing a dye-sensitized solar cell according to claim 1 or 2, wherein the dye solution is adjusted to a predetermined color by mixing a plurality of different kinds of dyes. The sealing member is a resin that is cured by irradiation with ultraviolet rays,
A process (4) is a manufacturing method of the dye-sensitized solar cell of any one of Claims 1-3 including the process of irradiating an ultraviolet-ray and hardening a sealing member.   Further, after step (4), a resistor is connected between the positive electrode and the negative electrode while irradiating light, or a voltage is applied between the positive electrode and the negative electrode while irradiating light, so that the dye in the electrolyte The manufacturing method of the dye-sensitized solar cell of any one of Claims 1-4 including the process (5) which makes a metal oxide film adsorb | suck. (I) a step of disposing a closed frame-shaped sealing member made of a resin curable by heat on one surface of the conductive substrate;
(II) A negative electrode having a conductive substrate and paste as a negative electrode precursor, and a sealing member filled with a paste containing a metal oxide in a frame of a sealing member disposed on one surface of the conductive substrate Obtaining a composite precursor;
(III) After superposing the negative electrode composite precursor and the positive electrode having holes for individually injecting the liquid electrolyte and the dye solution so that the seal member is disposed between the negative electrode precursor and the positive electrode The metal oxide-containing paste and the sealing member are simultaneously heated to form a metal oxide film to obtain a negative electrode composed of a conductive substrate and a metal oxide film, and the sealing member is cured to obtain a negative electrode and a positive electrode. A step of integrating the sealing member;
(IV) a step of closing the hole after individually injecting the liquid electrolyte and the dye solution on the metal oxide film in the frame of the seal member from the hole;
A method for producing a dye-sensitized solar cell, comprising:   The method for producing a dye-sensitized solar cell according to claim 6, wherein in step (IV), the liquid electrolyte is injected after the dye solution is injected.   The method for producing a dye-sensitized solar cell according to claim 6 or 7, wherein the dye solution is adjusted to a predetermined color by mixing a plurality of dyes of different types.   Further, after the step (IV), a resistor is connected between the positive electrode and the negative electrode while irradiating light, or a voltage is applied between the positive electrode and the negative electrode while irradiating light, The manufacturing method of the dye-sensitized solar cell of any one of Claims 6-8 including the process (V) which adsorb | sucks a pigment | dye to a metal oxide film.

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