JP2004288985A - Solar cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solar cell which supplies stable power by suppressing output variation by light intensity even when dark. <P>SOLUTION: The solar cell can be charged. The solar cell has an electrolytic solution 5 of a photoanode side and an electrolytic solution 6 of a charge storage electrode side via a cation exchange membrane 4. In the electrolytic solution 5, a photoanode 1 and a counter electrode 2 are included. In the electrolytic solution 6, a charge storage electrode 3 is included. In this case, photoanode 1 preferably has a sensitization pigment, and the charge storage electrode 3 preferably has a conductive polymer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a solar battery that can be used as a battery for a watch, a battery for a mobile phone, a battery for a portable radio, a battery for a calculator, a battery for a portable terminal, a battery for a camera, an emergency spare battery, and the like.
[0002]
[Prior art]
Fossil fuels, such as petroleum, simply deplete the Earth's reserves. Therefore, natural energy which is inexhaustible on the earth and which exists on the earth on average is dominant. Especially in the case of solar energy, the radiant energy of the sun, which falls on the earth, is huge and is noteworthy.
[0003]
As a method of using this solar energy, a solar cell is conceivable, and is rapidly developing in recent years. In particular, a dye-sensitized solar cell has been developed as a low-cost solar cell (for example, see Patent Document 1).
[0004]
On the other hand, rechargeable secondary batteries have been developed. In particular, a secondary battery using an electrochemically stable conductive polymer as a positive electrode material has attracted attention (for example, see Patent Document 2).
[0005]
[Patent Document 1]
JP-A-5-504033
[Patent Document 2]
JP-A-10-261418
[0006]
[Problems to be solved by the invention]
However, the conventional solar cell described above has an output fluctuation depending on the light intensity, and can be used only during the daytime during the day, and is not necessarily widely used as a power source. That is, even in the dark, the development of a solar cell that suppresses output fluctuations due to light intensity and supplies stable power is an important issue to be solved.
[0007]
By electrically connecting the solar battery and the secondary battery with a circuit, the electrical energy generated by the solar battery can be charged to the secondary battery, but the structure becomes complicated and takes up space and increases the weight In addition, it is difficult to realize this from the viewpoint of cost.
[0008]
The present invention has been made in view of such a problem, and has as its object to provide a novel solar cell.
[0009]
[Means for Solving the Problems]
The solar cell of the present invention can be charged.
In the solar cell of the present invention, a first electrolyte solution and a second electrolyte solution are present via a cation exchange membrane, and a photoanode and a counter electrode are present in the first electrolyte solution. A charge storage electrode is present in the solution.
[0010]
Here, the photoanode preferably has a sensitizing dye. Preferably, the photoanode has N3Dye. Preferably, the charge storage electrode has a conductive polymer. Preferably, the charge storage electrode has polypyrrole. Further, it is preferable that the charge storage electrode contains silver iodide.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the invention relating to a solar cell will be described.
FIG. 1 shows the principle of the solar cell of the present invention. In the solar cell, a photoanode-side electrolyte solution 5 and a charge-storage-electrode-side electrolyte solution 6 are present via a cation exchange membrane 4, and a photoanode 1 and a counter electrode 2 are present in the photoanode-side electrolyte solution 5. The charge storage electrode 3 exists in the charge storage electrode side electrolyte solution 6.
[0012]
The substrate of the photoanode 1 is a porous electrode having a large surface area. Specifically, a porous titanium oxide electrode (a product obtained by sintering titanium oxide on FTO) can be used. The photoanode 1 is not limited to this porous titanium oxide electrode. In addition, tin oxide, zinc oxide, niobium oxide, tungsten oxide, indium oxide, zirconium oxide, tantalum oxide, a mixture thereof, or the like can be used.
[0013]
The photoanode 1 is an electrode having a sensitizing dye. Specifically, a material in which N3Dye is adsorbed on a porous titanium oxide electrode (a product obtained by sintering titanium oxide on FTO) can be used. The photoanode 1 is not limited to the porous titanium oxide electrode having N3Dye adsorbed thereon. In addition, ruthenium dye, porphyrin dye, phthalocyanine dye, rhodamine dye, xanthene dye, chlorophyll dye, triphenylmethane dye, acridine dye, coumarin dye, oxazine dye, indigo dye, cyanine dye Dyes, merocyanine dyes, rhodacyanine dyes, eosin dyes, mercurochrome dyes, and the like can be used.
[0014]
As the counter electrode 2, a platinum mesh electrode can be used. The counter electrode 2 is not limited to this platinum mesh electrode. In addition, a gold mesh electrode, a silver mesh electrode, a carbon mesh electrode, a palladium mesh electrode, a porous diamond electrode, and the like can be used.
[0015]
The photoanode-side electrolyte solution 5 is lithium iodide, a propylene carbonate solution containing iodine, or an acetonitrile solution containing lithium iodide or iodine, or acetonitrile containing tetra-n-butylammonium iodide, lithium iodide, or iodine. A solution or the like can be used. The photoanode-side electrolyte solution 5 is not limited to these solutions. In addition, tetra-n-butylammonium iodide, lithium iodide and iodine are added to a solvent such as methoxypropionitrile, N-methyloxazolidinone, N-methylformamide, sulfolane, methoxyacetonitrile, dimethylsulfoxide, dimethylformamide, and nitromethane. And an electrolyte solution containing the same. In addition, a mixture of these electrolyte solutions at an appropriate ratio can be employed. Further, tetra-n-butylammonium iodide or iodide is added to a room-temperature molten salt obtained by combining cations such as imidazolium, pyridinium, ammonium and sulfonium with aluminum tetrachloride anion, boron tetrafluoride anion and phosphorus hexafluoride anion. A solution in which lithium and iodine are added can be used.
[0016]
For the cation exchange membrane 4, selemion or the like can be used. The cation exchange membrane 4 is not limited to this selemion. In addition, Flemion, Nafion, Gore-Tex, etc. can be adopted.
[0017]
When a cationic redox couple is used for the photoanode-side electrolyte solution 5, an anion exchange membrane or the like can be used as the cation exchange membrane 4.
[0018]
The charge storage electrode 3 has a conductive polymer. As the charge storage electrode 3, specifically, one obtained by depositing a polypyrrole film on ITO by electrolytic oxidation polymerization of pyrrole or the like can be used. The charge storage electrode 3 is not limited to this electrode. In addition, polyaniline, polythiophene, polyacetylene, polyphenylene, polyphenylenevinylene, polyviologen, polyporphyrin, polyphthalocyanine, polyferrocene, polyamine, and the like can be used.
[0019]
Further, as the charge storage electrode 3, a material obtained by depositing silver iodide on FTO can be used. The charge storage electrode 3 is not limited to this electrode. In addition, as the inorganic compound, silver sulfide, silver cyanide, silver bromide, silver chloride, tungsten oxide, and the like can be used. Further, as the organic compound, viologen, tetracyanoethylene, porphyrin, phthalocyanine, fullerene, carbon nanotube, or the like can be used.
[0020]
The charge storage electrode side electrolyte solution 6 is a propylene carbonate solution containing lithium perchlorate, an acetonitrile solution containing lithium perchlorate, an acetonitrile solution containing tetra-n-butylammonium tetrafluoroborate, or An acetonitrile solution containing tetra-n-butylammonium chlorate can be used. The charge storage electrode side electrolyte solution 6 is not limited to these solutions. In addition, in a solvent such as methoxypropionitrile, N-methyloxazolidinone, N-methylformamide, sulfolane, methoxyacetonitrile, dimethylsulfoxide, dimethylformamide, nitromethane, lithium perchlorate, tetra-n-butylammonium tetrafluoroborate, etc. And an electrolyte solution containing tetra-n-butylammonium perchlorate, tetra-n-butylammonium hexafluorophosphate, or the like. In addition, a mixture of these electrolyte solutions at an appropriate ratio can be employed. Further, a room-temperature molten salt obtained by combining a cation such as imidazolium, pyridinium, ammonium, or sulfonium with an aluminum tetrachloride anion, a boron tetrafluoride anion, or a phosphorus hexafluoride anion can be used.
[0021]
The electrons generated at the photoanode by the light irradiation must pass through the titanium oxide to reduce the redox species present at the charge storage electrode. In order to achieve this, it is necessary that the oxidation-reduction potential of the charge storage electrode be higher (positive side) than the flat band potential of the semiconductor. When this condition is satisfied, the charge storage electrode is reduced using light energy, and conversion and storage of chemical energy can be achieved.
[0022]
On the other hand, in order to extract the stored chemical energy as electricity, it is necessary that the oxidation-reduction potential of the charge storage electrode is lower (negative) than the oxidation-reduction potential of the oxidation-reduction pair existing on the counter electrode side. If this condition is satisfied, the redox species present on the charge storage electrode can reduce the redox species present on the counter electrode side, and can convert chemical energy into electricity and use it.
[0023]
From the above, the redox potential of the charge storage electrode needs to be higher than the flat band potential of the semiconductor and lower than the redox potential on the counter electrode side. Thus, the light energy can be stored as chemical energy in the charge storage electrode at the time of light irradiation, and the chemical energy stored between the charge storage electrode and the counter electrode can be converted to electricity and used in the dark.
[0024]
From the above, in the present embodiment, the dye-sensitized solar cell is one of the wet type solar cells, and takes advantage of the feature of the wet type solar cell that the main process is a conversion reaction of light energy into chemical energy. With the aim of developing an energy storage type dye-sensitized solar cell that is small in output fluctuation due to light intensity, chargeable and dischargeable, and can be used in dark places, a charge storage electrode is used in addition to the photoanode and cathode of the dye-sensitized solar cell. We fabricated a tri-polar solar cell and demonstrated that the solar cell can actually store light energy.
[0025]
In the solar cell of the present invention, a first electrolyte solution and a second electrolyte solution are present via a cation exchange membrane, and a photoanode and a counter electrode are present in the first electrolyte solution. Since the charge storage electrode exists in the solution, a novel solar cell that can be charged can be provided.
The manufacturing process of the solar cell of the present invention is extremely simple as compared with conventional silicon-based solar cells and lithium secondary batteries. Therefore, it can be manufactured at low cost.
[0026]
Note that the present invention is not limited to the above-described embodiment, but can adopt various other configurations without departing from the gist of the present invention.
[0027]
【Example】
Next, examples according to the present invention will be specifically described. However, needless to say, the present invention is not limited to these examples.
[0028]
[Example 1]
First, a method for manufacturing a solar cell will be described with reference to FIGS.
The photoanode includes a porous titanium oxide electrode (a product obtained by sintering titanium oxide on FTO) (manufactured by Nishinoda Electric Works, the same applies to other examples), and N3Dye (manufactured by Kishimoto Sangyo, the same applies to other examples). ) Was prepared and used. The dye was adsorbed by heating the porous titanium oxide electrode on a hot plate at 450 ° C. for 30 minutes, cooling to room temperature, immersing this in an ethanol solution containing 0.3 mM N3Dye, and allowing it to stand for one day. Was.
[0029]
As the charge storage electrode, one obtained by depositing a polypyrrole film on ITO by electrolytic oxidation polymerization of pyrrole was used. The production conditions were as follows: ITO was immersed in a propylene carbonate solution of 0.1 M lithium perchlorate and 0.1 M pyrrole, and the current of the working electrode was set to 50 μA by a three-electrode method using a Pt electrode as a counter electrode and a reference electrode for SCE. / Cm ² , And constant-current electrolytic polymerization was performed at an electric quantity of 50 mC, and changes with time in the potential were observed.
[0030]
A propylene carbonate solution containing 0.5 M lithium iodide and 0.05 M iodine is used as an electrolyte solution at the photoanode portion, and a propylene carbonate solution containing 0.5 M lithium perchlorate is used as an electrolyte solution at the charge storage electrode portion. Was used.
[0031]
In the solar cell, the titanium oxide electrode prepared above was made of silicon rubber having a width of 3 mm and the effective electrode area was 1 cm. ² And using this as a separator, inserting a platinum mesh electrode, and passing through a cation exchange membrane (Selemion, manufactured by Asahi Glass Co., Ltd.) in the same manner with silicon rubber having a width of 3 mm and an effective electrode area of 1 cm. ² Was covered with a polypyrrole membrane electrode, and these were sandwiched between cocks to produce a cell.
[0032]
Next, characteristics of the solar cell manufactured as described above will be described.
When the number of electrons that can be supplied from the photoanode exceeds the oxidation-reduction reaction rate at the counter electrode and the current value is limited at the counter electrode, or when light irradiation is performed without outputting current, electrons are charged to the charge storage electrode. Flow light charging is performed. When a hole-doped conductive polymer is used for the charge storage electrode, electrons are accumulated by undoping. On the other hand, except for such a situation, even with the tripolar solar cell of this embodiment, when a load is applied between the BCs (see FIG. 1), a photocurrent-voltage curve similar to that of a normal solar cell is obtained. Should be done. FIG. 3 shows a photocurrent-voltage curve of the solar cell of this example under AM1.5 light irradiation. In the solar cell of this example, although the short-circuit current and the electromotive force are slightly reduced, the basic characteristics are almost the same as those of a normal bipolar dye-sensitized solar cell (Gretzel cell). Understand.
[0033]
When the light irradiation is performed for a predetermined time, some electrons flow to the storage portion, where energy is stored. From the change over time of the open circuit voltage of the cell after light irradiation (FIG. 4), it was confirmed that as the light irradiation time increases, the open circuit voltage of the cell and the holding time thereof become larger.
[0034]
FIG. 5 shows that the photoanode and the charge storage electrode of the dye-sensitized solar cell portion are connected and irradiated with light, and after completion of the light irradiation for various times (1 to 30 minutes), the photoanode and the charge storage electrode are shut off. The potential difference between the counter electrode and the charge storage electrode was set to 0 V using a potentiostat (manufactured by Hokuto Denko), and the change over time in the current value (closed circuit current value) was measured. Since a current can be obtained even with light irradiation for one minute, and the current value increases as the light irradiation time increases, the light energy is converted to chemical energy at the charge storage electrode, and energy storage is performed. confirmed. From these results, it has become clear that the solar cell can store energy by light irradiation and can be used even at night.
[0035]
FIG. 6 shows that the current value was 0.3 μA · cm based on each measurement data from the results of FIG. ^-2 The vertical axis indicates the amount of electricity obtained by integrating the current value until the time becomes, and shows how the amount of charged electricity increases with the light irradiation time. From these results, it was quantitatively confirmed that the amount of electricity charged by light irradiation increased with light irradiation time, that light energy was converted to chemical energy at the charge storage electrode, and that energy storage was performed. .
[0036]
In the solar cell according to the present embodiment, when light irradiation is performed without outputting current, light charging is performed. As shown in FIG. 7, from the discharge characteristics when the light charging time was changed from 1 minute to 30 minutes, it became clear that the amount of received electricity increased with the light irradiation time. In this measurement, the photoanode of the dye-sensitized solar cell portion and the charge storage electrode were connected to perform light irradiation for a predetermined time, and after the light irradiation was completed, the photoanode and the charge storage electrode were shut off. The voltage between the counter electrode and the charge storage electrode was measured by a potentiostat (manufactured by Hokuto Denko) with a resistance of 10 kΩ interposed therebetween. From this result, it is understood that the solar cell can store energy by light irradiation charging and can be used as a battery even after light is shut off.
[0037]
From the absorption spectrum of the polypyrrole film electrode 30 minutes after the light irradiation (FIG. 8), it was confirmed that the polypyrrole film was reduced and undoped by the light irradiation. In this experiment, the photoanode of the dye-sensitized solar cell was connected to the charge storage electrode, and light irradiation was performed for 30 minutes. The absorption spectrum measured in UV-Vis is compared with a similarly treated polypyrrole membrane electrode before light irradiation. From the absorption spectrum of the polypyrrole film electrode after the light irradiation, it was confirmed that the polypyrrole film electrode was almost undoped due to the accumulation of electric charge and energy was stored. From this result, it is understood that charging proceeds quantitatively with respect to polypyrrole, and the amount of charged electricity depends on the amount of the polypyrrole film, so that the capacity can be increased by increasing the weight of polypyrrole.
[0038]
Based on the above results, the charging and discharging mechanism of the solar cell of this embodiment will be described with reference to FIG.
When light is applied, as shown in FIG. 2, a part of the electrons generated by the excitation of the dye on the photoanode of the dye-sensitized solar cell part flow to the charge storage electrode, The conductive polymer film electrode is de-doped, converts light energy into chemical energy and stores it, and performs light charging. The remaining electrons form an external resistance between the counter electrode and the charge storage electrode (the resistance calculated from the current-voltage characteristics of the solar cell based on the balance between the voltage between the resistors and the oxidation-reduction potential of the charge storage electrode). It flows to the opposite pole. That is, by assembling a solar cell as shown in FIG. 2, at the time of light irradiation, charging can be performed by light, and at the same time, electricity can be extracted.
[0039]
When the light irradiation is cut off, the oxidation-reduction potential of the charge storage electrode is lower than the oxidation-reduction potential on the counter electrode side. Occurs, causing electrons to flow to the counter electrode and current to flow through the external resistance.
[0040]
[Example 2]
For the photoanode, a material prepared by adsorbing N3Dye on a porous titanium oxide electrode (a product obtained by sintering titanium oxide on FTO) was prepared and used. The dye was adsorbed by heating the porous titanium oxide electrode on a hot plate at 450 ° C. for 30 minutes, cooling to room temperature, immersing this in an ethanol solution containing 0.3 mM N3Dye, and allowing it to stand for one day. Was.
[0041]
As the charge storage electrode, one obtained by depositing a polypyrrole film on ITO by electrolytic oxidation polymerization of pyrrole was used. The production conditions were as follows: ITO was immersed in a propylene carbonate solution of 0.1 M lithium perchlorate and 0.1 M pyrrole, and the current of the working electrode was 100 μA by a three-electrode method using a Pt electrode as a counter electrode and a reference electrode for SCE. / Cm 2 and constant current electrolytic polymerization with an amount of electricity of 50 mC.
[0042]
A propylene carbonate solution containing 0.5 M lithium iodide and 0.05 M iodine is used as an electrolyte solution at the photoanode portion, and a propylene carbonate solution containing 0.5 M lithium perchlorate is used as an electrolyte solution at the charge storage electrode portion. Was used.
[0043]
In the solar cell, the titanium oxide electrode prepared above was covered with silicon rubber having a width of 3 mm so that the effective electrode area became 1 cm2, and this was used as a separator, a platinum mesh electrode was inserted, and a cation exchange membrane (Selemion) was used. Similarly, the polypyrrole membrane electrode was covered with silicon rubber of 3 mm width so that the effective electrode area was 1 cm 2, and these were sandwiched by a cock to produce a cell.
[0044]
This was irradiated with light for 15 minutes, 30 minutes, and 1 hour, and the change over time in the cell voltage was observed. As a result, a voltage stabilizing effect and the dependency of the voltage on the light irradiation time were recognized.
[0045]
[Example 3]
For the photoanode, a material prepared by adsorbing N3Dye on a porous titanium oxide electrode (a product obtained by sintering titanium oxide on FTO) was prepared and used. For the adsorption of the dye, the purchased porous titanium oxide electrode is heated on a hot plate at 450 ° C. for 30 minutes, cooled to room temperature, immersed in an ethanol solution containing 0.3 mM N3Dye, and allowed to stand for one day. It was performed by.
[0046]
As the charge storage electrode, one obtained by depositing a polypyrrole film on ITO by electrolytic oxidation polymerization of pyrrole was used. The fabrication conditions were as follows: ITO was immersed in an acetonitrile solution of 0.1 M tetra-n-butylammonium tetrafluoroborate and 0.1 M pyrrole, and a triode method using a Pt electrode as a counter electrode and a reference electrode for SCE was used. The potential of the electrode was maintained at 1 V / SCE, and constant potential electropolymerization was performed at an electric quantity of 500 mC.
[0047]
An acetonitrile solution containing 0.5 M tetra-n-butylammonium iodide, 0.02 M lithium iodide, and 0.04 M iodine was used for the electrolyte solution at the photoanode portion, and 0% for the electrolyte solution at the charge storage electrode portion. An acetonitrile solution containing 0.5 M tetra-n-butylammonium tetrafluoroborate was used.
[0048]
In the solar cell, the titanium oxide electrode prepared above was made of silicon rubber having a width of 3 mm and the effective electrode area was 1 cm. ² And using this as a separator, inserting a platinum mesh electrode, through a cation exchange membrane (Selemion), and similarly using a 3 mm wide silicon rubber to obtain an effective electrode area of 1 cm. ² Was covered with a polypyrrole membrane electrode, and these were sandwiched between cocks to produce a cell.
[0049]
This was irradiated with light for one hour, and as a result of observing the change over time in the cell voltage, a voltage stabilizing effect was observed.
[0050]
[Example 4]
For the photoanode, a material prepared by adsorbing N3Dye on a porous titanium oxide electrode (a product obtained by sintering titanium oxide on FTO) was prepared and used. The dye was adsorbed by heating the porous titanium oxide electrode on a hot plate at 450 ° C. for 30 minutes, cooling to room temperature, immersing this in an ethanol solution containing 0.3 mM N3Dye, and allowing it to stand for one day. Was.
[0051]
As the charge storage electrode, one obtained by depositing a polypyrrole film on ITO by electrolytic oxidation polymerization of pyrrole was used. The preparation conditions were as follows: ITO was immersed in acetonitrile solution of 0.1 M tetra-n-butylammonium perchlorate and 0.1 M pyrrole; Was maintained at 1 V / SCE, and constant-potential electrolytic polymerization was performed at an electric quantity of 500 mC.
[0052]
An acetonitrile solution containing 0.5 M tetra-n-butylammonium iodide, 0.02 M lithium iodide, and 0.04 M iodine was used for the electrolyte solution at the photoanode portion, and 0% for the electrolyte solution at the charge storage electrode portion. An acetonitrile solution containing 0.5 M tetra-n-butylammonium perchlorate was used.
[0053]
In the solar cell, the titanium oxide electrode prepared above was made of silicon rubber having a width of 3 mm and the effective electrode area was 1 cm. ² And using this as a separator, inserting a platinum mesh electrode, through a cation exchange membrane (Selemion), and similarly using a 3 mm wide silicon rubber to obtain an effective electrode area of 1 cm. ² Was covered with a polypyrrole membrane electrode, and these were sandwiched between cocks to produce a cell.
[0054]
This was irradiated with light for one hour, and as a result of observing the change over time in the cell voltage, a voltage stabilizing effect was observed.
[0055]
[Example 5]
For the photoanode, a material prepared by adsorbing N3Dye on a porous titanium oxide electrode (a product obtained by sintering titanium oxide on FTO) was prepared and used. The dye was adsorbed by heating the porous titanium oxide electrode on a hot plate at 450 ° C. for 30 minutes, cooling to room temperature, immersing this in an ethanol solution containing 0.3 mM N3Dye, and allowing it to stand for one day. Was.
[0056]
As the charge storage electrode, one obtained by depositing a polypyrrole film on ITO by electrolytic oxidation polymerization of pyrrole was used. The production conditions were as follows: ITO was immersed in an acetonitrile solution of 0.1 M lithium perchlorate and 0.1 M pyrrole, and the current of the working electrode was 100 μA / cm ² , And constant-current electrolytic polymerization was performed at an electric quantity of 50 mC, and changes with time in the potential were observed.
[0057]
An acetonitrile solution containing 0.5 M lithium iodide and 0.05 M iodine was used as the electrolyte solution at the photoanode portion, and an acetonitrile solution containing 0.5 M lithium perchlorate was used as the electrolyte solution at the charge storage electrode portion. Was.
[0058]
In the solar cell, the titanium oxide electrode prepared above was made of silicon rubber having a width of 3 mm and the effective electrode area was 1 cm. ² And using this as a separator, inserting a platinum mesh electrode, through a cation exchange membrane (Selemion), and similarly using a 3 mm wide silicon rubber to obtain an effective electrode area of 1 cm. ² Was covered with a polypyrrole membrane electrode, and these were sandwiched between cocks to produce a cell.
[0059]
This was irradiated with light for 15 minutes, 30 minutes, and 1 hour, and the change over time in the cell voltage was observed. As a result, a voltage stabilizing effect and the dependency of the voltage on the light irradiation time were recognized.
[0060]
[Example 6]
For the photoanode, a material prepared by adsorbing N3Dye on a porous titanium oxide electrode (a product obtained by sintering titanium oxide on FTO) was prepared and used. The adsorption of the dye was performed by heating the porous titanium oxide electrode on a hot plate at 450 ° C. for 30 minutes, cooling it to room temperature, immersing it in an ethanol solution containing 0.3 mM N3Dye, and allowing it to stand for one day. went.
[0061]
As the charge storage electrode, one obtained by depositing a polypyrrole film on ITO by electrolytic oxidation polymerization of pyrrole was used. The production conditions were as follows: ITO was immersed in a propylene carbonate solution of 0.1 M lithium perchlorate and 0.1 M pyrrole, and the current of the working electrode was 100 μA by a three-electrode method using a Pt electrode as a counter electrode and a reference electrode for SCE. / Cm 2 and constant current electrolytic polymerization with an amount of electricity of 50 mC.
[0062]
A propylene carbonate solution containing 0.5 M lithium iodide and 0.05 M iodine is used as an electrolyte solution at the photoanode portion, and a propylene carbonate solution containing 0.5 M lithium perchlorate is used as an electrolyte solution at the charge storage electrode portion. Was used.
[0063]
In the solar cell, the titanium oxide electrode prepared above was made of silicon rubber having a width of 3 mm and the effective electrode area was 1 cm. ² And using this as a separator, inserting a platinum mesh electrode, through a cation exchange membrane (Selemion), and similarly using a 3 mm wide silicon rubber to obtain an effective electrode area of 1 cm. ² Was covered with a polypyrrole electrode, and these were sandwiched between cocks to produce a cell.
[0064]
This was irradiated with light for 15 minutes, 30 minutes, and 1 hour, and the change over time in the cell voltage was observed. As a result, a voltage stabilizing effect and the dependency of the voltage on the light irradiation time were recognized.
[0065]
[Example 7]
As the photoanode, a material prepared by adsorbing N3Dye on porous titanium oxide (a product obtained by sintering titanium oxide particles on FTO) was used. For dye adsorption, the porous titanium oxide electrode was heated on a hot plate at 450 ° C. for 30 minutes, cooled to room temperature, immersed in an ethanol solution containing 0.3 mM N3Dye, and allowed to stand for one day. went.
[0066]
An electrode obtained by depositing silver iodide on FTO was prepared as a charge storage electrode, and a platinum mesh electrode was used as a counter electrode. In the solar cell, the photoanode prepared above was made of silicon rubber having a width of 3 mm and the effective electrode area was 1 cm. ² And sandwiched between the silver iodide electrodes prepared above, which were used as separators, and a platinum mesh electrode was inserted between the two electrodes. For the electrolyte solution of the cell, a solution in which propylene carbonate containing 0.5 M tetra-n-butylammonium iodide, 0.02 M potassium iodide, and 0.04 M iodine and acetonitrile were mixed at a ratio of 4 to 1 was used. . After the cell production, light irradiation was performed for an appropriate time.
Cell voltage stability was shown.
[0067]
【The invention's effect】
The present invention has the following effects.
Through a cation exchange membrane, a first electrolyte solution and a second electrolyte solution are present, a photoanode and a counter electrode are present in the first electrolyte solution, and a charge accumulation is present in the second electrolyte solution. By using a solar cell having electrodes, a novel solar cell can be provided.
[Brief description of the drawings]
FIG. 1 is a diagram showing the principle of a solar cell of the present invention.
FIG. 2 is a diagram showing an example of the solar cell of the present invention.
FIG. 3 is a diagram showing photocurrent-voltage characteristics of DSSC and ES-DSSC under AM1.5 light irradiation.
FIG. 4 is a diagram showing the light irradiation time dependency of the cell voltage.
FIG. 5 is a diagram showing an open circuit current density value and light irradiation time dependency.
FIG. 6 is a diagram showing the relationship between the amount of charged electricity and the light irradiation time.
FIG. 7 is a diagram showing the photocharging time dependency of the discharge characteristics of the ES-DSSC (using 10 kΩ for the external resistance).
FIG. 8 is a diagram showing absorption spectra of a polypyrrole film electrode before light irradiation and 30 minutes after light irradiation.
[Explanation of symbols]
1 photoanode, 2 counter electrode, 3 charge storage electrode, 4 cation exchange membrane, 5 photoelectrode side electrolyte solution, 6 charge storage electrode side electrolyte solution

Claims (7)

A solar cell characterized by being rechargeable. A first electrolyte solution and a second electrolyte solution are present via the cation exchange membrane;
In the first electrolyte solution, there is a photoanode and a counter electrode,
The solar cell according to claim 1, wherein a charge storage electrode is present in the second electrolyte solution. The solar cell according to claim 2, wherein the photoanode has a sensitizing dye. 3. The solar cell according to claim 2, wherein the photoanode has N3Dye. The solar cell according to claim 2, wherein the charge storage electrode has a conductive polymer. The solar cell according to claim 2, wherein the charge storage electrode includes polypyrrole. The solar cell according to claim 2, wherein the charge storage electrode comprises silver iodide.

Images