KR20120133739A - UV curing gel-typed solid electrolyte for dye-sensitized solar cell - Google Patents

Abstract

PURPOSE: A gel type polymeric electrolyte for dye-sensitized solar battery is provided to extend lifetime of dye-sensitized solar cell, to be stably operated at high temperatures, and to have excellent photo-conversion efficiency. CONSTITUTION: A gel type polymeric electrolyte for dye-sensitized solar battery comprises liquid electrolyte and UV curable resin. The UV curable resin comprises: one or two more UV-curable acylate monomers selected from a monofunctional acrylate monomer, a bifunctional acrylate monomer, and polyfunctional acrylate monomer; an epoxy acrylate, urethane acrylate, polyester acrylate, silicone acrylate, and an acryl-based acrylate; a photoinitiator; and an antioxidant as an additive, a photostabilizer or a mixture thereof.

Description

UV curable gel-type polymer electrolyte for dye-sensitized solar cell and dye-sensitized solar cell comprising same {UV curing gel-typed solid electrolyte for dye-sensitized solar cell}

The present invention relates to a UV-curable gel polymer electrolyte for dye-sensitized solar cells (DSSC) and a dye-sensitized solar cell comprising the same.

As an alternative to fossil fuels, the first silicon-based solar cell was developed at Bell Labs in 1954 with an efficiency of about 6%. Since then, the development of solar cells has focused on inorganic silicon.

Inorganic solar cells consist of p-n junctions of inorganic semiconductors such as silicon. Silicon used as a solar cell material is largely divided into crystalline silicon such as monocrystalline or polycrystalline silicon and amorphous silicon. The crystalline silicon series is superior to the amorphous silicon series in terms of energy conversion efficiency of converting solar energy into electrical energy, but productivity is low due to the time and energy required to grow crystals. Compared with crystalline silicon, amorphous silicon series has better light absorption, easier to enlarge area, and more advantageous in terms of productivity, but it is inefficient in terms of equipment because it requires a vacuuming process. As a result of this problem, a study has been made on solar cells using photovoltaic phenomena of organic materials instead of silicon.

Recently, research on fuel-sensitized solar cells (DSSC) has been actively conducted due to high photoelectric efficiency and low manufacturing cost. The dye-sensitized solar cell is a solar cell manufactured using a photoelectrochemical reaction by inserting an electrolyte into an oxide layer such as titanium oxide in which a dye is adsorbed between a transparent electrode and a metal electrode. In general, dye-sensitized solar cells are composed of two electrodes (photoelectrode and counter electrode), inorganic oxides, dyes, and electrolytes. Dye-sensitized solar cells are environmentally friendly because they use environmentally harmless materials. It is reported that the inorganic solar cell has a high energy conversion efficiency of about 10% that is comparable to that of the amorphous silicon-based solar cell, and the manufacturing cost is only about 20% of the silicon solar cell. Out of the conventional pn junction method a large surface area and the band gap (band gap) nano-oxide particles, can absorb light to generate electron dye (dye) that has a characteristic, and oxidation / reduction pair (I ^- / I ₃ ^- The dye-sensitized solar cell composed of an electrolyte containing) is proposed as a new alternative to the expensive silicon semiconductor solar cell.

The electrolyte is an electron transfer dye molecules (S ---> S *) oxide, as a result of light absorption is the oxidation of iodide ions in the electrolyte receives electrons provided in the back _{^{(3I - -> I 3 -}} - + 2e) D-sensitized solar cell is operated by the reduction of I ₃ ^- ions by electrons reaching the counter electrode. The photocurrent is obtained by diffusion of electrons injected into the semiconductor oxide electrode, and the photovoltage is the semiconductor oxide Fermi energy and electrolyte. Is determined by the redox potential difference. As can be seen from this principle, the electrolyte of a dye-sensitized solar cell can often be evaluated for its efficiency by conductivity and diffusion coefficient.

However, such a dye-sensitized solar cell is a situation in which leakage and evaporation due to a highly efficient liquid electrolyte are problematic. Therefore, the solar cell has a short lifespan and is unstable at high temperatures, requiring a new type of electrolyte.

The present invention has been made to solve the problems of the prior art as described above, the object of the present invention is almost no problem of water leakage and evaporation, it is possible to extend the life of the dye-sensitized solar cell and to drive stable at high temperature In addition, the present invention provides a UV-curable gel polymer electrolyte for dye-sensitized solar cells having excellent light conversion efficiency and a dye-sensitized solar cell including the same.

In order to achieve the above and other objects, the present invention, in the UV-curable gel polymer electrolyte for dye-sensitized solar cells comprising a liquid electrolyte,

(a) one or two or more ultraviolet curable acrylate monomers selected from the group consisting of monofunctional acrylate monomers, difunctional acrylate monomers and polyfunctional acrylate monomers; (b) one or two or more acrylic oligomers selected from the group consisting of epoxy acrylates, urethane acrylates, polyester acrylates, silicone acrylates and acrylic acrylates; (c) photoinitiators; And (d) provides a UV curable gel polymer electrolyte for dye-sensitized solar cell comprising a UV curable resin comprising an antioxidant, light stabilizer or a mixture thereof as an additive.

The liquid electrolyte used in the present invention is not limited, but 1,2-dimethyl-3-propyl imidazolium iodine ((1,2-dimethyl-3-propyl imidazolium iodide, DMPII), iodine (I ₂ ), lithium iodide Redox derivatives and organic solvents selected from the group consisting of (LiI), sodium iodide, potassium iodide, lithium bromide, sodium bromide, potassium bromide, quaternary ammonium salts, imidazolium salts and pyridinium salts; In particular, 1,2-dimethyl-3-propyl imidazolium iodine ((1,2-dimethyl-3-propyl imidazolium iodide, DMPII) may be particularly preferably used as the redox derivative. have.

Organic solvents that can be used in the liquid electrolyte include acetonitrile, 3-methoxypropionitrile, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, tetrahydrofuran and gamma-buty. One or two or more mixed solvents selected from the group consisting of rockactone may be mentioned.

UV-curable acrylate monomers and acrylic oligomers that can be used in the present invention are independently of each other 2-HEMA (2-hydroxyethyl methacrylate), ODA (octyl / decyl acrylate), IDA (isodecyl acrylate), LA (Lauyl acrylate), SA (stearyl acrylate), GMA (glycidyl methacrylate), EMA (ethyl methacrylate), PEA (phenoxyethyl acrylate), MNPEOA (nonyl phenol ethoxylate mono Acrylates), tetrahydrofurfuryl acrylate, tetrahydrofurfuryl methacrylate, cyclohexyl acrylate, 4-butylcyclohexyl acrylate, dicyclopentenyl acrylate, dicyclophene Tenyl oxyethyl acrylate, butyl glycidyl ether acrylate, 4-HBA (4-hydroxybutyl acrylate), NBMA (N-butyl methacrylate E), phenoxyethyl acrylate, isobornyl acrylate, styrene, vinyl toluene, vinyl acetate and / or monovinyl ether (ODVE, CHMVE, MVE-2, PEPC); 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, tripropylene glycol diacrylate, tripropylene glycol dimethacrylate, β-carboxyethyl acrylate, ethylene glycol dimethacrylate , Diethylene glycol diacrylate, diethylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, dipropylene glycol diacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate , Diol diacrylate, acrylated bisphenol ethoxylate, allyl methacrylate and / or WS-2100 (water soluble acrylate); Trimethyllopropane Triacrylate, Trimethyllopropane Trimethacrylate, Pentaerythritol Triacrylate, Ethoxylated and Propoxylated Trimetylopropane Triacrylate, Glyceryl Propoxylated Glyceryl Propoxylated Triacrylate, Pentaerythritol Tetra-acrylate, Ditrimethyllopropane Tetra-acrylate, Alkoxylated Tetra-acrylate, SU-550 (Moisture-containing Aliphatic Urethane Triacrylate), SU-560 (Aliphatic urethane triacrylate) and / or EB9260 (aliphatic urethane triacrylate oligomer) can be selected from the group consisting of one or two or more.

Further, photoinitiators that can be used in the present invention are ethylbenzoin ether, isopropylbenzoin ether, α-methylbenzoin ethyl ether, benzoin phenyl ether, α-acyl oxime ester, α, α-diethoxy acetophenone, 1 , 1-dichloroacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxy cyclohexylphenyl ketone, anthraquinone, 2-anthraquinone, 2-chloroanthraquinone, thioxane It may be selected from the group consisting of tones, isopropyl thioxanthone, chlorothioxanthone, benzophenone, p-chlorobenzophenone, benzyl benzoate, benzoyl benzoate and mickle ketone.

In the present invention, the UV curable resin and the liquid electrolyte are preferably included in a weight ratio of 1: 1 to 9: 1. If less UV curable resin is contained, gel formation will not occur.

In the present invention, the UV curable resin based on the total weight of the UV curable resin 30 to 95% by weight of the ultraviolet curable acrylate monomer, 1 to 70% by weight of the acrylic oligomer, 1-5% by weight of the photoinitiator and additives Include. As the additive, conventional antioxidants and / or ultraviolet stabilizers may be used.

The UV-curable gel polymer electrolyte for dye-sensitized solar cells according to the present invention has almost no problems of leakage and evaporation as in liquid electrolytes, prolongs the life of dye-sensitized solar cells, operates stably at high temperatures, and converts light. The efficiency is excellent.

1 is a diagram illustrating a process of manufacturing a solar cell using a gel polymer electrolyte applied to a dye-sensitized solar cell according to the present invention.

Hereinafter, the present invention will be described by the following examples. The following examples are only for illustrating the present invention more specifically, but the present invention is not limited to the following examples.

Laboratory Instruments and Reagents

Experimental instruments and reagents used in the following Examples and Experimental Examples are as follows.

* FTO-8Ω, 2.2T

TiO ₂ aqueous solution-TiCl 4 diluted with 40 mM

* TiO ₂ paste (Dyesol, 18NR-T)

* Dye (Dyesol, N719)-0.5 mM in Acetonitrile: tert-butanol (1: 1 v / v%)

* Pt (KOJIMA chemical Ltd., H ₂ PtCl ₆ nH ₂ O)-10.2mM in IPA

* Electrolyte-Manufactured Liquid Electrolyte (50%) + UV Curing Resin (50%)

* Sealing-Surlyn (thickness: 25 μm)

Example  1-1

0.7 M 1,2-dimethyl-3-propyl imidazolium iodine (1,2-dimethyl-3-propyl imidazolium iodide, DMPII , Sigma Aldrich) 18.6 g, 0.1 M LiI (Siggma Aldrich) 1.3 g, 40 mM 1.0 g of I ₂ (DukSan), 1.7 g of 4-tert-butylpyridine, Sigma Aldrich, 1.7 g, 15.5 M of acetonitrile (Acetonitrile, Sigma Aldrich) 64 g, 1.79 M of tetra 16 g of hydrofuran (Tetrahydrofuran, Sigma Aldrich) was mixed to prepare a liquid electrolyte, wherein 1,6-hexanediol diacrylate as a monomer and α-aminoketone as a photoinitiator were mixed at a weight ratio of 97.5: 2.5. The resin was mixed to prepare an electrolyte, wherein the UV curable resin and the liquid electrolyte were mixed in a weight ratio of 1: 1.

Example  1-2

Each electrolyte solution was prepared in the same manner as in Example 1-1, except that the UV curing resin mixing ratio was 97: 3.

Example  1-3

Each electrolyte solution was prepared in the same manner as in Example 1-1, except that the UV curing resin mixing ratio was 96: 4.

Example  1-4

Each electrolyte solution was prepared in the same manner as in Example 1-1, except that the UV curing resin mixing ratio was 95: 5.

Example  1-5

Each electrolyte solution was prepared in the same manner as in Example 1-1, except that the UV curing resin mixing ratio was 94: 6.

Example  2-1 to 4

UV-curing using water-containing aliphatic urethane triacrylate with water (SU-550) as oligomer, 1,6-hexanediol diacrylate as monomer, hydroxycyclohexyl-phenyl-ketone as photoinitiator Each electrolyte was prepared in the same manner as in Example 1-1, except that the resin and the liquid electrolyte were mixed in a weight ratio of 5: 5, 6: 4, 7: 3, and 8: 2, respectively.

Example  3-1 to 4

As oligomers, water-containing aliphatic urethane triacrylate with water (SU-550), 1,6-Hexanediol diacrylate as monomer, and α-aminoketone as photoinitiator were used, and the ratio of oligomer and monomer was 3: Each electrolyte solution was prepared in the same manner as in Example 1-1, except that 7, 2: 8, 1: 9, and 0:10 were used.

Example  4-1 ~ 4

Example 1 except that α-hydroketone, α-aminoketone, bis-acylphosphine, and monoacylphosphine were used as photoinitiators, and the UV curable resin and the liquid electrolyte were mixed in a weight ratio of 1: 1. Each electrolyte was prepared by the same method as the method of −1.

Example  5-1 ~ 4

Each electrolyte was prepared in the same manner as in Example 1-1, except that 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, and dipropylene glycol diacrylate were used as monomers. It was.

Comparative example  One

The efficiency was compared with the electrolyte of the present invention using an electrolyte EL-HSE manufactured and sold by Dyesol as a commercially available liquid electrolyte.

Comparative example  2

An electrolyte was prepared in the same manner as in Example 1-1, except that CH ₃ I was used as the liquid electrolyte component.

Comparative example  3

An electrolyte was prepared in the same manner as in Example 1-1, except that C ₂ H ₅ I was used as the liquid electrolyte component.

Comparative example  4

An electrolyte was prepared in the same manner as in Example 1-1, except that a 1: 1 mixture (weight) of CH ₃ I and C ₂ H ₅ I was used as the liquid electrolyte component.

Experimental Example

Titanium dioxide (TiO ₂ ) paste (Dyesol, 18NR-T) was coated on a fluorine-containing tin oxide (FTO, 8 Pa, 2.2T) transparent glass substrate to a thickness of 30 µm, and then fired at a temperature of 500 ° C. Then, the calcined FTO glass substrate was deposited on a solution in which a dye (Dyesol, N719, 0.5 mM in Acetonitrile: tert-butanol (1: 1 v / v%)) was dissolved in alcohol, and then dried at 80 ° C. Dried for 24 hours. Subsequently, after coating the electrolyte prepared through the above Examples and Comparative Examples, it was cured at an exposure dose of 2000mJ using an ultraviolet irradiator to form a gel polymer electrolyte coating layer. It was then sealed with platinum (KOJIMA chemical Ltd., H ₂ PtCl ₆ nH ₂ O, 10.2 mM in IPA) coated FTO glass substrate in accordance with conventional methods. Film conversion or gelation and the Orion 5-Star Meter (pH / ORP / ISE / DO / Conductivity) were measured using Termo Scientific to evaluate the light conversion efficiency. The results are shown in Table 1 below.

Example No. Film and Gel Formation V _oc
(v) I _sc
(mA) J _sc
(mA / cm ² ) Fill factor
(%) I _max
(mA) V _max
(v) P _max
(mW) Optical conversion efficiency
(%) Example 1-1 Film and Gel Formation 0.66 4.98 19.86 62.28 4.33 0.47 2.05 8.21 Examples 1-2 Film and Gel Formation 0.64 4.55 18.20 66.73 4.09 0.48 1.96 7.83 Example 1-3 Film and Gel Formation 0.67 4.85 19.41 63.30 4.30 0.48 2.06 8.24 Example 1-4 Film and Gel Formation 0.68 4.83 19.3 64.86 4.18 0.51 2.13 8.51 Examples 1-5 Film and Gel Formation 0.66 4.73 18.92 65.43 4.09 0.50 2.03 8.14 Example 2-1 Film and Gel Formation 0.71 3.99 15.99 63.99 3.49 0.52 1.81 7.245 Example 2-2 Film and Gel Formation 0.67 3.05 12.20 63.88 2.77 0.47 1.31 5.24 Example 2-3 Film and Gel Formation 0.71 1.58 6.33 55.36 1.32 0.48 0.63 2.515 Examples 2-4 Film and Gel Formation 0.69 0.74 2.85 47.83 0.53 0.46 0.24 0.97 Example 3-1 Film and Gel Formation 0.69 2.50 9.99 59.08 2.05 0.49 1.02 4.09 Example 3-2 Film and Gel Formation 0.70 3.07 12.27 52.91 2.45 0.46 1.14 4.57 Example 3-3 Film and Gel Formation 0.69 2.95 11.80 54.75 2.30 0.49 1.13 4.51 Example 3-4 Film and Gel Formation 0.71 3.16 12.63 57.63 2.61 0.49 1.29 5.17 Example 4-1 Film and Gel Formation 0.63 4.50 17.99 65.71 3.94 0.47 1.86 7.43 Example 4-2 Film and Gel Formation 0.66 4.98 19.86 62.28 4.33 0.47 2.05 8.21 Example 4-3 Film and Gel Formation 0.64 4.07 16.29 62.84 3.49 0.47 1.65 6.59 Example 4-4 Film and Gel Formation 0.61 4.74 18.97 65.00 4.21 0.45 1.88 7.50 Example 5-1 Film and Gel Formation 0.64 5.13 20.52 58.14 4.14 0.46 1.91 7.68 Example 5-2 Film and Gel Formation 0.64 5.72 22.87 57.37 4.56 0.45 2.09 8.36 Example 5-3 Film and Gel Formation 0.62 5.22 20.88 58.09 4.20 0.448 1.88 7.52 Example 5-4 Film and Gel Formation 0.64 5.23 20.94 58.76 4.27 0.46 1.97 7.88 Comparative Example 1 Not formed 0.67 3.99 15.96 73.82 3.69 0.54 1.99 7.94 Comparative Example 2 Not formed 0.69 4.09 16.36 56.55 3.34 0.48 1.61 6.46 Comparative Example 3 Not formed 0.71 3.87 15.49 55.83 3.28 0.47 1.54 6.18 Comparative Example 4 Not formed 0.73 3.55 14.24 51.84 2.93 0.45 1.34 5.38

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention as defined in the following claims. It can be understood that it is possible.

Claims (8)

In the UV curable gel polymer electrolyte for dye-sensitized solar cells containing a liquid electrolyte,
(a) one or two or more ultraviolet curable acrylate monomers selected from the group consisting of monofunctional acrylate monomers, difunctional acrylate monomers and polyfunctional acrylate monomers; (b) one or two or more acrylic oligomers selected from the group consisting of epoxy acrylates, urethane acrylates, polyester acrylates, silicone acrylates and acrylic acrylates; (c) photoinitiators; And (d) UV curable gel-type polymer electrolyte for dye-sensitized solar cell comprising a UV curable resin comprising an antioxidant, light stabilizer or a mixture thereof as an additive. The method of claim 1, wherein the liquid electrolyte is 1,2-dimethyl-3-propyl imidazolium iodine (1,2-dimethyl-3-propyl imidazolium iodide, DMPII), iodine (I ₂ ), lithium iodide (LiI) And a redox derivative and an organic solvent selected from the group consisting of sodium iodide, potassium iodide, lithium bromide, sodium bromide, potassium bromide, quaternary ammonium salt, imidazolium salt and pyridinium salt, and an organic solvent. UV curable gel polymer electrolyte for dye-sensitized solar cells, characterized in that. The group of claim 2, wherein the organic solvent is composed of acetonitrile, 3-methoxypropionitrile, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, tetrahydrofuran and gamma-butyrolactone. UV-curable gel polymer electrolyte for dye-sensitized solar cells, characterized in that one or two or more mixed solvents selected from. The UV curable acrylate monomer and the acrylic oligomer are independently of each other 2-HEMA (2-hydroxyethyl methacrylate), ODA (octyl / decyl acrylate), IDA (isodecyl acrylate), LA (Lauyl acrylate), SA (stearyl acrylate), GMA (glycidyl methacrylate), EMA (ethyl methacrylate), PEA (phenoxyethyl acrylate), MNPEOA (nonyl phenol ethoxylate mono Acrylates), tetrahydrofurfuryl acrylate, tetrahydrofurfuryl methacrylate, cyclohexyl acrylate, 4-butylcyclohexyl acrylate, dicyclopentenyl acrylate, dicyclophene Tenyl oxyethyl acrylate, butylglycidylether acrylate, 4-HBA (4-hydroxybutyl acrylate), NBMA (N-butyl methacrylate), phenoxy Ethyl acrylate, isobornyl acrylate, styrene, vinyl toluene, vinyl acetate and / or monovinyl ether (ODVE, CHMVE, MVE-2, PEPC); 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, tripropylene glycol diacrylate, tripropylene glycol dimethacrylate, β-carboxyethyl acrylate, ethylene glycol dimethacrylate , Diethylene glycol diacrylate, diethylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, dipropylene glycol diacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate , Diol diacrylate, acrylated bisphenol ethoxylate, allyl methacrylate and / or WS-2100 (water soluble acrylate); Trimethyllopropane Triacrylate, Trimethyllopropane Trimethacrylate, Pentaerythritol Triacrylate, Ethoxylated and Propoxylated Trimetylopropane Triacrylate, Glyceryl Propoxylated Glyceryl Propoxylated Triacrylate, Pentaerythritol Tetra-acrylate, Ditrimethyllopropane Tetra-acrylate, Alkoxylated Tetra-acrylate, SU-550 (Moisture-containing Aliphatic Urethane Triacrylate), SU-560 UV curable gel polymer electrolyte for dye-sensitized solar cells, characterized in that at least one selected from the group consisting of (aliphatic urethane triacrylate) and / or EB9260 (aliphatic urethane triacrylate oligomer). The photoinitiator of claim 1, wherein the photoinitiator is ethylbenzoin ether, isopropylbenzoin ether, α-methylbenzoin ethylether, benzoin phenylether, α-acyl oxime ester, α, α-diethoxy acetophenone, 1,1 -Dichloroacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxy cyclohexylphenyl ketone, anthraquinone, 2-anthraquinone, 2-chloroanthraquinone, thioxanthone, Dye-sensitized type, characterized in that one or more selected from the group consisting of isopropyl thioxanthone, chlorothioxanthone, benzophenone, p-chlorobenzophenone, benzyl benzoate, benzoyl benzoate and mickle ketone UV curable gel polymer electrolyte for solar cells. The UV-curable gel polymer electrolyte for dye-sensitized solar cell of claim 1, wherein the UV curable resin and the liquid electrolyte are included in a weight ratio of 1: 1 to 9: 1. According to claim 6, wherein the UV curable resin based on the total weight of the UV curable resin 30 to 95% by weight of the ultraviolet curable acrylate monomer, 1 to 70% by weight of the acrylic oligomer, the remaining 1 to 5% by weight photoinitiator and additives UV curable gel polymer electrolyte for dye-sensitized solar cell comprising a. A dye-sensitized solar cell comprising the electrolyte according to any one of claims 1 to 7.

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