WO2014104644A1

WO2014104644A1 - Electrolyte

Info

Publication number: WO2014104644A1
Application number: PCT/KR2013/011780
Authority: WO
Inventors: 장송림; 이재철; 이민종; 율리에비치 가돕스키드미트리; 세르게에비치 샤플로프알렉산더; 아이오시포브나 로진스카야엘리나; 에브게니브나 오지모바아나스타시아; 올레고비치 판크라토프데니스; 세메노비치 비고츠키야코프
Original assignee: 주식회사 엘지화학
Priority date: 2012-12-27
Filing date: 2013-12-18
Publication date: 2014-07-03

Abstract

The present application relates to an electrolyte, to a precursor thereof, and to a dye-sensitized solar cell. The present application provides a photovoltaic device which has, for example, an elastic film shape, has excellent solvent holding capacity and ion conductivity or liquidity, and can be operated with excellent efficiency over a long period of time. The present application also provides an electrolyte which is capable of forming, for example, the dye-sensitized solar cell. Further, according to the present application, a precursor for forming the electrolyte and the photovoltaic device -for example, the dye-sensitized solar cell - containing the electrolyte are provided.

Description

Electrolyte

The present application relates to an electrolyte, a precursor thereof, and a dye-sensitized solar cell.

Solar cells based on crystalline titanium dioxide, organic dyes and electrolytes have been proposed by Michael Grtzel, Ph.D., Federal University of Technology, Lausanne, Switzerland (Non-Patent Documents 1 and 2). The photoelectric device is known as a dye-sensitized solar cell (DSSC) or a grachel cell. The highest conversion efficiency reported for dye-sensitized solar cells is 11% or more (Non Patent Literatures 3 to 6).

The dye-sensitized solar cell contains an organic solvent, and the evaporation of the organic solvent causes the photoelectrochemical process to become unstable and causes adverse effects on the environment and malfunctions.

Accordingly, it has been attempted to manufacture dye-sensitized solar cells using a minimum amount of organic solvent or without using an organic solvent. For example, there are attempts to manufacture dye-sensitized solar cells using solid electrolytes. New types of solvents are known, for example, quasi solid (gel) electrolytes using ionic liquids and / or polymeric analogues (polymeric ionic liquids) thereof.

Non-Patent Document 7 describes an electrolyte including a poly (1-vinyl-3-propylimidazolysin) iodide and a liquid electrolyte. The liquid electrolyte is a solution of iodine, 1,2-dimethyl-3-propylimidazolysin iodide, thiocyanate of guanidinium and 4-t-butylpyridine. The dye-sensitized solar cell prepared using the electrolyte exhibits an energy conversion efficiency of about 2.8% (radiation intensity: 100 mW / cm ² ). In this method, an additional step of preparing the ionic polymer is required, and the ionic polymer dissolves in the liquid electrolyte, which adversely affects the dimensional stability and the mechanical strength, and may also contain a large amount of organic solvent. Is generated and not appropriate in terms of environmental or device performance. In addition, in the above technique, only an ionic polymer exists as a source of iodine ions required to form a redox couple (I ⁻ / I ₃ ), and an ion center is directly attached to the polymer chain, The fluidity of is greatly reduced.

Non-Patent Document 8 describes a composition containing poly (1-vinyl-3-propylimidazolium) bis (trifluoromethanesulfonyl) imide and a liquid electrolyte. The energy conversion efficiency of the dye-sensitized solar cell based on this is about 4.4% at a radiation intensity of 100 mW / cm ² . However, the above technique also requires an additional step of preparing the ionic polymer, and the gel mass is formed as the ionic polymer is dissolved in the liquid electrolyte, due to the high viscosity of the gel mass and the ion center attached to the polymer chain. The fluidity of ions is greatly reduced.

[선행기술문헌][Preceding technical literature]

[비특허문헌][Non-Patent Documents]

(Non-Patent Document 1) B. O'Regan, M. Gratzel. A low-cost, high-efficiency solar cell based on dye-sensitized colloidal TiO ₂ films. Nature 1991, 353 (6346), 737-740

(Non-Patent Document 2) M. Gratzel. Photoelectrochemical cells. Nature 2001, 414 (6861), 338-344

(Non-Patent Document 3) M. Gratzel. Conversion of sunlight to electric power by nanocrystalline dye-sensitized solar cells. J. Photochem. Photobiol. A 2004, 164 (1-3), 3-14

(Non-Patent Document 4) Y. Chiba, A. Islam, Y. Watanabe, R. Komiya, N. Koide, L. Y. Han. Dye-sensitized solar cells with conversion efficiency of 11.1%. Japanese Journal of Applied Physics Part 2-Letters & Express Letters 2006, 45 (24-28), L638-L640

(Non-Patent Document 5) M. Gratzel. Dye-sensitized solar cells. J. Photochem. Photobiol. C 2003, 4, 145-153

(Non-Patent Document 6) Y. Bai, Y. Cao, J. Zhang, M. Wang, R. Li, P. Wang, S. M. Zakeeruddin, M. Gratzel. High-performance dye-sensitized solar cells based on solvent-free electrolytes produced from eutectic melts. Nature Materials 2008, 7 (8), 626-630

(Non-Patent Document 7) E. Azaceta, R. Marcilla, A. Sanchez-Diazb, E. Palomares, D. Mecerreyes. Synthesis and characterization of poly (1-vinyl-3-alkylimidazolium) iodide polymers for quasi-solid electrolytes in dye sensitized solar cells. Electrochimica Acta. 2010, 56, 4246

(Non-Patent Document 8) J. Zhao, X. Shen, F. Yan, L. Qiu, S. Lee, B. Sun. Solvent-free ionic liquid / poly (ionic liquid) electrolytes for quasi-solid-state dye-sensitized solar cells. J. Mater. Chem. 2011, 21, 7326-7330

The present application provides an electrolyte, a precursor thereof, and a dye-sensitized solar cell.

Exemplary electrolytes may include a polymer network that is crosslinked by a compound of Formula 1 below. The compound of formula 1 may also be referred to herein as a crosslinking agent. The electrolyte may be, for example, a polymer electrolyte or a solid polymer electrolyte. Such electrolytes can be usefully used in photoelectrical devices. As the photoelectric device, for example, a photoelectrochemical cell such as a dye-sensitized solar cell and the like can be exemplified, but is not limited thereto.

[Formula 1]

In Formula 1, R is hydrogen or an alkyl group, A is an alkylene group or an alkylidene group, n is a number of 1 to 17.

As used herein, unless otherwise specified, the term alkyl group may mean an alkyl group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. The alkyl group may have a straight chain, branched chain or ring structure, and may be optionally substituted with one or more substituents if necessary.

As used herein, unless otherwise specified, the term alkylene group or alkylidene group means an alkylene group or alkylidene group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. can do. The alkylene group or alkylidene group may have a straight chain, branched chain or ring structure, and optionally may be optionally substituted with one or more substituents.

N in Formula 1 may be, for example, in the range of 3 to 15 or 5 to 13.

The polymer network may include a compound of Formula 2 below. The compound of formula 2 may be included in the polymer network, for example in the form of a crosslinked product. In the above, the form of the crosslinked product may mean that the compound of Formula 2 is present in a state in which the compound of Formula 1 is reacted with another compound of Formula 2 and / or a compound of Formula 3 to be described later.

[Formula 2]

In Formula 2, R is hydrogen or an alkyl group, A is an alkylene group or an alkylidene group, R ₁ is an alkyl group, m is a number of 2 to 19.

M in Formula 2 may be, for example, 4 to 17 or 6 to 15.

The compound of Formula 2 or a crosslinked product thereof may be included, for example, in 20 parts by weight to 80 parts by weight, 30 parts by weight to 70 parts by weight, or 40 parts by weight to 60 parts by weight relative to 100 parts by weight of the compound of Formula 1 in the polymer network. have. In this range, an appropriate crosslinked structure of the polymer network can be realized. In this specification, a unit weight part means the ratio of the weight between each component.

The polymer network may include a compound of Formula 3 below. The compound of Formula 3 may be included alone or in combination with the compound of Formula 2. The compound of formula 3 may be included in the polymer network, for example in the form of a crosslinked product. In the form of the crosslinked product, it may mean that the compound of Formula 3 is present in a state in which the compound of Formula 1 is reacted with another compound of Formula 3 and / or the compound of Formula 2.

[Formula 3]

In Formula 3, R is hydrogen or an alkyl group, A is an alkylene group or an alkylidene group, Y is a cationic moiety of a quaternary ammonium series, X is an anion, and a dotted line between X and Y is X and Y Are ionic bonds or dissociated with each other, and p is a number from 2 to 11.

In Formula 3, p may be about 4 to about 9, for example.

The compound of formula 3 is a compound containing an ionic bond site. In the compound of Formula 3, X and Y may form an ionic bond or may be present in the polymer network in a state in which the ionic bond is dissociated.

As the cationic moiety forming the ion binding site, for example, a moiety represented by one of the following formulas (4) to (7) may be exemplified.

[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

In Formulas 4 to 7, R ₂ to R ₆ are alkyl groups.

In one example, R ₂ to R ₄ of Formulas 4 to 7 may each independently represent an alkyl group having 1 to 8 carbon atoms, and R ₅ and R ₆ of Formula 7 may each independently represent an alkyl group having 1 to 10 carbon atoms. . The alkyl group may be linear, branched or cyclic, and optionally substituted with one or more substituents if necessary.

In the formulas 4 to 7, the symbol "

Means that the site is linked to A in the general formula (3).

As the anion forming the ionic bond in the formula (3), various kinds can be used without particular limitation. Anion is fluoride (F ^-), chloride (Cl ^-), bromide (Br ^-) or iodide (I ^{^-) -} phosphate, hexafluoro (PF halogen ion, a tetra-borate (BF ₄₎ fluoroalkyl, such as ₆ ^-), trifluoromethane sulfonate (CF _₃ SO ₃ ^-) or a may be exemplified by anions represented by the following general formula 8 or 9.

[Formula 8]

(CN) _r Q ^-

[Formula 9]

[X (YO _m R _f ) _n ] ^-

In Formulas 8 and 9, Q is N, C or B, r is a number from 2 to 4, X is N or C, Y is C or S, and R _f is a perfluoroalkyl group, for example , A C 1-20, C 1-16, C 1-12, C 1-8 or C 1-4 perfluoroalkyl group or a fluorine group, m is 1 or 2, n is 2 or 3.

With anions of formula (8), the dish hold imide _{(dicyanamide) ((CN) 2} N -), tricyclic Anno meth arsenide _{(tricyanomethanide) ((CN) 3} C -) , or tetra-dicyano borate (tetracyanoborate) ((CN) ₄ B ^-) or the like it can be illustrated.

An anion of formula 9, with bis-fluoro sulfonyl imide _{_{^{((FSO 2) 2 N -}}} ), bis-trifluoro methane sulfonyl imide _{_{_{((CF 3 SO 2) 2}}} N -) or a bis pentafluoroethane sulfonyl imide _{_{_{((C 2 F 5 SO 2}}} ) 2 N -) , but the like can be illustrated, without being limited thereto.

As the anion, an imide anion including fluorine having a good role of electron withdrawing and good hydrophobicity and high ion stability may be used, but is not limited thereto.

The compound of formula 3 or a crosslinked product thereof is, for example, 45 to 105 parts by weight, 55 to 95 parts by weight or 65 to 85 parts by weight relative to 100 parts by weight of the compound of formula 1 May be included. In addition, when the compound of the formula (2) or the crosslinked product thereof and the compound of the formula (3) or the crosslinked product thereof are simultaneously included in the polymer network, the compound of the formula (2) or the crosslinked product thereof is, for example, in the polymer network, for example, 20 parts by weight to 80 parts by weight, 30 parts by weight to 70 parts by weight, or 40 parts by weight to 60 parts by weight with respect to 100 parts by weight of the compound, and the compound of Formula 3 or a crosslinked product thereof, for example, a compound of Formula 1 45 parts by weight to 105 parts by weight, 55 parts by weight to 95 parts by weight, or 65 parts by weight to 85 parts by weight relative to 100 parts by weight. In this range, an appropriate crosslinked structure of the polymer network can be realized.

For example, the polymer network may have a glass transition temperature of -50 ° C to 15 ° C, -50 ° C to 5 ° C, -40 ° C to 5 ° C, or -30 ° C to 5 ° C. The glass transition temperature of the polymer network can be controlled by adjusting the structure of the compound, for example, the compound of Formulas 1 to 3, or the degree of crosslinking of the network formed by them. If the glass transition temperature is maintained in the above range, an appropriate crosslinked structure can be realized to ensure ion fluidity and to prevent the electrolyte from crystallizing during use.

The electrolyte may further comprise iodine, for example crystalline iodine. The electrolyte may contain iodine, for example, 0.1 to 5 parts by weight, 0.1 to 4 parts by weight, 0.1 to 3 parts by weight, 0.1 to 2.5 parts by weight of crystalline iodine relative to 100 parts by weight of the polymer network. Or 0.2 parts to 2.5 parts by weight.

The electrolyte may further comprise, for example, an iodine salt as an ion source. The type of iodine salt that can be used is not particularly limited, and for example, an iodine salt of an alkali metal or alkaline earth metal such as lithium salt, sodium salt or potassium salt can be used. The proportion of iodine salt may be selected according to the application, and for example, 0.1 parts by weight to 5 parts by weight, 0.1 parts by weight to 4 parts by weight, 0.1 parts by weight to 3 parts by weight, 0.1 parts by weight based on 100 parts by weight of the polymer network. To 2.5 parts by weight or 0.2 to 2.5 parts by weight may be included.

The electrolyte may further comprise an aromatic heterocyclic compound. As said compound, benzimidazole or its derivative (s) can be used, for example. As the derivative of benzimidazole in the above, the compound of Formula 10 may be exemplified, but is not limited thereto.

[Formula 10]

In Formula 10, R ₇ is an alkyl group.

The aromatic heterocyclic compound may include, for example, 1.0 part by weight to 20 parts by weight, 1.0 part by weight to 15 parts by weight, or 1.0 part by weight to 10 parts by weight with respect to 100 parts by weight of the polymer network.

The electrolyte may further comprise an iodine salt that also includes a quaternary ammonium cation. The iodine salt may be liquid, for example. As an example of the quaternary ammonium cation which forms an iodine salt, the cation represented by the general formula of any one of following formula (11)-(14) is mentioned.

[Formula 11]

[Formula 12]

[Formula 13]

[Formula 14]

In Formulas 11 to 14, R ₈ to R ₁₅ are alkyl groups.

In one example, in Formulas 11 to 14, R ₈ and R ₁₀ are each independently an alkyl group having 1 to 4 carbon atoms, R ₉ and R ₁₁ are each independently an alkyl group having 1 to 12 carbon atoms, and R ₁₂ is carbon number It is an alkyl group of 1 to 16, R ₁₃ to R ₁₅ may be each independently an alkyl group having 3 to 8 carbon atoms, but is not limited thereto.

Iodine salt, 1.5 parts by weight to 30 parts by weight, 1.5 parts by weight to 25 parts by weight, 1.5 parts by weight to 20 parts by weight, 3 parts by weight to 20 parts by weight or 3 parts by weight to 15 parts by weight relative to 100 parts by weight of the polymer network However, this may be changed according to the purpose.

The electrolyte may further comprise acrylonitrile, if necessary. Acrylonitrile may be included, for example, in a proportion of 70 parts by weight or less, 60 parts by weight or less, 50 parts by weight or less, 40 parts by weight or less, or 35 parts by weight or less.

The electrolyte may be in the form of an elastic film having a predetermined defined shape and thickness. The electrolyte may include polar oxy moieties to improve the solvation and solubility of the ions present in the electrolyte system to improve the efficiency of the photovoltaic device including ion conductivity.

In addition, through the appropriate degree of crosslinking of the polymer network excellent solvent retention capacity, it is possible to improve the stability and life characteristics of the device. The electrolyte can be easily swelled with high swelling, for example, by an electrolyte solution such as an iodine-based electrolyte solution, and can ensure excellent ion fluidity and conductivity by the flexible property of the network.

The present application also relates to a precursor capable of forming such an electrolyte. Exemplary precursors may include precursors of the polymer network capable of forming the polymer network and the compound of Formula 1.

As a precursor of the polymer network, the compound of Formula 2 or 3 described above may be exemplified. In the precursor, for example, the compound of Formula 2 may be included in an amount of 20 parts by weight to 80 parts by weight, 30 parts by weight to 70 parts by weight, or 40 parts by weight to 60 parts by weight, relative to 100 parts by weight of the compound of Formula 1, which is a crosslinking agent. Also, the compound of Formula 3 may be included in an amount of 45 parts by weight to 105 parts by weight, 55 parts by weight to 95 parts by weight, or 65 parts by weight to 85 parts by weight, based on 100 parts by weight of the compound of Formula 1, which is a crosslinking agent in the precursor. When both the compound of Formula 2 and the compound of Formula 3 are included in the precursor, for example, 20 parts by weight to 80 parts by weight, 30 parts by weight to 70 parts by weight, or 40 parts by weight based on 100 parts by weight of the compound of Formula 1 as a crosslinking agent Part to 60 parts by weight of the compound of Formula 2 and 45 parts by weight to 105 parts by weight, 55 parts by weight to 95 parts by weight or 65 parts by weight to 85 parts by weight relative to 100 parts by weight of the compound of Formula 1 may be included. Within this range, a polymer network having an appropriate crosslinked structure can be formed.

The forming material of the polymer network as described above, for example, the compound of Formulas 1 to 3, may be present in the precursor 40 to 99 parts by weight or 45 to 05 parts by weight.

The precursor may further comprise iodine, for example crystalline iodine. Iodine, for example crystalline iodine, is present in the precursor in a proportion of, for example, 0.1 parts by weight to 2 parts by weight, 0.2 parts by weight to 2 parts by weight, 0.2 parts by weight to 1.5 parts by weight, or 0.25 parts by weight to 1 parts by weight. May be included.

The precursor may also comprise iodine salts, for example iodine salts of alkali metals or alkaline earth metals. The iodine salt may be included in the precursor in a ratio of, for example, 0.1 parts by weight to 2 parts by weight, 0.2 parts by weight to 2 parts by weight, 0.2 parts by weight to 1.5 parts by weight, or 0.25 parts by weight to 1 parts by weight.

The precursor may further contain an aromatic heterocyclic compound, for example benzimidazole or a derivative thereof. The heterocyclic compound may be included, for example, in a proportion of 0.5 parts by weight to 15 parts by weight, 0.5 parts by weight to 10 parts by weight, 1 part by weight to 8 parts by weight, or 1.5 parts by weight to 8 parts by weight.

The precursor may also further comprise an iodine salt comprising the quaternary ammonium cation described above. The iodine salt may be included, for example, in a proportion of 1 part by weight to 20 parts by weight, 1 part by weight to 15 parts by weight, or 2 parts by weight to 15 parts by weight, but is not limited thereto.

The precursor may also further comprise acrylonitrile, if necessary, in proportions of up to 50 parts by weight, up to 40 parts by weight or up to 35 parts by weight.

The precursor also induces a reaction between the forming material of the polymer network, for example, the compounds of Formulas 1 to 3, thereby adding a radical initiator such as a radical photoinitiator or a radical thermal initiator in terms of increasing the formation efficiency of the network. It can be included as. The precursor may suitably include a thermal initiator.

As a photoinitiator, for example, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylanino acetophenone, 2 , 2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropane-1one, 1-hydroxycyclohexylphenylketone , 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propane-1-one, 4- (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) Ketone, benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-aminoanthra Quinone, 2-methyl thioxanthone, 2-ethyl thioxanthone, 2-chloro thioxanthone, 2,4-dimethyl thioxanthone, 2,4-diethyl thioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p -Dimethylamino benzoate Ter, oligo [2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanone] and 2,4,6-trimethylbenzoyl-diphenyl-phosphineoxide and the like can be exemplified. have. As the thermal initiator, an azo compound or a peroxide compound may be exemplified, and as the azo compound, 2,2'-azobis (2-methylbutyronitrile), 2,2'- Azobis (isobutyronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile) and 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile) Examples of the peroxide-based compound include tetramethylbutylperoxy neodecanoate (ex. Perocta ND, manufactured by NOF), and bis (4-butylcyclohexyl) peroxydicarbonate (ex.Peroyl TCP). NOF Co., Ltd.), di (2-ethylhexyl) peroxy carbonate, butyl peroxy neodecanoate (ex. Perbutyl ND, NOF Co., Ltd.), dipropyl peroxy dicarbonate (ex. Peroyl NPP , NOF company (made), diisopropyl peroxy dicarbonate (ex. Peroyl IPP, NOF company made), diethoxyethyl peroxy dicarbonate (ex. Peroyl EEP, NOF company made), diethoxy Hexyl peroxy dicarbonate (ex.P eroyl OEP, NOF Co., Ltd., hexyl peroxy dicarbonate (ex. Perhexyl ND, NOF Co., Ltd.), dimethoxybutyl peroxy dicarbonate (ex. Peroyl MBP, NOF Co., Ltd.), bis ( 3-methoxy-3-methoxybutyl) peroxy dicarbonate (ex. Peroyl SOP, NOF Co., Ltd.), dibutyl peroxy dicarbonate, dicetyl peroxy dicarbonate, dimyristyl Peroxy dicarbonate, 1,1,3,3-tetramethylbutyl peroxypivalate, hexyl peroxy pivalate (ex. Perhexyl PV, NOF Co.), butyl peroxy pivalate (ex Perbutyl, NOF Co., Ltd., trimethyl hexanoyl peroxide (ex. Peroyl 355, NOF Co., Ltd.), dimethyl hydroxybutyl peroxy neodecanoate (ex. Luperox 610M75, Atofina, Ltd.), Amyl peroxyneodecanoate (ex. Luperox 546M75, Atofina (manufactured)), butyl peroxyneodecanoate (ex. Luperox 10M75, Atofina), t-butylperoxy neoheptanoate, amylperoxy pivalate (ex. Luperox 546M75, Alofina), t-butylperoxy pivalate, t-amyl Peroxy-2-ethylhexanoate, lauryl peroxide, dilauuroyl peroxide, didecanoyl peroxide, benzoyl peroxide or dibenzoyl peroxide and the like can be exemplified.

As the radical initiator, an appropriate kind may be selected and used in consideration of the formation efficiency of the polymer network among the above-exemplified initiators or other initiators known in the field of radical polymerization. In addition, the ratio in the precursor of a radical initiator is not specifically limited, What is necessary is just to select suitably in consideration of reaction efficiency.

The precursor may be prepared by selecting a necessary material from the above-described materials and mixing the selected materials. In this case, all necessary materials may be mixed at one time to prepare a precursor, or may be mixed and divided. For example, a material for forming a polymer network, for example, a compound of Formulas 1 to 3 and other components except for a radical initiator may be mixed in advance to prepare a liquid electrolyte, and then a mixture of the material for forming a network and a radical initiator. Precursors can be prepared by mixing with again.

The method for preparing the electrolyte using the precursor is not particularly limited. For example, the electrolyte may be prepared in a manner that induces a reaction between the forming materials of the polymer network while maintaining the precursor in a mold having a desired shape. In the above, the reaction may proceed, for example, by applying appropriate light or by applying heat.

The present application also relates to dye-sensitized solar cells. An exemplary solar cell may include the electrolyte described above. For example, the solar cell may include a working electrode and a counter electrode disposed to face each other, and may also include the electrolyte present between the working electrode and the counter electrode.

As a working electrode and a counter electrode used above, what is generally used for the construction of a dye-sensitized solar cell can be used, for example.

For example, the working electrode may include a base layer having a conductive layer formed thereon. As the base layer, for example, a rigid or flexible substrate made of any suitable material may be used as having transparency. The rigid substrate can be made of glass, for example. The flexible transparent substrate can be made of a suitable polymer, for example. In one example, the base layer may be a polyester film such as a flexible polymer film, for example, a poly (ethylene terephthalate) film, but is not limited thereto.

The conductive layer may be a transparent conductive layer and may be, for example, a layer of indium-doped tin oxide (ITO) or a layer of fluorine-doped tin oxide (FTO). In one example, the conductive layer may be a layer of FTO.

The working electrode may comprise a layer of nanocrystalline semiconductor oxide. The layer may be formed, for example, on top of the conductive layer. As the material of the semiconductor oxide, as the material capable of adsorbing the dye, an oxide of semiconductor nanocrystals having a large band gap energy and lower than the LUMO of the dye in which the conductive band energy is used may be used. As such a semiconductor oxide, TiO ₂ , SnO ₂ , ZnO, Nb ₂ O _5, or the like is known, and in general, titanium dioxide (TiO ₂ ) may be used. The semiconductor oxide is, for example, crystalline and may be involved in converting sunlight into electrical energy.

The working electrode may comprise a photosensitive dye adsorbed onto the semiconductor oxide. As the dye, any material capable of absorbing light in the visible region, forming chemical bonds with the surface of the semiconductor oxide, and having thermal and optical stability can be used without particular limitation. As the photosensitive dye, ruthenium organometallic compounds, quantum dot inorganic compounds such as InP or CdSe, and the like are known, and ruthenium-based organometallic compounds are usually used.

The counter electrode can be produced, for example, by depositing an electrode layer, for example, a platinum layer, on a substrate, for example, a substrate washed with an ultrasonic cleaner or the like. The main purpose of the platinum layer is to transfer electrons to the electrolyte, in which other compounds, for example carbon containing compounds, may also be used. The deposition method depends on the compound used. For example, the platinum may be deposited by applying a solution containing platinum to a brushing method or the like.

After deposition of the platinum layer, the layer can be annealed in a furnace. Conditions for annealing are determined depending on the compound used. For example, the annealing process for the solution of the compound containing platinum used may be carried out at 500 ° C. for 5 minutes.

The solar cell may be manufactured by, for example, arranging the working electrode and the counter electrode so as to form a predetermined gap, attaching each other with a thermofilm or epoxy resin, and placing the electrolyte in the gap between the electrodes. have.

In the present application, for example, in the form of an elastic film, an electrolyte capable of forming a photovoltaic device, for example, a dye-sensitized solar cell, which is excellent in solvent retention capacity and ion conductivity or fluidity, and which can operate with excellent efficiency for a long time, is provided. do. In the present application, there is also provided a precursor for forming the electrolyte and a photoelectric device, for example a dye-sensitized solar cell, comprising the electrolyte.

1 is a diagram schematically showing a solar cell produced in an embodiment.

2 is a diagram schematically showing the equipment used to measure the performance of the cell manufactured in the embodiment.

Hereinafter, the above-described matters will be described in detail, but the scope of the above matters is not limited to the following examples.

제조예 1. 액상 전해질(liquid electrolyte)의 조제Preparation Example 1 Preparation of Liquid Electrolyte

The liquid electrolyte is 1.67 parts by weight of crystalline iodine, 1.76 parts by weight of lithium iodide, 1-methylbenzimidazole, iodide ionic liquid (1-propyl-3-methylimidazolium eye Odydide) 20.21 parts by weight and 65.75 parts by weight of acetonitrile were prepared by uniformly mixing.

제조예 2. 반응 혼합물(A)의 제조Preparation Example 2 Preparation of Reaction Mixture (A)

23.06 parts by weight of polyethylene glycol methacrylate (polymerization degree: about 8 to 13, PEGM), 46.13 parts by weight of polyethylene glycol dimethacrylate (polymerization degree: about 8 to 10, PEGDM), azobisisobutyronitrile (AIBN) 2.08 The reaction mixture (A) was prepared by mixing parts by weight and 28.73 parts by weight of ethanol.

제조예 3. 반응 혼합물(B)의 제조Preparation Example 3 Preparation of Reaction Mixture (B)

23.06 parts by weight of polyethylene glycol methacrylate (polymerization degree: about 4 to 8, PEGM), 46.13 parts by weight of polyethylene glycol dimethacrylate (polymerization degree: about 12 to 15 PEGGDM), 1.96 parts by weight of azobisisobutyronitrile (AIBN) , 65.75 parts by weight of acetonitrile and 10.89 parts by weight of the liquid electrolyte prepared in Preparation Example 1 were mixed to prepare a reaction mixture (B).

제조예 4. 반응 혼합물(C)의 제조Preparation Example 4 Preparation of Reaction Mixture (C)

29.93 parts by weight of polyethylene glycol methacrylate (polymerization degree: about 14 to 17, PEGM), 25.65 parts by weight of polyethylene glycol dimethacrylate (polymerization degree: about 4 to 6, PEGDM), azobisisobutyronitrile (AIBN) 1.67 A reaction mixture (C) was prepared by mixing parts by weight, 17.10 parts by weight of acetonitrile and 25.65 parts by weight of the liquid electrolyte prepared in Preparation Example 1.

제조예 5. 필름의 제조Preparation Example 5 Preparation of Film

The reaction mixtures (A), (B) or (C) prepared in Preparation Examples 2 to 4 were stirred until the components contained in each mixture were thoroughly mixed. The stirred mixture was then cooled in liquid nitrogen and degassed under vacuum conditions of 1-2 mm Hg. Subsequently, the mixture was thawed at room temperature and injected into a mold having a thickness of 0.25 mm, a width of 50 mm, and a length of 50 mm. After the mold was sealed and held at 60 ° C. for about 15 hours to form a film, the film was taken out of the mold and dried (drying condition: 1 hour at 60 ° C. under atmospheric pressure, and then again at 80 ° C. under a pressure of 1 mmHg. Time drying) (hereinafter, the film formed from the reaction mixture (A) is referred to as film (I), the film formed from the reaction mixture (B) is referred to as film (II), and the film formed from the reaction mixture (C) is referred to as film (III)). . Sample (I) in which one film (I) is cut to 12 mm in width and length, and two samples (IIa) and sample in which two films (II) are cut to be in width and length of 12 mm respectively. Two samples (IIIa) and (IIIb) were prepared by cutting (IIb) and two films (III) so as to be 12 mm in width and length, respectively. Samples (IIa) and (IIIa) were used in the following examples without further treatment. Samples (I), (IIb) and (IIIb) were further swelled in an iodine-based electrolyte for about 24 hours, and then Used in the examples. In the case of the swollen sample, it was taken out of the electrolyte solution immediately before assembly of the solar cell and used after removing the excess solution from the surface.

실시예 1Example 1

The solar cell was manufactured in the following manner using the film of sample IIa, the following operation, and a counter electrode.

작동 전극(working electrode)Working electrode

A transparent conductive layer (FTO, SnO ₂ : F, tin oxide doped with fluorine) was present on the top, and a glass substrate (TCO22-15, Solaronix SA) having a length of 15 mm in width and length was used as a substrate for the electrode. . The substrate was used after washing with distilled water in an ultrasonic washing apparatus, followed by rinsing with a mixture of distilled water and isopropanol and drying at a temperature of about 70 ° C. A predetermined amount of titanium dioxide paste (Ti-Nanoxide D, Solaronix SA or Eversolar P-200, Everlight Chemical) was placed on the substrate with a spatula, evenly distributed, and then slowly heated to remove the solvent. The thickness of the formed titanium dioxide paste layer was about 8-12 micrometers. The formed titanium dioxide paste layer was baked at about 450 ° C. for about 15 minutes. After cooling to 70 ° C. at a rate of 120 ° C./min, it was kept at this temperature until use to prevent moisture adsorption. Dye (cis-diisocyanate- (2,2'-bipyridile-4,4'-dicarboxylic acid)-(2,2'-bipyridil-4,4'-dinonyl) of ruthenium (II), Ruthenizer 520-DN, Solaronix SA or Eversolar Z907, Everlight Chemical) was dissolved in a mixture of acetonitrile and isopropyl alcohol in a volume ratio of 1: 1 to prepare a dye solution (20 mg of dye was dissolved in 100 mL of mixture). The working electrode cooled to 70 ° C. was immersed in the dye solution with the titanium dioxide layer facing upwards, and maintained at room temperature for 24 hours for dye sensitization.

상대 전극(counter electrode)Counter electrode

The platinum counter electrode was prepared by applying a plastisol substance (Solaronix SA) to a glass substrate with a transparent conductive layer with a brush and further heating until the solvent was removed. The prepared electrode was further backed at 450 ° C.

태양전지 셀(working electrode)의 제조Fabrication of solar cell

The solar cell was manufactured in the same structure as in FIG. 1. The prepared electrodes were used after rinsing with isopropyl alcohol and drying at about 80 ° C. After the working electrode 101 and the counter electrode 102 were positioned as shown in FIG. 1, the film sample IIa 103 was positioned between the

electrodes

101, 102. The

electrodes

101 and 102 were positioned so that the width of the contact area was about 5 to 6 mm. Subsequently, an epoxy paste (Amosil 4, Solaronix SA) 104 was applied in a thin stripe shape with a thickness of about 2 mm or less along the edge of the electrode and then cured to prepare a cell (the curing of the epoxy paste was about 60 to It may be carried out by maintaining for 3 hours at a temperature of 70 ℃ or about 24 hours at room temperature.). The film sample (IIa) used in the production of the solar cell includes 94.752 parts by weight of a crosslinked polymer network, 0.256 parts by weight of crystalline iodine, 0.270 parts by weight of lithium iodide, 1.626 parts by weight of 1-methylbenzimidazole and 1-propyl- 3.096 parts by weight of 3-methylimidazolysin iodide was present.

실시예 2Example 2

A solar cell was manufactured in the same manner as in Example 1, except that Film Sample (IIIa) was used. The film sample (IIIa) used in the production of the solar cell includes 86.698 parts by weight of a crosslinked polymer network, 0.648 parts by weight of crystalline iodine, 0.683 parts by weight of lithium iodide, 4.121 parts by weight of 1-methylbenzimidazole and 1-propyl- 7.851 parts by weight of 3-methylimidazolysin iodide was present.

실시예 3Example 3

A solar cell was manufactured in the same manner as in Example 1, except that Film Sample (I) was used. The film sample (I) used for the production of the solar cell includes 56.520 parts by weight of a crosslinked polymer network, 0.726 parts by weight of crystalline iodine, 0.765 parts by weight of lithium iodide, 4.613 parts by weight of 1-methylbenzimidazole, 1-propyl- 8.787 parts by weight of 3-methylimidazolysin iodide and 28.588 parts by weight of acetonitrile were present.

실시예 4Example 4

A solar cell was manufactured in the same manner as in Example 1, except that Film Sample (IIb) was used. The film sample (IIb) used in the production of the solar cell includes 56.775 parts by weight of a crosslinked polymer network, 0.823 part by weight of crystalline iodine, 0.867 part by weight of lithium iodide, 5.227 parts by weight of 1-methylbenzimidazole, 1-propyl- 9.955 parts by weight of 3-methylimidazolysin iodide and 26.353 parts by weight of acetonitrile were present.

실시예 5Example 5

A solar cell was manufactured in the same manner as in Example 1, except that Film Sample (IIIb) was used. The film sample (IIIb) used in the production of the solar cell includes 61.674 parts by weight of a crosslinked polymer network, 0.943 parts by weight of crystalline iodine, 0.994 parts by weight of lithium iodide, 5.994 parts by weight of 1-methylbenzimidazole, 1-propyl- 11.413 parts by weight of 3-methylimidazolysin iodide and 18.982 parts by weight of acetonitrile were present.

시험예 1. 태양전지 셀의 성능 평가Test Example 1 Performance Evaluation of Solar Cell

The performance of the cell fabricated in the examples is based on the open-circuit voltage (Voc), short-circuit current (Jsc), fill factor (FF) and efficiency factor of the dye-sensitized solar cell. (efficiency coefficient,) was measured and evaluated. The position of the sample 205 in the measuring device including the lens system 201, the optical filter 202, the light source 203, the mirror 204 and the source-meter 2400 as shown in FIG. Was evaluated in a conventional manner.

As a result of the evaluation, the cell manufactured in Example 3 had an open-circuit voltage (Voc) of about 0.09 V, and a short-circuit current (Jsc) of about 1.15 mA / cm ² . Fill factor (FF) and efficiency coefficient () were 24.8 and 0.26, respectively. In addition, it was confirmed that other examples other than Example 3 exhibited the same performance as above.

[Description of the code]

101: working electrode

102: counter electrode

103: film sample

104: epoxy paste (Amosil 4, Solaronix SA)

201: lens system

202: optical filter

203: light source

204 mirror

205: Source-meter 2400

Claims

An electrolyte for a photovoltaic device comprising a polymer network crosslinked by a compound of formula (I):

[Formula 1]

In Formula 1, R is hydrogen or an alkyl group, A is an alkylene group or an alkylidene group, n is a number of 1 to 17.
The electrolyte of claim 1, wherein the polymer network comprises a compound represented by the following Chemical Formula 2 or a crosslinked product thereof:

[Formula 2]

In Formula 2, R is hydrogen or an alkyl group, A is an alkylene group or an alkylidene group, R 1 is an alkyl group, m is a number of 2 to 19.
The electrolyte of claim 2, wherein the polymer network comprises 20 parts by weight to 80 parts by weight of the compound of formula 2 or a crosslinked product thereof based on 100 parts by weight of the compound of Formula 1. 4.
The electrolyte of claim 1, wherein the polymer network further comprises a compound of formula 3 or a crosslinked product thereof:

[Formula 3]

In Formula 3, R is hydrogen or an alkyl group, A is an alkylene group or an alkylidene group, Y is a cationic moiety of a quaternary ammonium series, X is an anion, and a dotted line between X and Y is X and Y Are ion-bonded or dissociated with each other.
The electrolyte for an optoelectronic device according to claim 4, wherein the cationic moiety is represented by one of the following Chemical Formulas 4 to 7:

[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

In Formulas 4 to 7, R 2 to R 6 are alkyl groups.
The electrolyte of claim 4, wherein the anion is a halogen ion, tetrafluoroborate, hexafluorophosphate, trifluoromethanesulfonate, an anion of Formula 8 or an anion of Formula 9

[Formula 8]

(CN) r Q -

[Formula 9]

[X (YO m R f ) n ] -

In Formulas 8 and 9, Q is N, C or B, r is a number of 2 to 4, X is N or C, Y is C or S, R f is a perfluoroalkyl group, m is 1 or 2, and n is 2 or 3.
The electrolyte of claim 4, wherein the polymer network comprises 45 parts by weight to 105 parts by weight of a compound of Formula 3 or a crosslinked product thereof based on 100 parts by weight of the compound of Formula 1. 6.
The electrolyte of claim 1, wherein the polymer network has a glass transition temperature of -50 ° C to 15 ° C.
The electrolyte of claim 1, further comprising iodine.
10. The electrolyte of claim 9, wherein the iodine is contained in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the polymer network.
The electrolyte of claim 1, further comprising an iodine salt.
The electrolyte for an optoelectronic device according to claim 11, wherein the iodine salt is an alkali metal salt or an alkaline earth metal salt.
The electrolyte of claim 11, wherein the iodine salt is present in an amount of 0.1 parts by weight to 5 parts by weight based on 100 parts by weight of the polymer network.
The electrolyte of claim 1, further comprising an aromatic heterocyclic compound.
The electrolyte for an optoelectronic device according to claim 14, wherein the aromatic heterocyclic compound is benzimidazole or a derivative thereof.
The electrolyte of claim 14, wherein the aromatic heterocyclic compound is present in an amount of 1.0 to 20 parts by weight based on 100 parts by weight of the polymer network.
10. The electrolyte of claim 1, further comprising an iodine salt comprising quaternary ammonium cations.
18. The electrolyte of claim 17, wherein the quaternary ammonium cation is represented by one of formulas 11-14:

[Formula 11]

[Formula 12]

[Formula 13]

[Formula 14]

In Formulas 11 to 14, R 8 to R 15 are alkyl groups.
The electrolyte of claim 14, wherein the iodine salt is present in an amount of 1.5 parts by weight to 30 parts by weight with respect to 100 parts by weight of the polymer network.
A precursor of an electrolyte of claim 1 comprising a precursor of a polymer network and a compound of formula

[Formula 1]

In Formula 1, R is hydrogen or an alkyl group, A is an alkylene group or an alkylidene group, n is a number of 1 to 17.
The precursor of claim 20 further comprising a radical initiator.
The precursor of claim 21, wherein the radical initiator is a thermal initiator.
A dye-sensitized solar cell comprising the electrolyte of claim 1.
24. The dye-sensitized solar cell of claim 23, wherein the dye-sensitized solar cell includes a working electrode and a counter electrode disposed to face each other, and an electrolyte is positioned between the working and counter electrodes.