KR101381705B1 - Dye-sensitized solar cell comprising hybrid nano fibers by electrospinning and sprayng as a polymer electrolyte, and the fabrication method thereof - Google Patents

Abstract

The present invention relates to a dye-sensitized solar cell comprising a hybrid nanofiber matric by electrospinning and spraying as a polymer electrolyte, and a fabrication method thereof. More particularly, the present invention relates to a dye-sensitized solar cell comprising hybrid nanofibers filled with an electrolyte material as a polymer electrolyte. At this time, the hybrid nanofiber matric includes a nultrafine fiber made of a hydrophilic polymer and a hydrophobic polymer, and an inorganic material is attached to on its surface. The dye-sensitized solar cell increases ion conductivity by using the hybrid nanofiber matric, improves energy conversion efficiency, and improves greatly thermal stability.

Description

DYE-SENSITIZED SOLAR CELL COMPRISING HYBRID NANO FIBERS BY ELECTROSPINNING AND SPRAYNG AS A POLYMER ELECTROLYTE, AND THE FABRICATION METHOD THEREOF}

The present invention relates to a method for manufacturing a dye-sensitized solar cell including a hybrid nanofiber matrix in which a polymer electrolyte is prepared by an electrospinning and spraying process to have high stability and energy conversion efficiency.

Energy supply and demand for renewable energies such as solar energy, wind power and hydro energy are becoming more and more important. Among them, research on solar energy is rapidly progressing among renewable energy sources.

A solar cell is a device that produces electricity directly using light-absorbing materials that generate electrons and holes when light is irradiated. The types of solar cells are classified into silicon solar cells, compound semiconductor solar cells, dye-sensitized solar cells, and organic solar cells depending on materials.

Currently, the development of fuel cells using solar cells domestically has been focused on the development of dye-sensitized solar cells using photosynthesis principles in order to reduce the manufacturing cost of batteries and reduce the initial investment cost.

Dye-sensitized solar cells have a simpler manufacturing process than conventional silicon solar cells, and the price of the dye-sensitized solar cell is about 20 to 30% of the price of the silicon cell. In addition, the stability is very high, and even when used for 10 years or more, the initial efficiency is almost maintained, and there is an advantage that it is less influenced by the sunlight amount compared with the silicon solar cell.

However, the energy conversion efficiency is lower than that of the conventional solar cells, the stability of the electrolyte is not high, and the liquid electrolyte has a property of volatilization. Therefore, a number of researches and experiments have been proposed to improve the efficiency, and the problem of electrolyte leakage or volatilization is being solved by changing the liquid electrolyte into a polymer electrolyte.

For example, a method of applying a gel electrolyte using a polymer electrolyte and an ionic liquid as an electrolyte has been proposed.

Korean Patent Laid-Open Publication No. 2008-0029231 discloses a semiconductor device comprising a first conductive substrate, a metal oxide semiconductor layer formed on the first substrate, a semiconductor electrode including a dye molecule layer adsorbed on the metal oxide semiconductor layer, A counter electrode including a metal layer formed on the second substrate, and a second electrode interposed between the semiconductor electrode and the counter electrode, wherein the first electrode is made of polyvinylidene fluoride (PVDF), poly (ethylene glycol) a polymer electrolyte comprising at least one polymer selected from the group consisting of ethylene glycol (PEG), polyethylene oxide (PEO), and derivatives thereof; and a plurality of conductive particles The present invention relates to a dye-sensitized solar cell.

The polymer electrolyte has a low ionic conductivity, and the solid-solid contact between the polymer electrolyte and the electrode is different from that of the liquid electrolyte, resulting in poor ion transfer characteristics at the interface, resulting in low energy conversion efficiency.

Korean Patent Laid-Open Publication No. 2003-0065957 discloses a dye-sensitized solar cell comprising polyvinylidene fluoride dissolved in a solvent such as N-methyl-2-pyrrolidone or 3-methoxypropionitrile . The gel polymer electrolyte thus produced exhibits a high ionic conductivity similar to that of a liquid electrolyte at room temperature, but it has a disadvantage in that it is difficult to manufacture the battery because the mechanical properties thereof are poor, and the liquid electrolyte of the polymer electrolyte is poor.

In order to increase the ionic conductivity, it is necessary to increase the specific surface area of the electrolyte or to rapidly generate the ionic conductivity. Thus, a method of using a nanofibrillated polymer having a high specific surface area as an electrolyte has been proposed.

Korean Patent Laid-Open Publication No. 2009-0012595 discloses a method of manufacturing a semiconductor device, comprising: preparing a first substrate; Forming an inorganic oxide layer on one surface of the first substrate and adsorbing a dye layer on the inorganic oxide layer to form a first electrode; Forming a nanoscale polymer fiber formed by electrospinning a polymer solution through an electrospinning layer on the inorganic oxide to which the dye layer is adsorbed, applying an electrolyte solution to the polymer fiber, and then evaporating it to form a polymer electrolyte ; And forming a second electrode and a second substrate on the first electrode. The present invention also provides a method of fabricating the dye-sensitized solar cell.

Korean Patent Laid-Open Publication No. 2010-0037796 discloses a plasma display panel comprising a first electrode; A semiconductor layer on the first electrode, the semiconductor layer including semiconductor particles on which dye is adsorbed; A polymer electrolyte membrane disposed on the semiconductor layer; And a second electrode disposed on the polymer electrolyte membrane, wherein the polymer electrolyte membrane comprises a fibrous polymer matrix having metal particles or metalloid particles adhered to the surface of the polymer fibers, and a polymer electrolyte membrane embedded in the fibrous polymer matrix And a dye-sensitized solar cell comprising the polymer electrolyte membrane.

The above patent suggests a nanofiber or a polymer electrolyte on a fiber, but it is not yet possible to secure sufficient ionic conductivity.

Korean Patent Publication No. 2008-0029231 Korean Patent Publication No. 2003-0065957 Korean Patent Publication No. 2009-0012595 Korean Patent Publication No. 2010-0037796

In order to solve the above problems, the present inventors produce a micro fiber by electrospinning and applying an inorganic nanomaterial to the spray to produce a hybrid nanofiber matrix, impregnating the inside of the matrix with an electrolytic material When used as a polymer electrolyte, the present invention was completed by confirming that it has high ion conductivity and energy conversion efficiency and excellent thermal stability.

Accordingly, an object of the present invention is to provide a dye-sensitized solar cell having high ion conductivity, energy conversion efficiency and thermal stability, and a method for producing the same.

In order to achieve the above object, the present invention provides a dye-sensitized solar cell comprising a working electrode, a counter electrode, and a polymer electrolyte interposed therebetween,

Wherein the polymer electrolyte is a hybrid nanofiber matrix impregnated with an electrolytic material, wherein the hybrid nanofiber matrix comprises

Ultrafine fibers consisting of a hydrophilic polymer and a hydrophobic polymer, and

It provides a dye-sensitized solar cell, characterized in that the inorganic nanomaterial is attached to the surface thereof.

In addition,

The hydrophilic polymer and the hydrophobic polymer are dispersed in a solvent to prepare a spinning solution,

By using the spinning solution to produce a very fine fiber through electrospinning,

A hybrid nanofiber matrix is prepared by spraying a solution containing an inorganic nanomaterial on the ultrafine fibers,

It provides a method for producing a dye-sensitized solar cell comprising the step of impregnating the hybrid nanofiber matrix with an electrolyte solution to produce a polymer electrolyte.

The dye-sensitized solar cell of the present invention includes a hybrid nanofiber matrix as a polymer electrolyte, thereby enhancing ion conductivity of the electrolyte, improving energy conversion efficiency, and further enhancing thermal stability.

In addition, the manufacturing process is simple as the ultrafine fibers are produced through electrospinning and the inorganic nanomaterials are attached through the spraying process to prepare the hybrid nanofiber matrix, and the hybrid nano is easily changed by simply changing the parameters of the electrospinning or spraying process. There is an advantage that the physical properties of the fiber matrix can be easily controlled.

FIG. 1 (a) is a transmission electron microscope image showing the hybrid nanofiber matrix prepared in Example 1 of the present invention, and FIG. 1 (b) is an enlarged image thereof.
2 is a photocurrent-voltage curve graph of a solar cell using the hybrid nanofiber matrix of Example 1 as a polymer electrolyte.
3 is a photocurrent-voltage curve graph of a solar cell using the hybrid nanofiber matrix of Example 2 as a polymer electrolyte.
4 is a photocurrent-voltage curve graph of a solar cell using the hybrid nanofiber matrix of Example 3 as a polymer electrolyte.
5 is a photocurrent-voltage curve graph of a solar cell using the hybrid nanofiber matrix of Example 4 as a polymer electrolyte.
6 is a photocurrent-voltage curve graph of a solar cell using the hybrid nanofiber matrix of Comparative Example 1 as a polymer electrolyte.

Hereinafter, the present invention will be described in more detail.

The dye-sensitized solar cell has a structure including a working electrode, a counter electrode, and a polymer electrolyte interposed therebetween. In the present invention, a hybrid nanofiber matrix made of an inorganic nanomaterial and an ultrafine fiber is prepared through an electrospinning and spraying process as a matrix of the polymer electrolyte to have high energy conversion efficiency and thermal stability.

Specifically, a dye-sensitized solar cell is manufactured by interposing an electrolyte between a working electrode and a counter electrode, and then laminating them.

In particular, the electrolyte used in the dye-sensitized solar cell according to the present invention

The hydrophilic polymer and the hydrophobic polymer are dispersed in a solvent to prepare a spinning solution,

By using the spinning solution to produce a very fine fiber through electrospinning,

A hybrid nanofiber matrix is prepared by spraying a solution containing an inorganic nanomaterial on the ultrafine fibers,

The hybrid nanofiber matrix is impregnated with an electrolyte solution to prepare a polymer electrolyte.

Each step will be described in more detail below.

First, in order to manufacture ultrafine fibers used as a matrix of a polymer electrolyte, a hydrophilic polymer and a hydrophobic polymer are mixed in a solvent in a predetermined ratio to prepare a spinning solution.

Since the microfine fibers are formed into fibers and have a high porosity, they can sufficiently penetrate the electrolytic materials when used as a matrix of the polymer electrolyte, thereby improving the ionic conductivity of the polymer electrolyte and increasing the interfacial stability of the electrodes upon bonding with the electrodes. There is an advantage that the same mechanical properties are improved.

The hydrophilic polymer and the hydrophobic polymer used as the ultrafine fibers have no compatibility with each other, but when they are dissolved in the solvent, phase separation does not occur in the mixed solution state. These hydrophilic polymers and hydrophobic polymers are made of ultrafine fibers through subsequent electrospinning.

The usable hydrophilic polymer is not particularly limited in the present invention, and any known hydrophilic polymer may be used. Representative examples of the hydrophilic polymer include polyvinylpyrrolidone, polyethylene, polypropylene, polyalkylene (C1-C4) glycol, polyethyleneimine, polyvinyl alcohol, polyacrylic acid, polyurethane, polyvinylpyridine, (Meth) acrylate, polydioethylaminoethyl (meth) acrylate, polydodecyl (meth) acrylamide, polyvinylpyridine oxide, polyaminostyrene, polyallylamine hydrochloride, polymethylvinylamine, ethylene- Dienes (EPDM), and combinations thereof.

The hydrophobic polymer is not particularly limited in the present invention, and any known hydrophobic polymer may be used. Representative examples of the hydrophobic polymer include polyacrylonitrile, polymethyl methacrylate, polyacrylate, polyamide, polyaramid, polyaryl ether sulfone, polyethersulfone, polysulfone, polyaryl sulfone, polycarbonate, poly (C1-C4) oxide, polyvinylidene chloride, polyvinylidene fluoride, polyvinylidene fluoride-co-chlorotrifluoroethylene, polychlorotrifluoroethylene, polydichloro di One kind selected from the group consisting of fluoromethane, polyvinylidene dichloride, polystyrene, polyalkylstyrene, polyisoprene, polybutadiene, polyacrylamide, polyvinyl ether, and combinations thereof is possible.

Preferably, the hydrophilic / hydrophobic polymer combination for the preparation of microfine fibers is selected from the group consisting of polyvinylpyrrolidone / polystyrene, polybutadiene / polystyrene, polyethylene / polystyrene, polypropylene / polystyrene, ethylene-propylene diene / polyisobutyl, Pyridine / polystyrene may be used.

The above hydrophilic / hydrophobic polymer is mixed in a weight ratio of 2 to 8 to 8 to 2 by weight, preferably 4 to 6 to 4 to 6, in terms of solid content. If the content of the hydrophilic polymer or the hydrophobic polymer is out of the above range, phase separation occurs in the mixed solution state.

The solvent to be used herein is not particularly limited in the present invention, and any solvent which can sufficiently swell or dissolve the above-mentioned polymer can be used. Examples of the solvent include dimethylformamide (DMF), toluene, tetrahydrofuran (THF), dimethylsulfoxide, dimethylacetamide, N-methylpyrrolidone (NMP), chloroform, methylene chloride, carbon tetrachloride, One kind selected from the group consisting of benzene, cresol, xylene, acetone, methyl ethyl ketone, acrylonitrile, cyclohexane, cyclohexanone, ethyl ether, hexane, isopropyl alcohol, methanol, ethanol, , If necessary, alone or in combination. It is also possible to dissolve the respective polymers in different solvents and mix them.

At this time, the content of the solvent can be used in the electrospinning apparatus, the content of the level having a suitable concentration and viscosity so as to easily prepare the ultrafine fibers, preferably 100% by weight of the total solid (hydrophilic polymer, hydrophobic polymer) 20 to 1000 parts by weight based on parts.

Next, using the spinning solution to produce a very fine fiber through electrospinning.

Electrospinning is not particularly limited in the present invention, and can be carried out by using an electrospinning device as is known in the art. The electrospinning device comprises a power supply for applying a voltage, a spinneret, and a collector for collecting the fibers.

The flow rate of the spinning solution is regulated at a constant rate through a pump and discharged through a nozzle serving as a spinneret. At this time, one electrode connects the voltage regulator and the nozzle tip to charge the discharged spinning solution to charge the spinning solution. The electrode is connected to the dust collecting plate. Before the spinning solution discharged to the nozzle tip reaches the collector, the elongation and the volatilization of the solvent are performed together to obtain ultra fine fibers on the collector.

At this time, the shape of the finally obtained hybrid nanofiber matrix can be controlled according to various parameters such as the voltage applied between the spinneret and the collector, the distance therebetween, the spinning solution flow rate, the nozzle diameter, the arrangement of the spinneret and the collector.

Preferably, the voltage between the emitter and collector is in the range of 5 to 50V, preferably 10 to 40V, more preferably 15 to 20V. The voltage directly affects the diameter of the microfine fibers. In addition, if the voltage is increased, the diameter of the microfine fibers becomes small, but the surface of the fibers becomes very rough. On the other hand, when the voltage is too low, it is difficult to produce ultra fine fibers having a diameter of nm. do.

Further, since the diameter of the extremely fine fibers becomes smaller as the diameter of the spinneret becomes smaller, it is preferable to use a spinneret having a spinner diameter of 0.005 to 0.5 mm in order to produce a very fine fiber having a uniform nm- use.

In the present invention, various experiments were conducted to apply the ultrafine fibers to the electrolyte of the dye-sensitized solar cell, wherein a voltage was applied at 5 to 50 V between the spinneret and the collector, and these were spaced 5 to 20 cm apart, and the spinning solution flow rate was increased. Ultrafine fibers having a diameter at the nm level were prepared using 0.05 ml / h to 5 ml / h and having spinneret diameters of 0.005 to 0.5 mm.

Preferably, the ultrafine fibers produced by electrospinning have a diameter of 10-1000 nm, preferably 50-500 nm, more preferably 100-300 nm.

Next, a hybrid nanofiber matrix is prepared by spraying a solution containing an inorganic nanomaterial on the ultrafine fibers.

Inorganic nanomaterials have a high ionic conductivity by lowering the crystallinity of the polymer, which can increase the energy conversion efficiency of the dye-sensitized solar cell and have high thermal stability to prevent ignition or explosion of the battery and shorten the life of the battery due to heat deterioration Can be reduced.

The metal oxide materials that can be used include TiO ₂ , SiO ₂ , ZrO ₂ , MoO ₂ , SnO ₂ , WO ₃ , ZnO, ITO, BaTiO ₃ , Nb ₂ O ₅ , In ₂ O ₃ , ZrO ₂ , Ta ₂ O ₅ , La ₂ O _3, SrTiO _3, the _{Y 2 O 3, Ho 2 O} 3, Bi 2 O 3, CeO 2, Al 2 O 3, and TiO ₂ in the group consisting of to and the selected one member can be, and preferably use.

The inorganic nanomaterial may be any of nano-structured nanoparticles, but preferably nanoparticles having an average particle size of 10 to 1000 nm, preferably 50 to 500 nm, or nanoparticles having an average diameter of 10 to 1000 nm and a length of 10 to 1000 nm A rod is used.

When the inorganic nanomaterial has a nanoparticle form, it is advantageous in that it is well dispersed in ultrafine fibers, and in particular, when the particles are porous having pores of 1 to 5 nm, the contact area is further increased due to the presence of a liquid electrolyte between the pores. As a result, the ionic conductivity of the polymer electrolyte may be further increased.

In addition, when the inorganic nanomaterial has a nanorod form, it is dispersed in the ultrafine fibers and the ion conductivity in the longitudinal direction can be further increased.

In this case, the inorganic nanomaterial may be used in a certain content ratio with the hydrophilic / hydrophobic polymer constituting the ultrafine fibers to control ion conductivity and thermal stability. Preferably, the inorganic nanomaterial is used in an amount of 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the ultrafine fiber. If the content is less than the above range, the ion conductivity and thermal stability may not be sufficiently secured. On the contrary, if the content exceeds the above range, the inorganic nanomaterial may not be evenly dispersed on the surface of the ultrafine fibers and may be aggregated. Use suitably within the range.

The inorganic nanomaterial is dispersed in a solvent for spraying. In this case, the solvent may vary depending on the type of the nanomaterial, and preferably, a solvent having the same or similarity as the spinning solution is used. Examples of the solvent include dimethylformamide (DMF), toluene, tetrahydrofuran (THF), dimethylsulfoxide, dimethylacetamide, N-methylpyrrolidone (NMP), chloroform, methylene chloride, carbon tetrachloride, One kind selected from the group consisting of benzene, cresol, xylene, acetone, methyl ethyl ketone, acrylonitrile, cyclohexane, cyclohexanone, ethyl ether, hexane, isopropyl alcohol, methanol, ethanol, , If necessary, alone or in combination.

The solvent is used in the range of 5 to 100 parts by weight based on 1 part by weight of the inorganic nanomaterial, and the spray solution is used in the concentration range of 1 to 20% by weight.

In this case, in order to uniformly disperse the inorganic nanomaterial in the solution, various methods for increasing the dispersibility may be performed. For example, a method such as appropriate dispersion using ultrasonic waves and agitator at the same time may be used.

The spraying process is not particularly limited in the present invention, and may be performed using a spraying apparatus as known. In this case, the drying process may be further performed if necessary.

Through the spraying process, a hybrid nanofiber matrix having an nanometer diameter and having an inorganic nanomaterial attached to a surface of an ultrafine fiber having a polymer tunnel formed therein is obtained. Referring to (a) and (b) of FIG. 1, it can be seen that the inorganic nanomaterial has a structure uniformly attached to the surface of the ultrafine fiber.

Next, the prepared hybrid nanofiber matrix is impregnated with an electrolyte solution to prepare a polymer electrolyte, and a dye-sensitized solar cell is manufactured by assembling with a working electrode and a counter electrode.

The electrolyte solution includes an oxidation-reduction pair as an electrolytic material and a solvent for dissolving it.

Electrolyte material in the electrolyte solution penetrates into and on the surface of the hybrid nanofiber matrix and performs ion transfer between the working electrode and the counter electrode. In this case, the electrolytic material may penetrate between the hybrid nanofiber matrix, ie, the polymer tunnel of the ultrafine fiber, the internal pores, and the pores of the inorganic nanomaterial (if there are pores), thereby increasing the ion transport rate of the electrolytic material.

At this time, as an oxidation-reduction pair, in particular but not limited to, iodide ions (I ^-), bromide ion-(Br ^-), chloride ion (Cl ^-) ions and halide such as, I ^{3-, 5-} I, I _{^{7-, Br 3-, Cl 2 I}} -, ClI 2-, Br 2 I -, it is preferable to use a halogen-based redox pair made of halide ions of poly BrI ^2- and the like.

For example, it can be obtained by adding a pair of iodine / iodide ion, bromine / bromide ion or the like as an oxidation-reduction pair. As a source of iodide ion or bromide ion, a lithium salt, quaternary imidazolium salt, tetrabutylammonium salt, or the like can be used singly or in combination.

As the organic solvent for dissolving the redox pair, acetonitrile, methoxyacetonitrile, propionitrile, ethylene carbonate, propylene carbonate, diethyl carbonate, gamma -butyrolactone and the like can be used.

The electrolyte solution is used in a concentration range of 0.1 to 20% by weight, and can be appropriately adjusted by those skilled in the art.

As the composition of the polymer electrolyte, 0.1 to 100 parts by weight of the electrolytic material is contained relative to 100 parts by weight of the hybrid nanofiber matrix. If the amount of the electrolytic material is less than the above range, the ionic conductivity of the solar cell is not high. On the contrary, if the amount exceeds the above range, the use amount of the hybrid nanofiber matrix is relatively reduced due to excessive use.

The drying is carried out in a conventional range as long as the solvent is not removed, and is not particularly limited in the present invention.

Thus, in the present invention, the hybrid nanofiber matrix in which the electrolytic material penetrates the surface and the inside is used as a polymer electrolyte of a dye-sensitized solar cell.

At this time, the working electrode and the counter electrode are not specifically mentioned or limited in the present invention, and any electrode can be used as long as it is used in a dye-sensitized solar cell.

The working electrode may be an oxide semiconductor porous film on which a photosensitivity dye is supported, which is made of oxide semiconductor fine particles such as titanium oxide on a transparent substrate.

The transparent substrate may be glass or plastic. In the case of plastic, a transparent plastic sheet such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polyethersulfone (PES) A ceramic abrasive plate or the like.

The oxide semiconductor porous film is formed by combining one or two or more kinds of titanium dioxide (TiO ₂ ), tin oxide (SnO ₂ ), tungsten oxide (WO 3), zinc oxide (ZnO), and niobium oxide (Nb ₂ O ₅ ). Oxide semiconductor fine particles having an average particle diameter of 1 to 1000 nm are included.

The photosensitizer may be a ruthenium complex or iron complex having a ligand including a bipyridine structure or a terpyridine structure, a porphyrin-based or phthalocyanine-based metal complex, an organic dye such as eosin, rhodamine, merocyanine or coumarin It can be suitably selected and used depending on the application or the material of the oxide semiconductor porous film.

The counter electrode is formed by forming a thin film made of a conductive oxide semiconductor such as ITO or FTO on a substrate made of a nonconductive material such as glass, or depositing and applying a conductive material such as gold, platinum, or carbon-based material on the substrate. What formed the electrode can be used. Further, a layer such as platinum or carbon may be formed on a thin film of a conductive oxide semiconductor such as ITO or FTO.

As a method for producing such a counter electrode, for example, there is a method of forming a platinum layer by applying heat treatment after application of chloroplatinic acid. Alternatively, the electrode may be formed on the substrate by a vapor deposition method or a sputtering method.

As described above, in the present invention, by using a hybrid nanofiber matrix as a polymer electrolyte of a dye-sensitized solar cell, ion conductivity is improved to improve energy conversion efficiency, and mechanical stability (for example, thermal stability and dimensional stability) .

In addition, the mechanical properties of the hybrid nanofiber matrix are stabilized by the microfibers constituting the hybrid nanofiber matrix and there is no deformation due to high dimensional stability. The inorganic nanomaterial attached to the surface of the microfine fibers enhances the ion transfer rate The thermal stability of the electrolyte is further increased. Thus, ignition or explosion of the battery occurring during the battery manufacturing process or operation can be prevented, and shortening of the battery life due to heat deterioration can be reduced.

Particularly, the movement of ions in the electrolyte solution can be smoothly carried out between pores of ultrafine fibers, polymer tunnels, and pores (when pores exist) of inorganic nanomaterials. Also, the high specific surface area of the inorganic nanomaterials allows the ion to migrate faster. As a result, a high energy conversion efficiency can be secured compared with conventional metal nanoparticles or carbon nanotubes simply mixed and applied to an electrolyte.

In addition, the manufacturing method is simple as the hybrid nanofiber matrix is manufactured by performing an electrospinning and spraying process rather than a molding method, and the manufacturing process is simple. There is an advantage that the physical properties can be easily controlled.

Hereinafter, the present invention will be described in more detail by way of examples. It will be apparent to those skilled in the art that these embodiments are merely illustrative of the present invention and that the scope of the present invention is not limited to these embodiments. But are not construed as being limited by the examples.

Example 1: Preparation of Hybrid Nanofiber Matrix

(1) Preparation of spinning solution

(DMF, 500 ml) at a mixing ratio of 1: 1 by weight of polyacrylonitrile (PAN, 50 g) as a hydrophilic polymer and poly (vinylpyrrolidone), PVP ). The solution was turned completely into a stirrer for 24 hours to dissolve completely to prepare a spinning solution.

(2) spray solution preparation

After adding TiO ₂ nanoparticles (diameter: 20 nm, 10 g) to 100 ml of dimethylformamide, a spray solution in which TiO ₂ nanoparticles were uniformly dispersed using an ultrasonic disperser was prepared.

(3) Electrospinning

The spinning solution of (1) was injected into the spinneret with a syringe, placed in a syringe pump, and fixed at a flow rate of 0.005 ml / h.

At this time, the collector and the spinneret were placed vertically, and the collector was designed as a conductive metal electrode to obtain oriented microfine fibers. The distance between the spinneret and the collector was fixed at 15 cm, and a voltage was applied at 12 kV to prepare ultra-fine fibers (100-150 nm in diameter).

(4) spraying process

A hybrid nanofiber matrix was prepared by spraying the spray solution prepared in (2) on the ultrafine fibers of (3).

Example 2

A hybrid nanofiber matrix (100-150 nm in diameter) was prepared in the same manner as in Example 1 except that 2.5 g of the metal oxide nanoparticles was used.

Example 3

A hybrid nanofiber matrix (diameter 150 to 250 nm) was prepared in the same manner as in Example 1 except that 20 g of ZnO was used as the metal oxide.

Example 4

A hybrid nanofiber matrix (diameter 100 to 250 nm) was prepared in the same manner as in Example 1 except that TiO ₂ nano-rods (10 nm in diameter and 100 nm in length) were used instead of nanoparticles.

Comparative Example 1

Ultrafine fibers (100-150 nm in diameter) made of only polymer were prepared without using metal oxide nanoparticles.

Experimental Example 1: Identification of hybrid nanofiber matrix structure

In order to confirm the structure of the hybrid nanofiber matrix obtained in Example 1, the structure was measured using a transmission electron microscope.

FIG. 1 (a) is a transmission electron microscope image showing the hybrid nanofiber matrix prepared in Example 1 of the present invention, and FIG. 1 (b) is an enlarged image thereof. Referring to (a) and (b) of FIG. 1, it can be seen that the TiO ₂ nanoparticles have a structure uniformly dispersed on the surface of the ultrafine fiber.

Experimental Example 2: Test cell preparation

(1) Fabrication of Working Electrode

Slurry was prepared by using 0.5 g of TiO ₂ (P-25) and ₂ ml of an aqueous solution of polyethylene glycol (Junsei, average MW 20,000) (2.5 g / 37.5 ml in H ₂ O). TCO glass (FTO (Fluorin doped Tin Oxide, SnO ₂ : F, 8 Ω / cm ² ), Libbey-Owens-Ford) was ultrasonically washed in isopropyl alcohol, acetone, distilled water for 15 minutes, and then prepared slurry Was thinly coated using a doctor-blade method to a thickness of about 10㎛.

Subsequently, the mixture was heated to about 5 ° C. per minute to 450 ° C. at room temperature, sintered for 30 minutes to remove organic matter, and then lowered to about 5 ° C. per minute.

Then cis-bis (isothiocyanato) bis (2,2, '-bipyridyl-4,4'-dicarboxylato) ruthenium (II) (cis-bis (isothiocyanato) bis (2,2' 20 mg of -bipyridyl-4,4'-dicarboxylato) ruthenium (II), ruthenium 535 dye, Solaronix, Switzerland) was soaked in a Dye bath (ruthenium 535 dye solution) dissolved in 100 ml of ethanol for 24 hours and then adsorbed. . Then, the physically adsorbed dye layer was removed using ethanol, and then dried at 60 ° C to prepare a dye-adsorbed working electrode.

(2) Fabrication of Counter Electrode

The Pt counter electrode was washed with a TCO glass (FTO), applied with a brush, and sintered at 400 ° C for 20 minutes in an electric crucible to prepare a counter electrode.

(3) Preparation of electrolyte solution

The electrolyte solution was prepared by dissolving tetrabutylammonium iodide in a concentration of 0.1 mole and 1-propyl-3-methylimidazolium iodide in a concentration of 0.3 mole in ethylene carbonate (ethylene carbonate, propylene carbonate and acetonitrile in a volume ratio of 7: 2: 4 and stirring for 24 hours.

(4) Production of polymer electrolyte

The hybrid nanofiber matrix having the same dimensions (width and length) prepared in each of the above Examples and Comparative Examples was placed on the working electrode prepared in the above (1), and the hybrid nanofiber matrix prepared in the above (3) 0.035 ml of an electrolytic solution was dropped and the solvent was evaporated by drying in an oven at 50 ° C to form a polymer electrolyte on the working electrode.

(5) Test cell fabrication

The dye-sensitized solar cell was fabricated by bonding the counter electrode prepared in (2) to the working electrode having the polymer electrolyte formed in (4) above.

Experimental Example 3: Performance evaluation of dye-sensitized solar cell

Photocurrent density and photocurrent-voltage curve were measured to evaluate the performance of the dye-sensitized solar cell produced according to the present invention as a battery.

FIGS. 2 to 6 are graphs of photocurrent-voltage curves of the solar cells manufactured in Examples and Comparative Examples. FIG. 2 shows Example 1, FIG. 3 shows Example 2, FIG. 4 shows Example 3, 4, and Fig. 6 are graphs corresponding to Comparative Example 1. Fig.

2 to 6 calculate the energy conversion efficiency after measuring the voltage, current, and fill factor from the results, and the results are shown below.

division Open-circuit voltage (V) Short circuit current (mA / cm ² ) Fill factor Energy conversion efficiency (%) Example 1 TiO ₂ nanoparticles 0.72 14.13 73 7.6 Example 2 TiO ₂ nanoparticles 0.66 17.05 70 7.9 Example 3 ZnO nanoparticles 0.69 14.68 73 7.4 Example 4 TiO ₂ nanofibers 0.70 14.06 74 7.2 Comparative Example 1 Very fine fiber 0.68 12.88 72 6.3

Referring to Table 1, it can be seen that the energy conversion efficiency of the battery having a hybrid nanofiber matrix according to the present invention is excellent.

Claims (17)

In a dye-sensitized solar cell comprising a working electrode, a counter electrode, and a polymer electrolyte interposed therebetween,
Wherein the polymer electrolyte is a hybrid nanofiber matrix impregnated with an electrolytic material, wherein the hybrid nanofiber matrix comprises
Ultrafine fibers consisting of a hydrophilic polymer and a hydrophobic polymer, and
Dye-sensitized solar cell, characterized in that the inorganic nano-material is attached to the surface thereof. The dye-sensitized solar cell according to claim 1, wherein the ultrafine fibers have a diameter of 10 to 1000 nm. The method of claim 1, wherein the hydrophilic polymer is polyvinylpyrrolidone, polyethylene, polypropylene, polyalkylene (C1 to C4) glycol, polyethyleneimine, polyvinyl alcohol, polyacrylic acid, polyurethane, polydiethyl aminoethyl ( Meta) acrylate, polydiethylaminoethyl (meth) acrylate, polyvinylpyridine, polydodecyl (meth) acrylamide, polyvinylpyridine oxide, polyaminostyrene, polyallylamine hydrochloride, polymethylvinylamine, ethylene Dye-sensitized solar cell comprising one kind selected from the group consisting of -propylene-diene (EPDM), and combinations thereof. The method of claim 1, wherein the hydrophobic polymer is selected from the group consisting of polyacrylonitrile, polymethyl methacrylate, polyacrylate, polyamide, polyaramid, polyaryl ether sulfone, polyethersulfone, polysulfone, polyaryl sulfone, (C1 to C4) oxide, polyvinyl chloride, polyvinylidene fluoride, polyvinylidene fluoride-co-chlorotrifluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, Polyvinylidene chloride, polystyrene, polyalkylstyrene, polyisoprene, polybutadiene, polyacrylamide, polyvinyl ether, and combinations thereof. The present invention relates to a process for producing Dye - sensitized solar cell. The method of claim 1, wherein the hydrophilic polymer and the hydrophobic polymer are selected from the group consisting of polyvinylpyrrolidone / polystyrene, polybutadiene / polystyrene, polyethylene / polystyrene, polypropylene / polystyrene, ethylene-propylene diene / polyisobutyl, or polyvinylpyridine / polystyrene Wherein the dye-sensitized solar cell is used in combination with the dye-sensitized solar cell. The dye-sensitized solar cell according to claim 1, wherein the hydrophilic polymer and the hydrophobic polymer have a solid content of 2 to 8 to 8 to 2 by weight. The method of claim 1, wherein the inorganic nanomaterial is selected from the group consisting of TiO ₂ , SiO ₂ , ZrO ₂ , MoO ₂ , SnO ₂ , WO ₃ , ZnO, ITO, BaTiO ₃ , Nb ₂ O ₅ , In ₂ O ₃ , ZrO ₂ , Ta A material selected from the group consisting of Al ₂ O ₅ , La ₂ O ₃ , SrTiO ₃ , Y ₂ O ₃ , Ho ₂ O ₃ , Bi ₂ O ₃ , CeO ₂ , Al ₂ O ₃ , Wherein the dye-sensitized solar cell is a dye-sensitized solar cell. The dye-sensitized solar cell according to claim 1, wherein the inorganic nanomaterial is nanoparticles having an average particle diameter of 10 to 1000 nm. The dye-sensitized solar cell according to claim 1, wherein the inorganic nanomaterial is a nano rod having an average diameter of 10 to 1000 nm and a length of 10 to 1000 nm. The dye-sensitized solar cell according to claim 1, wherein the hybrid nanofiber matrix comprises 0.1 to 20 parts by weight of an inorganic nanomaterial relative to 100 parts by weight of ultrafine fibers. Claim in 1, wherein the electrolytic material is iodide ion (I ^-), bromide ion (Br ^-), chloride ion (Cl ^-) with a halide ion, including, I ^{3-, 5-} I, I ^{7 _{-, Br 3-, Cl 2 I}} -, ClI 2-, Br 2 I -, paragraph 1 of the dye-sensitized, characterized in that it comprises a halogen-based redox pair consisting of a polyhalide ion, including ^2- BrI Solar cells. The dye-sensitized solar cell according to claim 1, wherein the polymer electrolyte comprises 0.1 to 100 parts by weight of an electrolytic material per 100 parts by weight of the hybrid nanofiber matrix. The hydrophilic polymer and the hydrophobic polymer are dispersed in a solvent to prepare a spinning solution,
By using the spinning solution to produce a very fine fiber through electrospinning,
A hybrid nanofiber matrix is prepared by spraying a solution containing an inorganic nanomaterial on the ultrafine fibers,
The method of claim 1, further comprising the step of impregnating the hybrid nanofiber matrix with an electrolyte solution to prepare a polymer electrolyte. The method of claim 13, wherein the solvent is selected from the group consisting of dimethylformamide (DMF), toluene, tetrahydrofuran (THF), dimethylsulfoxide, dimethylacetamide, N-methylpyrrolidone (NMP), chloroform, methylene chloride, In the group consisting of chloride, trichlorobenzene, benzene, cresol, xylene, acetone, methyl ethyl ketone, acrylonitrile, cyclohexane, cyclohexanone, ethyl ether, hexane, isopropyl alcohol, methanol, ethanol and combinations thereof Wherein the dye-sensitized solar cell comprises a selected one species. 14. The method of claim 13, wherein the electrospinning is performed by applying a voltage between 5 and 50 volts between the emitter and collector, spacing them 5 to 20 cm apart, performing a spinning solution flow rate from 0.05 ml / h to 5 ml / Wherein the dye-sensitized solar cell has a spinneret diameter of 0.005 to 0.5 mm. The method of manufacturing a dye-sensitized solar cell according to claim 13, wherein the spray solution is used at a concentration of 1 to 20% by weight. 14. The method of claim 13, wherein the electrolyte solution comprises an electrolyte and a solvent.

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