KR101532421B1 - Quasi-solid electrolyte for dye-sensitized solar cell and dye-sensitized solar cell containing the electrolyte - Google Patents

Abstract

The present invention provides a quasi-solid electrolyte for a dye-sensitized solar cell which includes two or more kinds of lithium salt selected among LiBOB, LiTFSi, LiPF6, LiBF4, and LiClO4.

Description

TECHNICAL FIELD [0001] The present invention relates to a quasi-solid electrolyte for a dye-sensitized solar cell and a dye-sensitized solar cell comprising the same. BACKGROUND ART < RTI ID = 0.0 >

More particularly, the present invention relates to a dye-sensitized solar cell comprising a quasi-solid electrolyte for a dye-sensitized solar cell and a dye-sensitized solar cell comprising the same. More particularly, the present invention includes two or more lithium salts selected from LiBOB, LiTFSi, LiPF ₆ , LiBF ₄ and LiClO ₄ And a dye-sensitized solar cell comprising the electrolyte.

In general, a dye-sensitized solar cell is a photo-electrochemical solar cell, which is lower in manufacturing cost than the silicon type solar cell by about 1/5, the transparent property of the cell, the possibility of manufacturing a flexible battery, And it has been attracting attention as a next generation solar cell.

Such a dye-sensitized solar cell is a dye-sensitized solar cell that comprises a photo-electrode in which a photosensitive dye molecule absorbing a wavelength of a visible light ray to generate an electron-hole pair is adsorbed on nanocrystalline titanium oxide particles, and an iodide ion Based iodine electrolytic solution and a platinum counter electrode.

The dye-sensitized solar cell (Korean Patent Laid-Open No. 2001-0030478) to which a liquid electrolyte is applied (Korean Patent Laid-Open Publication No. 2001-0030478) exhibits high energy conversion efficiency and also causes stability problems such as deterioration of performance due to electrolyte leakage and solvent evaporation, Which is recognized as the biggest problem of the commercialization of the dye-sensitized solar cell. In order to solve such problems and improve the stability and durability of solar cells, a method of physically or chemically gelling a liquid electrolyte has been studied. In addition, due to the presence of the liquid electrolyte, it becomes a disadvantage for manufacturing a flexible solar cell.

As an example of development for solving the problems of the liquid electrolyte described above, there is a dye-sensitized solar cell to which an ionic liquid electrolyte is applied (Korean Patent Publication No. 2009-0022383). The dye-sensitized solar cell in which the solvent evaporation is fundamentally blocked at a low vapor pressure as compared with the dye-sensitized solar cell electrolyte using the conventional organic solvent, shows excellent durability and stability. However, the electrolyte having a liquid phase still has difficulties in solving the stability problem such as the deterioration of the performance of the dye-sensitized solar cell due to leakage of the electrolyte when the dye-sensitized solar cell can not be completely sealed.

Various researches have been conducted to solve such problems. In particular, development of a dye-sensitized solar cell using a semi-solid electrolyte or a solid electrolyte capable of increasing the lifetime of a solar cell by improving the durability and stability of the dye- .

The solid polymer electrolyte can provide a dye-sensitized solar cell that exhibits excellent durability and stability by providing a low price and a characteristic that provides a manufacturing process smoothness and excellent mechanical strength (MS Kang, JH Kim, JG Won, NG Park, YS Kang, Chem. Commun., 2005, 889-891). However, there is a disadvantage in that ion conductivity is low in a solar cell, and an electrolyte and a titanium oxide electrode adsorbed with a dye are incompletely contacted.

As described above, it is difficult to expect the durability and stability of the dye-sensitized solar cell in the conventional method, and the improvement of the photoconversion efficiency of the solar cell is limited. It is a necessary condition for the solar cell to improve the energy conversion efficiency of the solar cell through the excellent contact between the titanium oxide electrode and the electrolyte having both the characteristics of the ionic liquid electrolyte and the advantages of the solid polymer electrolyte and at the same time, Many researches have been carried out and many researches are needed in the future.

Korean Patent Publication No. 2001-0030478 Korean Patent Publication No. 2009-0022383

 M.S. Kang, J. H. Kim, Y. J. Kim, J. G. Won, N. G. Park, Y. S. Kang, Chem. Commun., 2005, 889-891

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a quasi-solid electrolyte which is advantageous for mass production because it is not difficult to manufacture, The present invention is intended to provide a quasi-solid electrolyte for a dye-sensitized solar cell which is capable of suppressing deterioration in the performance of dye molecules which are weak to heat.

Further, the present invention can increase the voltage-current characteristics of a solar cell to which a liquid electrolyte is applied as well as a quasi-solid electrolyte in which two or more kinds of lithium salts are mixed, and in the method for producing a gel polymer electrolyte, The ceramic particles are absorbed by the liquid electrolyte and semi-solidified, so that the viscosity can be easily controlled according to the content of the ceramic particles, and the ceramic particles can be dispersed by stirring without any mechanism. With the addition of the ceramic particles, And to provide a quasi-solid electrolyte for a dye-sensitized solar cell capable of further increasing the ionic conductivity.

Further, since the semi-solidification of the ceramic particles proceeds in the presence of the lithium salt, an additional process is not required, and the introduction of impurities that may lower the current or voltage characteristics of the solar cell in the electrolyte can be blocked. It is possible to increase the voltage-current characteristics of the solar cell by increasing the absorption of the liquid electrolyte and enhancing the effect according to the characteristics of the lithium salt to be added, The present invention provides a quasi-solid electrolyte for a dye-sensitized solar cell capable of improving the mobility of electrons by preventing the recombination of electrons at the interface between the electrode and the electrolyte, not by increasing the ionic conductivity of the electrolyte The purpose.

In addition, when preparing a solar cell using the quasi-solid electrolyte, the present invention can be applied not only to the inside of the cell through the hole but also to the electrode in the form of paste, thereby improving the adhesion with the electrolyte- electrode, And to provide a dye-sensitized solar cell capable of contributing to flexibility.

These and other objects and advantages of the present invention will become more apparent from the following description of a preferred embodiment thereof.

The above object is, LiBOB, LiTFSi, LiPF _6, it is achieved by a dye-sensitized solar cell quasi-solid electrolyte comprising the lithium salt, two or more species selected from the group consisting of LiBF ₄ and LiClO _4.

Here, the two or more kinds of lithium salts is characterized in that at least one selected from the group consisting of LiBOB and LiTFSi, LiPF _6, LiBF ₄ and LiClO _4.

Preferably, the lithium salt and the LiBOB LiTFSi, LiPF _6, at least one lithium salt in a weight ratio selected from the group consisting of LiBF ₄ and LiClO ₄ to 5: characterized in that the five.

Preferably, the lithium salt is contained in an amount of 1 to 10% by weight based on the total weight of the liquid electrolyte solution.

Preferably, the electrolyte composition comprises ceramic particles bonded with a nanocomposite, an ionic liquid, a non-volatile organic solvent and a redox derivative.

Preferably, the ceramic particles are at least one selected from SiO ₂ , Al ₂ O ₃ , TiO ₂ , SnO ₂ , CeO ₂ , ZrO ₂ , BaTiO ₃ , Y ₂ O ₃ and zeolite.

Preferably, the ceramic particles have a particle diameter of 0.001 to 1 占 퐉 and are contained in an amount of 0.5 to 30% by weight based on the total weight of the liquid electrolyte solution.

Preferably, the nonvolatile organic solvent is selected from the group consisting of 3-methoxy propionitrile (MPN), sulfolane, gamma-butyrolactone, ethylene carbonate (EC), propylene Carbonate (PC), and the like.

Preferably, the redox derivative is an ionic liquid such as 1-methyl-3-propyl imidazolium iodide (PMII), lithium iodide, sodium iodide, potassium iodide, lithium bromide, A halogenated metal salt such as sodium bromide or potassium bromide or a nitrogen heterocycle such as an imidazolinium salt, a pyridinium salt, a quaternary ammonium salt, a pyrrolidinium salt, a pyrazolinium salt, an isothiazolidinium salt or an isoxazolidinium salt Compound. ≪ / RTI >

The above object is also achieved by a photoelectric conversion element comprising: a photoelectrode including a first conductive film, a metal oxide layer positioned on the first conductive film and having a dye adsorbed thereon; A counter electrode disposed opposite to the photo electrode; And a quasi-solid electrolyte according to any one of claims 1 to 9 interposed between the photoelectrode and the counter electrode.

According to the present invention, as a quasi-solid electrolyte, it is advantageous for mass production because the manufacturing process is not complicated, and it is not influenced by moisture or oxygen, and the polymer does not contain any polymer, And deterioration of performance can be suppressed.

In addition, the voltage-current characteristics of a solar cell to which a liquid electrolyte is applied as well as a quasi-solid electrolyte in which two or more kinds of lithium salts are mixed can be increased.

 In addition, in the method for producing a gel polymer electrolyte, ceramic particles are added to the liquid electrolyte, so that the ceramic particles adsorb and solidify the liquid electrolyte. The viscosity is easily controlled according to the content of the ceramic particles and the ceramic particles are dispersed by stirring without any mechanism. With the addition of the ceramic particles, the ion conductivity can be further increased with the scattering effect of the sunlight.

In addition, since the semi-solidification of the ceramic particles proceeds in the presence of the lithium salt, an additional process is not required, and the introduction of impurities that may lower the current or voltage characteristics of the solar cell in the electrolyte can be prevented.

In addition, when two or more kinds of lithium salts are mixed in the quasi-solid electrolyte, it exhibits porous surface characteristics and increases the absorption of the liquid electrolyte and enhances the voltage-current characteristics of the solar cell by exhibiting a reinforcing effect according to the characteristics of the lithium salt to be added .

Further, the lithium salt contained in the quasi-solid electrolyte can improve the mobility of electrons by preventing the recombination of electrons at the interface between the electrode and the electrolyte, not by increasing the ionic conductivity of the electrolyte.

In addition, when the solar cell is manufactured using the quasi-solid electrolyte thus produced, it is possible to apply the paste to the electrode in addition to the injection into the cell through the hole, thereby improving the adhesion with the electrolyte-electrode, Thereby contributing to flexibility.

However, the effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned can be clearly understood by those skilled in the art from the following description.

1 is a current-voltage curve of a dye-sensitized solar cell using the electrolytes of Examples 1 to 3, Comparative Example 3 and Comparative Example 4 of the present invention.
2 is a current-voltage curve of a dye-sensitized solar cell using the electrolytes of Comparative Examples 1 to 4 of the present invention.
3 is a SEM photograph of a lithium salt alone applied.
FIG. 4 is a SEM photograph of a case where two or more kinds of lithium salts are mixed. FIG.

Hereinafter, the present invention will be described in detail with reference to embodiments and drawings of the present invention. It will be apparent to those skilled in the art that these embodiments are provided by way of illustration only for the purpose of more particularly illustrating the present invention and that the scope of the present invention is not limited by these embodiments .

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.

Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described herein.

Unless otherwise stated, all percentages, parts, and percentages are by weight. It will also be understood that when an amount, concentration, or other value or parameter is given in any one of a range, a preferred range, or a list of preferred upper limits and preferred lower limits, it is understood that any upper limit range, It should be understood that specifically all ranges formed from any pair of range limits or desirable values are to be understood. Where a range of numerical values is referred to in this specification, unless otherwise stated, the range is intended to include all the integers and fractions within the endpoint and its range. The scope of the present invention is not intended to be limited to the specific values that are mentioned when defining the scope.

When the term "about" is used to describe the endpoint of a value or range, it is to be understood that the present disclosure encompasses the particular value or endpoint mentioned.

As used herein, the terms "comprise," "include," "including," "including," "containing," " Having ", " having ", " having ", or any other variation thereof, are intended to cover an inclusion not exclusive. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to such elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus It is possible. Also, unless explicitly stated to the contrary, "or" does not mean " comprehensive " or " exclusive "

Where an applicant defines an invention or portion thereof in an open term such as "comprising ", it should be readily understood that the description should be interpreted as describing the invention using the term" consisting essentially & do.

As used herein, the term "electrolyte precursor solution" means an electrolyte solution containing no lithium salt and ceramic particles, and "liquid electrolyte " means a liquid electrolyte in which a lithium salt is mixed with an electrolyte precursor solution , "Quasi-solid electrolyte" refers to a quasi-solid electrolyte (nanocomposite) containing ceramic particles in a liquid electrolyte.

The dye-sensitized solar cell according to the present invention comprises a first conductive layer, a photoelectrode located on the first conductive layer and including a dye-adsorbed metal oxide layer, a counter electrode disposed opposite to the photoelectrode, And a quasi-solid electrolyte interposed between the counter electrodes, which will be described later. Hereinafter, a method for producing a dye-sensitized solar cell will be described, and a description of a semi-solid electrolyte for a dye-sensitized solar cell will be given.

First, a photoelectrode including a dye-adsorbed metal oxide layer and a counter electrode including a metal layer are prepared.

Specifically, the photoelectrode may include a metal oxide layer on the first conductive layer and on which the dye is adsorbed.

The first conductive film may be formed of a conductive metal such as indium tin oxide (ITO), fluorine-doped tin oxide (FTO), ZnO-Ga ₂ O ₃ , ZnO-Al ₂ O ₃ or SnO ₂ -Sb ₂ O ₃ on a light- The oxide film may be coated. The light transmitting substrate may be a plastic substrate of PET (Poly Ethylene Terephthalate), PEN (Poly Ethylene Naphthalate), PC (Poly Carbonate), PP (Polypropylene), PI (Poly Imide) . However, the present invention is not limited thereto. Such a first conductive film can be formed, for example, on a light-transmitting substrate by using a metal oxide film by a sputtering method, an electrolytic plating method, an electron beam evaporation method, or the like.

The metal oxide layer located on the first conductive film is a layer formed of metal oxide particles having a nano-sized particle diameter and adsorbed on the dye. The metal oxide may be selected from the group consisting of titanium oxide, tin oxide, zinc oxide, tungsten oxide, zirconium oxide, strontium oxide, indium oxide, magnesium oxide, Oxides, aluminum (Al) oxides, and the like.

The thickness of the metal oxide layer is preferably 5 to 20 mu m.

The dye is not particularly limited as long as it is a dye capable of efficiently absorbing visible light and electron emission and includes, for example, a lutetium complex or coumarin, porphyrin, xanthene, riboflavin, And organic dyes such as triphenyl methane may be used.

The metal oxide layer can be formed by applying a coating composition containing metal oxide particles on the first conductive film by a usual coating process and then heat-treating the coating composition. Then, the dye can be adsorbed to the metal oxide layer by spraying, applying or immersing a dispersion containing the dye in the formed metal oxide layer.

The counter electrode may include a second conductive layer and a metal layer disposed on the second conductive layer. The second conductive film may be a conductive metal oxide film coated on the light-transmitting substrate, as described in the first conductive film. The metal layer located on the second conductive layer is a layer that catalyzes the reduction reaction of the redox derivative present in the electrolyte and is formed of platinum Pt, gold Au, ruthenium Ru, palladium Pd, Rhodium (Rh), iridium (Ir), osmium (Os), carbon (C), and the like. When the metal layer is a platinum layer, for example, the platinum precursor solution may be spin-coated on the second conductive layer and then heat-treated at 400 to 600 ° C or anodic oxidation of platinum.

After the photoelectrode and the counter electrode are prepared, the metal oxide layer of the photoelectrode and the metal layer of the counter electrode are arranged so as to face each other. For this, a metal oxide layer of the photoelectrode and a metal layer of the counter electrode are made to face each other, and a thermoplastic film having a thickness of 20 to 100 탆 is inserted between the edges of both electrodes, For 20 seconds so that both electrodes are in close contact with each other. Then, an electrolyte is injected into the space between the photoelectrode and the counter electrode through a previously drilled hole. Or a sandwich type in which a thermoplastic film is inserted into a photoelectrode and then a quasi-solid electrolyte is applied to the photoelectrode and a positive electrode is covered and adhered to the photoelectrode.

LiBOB, which is a lithium salt used in the present invention, is a lithium-bis (oxalato) borate having the following formula (1).

[Chemical Formula 1]

The lithium salt LiTFSI used in the present invention is Lithium Bis (Trifluoromethanesulfonyl Imide) having the structure of the following formula (2).

 (2)

It may be used, (lithium perchlorate Lithium Perchlorate) Furthermore the present invention, the lithium salt, LiPF ₆ (Lithium Hexafluorophosphate;; lithium hexafluorophosphate six), LiBF ₄ (lithium tetrafluoroborate boron lithium) and LiClO _4.

The quasi-solid electrolyte for a dye-sensitized solar cell according to the present invention comprises at least two kinds of lithium salts selected from LiBOB, LiTFSi, LiPF ₆ , LiBF ₄ and LiClO ₄ . At this time, two or more kinds of lithium salts are mixed at an appropriate ratio, and these are dissolved in the liquid electrolyte. The lithium salt contained in the quasi-solid electrolyte can improve the mobility of electrons by preventing the recombination of electrons at the interface between the electrode and the electrolyte, not by increasing the ionic conductivity of the electrolyte.

The amount of the lithium salt is preferably 1 to 10% by weight, more preferably 1 to 5% by weight based on the total weight of the liquid electrolyte solution. When the content of the lithium salt is less than 1% by weight, the lithium salt to be added is very small, which makes it difficult to accurately weigh and has a weak effect. When the content exceeds 10% by weight, lithium salt particles aggregate, This is because there is a disadvantage that the characteristics are rapidly lowered.

Preferably lithium salts of two or more is at least one selected from the group consisting of LiBOB and LiTFSi, LiPF _6, LiBF ₄ and LiClO _4. That is, LiBOB in the lithium salt must be contained and at least one other lithium salt may be mixed and used. When two or more kinds of lithium salts are mixed in a quasi-solid electrolyte, they exhibit porous surface characteristics, increase the absorption of the liquid electrolyte, and enhance the voltage-current characteristics of the solar cell by exhibiting a reinforcing effect according to the characteristics of the lithium salt to be added have.

The electrolyte composition is characterized in that it comprises ceramic particles bonded with a nanocomposite, an ionic liquid, a non-volatile organic solvent and a redox derivative.

The ceramic particles bonded with the nanocomposite of the electrolyte composition can increase the ionic conductivity to prevent decrease in ionic conductivity due to gelation and increase the photoelectric conversion current of the solar cell by increasing the scattering effect of sunlight. In the method of producing a gel polymer electrolyte, ceramic particles are added to a liquid electrolyte to allow the ceramic particles to absorb and solidify the liquid electrolyte. The viscosity is easily controlled according to the content of the ceramic particles and the ceramic particles are dispersed by stirring without any mechanism. With the addition of the ceramic particles, the ion conductivity can be further increased with the scattering effect of the sunlight. In addition, since the semi-solidification of the ceramic particles proceeds in the presence of the lithium salt, an additional process is not required and the introduction of impurities that may degrade the current or voltage characteristics of the solar cell in the electrolyte can be prevented.

These ceramic particles may be particles containing at least any one selected from SiO ₂ , Al ₂ O ₃ , TiO ₂ , SnO ₂ , CeO ₂ , ZrO ₂ , BaTiO ₃ , Y ₂ O ₃ and zeolite. The size of the ceramic particles is not limited, but is preferably in the range of 0.001 to 1 μm for uniform dispersion and thickness control of the electrolyte. The content of the added ceramic particles is preferably 0.5 to 30% by weight, more preferably 5 to 15% by weight based on the total weight of the liquid electrolyte solution. If the content of the ceramic particles is less than 0.5 wt%, the effect of improving the ionic conductivity hardly appears. If the content of the ceramic particles is more than 30 wt%, the flexibility of the gel polymer electrolyte deteriorates and the ionic conductivity decreases again, Because.

Also, the ionic liquid is not particularly limited, and there is imidazoliyide obtained from iodide (I ₂ ). The imidazole may be, for example, 1-methyl-3-propyl imidazole, 1,2-dimethyl-3-propyl imidazole, 3-hexyl- , 1,3-dimethylimidazole, and 1-butyl-3-methylimidazole. It may further comprise an ionic liquid used in the technical field to which the present invention belongs. For example, 1-methyl-3-ethyl imidazolium dicyanamide (EMIDCA), 1-ethyl-3-methylimidazolium thionate (EMINCS) [1-ethyl- 3-methylimidazolium thiocyanate].

The nonvolatile organic solvent may be an organic solvent having a high boiling point, for example, 3-methoxy propionitrile (MPN), sulfolane, gamma-butyrolactone, ethylene Carbonate (EC), propylene carbonate (PC), and the like.

Also, the redox derivative refers to a substance capable of providing redox pair, which serves to transfer electrons between the photoelectrode and the counter electrode through a reversible redox reaction in the electrolyte. Redox derivatives include, for example, ionic liquids such as 1-methyl-3-propyl imidazolium iodide (PMII), lithium iodide, sodium iodide, potassium iodide, lithium bromide A halogenated metal salt such as sodium or potassium bromide or a nitrogen-containing heterocyclic compound such as an imidazolinium salt, a pyridinium salt, a quaternary ammonium salt, a pyrrolidinium salt, a pyrazolinium salt, an isothiazolidinium salt or an isoxazolidinium salt Lt; / RTI > As the redox derivative, it is more preferable to provide an oxidation-reduction pair composed of I- and I ₃ -, for example, the redox pair of I- / I ₃ - is obtained by dissolving iodine in the molten salt of iodide Or by dissolving iodine or an oder active in a molten salt of a compound other than iodide.

Hereinafter, the structure and effect of the present invention will be described in more detail with reference to examples and comparative examples. However, this embodiment is intended to explain the present invention more specifically, and the scope of the present invention is not limited to these embodiments.

[Examples 1 to 3]

First, 0.8 M (2.016 g) of 1-methyl-3-propyl imidazolium iodide (PMII) (produced by C-TRI) having an oxidation-reduction pair was added to prepare an electrolyte precursor solution. And 0.06 M (0.152 g) of iodine (I2) (manufactured by Aldrich) are dissolved in 10 ml of a nonvolatile organic solvent 3-methoxypropionitrile (MPN) (manufactured by Aldrich). 0.05 M (0.059 g) of guanidine thiocyanate (GSCN) (manufactured by Aldrich) and 0.5 M (0.676 g) of 4-tert-butylpyridine (TBP) To form an electrolyte precursor solution.

Lithium bis (oxalato) borate (LiBOB) (manufactured by SOILBRAIN), lithium bis (trifluoromethanesulfonylimide) (lithium bis (oxalato) borate) which is a lithium salt was added to the prepared electrolyte precursor solution. (Trifluoromethanesulfonyl) Imide, LiTFSi) (manufactured by SOILBRAIN) was added in an amount of 1 wt% based on the total weight of the liquid electrolyte solution to prepare a liquid electrolyte solution. Here, LiBOB and LiTFSi, which are lithium salts, were mixed and added at a weight ratio of 3: 7, 5: 5, and 7: 3, respectively, to prepare a liquid electrolyte solution.

10 wt% of ceramic particle aluminum oxide (Al ₂ O ₃ , Al ₂ O ₃ ) (manufactured by Aldrich) was added to the prepared liquid electrolyte solution in an amount of 10 wt% based on the total weight of the liquid electrolyte solution and stirred to prepare a semi solid electrolyte (nanocomposite) .

In this case, the lithium salt LiBOB and LiTFSi were mixed at a weight ratio of 3: 7 in Example 1, 5: 5 in Example 2, and 7: 3, respectively.

[Comparative Example 1]

To prepare an electrolyte precursor solution, 0.8 M (2.016 g) of 1-methyl-3-propyl imidazolium iodide (PMII) having an oxidation-reduction pair (manufactured by C-TRI) 0.06M (0.152 g) of Odin I2 (manufactured by Aldrich) is dissolved in 10 ml of a nonvolatile organic solvent 3-Methoxypropionitrile (MPN) (manufactured by Aldrich). 0.05 M (0.059 g) of guanidine thiocyanate (GSCN) (manufactured by Aldrich) and 0.5 M (0.676 g) of 4-tert-butylpyridine (TBP) To form an electrolyte precursor solution.

Lithium bis (oxalato) borate (LiBOB) (manufactured by SOILBRAIN), lithium bis (trifluoromethanesulfonylimide) (lithium bis (oxalato) borate) which is a lithium salt was added to the prepared electrolyte precursor solution. (Trifluoromethanesulfonyl) Imide, LiTFSi) (manufactured by SOILBRAIN) was added in an amount of 1 wt% based on the total weight of the liquid electrolyte solution to prepare a liquid electrolyte solution. Here, LiBOB and LiTFSi, which are lithium salts, were mixed and added at a weight ratio of 5: 5 to prepare a liquid electrolyte solution.

[Comparative Example 2]

A quasi-solid electrolyte was prepared in the same manner as in Example 1, except that the lithium salt was not included.

[Comparative Example 3]

A quasi-solid electrolyte was prepared in the same manner as in Example 1, except that only LiBOB in the lithium salt was added in an amount of 1 wt% based on the total weight of the liquid electrolyte solution.

[Comparative Example 4]

A quasi-solid electrolyte was prepared in the same manner as in Example 1, except that only LiTFSi in the lithium salt was added in an amount of 1 wt% based on the total weight of the liquid electrolyte solution.

[Experimental Example] Evaluation of performance of dye-sensitized solar cell

The photocurrent-voltage was measured under 1 sun (100 mW / cm ² ) illumination conditions using the dye-sensitized solar cell comprising the electrolyte prepared in Examples 1 to 3 and Comparative Examples 1 to 4, Are shown in Tables 1 and 2 below. The current-voltage curves of the dye-sensitized solar cell including the electrolytes of Examples 1 to 3 and Comparative Examples 1 to 4 are shown in FIGS. 1 and 2. FIG.

Dyes Jsc
(mAcm ^-2 ) Voc
(V) FF η
(%) Comparative Example 4 7.21 0.719 64.68 3.36 Example 1 9.25 0.697 61.70 3.98 Example 2 10.44 0.695 57.07 4.15 Example 3 9.99 0.686 58.75 4.03 Comparative Example 3 7.90 0.695 64.22 3.53

As can be seen from Table 1 and FIG. 1, in the case of a solar cell using a quasi-solid electrolyte using a lithium salt mixed with LiBOB: LITFSI 5: 5, Voc was 0.695 V at 1 sun (100 mW / cm ² ) Jsc of 10.44 mA / cm ² , fill factor of 57.07 and η of 4.15%. In addition, it can be confirmed that the efficiency increases when the lithium salt is applied. Further, when the weight ratio is 5: 5 as in Example 2, it can be confirmed that the efficiency is 98% of the liquid electrolyte.

Jsc
(mAcm ^-2 ) Voc
(V) FF η
(%) Comparative Example 1 10.11 0.695 59.97 4.22 Comparative Example 2 5.38 0.728 65.67 2.58 Comparative Example 3 7.90 0.695 64.22 3.53 Comparative Example 4 7.21 0.719 64.68 3.36

From FIG. 3, which is an SEM image when the lithium salt LITFSI is applied singly, and FIG. 4, which is an SEM photograph obtained by mixing two or more types of lithium salt LiBOB: LITFSI (5: 5) Sized particles, whereas the case of applying two or more kinds of lithium salts shows a porous surface property.

Claims (10)

Including, but two or more kinds of lithium salts selected from the _{LiBOB, LiTFSi, LiPF 6, LiBF} 4 and LiClO _4,
The two or more kinds of the lithium salt is at least one selected from the group consisting of LiBOB and LiTFSi, LiPF _6, LiBF ₄ and LiClO _4,
The lithium salt and the LiBOB LiTFSi, LiPF _6, LiBF _4, and at least one lithium salt selected from LiClO ₄ weight ratio is 5: 5, characterized in that the dye-sensitized solar cell quasi-solid electrolyte. delete delete The method according to claim 1,
The semi-solid electrolyte for a dye-sensitized solar cell, wherein the lithium salt is contained in an amount of 1 to 10 wt% based on the total weight of the liquid electrolyte solution. The method according to claim 1,
Wherein the electrolyte composition comprises ceramic particles, an ionic liquid, a non-volatile organic solvent, and a redox derivative bonded to the nanocomposite. 6. The method of claim 5,
Wherein the ceramic particles are at least one selected from the group consisting of SiO ₂ , Al ₂ O ₃ , TiO ₂ , SnO ₂ , CeO ₂ , ZrO ₂ , BaTiO ₃ , Y ₂ O ₃ and zeolite. Electrolyte. The method according to claim 6,
Wherein the ceramic particles have a particle diameter of 0.001 to 1 占 퐉 and are contained in an amount of 0.5 to 30% by weight based on the total weight of the liquid electrolyte solution. 6. The method of claim 5,
The non-volatile organic solvent may be 3-methoxy propionitrile (MPN), sulfolane, gamma-butyrolactone, ethylene carbonate (EC), propylene carbonate (PC) Wherein the quaternary solid electrolyte is a cyclic carbonate of formula (I) or a salt thereof. 6. The method of claim 5,
The redox derivative may be an ionic liquid such as 1-methyl-3-propyl imidazolium iodide (PMII), lithium iodide, sodium iodide, potassium iodide, lithium bromide, sodium bromide or bromide At least one of a nitrogen-containing heterocyclic compound such as a halogenated metal salt such as potassium or an imidazolinium salt, a pyridinium salt, a quaternary ammonium salt, a pyrrolidinium salt, a pyrazolinium salt, an isothiazolidinium salt or an isoxazolidinium salt Wherein the quasi-solid electrolyte for a dye-sensitized solar cell is a quasi-solid electrolyte for a dye-sensitized solar cell. A first conductive film,
A photoelectrode disposed on the first conductive film and including a dye-adsorbed metal oxide layer;
A counter electrode disposed opposite to the photo electrode; And
The dye-sensitized solar cell according to any one of claims 1 to 9, which is interposed between the photoelectrode and the counter electrode, and comprises the quasi-solid electrolyte according to any one of claims 1 to 9.

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