JP2013084551A - Collector for dye sensitized solar cell, method for producing material for the same, and dye sensitized solar cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a collector for a dye sensitized solar cell, which is excellent in liquid permeability of an electrolyte when used in a dye sensitized solar cell, so that high power generation efficiency can be obtained; a method for producing a material for the collector for a dye sensitized solar cell; and a dye sensitized solar cell including the collector for a dye sensitized solar cell.SOLUTION: A porous sintered metal sheet has a thickness of 5-60 μm and a porosity of 30-80%, and has a plurality of through holes which isotropically communicate with each other. A collector 18 for a dye sensitized solar cell comprises the porous sintered metal sheet.

Description

  The present invention relates to a current collector for a dye-sensitized solar cell, a method for producing the current collector, and a dye-sensitized solar cell.

  The dye-sensitized solar cell is called a wet solar cell or a Gretzel battery, and is characterized in that it has an electrochemical cell structure using an electrolytic solution without using a silicon semiconductor. For example, a porous semiconductor layer such as a titania layer formed by baking titanium dioxide powder or the like on an anode electrode using a transparent conductive film such as a transparent conductive glass plate and adsorbing a pigment to the anode, and a conductive glass plate (conductive A simple structure in which an iodine solution or the like is disposed as an electrolyte between a counter electrode (cathode electrode) composed of a conductive substrate)

The power generation mechanism of the dye-sensitized solar cell is as follows.
Light incident from the transparent conductive film surface, which is the light-receiving surface, is absorbed by the dye adsorbed on the porous semiconductor layer, causing electronic excitation, and the excited electrons move to the semiconductor and are guided to the conductive glass. . Next, the electrons that have returned to the counter electrode are led to the dye that has lost the electrons through an electrolyte such as iodine, and the dye is regenerated.

  Dye-sensitized solar cells are attracting attention as low-cost solar cells because they are less expensive than silicon-based solar cells and do not require large-scale production facilities. For example, it is considered to omit an expensive transparent conductive film. In addition, since the transparent conductive film has a large electric resistance, there is also a problem that it is not suitable for increasing the size of the battery.

  One method for omitting the transparent conductive film is to provide a wiring made of a conductive metal instead of the transparent conductive film disposed on the glass surface. However, in this case, a part of the incident light is blocked by the metal wiring part, resulting in a decrease in efficiency.

  To improve this point, for example, a photoelectric conversion element in which a dye-carrying semiconductor layer is formed on a transparent substrate that does not have a transparent conductive film on the light irradiation side, and a perforated current collecting electrode is disposed on the dye-carrying semiconductor layer Is disclosed (see Patent Document 1). The perforated current collecting electrode has a network or lattice structure, and is placed on a coating film on a porous semiconductor substrate and fired at 500 ° C. for 30 minutes.

  In addition, for example, a wire mesh having a wire diameter of 1 μm to 10 mm is used as a collecting electrode having holes, a paste which is a material of the porous semiconductor layer is applied to the wire mesh, and the paste is baked to form a porous semiconductor layer. Later, a technique has been disclosed in which a wire mesh is disposed with a porous semiconductor layer facing a glass transparent substrate having no transparent conductive film (see Patent Document 2).

  However, these techniques use a wire mesh or other perforated plate that has been processed and formed in advance as a current collecting electrode, and therefore there is a limit to reducing the thickness of the wire mesh etc. due to the size restrictions of materials such as fine metal wires is there. Therefore, due to the thick thickness of the wire mesh or the like, the diffusion resistance when the electrolyte moves to the porous semiconductor layer through the wire mesh or the like is increased, which may cause a decrease in photoelectric conversion efficiency.

On the other hand, for example, a method of depositing a metal such as tungsten, titanium, nickel or the like as a collecting electrode by a method such as sputtering or vapor deposition and then patterning by photolithography or the like is disclosed (see Patent Document 3). ). The resulting collector electrode is a very thin metal film.
However, in this method, the manufacturing process of the collecting electrode is complicated. Moreover, when the current collecting electrode is too thin, there is a risk that the role and performance as the current collecting electrode may be insufficient. At this time, if it is attempted to form the current collecting electrode in a moderately thick film, the film formation may take too much time and cost.

On the other hand, it is composed of a sintered metal body obtained by sintering metal powder, and has a plurality of pore portions dispersed and arranged therein, and the porosity thereof is 10% by volume or more and 50% by volume or less. A sintered metal sheet material for an electrochemical member is disclosed in which the average pore diameter is 1 μm or more and 30 μm or less, and a part of the plurality of pores is arranged to open to the surface. (Patent Document 4). The sintered metal sheet material for electrochemical members is obtained by sintering a raw material slurry formed into a green sheet. The thickness of the metal sheet material is, for example, about 0.03 mm to 0.3 mm.
In view of the description in the technical field column of the specification, the above sintered metal sheet material for an electrochemical member includes an electrode plate for an electrolysis apparatus, an electrode for an electroplating apparatus, a current collector for an electric double layer capacitor, Although it is thought that it aims at improving the malfunction of the prior art in uses, such as a collector of a water electrolyte secondary battery, there is no concrete disclosure. In addition, in the above-described method for producing a sintered metal sheet material for electrochemical members for handling a green sheet, it seems that it is actually difficult to obtain a sheet material having a thickness of about 0.03 mm which is the lower limit value.

  In addition, a slurry manufacturing process for preparing a slurry made of a material containing a raw material powder, a binder, and water, in which bubbles are dispersed and formed, a green body forming process for forming a green body from the slurry, and sintering the green body A method for producing a porous sintered body having a sintering process is disclosed, wherein a green body forming process includes a predetermined resting process, a freeze-solidifying process, and a vacuum freeze-drying process (Patent Document 5). The slurry manufacturing process is added to the slurry by mixing the materials and adjusting the slurry, removing the bubbles and dissolved gas from the slurry, and stirring while introducing the additive gas into the slurry. It is said that the amount of gas contained in the slurry can be precisely controlled by having a bubble nucleus forming step of dispersing and forming bubble nuclei made of gas. As an example using titanium powder as a raw material, a porous sintered body having a high porosity significantly exceeding 80% and an average pore diameter of several hundred μm or more is disclosed.

  In addition, regarding the metal sintered body described above, the present inventors have disclosed a technique of using a commercially available porous titanium sheet (trade name: Typorus, made by Osaka Titanium Co., Ltd., thickness: 100 μm) as a collecting electrode of a dye-sensitized solar cell. (Patent Document 6). This porous titanium sheet is a porous metal body in which a large number of pores communicate isotropically, and contributes to improvement in power generation efficiency.

JP 2001-283941 A JP 2007-73505 A JP 2005-158470 A JP 2011-99146 A JP 2010-229432 A WO2010 / 150461

  The problem to be solved is that the conventional technique using a porous sintered metal sheet as a current collecting electrode of a dye-sensitized solar cell requires further improvement in order to contribute to further improvement in power generation efficiency. is there.

  The current collector for a dye-sensitized solar cell according to the present invention has a thickness of 5 to 60 μm, a porosity of 30 to 80%, and a porous sintered metal sheet having a number of isotropically communicating through holes. Consists of.

  Further, the current collector for a dye-sensitized solar cell according to the present invention is preferably a non-foamed porous sintered metal in which the porous sintered metal sheet has a thickness of 10 to 30 μm and a porosity of 30 to 60%. It is a sheet.

The dye-sensitized solar cell current collector according to the present invention is preferably characterized in that the average pore diameter is 5 to 25 μm.
At this time, the average pore diameter is more preferably 15 μm or less.

  Moreover, the current collector for the dye-sensitized solar cell according to the present invention is preferably any one selected from Ti, W, Mo, Rh, Pt and Ta as the metal species of the porous sintered metal sheet or It is an alloy containing one or more of these.

  Further, the current collector for a dye-sensitized solar cell according to the present invention is preferably characterized in that the metal powder as a raw material of the porous sintered metal sheet is a titanium powder produced by a hydrodehydrogenation method. To do.

The current collector for a dye-sensitized solar cell according to the present invention preferably has an electrical conductivity of 0.5 × 10 ³ Ω ⁻¹ · m ⁻¹ or more.

  The dye-sensitized solar cell according to the present invention is disposed between a transparent substrate, a conductive substrate serving as a cathode electrode, and between or in contact with the transparent substrate between the transparent substrate and the conductive substrate. A porous semiconductor layer adsorbed with a dye, and the above-described dye-sensitized solar cell current collector that is disposed in contact with the opposite side of the porous semiconductor layer to the transparent substrate and serves as an anode electrode. It is sealed.

  Also, the method for producing a current collector material for a dye-sensitized solar cell according to the present invention comprises forming a slurry-like composition containing a metal powder and a solvent on a base material that is soluble in an acid and sintering it. Pre-sintered green body forming step for obtaining a pre-formed body, a sintering step for sintering the pre-sintered green body to obtain a sintered body, and base material removal for separating and removing the base material from the sintered body with an acid Including a process.

  In the method for producing a current collector material for a dye-sensitized solar cell according to the present invention, preferably, the base material is formed of Fe or an alloy containing Fe.

  Further, in the method for producing a current collector material for a dye-sensitized solar cell according to the present invention, preferably, the sintering step is performed in a substantially sealed container, and the standard free energy of formation of carbides and oxides. A metal having a value larger than the metal powder in the sintering temperature range is disposed in the vicinity of the green body before sintering.

  Moreover, the method for producing a current collector material for a dye-sensitized solar cell according to the present invention is preferably characterized in that the metal is one selected from Ti, Zr and Hf.

  In addition, the method for producing a current collector material for a dye-sensitized solar cell according to the present invention includes a molding step of molding a mixed powder of a base metal and a medium metal to obtain a molded body, and heating and sintering the molded body. A sintering step for obtaining a body, and after one or both of the forming step and the sintering step, the formed body or the sintered body is chemically or physically treated to form the medium metal. The method further includes a medium metal separation and removal step of separating and removing.

  Moreover, the manufacturing method of the collector material for dye-sensitized solar cells which concerns on this invention, Preferably, the said chemical treatment is a pickling process, It is for dye-sensitized solar cells of Claim 12 characterized by the above-mentioned. A method for producing a current collector material.

  In the method for producing a current collector material for a dye-sensitized solar cell according to the present invention, preferably, the physical treatment is a volatile separation treatment or a melt separation treatment.

  In the method for producing a current collector material for a dye-sensitized solar cell according to the present invention, preferably, the base metal is Ti or a Ti alloy.

  In the method for producing a dye-sensitized solar cell current collector material according to the present invention, preferably, the medium metal is iron, iron-chromium alloy, copper, magnesium, selenium, calcium, zinc, cadmium, bismuth, It is characterized by being one or more selected from lead and lead-tin alloys.

  The dye-sensitized solar cell according to the present invention is disposed between a transparent substrate, a conductive substrate serving as a cathode electrode, and between or in contact with the transparent substrate between the transparent substrate and the conductive substrate. And a method for producing a current collector material for a dye-sensitized solar cell that is disposed in contact with the opposite side of the porous semiconductor layer to the transparent substrate and serves as an anode electrode. A current collector using the obtained dye-sensitized solar cell current collector material is provided, and the electrolyte is sealed.

The current collector for a dye-sensitized solar cell according to the present invention has a thickness of 5 to 60 μm, a porosity of 30 to 80%, and a porous sintered metal sheet having a number of isotropically communicating through holes. Therefore, when used in a dye-sensitized solar cell, the electrolyte has excellent liquid permeability and high power generation efficiency can be obtained.
Also, the method for producing a current collector material for a dye-sensitized solar cell according to the present invention comprises forming a slurry-like composition containing a metal powder and a solvent on a base material that is soluble in an acid and sintering it. Pre-sintered green body forming step for obtaining a pre-formed body, a sintering step for sintering the pre-sintered green body to obtain a sintered body, and base material removal for separating and removing the base material from the sintered body with an acid A molding step including molding a mixed powder of a base metal and a medium metal to obtain a molded body, a sintering process for heating the molded body to obtain a sintered body, the molding process and the sintering The method further includes a medium metal separation / removal step of separating or removing the medium metal by chemical treatment or physical treatment of the molded body or the sintered body after any one or both of the steps. The current collector for a dye-sensitized solar cell according to the invention can be suitably obtained.
Moreover, the dye-sensitized solar cell according to the present invention includes the current collector for a dye-sensitized solar cell according to the present invention, or a method for producing a current collector material for a dye-sensitized solar cell according to the present invention. Since the current collector for dye-sensitized solar cell using the material obtained by the above is provided, the electrolyte has excellent liquid permeability and high power generation efficiency can be obtained.

FIG. 1 is a diagram showing a schematic configuration of a dye-sensitized solar cell according to the present embodiment. FIG. 2 is a SEM photograph of the porous titanium of Example 1 as seen from the main surface (surface). 3 is a SEM photograph of a cross section of the porous titanium of Example 1. FIG.

  An embodiment of the present invention (hereinafter referred to as this embodiment) will be described below.

First, the current collector for a dye-sensitized solar cell according to this embodiment will be described.
The current collector for a dye-sensitized solar cell according to the present embodiment (hereinafter, this may be simply referred to as a current collector. The current collector is generally synonymous with the current collector electrode) has a thickness of 5 to 5. The porous sintered metal sheet is 60 μm and has a porosity of 30 to 80% and has a number of isotropically communicating through holes.
Since a porous sintered metal sheet is used, compared with the case where a current collector is provided on the porous semiconductor layer by a thin film forming method, the current collector production work and thus the dye-sensitized solar cell production work are more complicated. Is greatly reduced.

  As described above, the thickness of the porous sintered metal sheet is 5 to 60 μm, preferably 5 to 50 μm, and more preferably 10 to 30 μm. When the thickness of the porous sintered metal sheet is significantly less than 5 μm, the number of particles present in the thickness direction is reduced, and the strength as a metal porous body may be impaired. On the other hand, when the thickness of the porous sintered metal sheet greatly exceeds 60 μm, when used in a dye-sensitized solar cell, the flow resistance of the electrolyte solution inside the sheet increases, and the electrolyte inside the sheet or between both surfaces There is a possibility that the flowability and diffusibility are deteriorated, and that the adhesion to the porous semiconductor layer and the bonding force are impaired. The thickness of the porous sintered metal sheet refers to the average thickness.

  The porosity of the porous sintered metal sheet is 30 to 80% as described above, but preferably 30 to 60%. When the porosity of the porous sintered metal sheet is significantly lower than 30%, when used in a dye-sensitized solar cell, the flow resistance of the electrolytic solution inside the sheet increases, and the electrolyte inside the sheet or between both surfaces The flowability and diffusibility are deteriorated, and the distribution / diffusion of the electrolyte inside the sheet is insufficient, which may impair the uniform penetration of the electrolyte into the porous semiconductor layer. On the other hand, when the porosity of the porous sintered metal sheet greatly exceeds 80%, the adhesion and bonding strength with the porous semiconductor layer may be impaired. Moreover, there exists a possibility that the intensity | strength as a metal porous body may be impaired. Moreover, there exists a possibility that electroconductivity suitable as an electrode may not be obtained. In addition, it goes without saying that the definition of terms is obvious, but the unit of porosity is volume%.

  The porous sintered metal sheet has an average pore diameter of preferably 5 to 25 μm, more preferably 5 to 15 μm. When the average pore diameter of the porous sintered metal sheet is much less than 5 μm, the flow resistance of the electrolyte solution inside the sheet increases when used in a dye-sensitized solar cell, and the electrolyte inside or between both sides of the sheet As a result, the flowability and diffusibility of the electrolyte deteriorate, and the distribution / diffusion of the electrolyte inside the conductive metal layer becomes insufficient, which may impair the uniform penetration of the electrolyte into the porous semiconductor layer. On the other hand, when the average pore diameter of the porous sintered metal sheet greatly exceeds 25 μm, the strength as the metal porous body may be impaired. In addition, if the average pore diameter is excessively large, the area of the non-voided portion is also increased, so that the uniform distribution of the electrolyte inside the sheet and the uniform diffusion of the electrolyte from the opening of the sheet to the porous semiconductor layer are hindered. There is a risk.

The porosity and the average pore diameter are values when measured by a mercury intrusion method. Using a mercury intrusion type pore distribution measuring device (Pascal I 140 and Pascal 440 manufactured by CARLOERBA INSTRUMENTS, measurable range: specific surface area 0.1 m ² / g or more, pore distribution 0.0034 to 400 μm), pressure range 0. In the range of 3 to 400 kPa and 0.1 to 400 MPa, the press-fitted volume is calculated as a side area according to the cylindrical pore model, integrated and measured.

  As described above, the porous sintered metal sheet has a large number of through-holes communicating isotropically. Here, “isotropically communicating” means not only that a large number of pores communicate with each other only in the direction of the thickness of the porous sintered metal, that is, so as to have anisotropy, so that the through-holes are formed. The term “communication” means to communicate in a direction along the plane of the bonded metal so that it is isotropic in all directions in three dimensions. Thus, when used in a dye-sensitized solar cell, the electrolyte penetrates more uniformly in the sheet, and the electrolyte diffuses more uniformly from the opening of the sheet into the porous semiconductor layer.

  As the porous sintered metal sheet, for example, a so-called foam metal using a slurry foaming method or a technique equivalent thereto, such as the technique of Patent Document 5 described above, can be used. However, the porosity and the above-described porosity and the metal formed slurry without using the slurry foaming method, such as the method for producing the current collector material for dye-sensitized solar cell according to the present embodiment described later A porous sintered metal sheet having a more preferable average pore diameter can be obtained, which is more preferable. In this specification, the metal which formed the slurry without using this slurry foaming method etc. is called a non-foamed porous sintered metal sheet, and is distinguished from a foam metal.

  When a current collector made of a porous sintered metal sheet is used for a dye-sensitized solar cell in contact with the porous semiconductor layer as a current collecting electrode, the contact area with the porous semiconductor layer that is an aggregate of particles is large, In addition, the particles on the surface of the porous semiconductor layer engage with the pores on the surface of the sheet so as to engage with each other. Thereby, the bonding force between the sheet and the porous semiconductor layer is large. On the other hand, when the conductive metal layer formed by the conventional thin film forming method is used as the current collector, the openings of the through holes are discretely arranged in the direction along the plane of the conductive metal layer, and Because the number of openings is often limited, or because the conductive metal layer is formed in a smooth sheet, it is difficult to increase the bonding force between the conductive metal layer and the porous semiconductor layer. There is. This problem is more noticeable when a wire mesh is used as a current collector or when a through hole is formed in a thin plate by processing. If the bonding force between the current collector and the porous semiconductor layer is small, cracks may be generated in the electrical bonding step by heating at, for example, about 500 ° C., and the current collector and the porous semiconductor layer may be separated.

The porous sintered metal sheet is a dye-sensitized solar cell in which the metal species is any one selected from Ti, W, Mo, Rh, Pt and Ta, or an alloy containing one or more of these. When it is used, it is preferable for obtaining high corrosion resistance to the electrolyte and obtaining high conductivity. The porous sintered metal sheet preferably has an electric conductivity of 0.5 × 10 ³ Ω ⁻¹ · m ⁻¹ or more. Electrical conductivity can be measured by a four-probe method.

  In the porous sintered metal sheet, it is preferable that the metal powder as the raw material is titanium powder or titanium hydride powder. In particular, when the titanium powder is produced by hydrodehydrogenation, necking between the metal powders is performed. It is preferable in that there are many parts. In addition, sponge metal powder, gas atomized metal powder, and the like can be applied.

  When a porous sintered metal sheet is used as a current collector, a glass fiber molded body, an inorganic porous body such as a porous alumina plate, an organic porous body such as a heat-resistant porous plastic, a metallic porous body, etc. It may be provided as an auxiliary substrate.

  The method for producing the porous sintered metal sheet is not particularly limited, and a known appropriate method can be adopted. However, the current collector for a dye-sensitized solar cell according to the present embodiment described below is used. It is preferable to use a method for manufacturing the material.

  The dye-sensitized solar cell current collector according to the present embodiment described above is excellent in liquid permeability of an electrolyte when using a dye-sensitized solar cell and can obtain high power generation efficiency. In addition, since the dye-sensitized solar cell current collector according to the present embodiment is flexible and lightweight, the dye-sensitized solar cell using the current collector can be made flexible and lightweight. .

Below, the manufacturing method of the collector material for dye-sensitized solar cells which concerns on the 1st and 2nd example of this Embodiment is demonstrated.
As for the manufacturing method of the collector material for dye-sensitized solar cells which concerns on the 1st and 2nd example of this Embodiment, all are 5-60 micrometers in thickness, and the porosity is 30-80%, etc. Thus, the current-collecting material for a dye-sensitized solar cell according to the present embodiment having a number of through-holes communicating in a rectangular manner can be suitably obtained. The manufacturing methods of the current collector material for dye-sensitized solar cells according to the first and second examples of the present embodiment are both extremely thin by providing a molding step before the sintering step. In addition, other components are mixed in the metal powder as a current collector material as a raw material in the molding process, and the other components are interposed between the metal powder particles. This is common in that it is a technology that finally removes other components, thereby generating voids at locations where other components are missing.

First, the manufacturing method of the collector material for dye-sensitized solar cells which concerns on the 1st example of this Embodiment is demonstrated.
In the method for producing a current collector material for a dye-sensitized solar cell according to the first example of the present embodiment, a slurry-like composition containing a metal powder and a solvent is formed on a base material that is soluble in acid. Forming a pre-sintered green body forming step for forming a pre-sintered green body (sintered precursor), sintering step for obtaining a sintered body by sintering the pre-sintered green body, and the sintered body using an acid A substrate removing step of separating and removing the substrate from the substrate.

  First, a pre-sintered green body forming step for obtaining a pre-sintered green body by forming a slurry-like composition containing a metal powder and a solvent on a base material that is soluble in acid will be described.

The kind of the metal powder that is a raw material of the porous sintered metal sheet is as described for the current collector for the dye-sensitized solar cell according to the above-described embodiment, and a duplicate description is omitted.
The average particle diameter of the metal powder is preferably 1 μm to 50 μm and has a particle diameter of 1 to 50 μm in order to impart appropriate viscosity and fluidity to the composition containing the solvent and to facilitate forming into a thin plate shape. It is preferable to contain 50 vol% or more of certain particles. Thereby, a porous sintered metal sheet having a more uniform film thickness, porosity, and pore diameter can be obtained. When the particle diameter is less than 1 μm, the thickness of the non-conductive coating with respect to the size of the particles increases during sintering, and a sufficient sintered body may not be obtained. Moreover, there exists a possibility that the electroconductivity of the porous sintered metal sheet after sintering may be impaired. On the other hand, when the particle diameter exceeds 50 μm, it becomes difficult to form the thickness of the porous sintered metal sheet to about 25 μm or less, for example.

  As the solvent, water or an organic solvent such as ethanol, toluene, isopropanol, terpineol, butyl carbitol, cyclohexane, and methyl ethyl ketone can be used. The proportion of the solvent may vary depending on the type of solvent used, the type of metal powder, and the like, but is preferably 25 to 150 parts by mass with respect to 100 parts by mass of the metal powder.

Furthermore, a binder may be added. When the solvent is water or a water-soluble organic solvent, a methylcellulose-based, ethylcellulose-based, or polyvinyl alcohol-based binder can be used. When the solvent is a water-insoluble organic solvent, Acrylic, polyvinyl butyral, and ethyl cellulose binders can be used. However, if the ratio of the binder to the metal powder is too large, the ratio of oxygen, carbon, hydrogen, etc. contained in the sintered body increases, and the sintered body may be damaged due to embrittlement. For this reason, it is preferable that the ratio of a binder is 30 mass parts or less with respect to 100 mass parts of metal powders.
Furthermore, a plasticizer may be added. When the solvent is water or a water-soluble organic solvent, glycerin, ethylene glycol, polyethylene glycol or the like can be used. When the solvent is a water-insoluble organic solvent, phthalate ester or the like can be used. Can be used. However, if the ratio of the binder to the metal powder is too large, the leveling property at the time of drying the slurry becomes poor and the film thickness becomes non-uniform. On the other hand, if the amount is too small, the extensibility of the pre-sintered compact deteriorates and causes damage There is a fear. For this reason, it is preferable that the ratio of a plasticizer is 2-30 mass parts with respect to 100 mass parts of metal powders.

The base material is soluble in acid, and has heat resistance at the sintering temperature of the metal powder and does not react with the metal powder. By using the base material, it is possible to suppress the occurrence of wrinkles and cracks and variations in the thickness of the porous sintered metal sheet during sintering of the metal powder. Therefore, it is preferable that the substrate has an appropriate rigidity.
The material type of the base material is not particularly limited as long as it has the above characteristics, but Zn, Fe, an alloy containing these, or an oxide containing them is suitable, and is composed of an alloy containing Fe or Fe Is particularly preferred.
Although the thickness of a base material is not specifically limited, It is preferable that it is thick so that it may not warp in a sintering process, for example, can be 100 micrometers or more.
The substrate may be a simple substance or may have a multilayer structure in which a release agent is surface-coated on the surface in contact with the sintered body.
In addition, it is possible to add a high-viscosity organic substance as a binder to the slurry composition without using a base material, and to form a pre-sintered molded body as a self-supporting film (green sheet). Residues are likely to remain, which is not preferable because carbides and oxides are formed in the sintering process and become a sintering inhibiting factor. Furthermore, wrinkles and cracks may occur during the sintering process.

A slurry-like composition containing a metal powder and a solvent is applied onto a substrate to a thickness of, for example, 6 to 100 μm in consideration of weight loss during drying, and is molded.
Application method is doctor blade method, dip coating method, die coating method, comma coating method, bar coating method, screen printing method, offset printing method, gravure printing method, ink jet method, spray method, dispensing method, spin coating method, etc. This method can be used.

  The obtained pre-sintered molded body shape is preferably dried in order to remove the organic solvent and the like. Drying can be performed under normal pressure, reduced pressure, or increased pressure, but if the drying rate is too high, cracks and warpage may occur in the molded body before sintering. Select an appropriate temperature, pressure, air volume, etc. according to the physical properties. In addition, when drying under pressure, it will serve also as the press processing of the pre-sintering molded object demonstrated below.

  The pre-sintered compact is preferably pressed. Since the contact area between the metal powders increases due to the press treatment, the number of necking sites increases. Moreover, the higher the pressure of the press treatment, the higher the electrical conductivity, the lower the film thickness, and the lower the porosity. Therefore, it is necessary to select a pressure condition according to the application. However, if the pressing pressure is too low, the contact area between the metal powders does not increase, and if it is too high, the porosity falls outside an appropriate range, or the metal powder undergoes plastic deformation. Therefore, the preferable press pressure range is 0.1 to 100 MPa. Moreover, it is preferable to use a suitable cushion material in a press process. As the cushioning material, an appropriate material such as paper, metal foil, silicon, heat resistant plastic, rubber or the like can be used. The pressing method can be performed by an appropriate method such as a flat plate press, a roll press, or a vacuum laminator.

Next, a sintering process for producing a sintered body by sintering the green body before sintering will be described.
Prior to sintering the green body before sintering, it is preferable to perform a degreasing treatment. The purpose of the degreasing treatment is to thermally decompose or evaporate and remove the solvent, binder and plasticizer (hereinafter collectively referred to as residual carbon component) contained in the green body before sintering. Usually, most of the remaining carbon component is removed at the time of temperature increase in the sintering process, but when the remaining carbon component remains in the pre-sintered molded body, Metals may react to form metal carbides. As a result, the mechanical strength of the sintered body is lowered and is easily damaged. In particular, when titanium is sintered, the remaining carbon component and titanium easily react at 800 ° C. or higher to form titanium carbide. For this reason, it is desirable to perform a degreasing process and to reliably remove residual carbon components.
For the degreasing treatment, methods such as heat treatment, plasma treatment, ozone treatment, and cleaning with a solvent can be used. In the case of heat treatment, the degreasing treatment and the sintering step can be performed continuously by lowering the rate of temperature rise or providing a holding time in the temperature raising step in the sintering step. The heating environment at this time can be appropriately selected depending on the type of metal powder, such as an inert gas such as argon or nitrogen, a gas containing oxygen atoms, an air current or an atmosphere, or a vacuum, but can effectively remove residual carbon components. Therefore, a gas containing oxygen atoms is preferable, and a gas containing 1% or more of oxygen atoms, such as oxygen gas, air, or a mixed gas of oxygen gas and inert gas, is more preferable. Further, the heating temperature and the heating time can be appropriately selected depending on the type and amount of the binder and the gas type. In particular, when performed in a gas containing oxygen atoms, the oxidation of the green body before sintering is suppressed. In that respect, it is preferably 400 ° C. or lower, more preferably less than 350 ° C. The heating time is preferably 0.1 to 6 hours.

  Sintering conditions vary depending on the type of metal to be sintered. For example, in the case of titanium, oxides and nitrides are easily formed. Therefore, it is preferably performed in a vacuum or under an inert atmosphere of argon and kept at a temperature of 700 to 1100 ° C. for 0.1 to 6 hours, 750 It is more preferable to hold at ˜1000 ° C. for 0.5 to 4 hours. When the temperature is too low, the sintering is not sufficient, and when the temperature is too high, the metal porous body is warped, and the metal powder is melted so that the pores are blocked and the porous body may not be formed.

The sintering process is performed in a substantially hermetically sealed container, and the standard free energy values of carbides and oxides in the vicinity of the green body before sintering are larger than the sintered metal powder in the sintering temperature range. It is preferable to perform by arranging a metal having the following (hereinafter referred to as a getter material).
The substantially sealed container is, for example, a vacuum baking furnace whose opening is closed by a door.
Sintering in a container with a getter material prevents oxygen from being mixed outside the container, and oxygen in the container is preferentially reacted and consumed by the getter material, so that oxidation of the sintered body is suppressed More preferable. The material of the getter material varies depending on the type of metal to be sintered. For example, when the metal powder is titanium, the getter material is preferably Ti, Zr or Hf.

Finally, the base material removal step of separating and removing the base material from the sintered body with an acid will be described.
The substrate removing method using an acid is preferable from the viewpoint of peeling efficiency. The type of acid is not particularly limited as long as the base material is peeled off, such as inorganic acid such as hydrochloric acid, sulfuric acid, nitric acid, aqua regia, organic acid such as phosphoric acid, carboxylic acid, etc., but the sintered body dissolves. Acids that do not react and those that do not chemically react with the sintered body are preferred. Specifically, nitric acid and sulfuric acid are preferably used. The substrate removal method using an acid is not particularly limited, and a method of immersing the sintered body in an acid solution or a method of spraying the acid solution onto the sintered body may be used. After the substrate is peeled off, it is quickly washed to remove the acid remaining in the sintered body. The cleaning liquid can be used without limitation as long as it dissolves acid, such as water or an organic solvent.

  According to the method for producing a dye-sensitized solar cell current collector material according to the first example of the present embodiment described above, the material of the dye-sensitized solar cell current collector according to the present embodiment, That is, a porous sintered metal sheet can be suitably obtained.

Below, the manufacturing method of the collector material for dye-sensitized solar cells which concerns on the 2nd example of this Embodiment is demonstrated.
The method for producing a current collector material for a dye-sensitized solar cell according to the second example of the present embodiment includes a molding step of molding a mixed powder of a base metal and a medium metal to obtain a molded body, and heating the molded body After the sintering process to obtain a sintered body and one or both of the molding process and the sintering process, the molded body or sintered body is chemically or physically treated to separate the medium metal A medium metal separation / removal step for removing is further included.
Here, it is preferable to mix the base metal and the medium metal after previously pulverizing the base metal and the medium metal separately in order to obtain different desired particle diameters. Is also preferable when pulverizing to desired conditions. On the other hand, from the viewpoint of simplifying the process, it is preferable that the base metal and the medium metal are mixed and then pulverized to be pulverized.

  The base metal powder means a metal powder that becomes a current-collecting material for a dye-sensitized solar cell, and the particle size thereof is preferably adjusted to a maximum particle size of 45 μm or less. If the base metal powder particles having a particle size greatly exceeding 45 μm are included excessively, the strength of the finally obtained sintered body may be insufficient. By adjusting the particle size within this particle size range, the base metal powder and the medium metal powder can be uniformly mixed, and the base metal can be suitably sintered.

The metal species of the base metal powder is not particularly limited, and metal powder produced by hydrodehydrogenation (HDH method), sponge metal powder, gas atomized metal powder, and the like can be applied. It is a metal powder produced by many hydrodehydrogenation methods.
Further, for example, from the viewpoint of adaptability to filters, electrodes, etc., titanium, tungsten, molybdenum, rhodium, platinum, tantalum, ruthenium, palladium, nickel, or an alloy containing these is preferable, and further, titanium or titanium alloy is used. It is preferable to use it.

  The medium metal powder means a metal powder that is mixed with the base metal powder and is removed after the production of the current collector material for dye-sensitized solar cells to function as a medium for forming voids. As described above, it is preferable that the obtained porous body, in other words, the current collector material to be manufactured, is sized so as to have a particle size suitable for obtaining a desired void size.

  The particle size of the medium metal powder should be determined in consideration of the ease of separation and the final void size, but it is practical to determine it empirically depending on the separation method. This is because the void size is influenced not only by the particle size of the medium metal but also by various factors such as the degree of dispersion of the medium metal and the shrinkage in the sintering process. Accordingly, the optimum particle size of the medium metal powder is determined through trial and error through preliminary experiments and the like according to the conditions of the current collector material that is specifically set. For example, when iron powder is used as the medium metal powder, using a powder having a particle size range of 1 to 10 μm is a preferred embodiment when iron is dissolved and removed by pickling treatment.

  The metal species of the medium metal powder is not limited as long as it can be separated from the sintered body by chemical treatment or physical treatment, but from the viewpoint of ease of separation, iron, iron-chromium alloy, copper, magnesium, selenium, calcium It is preferable to use zinc, cadmium, bismuth, lead or a lead-tin alloy. As the iron-chromium alloy, for example, an iron-based alloy such as iron-9% chromium, iron-11% chromium, iron-13% chromium, or the like can be suitably used. Further, iron and copper are preferable because they hardly react with the base metal and are easily dissolved during the pickling treatment.

The mixing ratio of the base metal powder and the medium metal powder is determined according to the condition of the void to be obtained.
The base metal powder and the medium metal powder can be mixed by any mixing method as long as a uniform mixed powder can be obtained, and can be sufficiently achieved by mixing with a V-type mixer often used in powder metallurgy.

The mixed powder composed of the base metal powder and the medium metal powder is molded in the molding process prior to the sintering process.
Although a shaping | molding method is not specifically limited, The press molding method and the rolling shaping | molding method can be used suitably. When using the latter rolling forming method, it is more preferable to perform sheath-covered rolling. The sheath-covered rolling can more reliably prevent the possibility that sufficient rolling cannot be performed when powder that does not pass through the rolling roll is generated.
In the case of the press molding method, a preferable press pressure range is 1 to 900 MPa. On the other hand, in the case of the rolling forming method, a preferable range of rolling load is 1 ton or less per 1 mm of roll width. As the sheath material, aluminum having excellent ductility can be used.

The obtained molded body is heated through a medium metal separation and removal step as necessary to obtain a sintered body.
It is preferable that the temperature which sinters a molded object is 800-1400 degreeC. Although it depends on the metal species of the base metal and medium metal to be used, if the temperature is much lower than 800 ° C, the porosity may be excessive. On the other hand, if the temperature is significantly higher than 1400 ° C, the porosity may be excessively low. There is. The heating time is preferably 0.1 to 2 hours.
Sintering is preferably performed in an inert gas atmosphere such as argon, a hydrogen gas atmosphere, or a high vacuum. Thereby, oxidation of titanium and iron during sintering can be effectively suppressed.

The medium metal powder separation and removal step will be described.
The medium metal powder separation / removal step is performed after one or both of the forming step and the sintering step. The medium metal powder separation / removal process after the forming process can be omitted from the viewpoint of process simplification when the medium metal powder separation / removal process is always performed after the sintering process. Conversely, the medium metal powder separation / removal step after the sintering step can be omitted from the viewpoint of process simplification when the medium metal powder separation / removal step is always performed after the molding step. Of course, it is preferable to perform the medium metal powder separation / removal step after the forming step and the sintering step, respectively, because the medium metal powder separation / removal can be performed more reliably.
As long as the chemical treatment is a treatment agent that does not react with the base metal and can react with only the medium metal and can remove only the medium metal, an appropriate treatment method such as chelation or alkali treatment can be used. Of these, pickling treatment is most convenient and preferable. As the physical process, a volatile separation process, a melt separation process, or the like can be used.
Chemical treatment is preferable for obtaining a sintered body having a relatively small porosity and average pore diameter, while physical treatment is preferred for obtaining a sintered body having a relatively large porosity and average pore diameter. The physical treatment also has an advantage that there is no treatment of the waste liquid generated in the pickling treatment used for the chemical treatment.
Among the physical treatments, the volatile separation treatment is preferable when using, as a medium metal, subsalt, magnesium, or the like that has low reactivity with the base metal and has a vapor pressure that is much higher than that of the base metal. On the other hand, in the melt separation treatment, tin, lead, calcium, selenium, cadmium, bismuth, Pb—Sn alloy, which is a metal having a lower melting point than the base metal and poor reactivity with the base metal at a temperature near the melting point, is used as a medium metal. Or when using the alloy etc., it is preferable.

In the pickling treatment, the type of acid is not particularly limited. For example, an inorganic acid or the like can be used, but it is more preferable to use nitric acid or sulfuric acid that does not react with the base metal.
The pickling treatment may be, for example, a method of immersing a molded body or a sintered body in an acid solution, or a method of spraying an acid solution onto the molded body or the sintered body. At least after the pickling treatment of the sintered body, the acid remaining in the sintered body is removed quickly by washing with water or the like.

Volatile separation treatment is performed by heating and holding at a temperature of 300 ° C. or higher under a reduced pressure of, for example, 10 ⁻⁴ Torr (1.3 × 10 ⁻² Pa) or less, which is higher than the vapor pressure of the medium metal. Evaporate (volatilization treatment) and disappear. The heating temperature is preferably 300 to 400 ° C. when the molded body is subjected to volatile separation treatment, and is preferably 800 to 1400 ° C. when the sintered body is subjected to volatile separation treatment. The heating and holding time is preferably 1 hour or longer in any case.

In the melt separation treatment, a molded body or a sintered body immersed in a metal bath is heated and held at a temperature higher than the melting point of the medium metal without melting the base metal powder to melt and remove the medium metal.
As the metal species of the metal bath, calcium, selenium, cadmium, lead, bismuth, or a Pb—Sn alloy is preferably used. Since these metals have a low melting point, only the medium metal can be selectively melted, and as a result, only the base metal can be effectively left.

  According to the example of the method for manufacturing the current collector material for dye-sensitized solar cell according to the second example of the present embodiment described above, the material of the current collector for dye-sensitized solar cell according to the present embodiment example That is, a porous sintered metal sheet can be suitably obtained.

Next, the dye-sensitized solar cell 10 according to the present embodiment schematically shown in FIG. 1 includes a transparent substrate 12, a conductive substrate 14 serving as a cathode electrode, and a space between the transparent substrate 12 and the conductive substrate 14. Furthermore, the porous semiconductor layer 16 that is disposed in the vicinity of or in contact with the transparent substrate 12 and adsorbs the pigment, and the pigment that is disposed in contact with the opposite side of the porous semiconductor layer 16 to the transparent substrate 12 and serves as an anode electrode A sensitized solar cell current collector 18 is provided, and the electrolyte 20 is sealed.
The dye-sensitized solar cell current collector 18 is the dye-sensitized solar cell current collector according to the present embodiment, or the dye-sensitized solar cell according to the first or second example of the present embodiment. It is the collector for dye-sensitized solar cells using the material obtained by the manufacturing method of the collector material for solar cells. In FIG. 1, reference numeral 22 denotes a sealing material.

  The constituent elements of the dye-sensitized solar cell 10 other than the current collector 18 for the dye-sensitized solar cell can be produced by an appropriate method using an appropriate material that is usually employed.

The transparent substrate 12 may be, for example, a glass plate or a plastic plate, but using a plastic plate is preferable because flexibility can be imparted to the dye-sensitized solar cell. When using a plastic plate, for example, PET, PEN, polyimide, cured acrylic resin, cured epoxy resin, cured silicone resin, various engineering plastics, cyclic polymers obtained by metathesis polymerization, and the like can be mentioned.
As the conductive substrate 14, a substrate similar to the transparent substrate 12 is used. For example, ITO (indium oxide film doped with tin) or FTO (fluorine is doped) on a part of the surface of the substrate facing the electrolyte 20. A conductive film such as a tin oxide film), a SnO ₂ film, a metal film such as Ti, W, Mo, Rh, Pt, or Ta is laminated, and a catalyst film such as a platinum film is provided on the conductive film. Further, the transparent substrate may be omitted, and a catalyst film such as a platinum film may be provided on the metal foil. The metal foil is preferably Ti.

The porous semiconductor layer 16 can be made of any suitable material such as ZnO or SnO _2, but TiO ₂ is preferred. The shape of fine particles such as TiO ₂ is not particularly limited, but is preferably about 1 nm to 100 nm.
The porous semiconductor layer 16 is preferably formed into a desired thick film by repeating the operation of baking at a temperature of, for example, 300 to 550 ° C. after forming a thin film of TiO ₂ paste.
A dye is adsorbed on the surface of the fine particles constituting the porous semiconductor layer 16. The dye has absorption in at least part of the wavelength region of 400 nm to 1000 nm, and examples thereof include metal complexes such as ruthenium dye and phthalocyanine dye, and organic dyes such as cyanine dye. The adsorption method is not particularly limited, and for example, a so-called impregnation method in which a dye-sensitized solar cell current collector 18 in which a porous semiconductor layer 16 is formed in a dye solution is immersed and the dye is chemically adsorbed on the fine particle surface can be used. .
The transparent substrate 12 and the porous semiconductor layer 16 may or may not be in contact with each other, but the distance between the two is preferably as short as possible. Since the dye-sensitized solar cell current collector 18 and the conductive substrate (counter electrode) 14 are arranged so as not to contact each other, for example, the dye-sensitized solar cell current collector 18 has corrosion resistance to the electrolyte 20 and does not hinder the diffusion of the electrolyte ions. There is also a method of insulating with a spacer such as glass paper having sufficient pores. The distance between the dye-sensitized solar cell current collector 18 and the conductive substrate 14 is preferably 100 μm or less.

The electrolyte 20 is not particularly limited, but includes, for example, iodine, lithium ions, ionic liquid, t-butylpyridine, and the like. In the case of iodine, an oxidation-reduction body composed of a combination of iodide ions and iodine is used. Can do. Further, a metal complex such as cobalt may be used as the redox pair. Moreover, it contains a solvent capable of dissolving this redox substance, and examples thereof include acetonitrile, γ-butyrolactone, propionitrile, ethylene carbonate, and ionic liquid.
The method for injecting the electrolyte 20 is not particularly limited, and for example, a part of the sealing material 22 may be left as an opening, and the electrolyte 20 may be injected from the opening to seal the opening. Alternatively, an opening may be provided in advance in a part of the conductive substrate 14, and the opening may be sealed after injecting the electrolyte 20 therefrom.
The sealing material 22 for sealing by injecting the electrolyte 20 between the transparent substrate 12 and the conductive substrate 14 is a thermoplastic resin sheet having a thickness of 100 μm or less after curing, a photocurable resin, a thermosetting resin. Etc. can be used.

  In the dye-sensitized solar cell 10 according to the present embodiment described above, the current collector 18 for the dye-sensitized solar cell is excellent in liquid permeability of the electrolyte 20 and high power generation efficiency can be obtained.

  In addition, the dye-sensitized solar cell other than the dye-sensitized solar cell according to the present embodiment described above, for example, the dye-sensitized solar cell according to the present embodiment is provided on a transparent substrate provided with a transparent conductive film. Dyes such as those provided with current collectors, or those in which one or more current collectors are arranged at a different site from those arranged on the opposite side of the porous semiconductor layer from the transparent substrate Needless to say, the dye-sensitized solar cell current collector according to the present embodiment can be used as appropriate for the entire sensitized solar cell.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to this Example.

Example 1
Titanium powder produced by hydrodehydrogenation method (particle size 3 to 40 μm, average particle size 10 μm) and ethylcellulose binder (EC-200FTD manufactured by Nisshin Kasei Co., Ltd.), titanium powder 60 mass % And a binder composition of 40% by mass to prepare a slurry composition. The binder is composed of about 80% by mass of terpineol and about 20% by mass of ethyl cellulose.
Next, this slurry-like composition was applied onto an iron foil having a thickness of 20 mm × 60 mm and a thickness of 100 μm by a squeegee method (screen printing method) using a metal mask having a thickness of 50 μm and an opening of 12 mm × 50 mm, This was dried under reduced pressure at 150 ° C. for 1.5 hours under 30 kPa to obtain a molded body before firing. Thereafter, the molded body before firing was pressed at 68.6 MPa.

Then, this pre-fired compact was put together with the iron foil in a vacuum firing furnace and heated at 1 × 10 −1 Pa, 300 ° C. for 1 hour to perform a degreasing treatment. Furthermore, after covering the entire upper surface of the pre-sintered compact in a vacuum firing furnace with a titanium foil, it was fired at a temperature of 800 ° C. for 2 hours under a pressure of 3 × 10 ⁻³ Pa, and fired. A sintered body was obtained.

Further, the sintered body was immersed in a 3N sulfuric acid aqueous solution for 1 hour to dissolve the iron foil portion in contact with the sintered body, and the iron foil was peeled off from the sintered body.
The obtained sintered body was washed repeatedly with distilled water and detergent water to remove sulfuric acid, and then dried by heating to obtain porous titanium (porous sintered metal sheet).
2 and 3 show SEM photographs of porous titanium. FIG. 2 shows the porous titanium as viewed from the main surface (surface) side. In the figure, reference numeral 24 indicates porous titanium, reference numeral 26 indicates a metal part, and reference numeral 28 indicates a hole part. . FIG. 3 is a cross-sectional view of porous titanium. In the figure, reference numeral 30 indicates a main surface, and reference numeral 32 indicates a cross section.
The thickness, porosity, average pore diameter, and electric conductivity of the obtained porous titanium (A-1) were measured. The obtained results are shown in Table 1 together with the particle size of the titanium powder.

  A titania paste (trade name Nanoxide D, manufactured by Solar Kunix Co., Ltd.) was printed in the range of 10 mm × 50 mm of the produced porous titanium (A-1), dried, and baked in air at 425 ° C. for 30 minutes. On the titania after firing, the operation of further printing and firing the titania base was repeated a total of 3 times to obtain a porous Ti sheet substrate with a titania layer.

  The prepared porous Ti sheet substrate with titania layer was impregnated for 64 hours in a mixed solvent solution of N719 dye (manufactured by Solar Kuniix Co., Ltd.) and acetonitrile and t-butyl alcohol, and the dye was adsorbed on the titania surface. The substrate after adsorption was washed with a mixed solvent of acetonitrile and t-butyl alcohol to obtain a porous Ti sheet substrate with a dye-adsorbed titania layer.

  A titanium foil having a size of 15 mm × 40 mm and a thickness of 20 μm was laminated on the end 2 mm of the surface of the porous Ti sheet substrate with the dye-adsorbing titania layer on which no titania paste was formed, to obtain an anode electrode with a takeout electrode.

  On one side of a 12 mm × 50 mm titanium foil having a thickness of 50 μm, platinum was deposited by 400 nm to obtain a Ti substrate with a Pt catalyst layer. Further, a titanium foil of 15 mm × 40 mm and a thickness of 20 μm was laminated on the end 2 mm of the Pt-free surface of the Ti substrate with the Pt catalyst layer to obtain a cathode electrode with a takeout electrode.

24 mm x 60 mm, 125 μm thick PEN film on which a 24 mm x 60 mm, 60 μm thick resin sheet (product name: MELTONIX 1170-60 manufactured by SOLARONIX) is bonded, and the cathode foil titanium foil with the take-out electrode Lamination was done so that the faces would face each other. Further, glass paper having a size of 16 mm × 52 mm, a thickness of 50 μm, and a porosity of 85% or more was laminated on the surface of the Pt catalyst layer of the counter electrode with the extraction electrode.
Furthermore, it laminated | stacked so that the titania paste non-film-forming surface of the said anode electrode with a taking-out electrode might face glass paper. Furthermore, the resin sheet surface of the 24 mm × 60 mm, 125 μm thick PEN film on which the resin sheet having a thickness of 24 mm × 60 mm and a thickness of 60 μm was laminated was laminated so that the dye adsorption titania layer surface of the anode electrode with the extraction electrode faced each other. . In addition, an electrolyte solution insertion hole of φ3 mm was provided in the PEN film on the cathode electrode side. These were roll-pressed at a temperature of 130 ° C.
Furthermore, after the electrolyte solution of γ-butyrolactone solvent containing iodine and LiI was injected under reduced pressure from the electrolyte solution insertion hole, the electrolyte solution insertion hole was sealed with a UV curable resin, and the dye-sensitized solar cell (C-1) Got.

The photoelectric conversion performance of the obtained dye-sensitized solar cell was examined by measuring an IV curve when a fluorescent lamp having an intensity of 0.1 mW / cm ² was irradiated from the anode electrode side. The obtained results are shown in Table 2.

(Example 2)
Instead of porous titanium (A-1), dye increase was performed in the same manner as in Example 1 except that a porous titanium sheet (A-2) manufactured by Mitsubishi Materials, which is a foam metal produced by a slurry foaming method, was used. A solar cell (C-2) was obtained. The results are shown in Tables 1 and 2.

(Example 3)
572 g of titanium powder (particle size 45 μm or less, average particle size 24 μm) manufactured by hydrodehydrogenation method and 428 g of iron powder (particle size 2 to 9.6 μm, average particle size 4.5 μm) manufactured by carbonyl and grinding method Using a mixer (V-5 type) manufactured by Tokuju Seisakusho, the mixture was uniformly mixed, charged into a mold, and then pressurized at 200 MPa to obtain a molded body. The obtained molded body was immersed in an aqueous solution containing 3% nitric acid for 72 hours and washed with water, and then sintered at 1150 ° C., 2 × 10 ⁻⁵ mbar for 2 hours to obtain porous titanium (A-3). .
The thickness, porosity, average pore diameter, and electrical conductivity of the obtained porous titanium (A-3) were measured. Furthermore, a dye-sensitized solar cell (C-3) was obtained in the same manner as in Example 1 except that porous titanium (A-3) was used instead of porous titanium (A-1). The results are shown in Tables 1 and 2.

Example 4
Porous titanium (A-) in the same manner as in Example 3 except that a compact was obtained by pressurization using sheath rolling (Yoshida Memorial Co., Ltd., experimental rolling mill) instead of charging the mold. 4) and a dye-sensitized solar cell (C-4) were obtained. The results are shown in Tables 1 and 2.

(Example 5)
A blender (V-5 type) manufactured by Tokuju Seisakusho Co., Ltd. with 596 g of titanium powder (particle size 45 μm or less, average particle size 24 μm) and 404 g of zinc powder (particle size 8 to 42 μm, average particle size 20 μm) manufactured by hydrodehydrogenation method. ) Were uniformly mixed, charged into a mold, and then pressed at 200 MPa to obtain a molded body. The obtained molded body was inserted into a laboratory furnace manufactured by Japan Vacuum Technology, heated at 300 ° C for 2 hours in a vacuum of 2 x 10 ^-5 mbar, then heated to 900 ° C and sintered for 2 hours. Porous titanium (A-5) was obtained.
The thickness, porosity, average pore diameter, and electrical conductivity of the obtained porous titanium (A-5) were measured. Furthermore, the dye-sensitized solar cell (C-5) was obtained by the method similar to Example 1 using porous titanium (A-5). The results are shown in Tables 1 and 2.

(Example 6)
687 g of titanium powder (particle size of 45 μm or less, average particle size of 32 μm) and 313 g of selenium powder (particle size of 10 to 42 μm, average particle size of 24 μm) manufactured by the atomizing method were used using a mixer (V-5 type) manufactured by Tokuju Seisakusho. The mixture was uniformly mixed, charged into a mold, and then pressed at 200 MPa to obtain a molded body. A titanium wire mesh was laid on a titanium container, and the obtained molded body was placed thereon and inserted into an experimental heating furnace manufactured by Nippon Vacuum Technology. After heating in a vacuum of 2 × 10 ⁻⁵ mbar at 800 ° C. for 2 hours, the temperature was raised to 1050 ° C. and sintering was performed for 2 hours to obtain porous titanium (A-6).
The thickness, porosity, average pore diameter, and electrical conductivity of the obtained porous titanium (A-6) were measured. Furthermore, the dye-sensitized solar cell (C-6) was obtained by the method similar to Example 1 using porous titanium (A-6). The results are shown in Tables 1 and 2.

(Example 7)
Instead of iron powder, Fe-12% Cr alloy powder (minimum particle size 4 μm, maximum particle size 9.8 μm, average particle size 7 μm) produced by the water atomization method is used, and pH 1. Porous titanium (A-7) and a dye-sensitized solar cell (C-7) were obtained in the same manner as in Example 3 except that the mixed solution containing hydrochloric acid 4 and nitric acid 4 was used. The results are shown in Tables 1 and 2.

(Example 8)
Titania paste (trade name Nanoxide D, manufactured by Solar Kunix Co., Ltd.) is printed in a range of 10 mm × 50 mm on the transparent conductive film side of the glass with a transparent conductive film (FTO) of 24 mm × 60 mm, and after drying, at 425 ° C. for 30 minutes, Baked in air. On the titania after firing, the operation of further printing and firing the titania base was repeated twice in total. Furthermore, after printing titania base on the titania after firing, porous titanium (A-1) is laminated on the titania side and dried, and fired in air at 425 ° C. for 30 minutes, glass with a transparent conductive film, A laminate substrate of titania and porous Ti sheet was obtained.
The prepared laminate substrate was impregnated for 64 hours with a mixed solvent solution of N719 dye (manufactured by Solar Kunix Co., Ltd.) and acetonitrile and t-butyl alcohol, and the dye was adsorbed on the titania surface. The substrate after adsorption was washed with a mixed solvent of acetonitrile and t-butyl alcohol to obtain a dye adsorption laminate substrate.

A titanium foil having a size of 15 mm × 40 mm and a thickness of 20 μm was laminated on the end 2 mm of the surface of the porous Ti sheet substrate with the dye-adsorbing titania layer on which no titania paste was formed, to obtain an anode electrode with a takeout electrode. The titanium foil was disposed and laminated so as to be in contact with both the porous Ti sheet and the transparent conductive film.
A sealing member provided with an opening of 16 mm × 52 mm in a resin sheet (product name: MELTONIX 1170-60, manufactured by SOLARONIX) having a thickness of 24 mm × 60 mm and a thickness of 60 μm was obtained. The sealing member is not hindered from contacting the porous Ti sheet and the transparent conductive film between the extraction electrode and the glass substrate between the extraction electrode and the glass substrate on the side of the dye adsorption titania layer of the anode electrode with the extraction electrode. Arranged.

  400 nm of platinum was vapor-deposited on one surface of a 12 mm × 50 mm titanium foil having a thickness of 50 μm to obtain a Ti substrate with a Pt catalyst layer. Further, a titanium foil of 15 mm × 40 mm and a thickness of 20 μm was laminated on the end 2 mm of the Pt-free surface of the Ti substrate with the Pt catalyst layer to obtain a cathode electrode with a takeout electrode.

24 mm x 60 mm, 125 μm thick PEN film bonded with a 24 mm x 60 mm, 60 μm thick resin sheet (product name: MELTONIX 1170-60, manufactured by SOLARONIX), and the cathode electrode titanium with the take-out electrode It laminated | stacked so that the foil surface might face. Further, glass paper having a size of 16 mm × 52 mm, a thickness of 50 μm, and a porosity of 85% or more was laminated on the surface of the Pt catalyst layer of the counter electrode with the extraction electrode. Furthermore, the titania paste non-film-forming surface on the porous Ti sheet side of the anode electrode with an extraction electrode on which the sealing member provided with the opening of 16 mm × 52 mm was disposed was laminated so as to face the glass paper. In addition, an electrolyte solution insertion hole of φ3 mm was provided in the PEN film on the cathode electrode side. These were roll-pressed at a temperature of 130 ° C.
Furthermore, after the electrolyte solution of γ-butyrolactone solvent containing iodine and LiI was injected under reduced pressure from the electrolyte solution insertion hole, the electrolyte solution insertion hole was sealed with a UV curable resin, and the dye-sensitized solar cell (C-7) Got. The results are shown in Tables 1 and 2.

Example 9
A slurry-like composition was prepared in the same manner as in Example 1, and the base material was 60 mm × 70 mm in thickness using a baker-type applicator (manufactured by Hosen Co., Ltd.) having a coating thickness of 75 μm. It apply | coated on 100 micrometers iron foil, this was dried under reduced pressure at the temperature of 150 degreeC under the pressure of 30 kPa for 1.5 hours, and the compacting body before sintering was obtained.

  Then, the green compact before sintering was put into a siliconit furnace together with the iron foil, and heated at 300 ° C. under atmospheric pressure for 1 hour to perform a degreasing treatment. Next, the green body before sintering that has been degreased is placed in a vacuum firing furnace and covered with a titanium foil so as to cover the entire upper surface of the green body before sintering, and then at 800 ° C. under a pressure of 3 × 10 −3 Pa. It heated at temperature for 2 hours and obtained the sintered compact.

Further, the sintered body was immersed in a 3N sulfuric acid aqueous solution for 1 hour to dissolve the iron foil portion in contact with the sintered body, and the iron foil was peeled off from the sintered body.
The obtained sintered body was pickled with 3N sulfuric acid, washed repeatedly with distilled water and detergent water to remove the sulfuric acid, and then dried by heating to obtain porous titanium (A-9). Furthermore, the dye-sensitized solar cell (C-9) was obtained by the method similar to Example 1 using porous titanium (A-9). The results are shown in Tables 1 and 2.

(Example 10)
Porous titanium (A-10) and a dye-sensitized solar cell (C-10) were obtained in the same manner as in Example 2 except that the compact before sintering was pressed at 294 MPa. The results are shown in Tables 1 and 2.

(Example 11)
Porous titanium (A--) was used in the same manner as in Example 2 except that titanium particles having an average particle diameter of 17 μm were used, and the slurry-like composition was applied by a squeegee method using a metal mask having a thickness of 50 μm and an opening of 10 × 30 mm. 11) and a dye-sensitized solar cell (C-11) were obtained. The results are shown in Tables 1 and 2.

(Example 12)
A slurry composition containing 30% by mass of titanium particles having an average particle size of 10 μm, 30% by mass of titanium hydride particles having an average particle size of 6 μm, and 40% by mass of an ethylcellulose binder is 50 μm in thickness and has an opening of 10 × 30 mm. A porous titanium (A-12) and a dye-sensitized solar cell (C-12) were obtained in the same manner as in Example 2 except that the metal mask was used and applied by the squeegee method. The results are shown in Tables 1 and 2.

(Example 13)
In the sintering step, porous titanium (A-13) and dye-sensitized solar cell (C-13) were obtained in the same manner as in Example 2 except that the entire upper surface of the green compact before sintering was covered with zirconium foil. . The results are shown in Tables 1 and 2.

(Example 14)
Porous titanium in the same manner as in Example 2 except that the slurry composition was applied by a squeegee method using a metal mask having a thickness of 50 μm and an opening of 10 × 30 mm, and degreasing was performed under 1 × 10 −1 Pa. (A-14) and a dye-sensitized solar cell (C-14) were obtained. The results are shown in Tables 1 and 2.

(Example 15)
The slurry-like composition was applied by a squeegee method using a metal mask having a thickness of 50 μm and an opening of 10 × 30 mm, the degreasing treatment was performed under 1 × 10 −1 Pa, and the substrate removal step was performed with 3N nitric acid. In the same manner as in Example 2, porous titanium (A-15) and a dye-sensitized solar cell (C-15) were obtained. The results are shown in Tables 1 and 2.

(Comparative Example 1)
A dye-sensitized solar cell (D-) was used in the same manner as in Example 1 except that the porous titanium sheet (B-1) (trade name Tybolus) made of Osaka Titanium was used instead of the porous titanium (A-1). 1) was obtained. The results are shown in Tables 1 and 2.
(Comparative Example 2)
Using titanium powder (particle size 3 to 5 μm, average particle size 4 μm) produced by hydrodehydrogenation, a slurry composition similar to that of Example 1 was used with a screen mask having a thickness of 20 μm and an opening of 10 mm × 30 mm. It apply | coated on the 20 mm x 40 mm and 100 micrometers thick iron foil which is a base material by the screen-printing method. Thereafter, in the same manner as in Example 1, porous titanium (porous sintered metal sheet B-2) was obtained. The obtained results are shown in Table 1 together with the particle size of the titanium powder.
Using the produced porous titanium (B-2), a porous Ti sheet substrate with a titania layer was obtained in the same manner as in Example 1. The obtained porous Ti sheet substrate with a titania layer was curled on the titania side, and a part of the titania was peeled off. A dye-sensitized solar cell (D-2) was obtained in the same manner as in Example 1 using porous titanium (B-2). The results are shown in Tables 1 and 2.

DESCRIPTION OF SYMBOLS 10 Dye-sensitized solar cell 12 Transparent substrate 14 Conductive substrate 16 Porous semiconductor layer 18 Current collector for dye-sensitized solar cell 20 Electrolyte 22 Sealing material 24 Porous sintered metal sheet 26 Metal portion 28 Hole portion 30 Main surface 32 cross section

Claims (18)

  A collector for a dye-sensitized solar cell, comprising a porous sintered metal sheet having a thickness of 5 to 60 μm and a porosity of 30 to 80% and having a number of isotropically communicating through holes.   2. The dye-sensitized solar cell collection according to claim 1, wherein the porous sintered metal sheet is a non-foamed porous sintered metal sheet having a thickness of 10 to 30 [mu] m and a porosity of 30 to 60%. Electric body.   3. The dye-sensitized solar cell current collector according to claim 2, wherein an average pore diameter is 5 to 25 [mu] m.   The current collector for a dye-sensitized solar cell according to claim 3, wherein the average pore diameter is 15 µm or less.   The metal species of the porous sintered metal sheet is any one selected from Ti, W, Mo, Rh, Pt and Ta, or an alloy containing one or more of these. The collector for a dye-sensitized solar cell as described.   The current collector for a dye-sensitized solar cell according to claim 1, wherein the metal powder as a raw material of the porous sintered metal sheet is a titanium powder produced by a hydrodehydrogenation method. 2. The dye-sensitized solar cell current collector according to claim ¹ , wherein the electrical conductivity is 0.5 × 10 ³ Ω ⁻¹ · m ⁻¹ or more.   A pre-sintered green body forming step for forming a pre-sintered green body by forming a slurry-like composition containing a metal powder and a solvent on a base material that is soluble in acid, and firing the pre-sintered green body. A method for producing a current-collecting material for a dye-sensitized solar cell, comprising: a sintering step for obtaining a sintered body by bonding; and a base material removing step for separating and removing the base material from the sintered body by an acid. .   The method for producing a current-collecting material for a dye-sensitized solar cell according to claim 8, wherein the base material is formed of Fe or an alloy containing Fe.   The sintering step is performed in a substantially sealed container, and a metal having a standard free energy value of carbide and oxide that is larger than the metal powder in the sintering temperature range is formed before the sintering. The method for producing a current collector material for a dye-sensitized solar cell according to claim 8, wherein the current collector material is disposed in the vicinity of the body.   The said metal is 1 type chosen from Ti, Zr, and Hf, The manufacturing method of the collector material for dye-sensitized solar cells of Claim 10 characterized by the above-mentioned.   A molding step of forming a mixed powder of a base metal and a medium metal to obtain a molded body, a sintering step of heating the molded body to obtain a sintered body, and any one of the molding step and the sintering step A dye-sensitized solar cell further comprising a medium metal separation and removal step of separating and removing the medium metal by chemical treatment or physical treatment of the molded body or the sintered body after the step or both steps Manufacturing method for current collector material.   13. The method for producing a current collector material for a dye-sensitized solar cell according to claim 12, wherein the chemical treatment is pickling treatment.   The method for producing a current collector material for a dye-sensitized solar cell according to claim 12, wherein the physical treatment is a volatile separation treatment or a melt separation treatment.   The method for producing a current collector material for a dye-sensitized solar cell according to claim 12, wherein the base metal is Ti or a Ti alloy.   The medium metal is any one or more selected from iron, iron-chromium alloy, copper, magnesium, selenium, calcium, zinc, cadmium, bismuth, lead and lead-tin alloy. The manufacturing method of the collector material for dye-sensitized solar cells of Claim 12.   A transparent substrate, a conductive substrate serving as a cathode electrode, a porous semiconductor layer that is disposed between or in contact with the transparent substrate and adsorbs a dye, between the transparent substrate and the conductive substrate; A dye-sensitized solar cell current collector according to any one of claims 1 to 7, which is disposed in contact with the opposite side of the transparent semiconductor layer to the transparent substrate and serves as an anode electrode, wherein the electrolyte is sealed A dye-sensitized solar cell.   A transparent substrate, a conductive substrate serving as a cathode electrode, a porous semiconductor layer that is disposed between or in contact with the transparent substrate and adsorbs a dye, between the transparent substrate and the conductive substrate; It obtains by the manufacturing method of the collector material for dye-sensitized solar cells of any one of Claims 8-16 arrange | positioned in contact with the opposite side to this transparent substrate of a porous semiconductor layer, and becoming an anode pole. A dye-sensitized solar cell including a current collector using a current collector material and having an electrolyte sealed.

Images