KR20200072290A - Semi-solid Electrolyte for Dye-Sensitized Solar Cell and Manufacturing Method Using the Same - Google Patents

Abstract

The present invention relates to a semi-solid electrolyte for a dye-sensitized solar cell and a method for manufacturing a dye-sensitized solar cell using the same and relates to the semi-solid electrolyte for the dye-sensitized solar cell, which comprises iodine-based no non-volatile liquid electrolyte and inorganic nanoparticles, wherein the liquid electrolyte contains 1-ethyl-3-methylimidazolium iodide and succinonitrile in a weight ratio of 1 : 2 to 3, and the nanoparticles are included in a weight ratio of 0.01 to 0.03 relative to the succinonitrile. Accordingly, it is possible to manufacture a low-cost and high-efficiency solar cell that can be manufactured by a printing method without a high-temperature process.

Description

Semi-solid Electrolyte for Dye-Sensitized Solar Cell and Manufacturing Method Using the Same

The present invention relates to a method for manufacturing a semi-solid electrolyte, a dye-sensitized solar cell using the same, and more particularly, a semi-solid electrolyte for a dye-sensitized solar cell capable of printing, including iodine-based non-volatile liquid electrolyte and inorganic nanoparticles, and It relates to a dye-sensitized solar cell manufacturing method using the same.

Due to environmental and energy problems due to exhaustion of fossil fuels, environmental pollution, and CO2 and SO2, the necessity and demand for clean and alternative energy are rising socially. Among these energy sources, solar energy has been spotlighted as an environmentally friendly next-generation alternative energy as infinite clean energy.

A solar cell is a device that can directly convert sunlight into a current (voltage), and can be divided into an inorganic solar cell using a p-n junction of a semiconductor and an organic solar cell made mainly of organic materials. Among them, the organic solar cell is inexpensive, environmentally friendly, and is applicable to indoor applications, and has a transparent, thin, and light characteristic to realize a power window. Among these organic solar cells, dye-sensitized solar cells (DSSCs) using a dye-sensitization that adsorbs a dye absorbing visible light to a semiconductor having a wide band gap are becoming an issue.

Here, in the dye-sensitization process, when sunlight (visible light) is absorbed, the dye molecules generate electron-hole pairs, and the generated electrons are injected into the conduction band of the semiconductor oxide electrode, and the injected electrons are transparent through the interface between nanoparticles. It is a principle that is transferred to a conductive film to generate an electric current. At this time, the hole generated in the dye molecule is reduced again by receiving electrons by the oxidation-reduction electrolyte.

The electrolyte used in the dye-sensitized solar cell includes a liquid electrolyte and an ionic liquid electrolyte, but has a problem in that safety, efficiency, and workability are large disadvantages due to electrolyte leakage and volatilization, and weak mechanical properties.

To solve this problem, a method of solidifying the electrolyte by adding an organic curing agent to the liquid electrolyte, a method of solidifying the electrolyte using a polymer, a method of preparing a semi-solid electrolyte by using a high-viscosity ionic liquid, and an organic hole transporter Methods for replacing (hole transporting materials, HTM) with electrolytes have been developed.

However, polyethylene oxide, which is mainly used for solidifying electrolytes using polymers, has a high molecular weight and thus has low ion conductivity at room temperature, and the method of replacing organic hole transporters with electrolytes absorbs visible light to absorb solar cells. There is a problem of lowering efficiency. In addition, these technologies do not secure low-cost mass production technologies, and thus do not exceed the barriers to entry of existing silicon solar cells and other technologies.

In order to solve this problem, a semi-solid electrolyte technology having both processability and stability of the solid polymer electrolyte and high ionic conductivity of the liquid electrolyte has been spotlighted, but the mechanical strength is still weak and sealing problems still exist. There are many difficulties in applying the role to role process. Specifically, an improvement method is needed in the existing technology in which a fatal defect occurs in the step of drilling and resealing for semi-solid electrolytic injection into the substrate.

Therefore, it is possible to manufacture a printing and roll-to-roll method, and an energy-efficient electrolyte and a solar cell manufacturing method using the same are required.

Republic of Korea Patent Registration No. 10-1773124'Dye-sensitized solar cell manufacturing method' Republic of Korea Patent Registration No. 10-1532421'Semi-solid electrolyte for dye-sensitized solar cells and dye-sensitized solar cells containing the electrolyte'

The present invention is to solve the above problem, it is possible to print on a substrate, and a high temperature process of dissolving the electrolyte is unnecessary and providing a semi-solid electrolyte for a dye-sensitized solar cell that maintains the ion conductivity characteristics of the liquid electrolyte as it is. Let's do it as an assignment.

In addition, another object of the present invention is to provide a method for manufacturing a dye-sensitized solar cell based on a glass substrate using the semi-solid electrolyte.

In addition, another object of the present invention is to provide a method for manufacturing a dye-sensitized solar cell based on a flexible substrate using the semi-solid electrolyte.

In order to solve the above problems, the present invention includes iodine-based non-volatile liquid electrolyte and inorganic nanoparticles, and the liquid electrolyte is 1-ethyl-3-methylimidazolium iodide (1-ethyl-3-methylimidazolium) iodid) and succinonitrile (Succinonitrile) is included in a weight ratio of 1:2 to 3, the nanoparticles are characterized in that contained in a weight ratio of 0.01 to 0.03 compared to the succinonitrile, dye-sensitized semi-solid for solar cells Provide electrolyte.

In addition, in the present invention, the nanoparticles are preferably 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.

In addition, in the present invention, the semi-solid electrolyte is formed in a printable form, it is preferable to print by any one or more methods of doctor blade printing (doctor blade printing) and screen printing (screen printing).

In addition, in order to solve the other problems, the present invention, (1) a first electrode made of a first glass substrate, a photoelectrode layer formed on one surface of the first glass substrate and an electrolyte layer formed on the top surface of the photoelectrode layer Manufacturing; (2) manufacturing a second electrode comprising a second glass substrate, a counter electrode layer formed on one surface of the second glass substrate, and an electrolyte layer formed on an upper surface of the counter electrode layer; And (3) attaching the first electrode and the second electrode so that the electrolyte layers of the first electrode and the second electrode face each other, and then squeezing them to prepare a unit cell. Provided is a method for manufacturing a dye-sensitized solar cell based on a glass substrate using a semi-solid electrolyte, characterized in that each electrolyte layer of each of the two electrodes is formed of a semi-solid electrolyte according to any one of claims 1 to 3. .

In addition, in order to solve the above another problem, the present invention comprises (a) a first flexible substrate, a first electrode comprising a photoelectrode layer formed on one surface of the first flexible substrate and an electrolyte layer formed on the other surface of the first flexible substrate. Manufacturing an electrode; (b) manufacturing a second electrode comprising a second flexible substrate, a counter electrode layer formed on one surface of the second flexible substrate, and an electrolyte layer formed on an upper surface of the counter electrode layer; (c) manufacturing a unit electrode by attaching a first electrode and a second electrode such that the electrolyte layers of the first electrode and the second electrode face each other; (d) forming a film layer on both sides of the unit electrode subjected to the step (c), followed by thermocompression to prepare a unit cell, and the electrolyte layers of the first and second electrodes, respectively. It provides a method for manufacturing a dye-sensitized solar cell based on a flexible substrate using a semi-solid electrolyte, characterized in that it is formed of a semi-solid electrolyte according to any one of claims 1 to 3.

According to the present invention, it is possible to manufacture a dye-sensitized solar cell by a simple printing method without a separate high-temperature process by providing a semi-solid electrolyte excellent in processability and stability due to high viscosity and ion conductivity.

1 is a photograph observing a container containing a semi-solid electrolyte for a dye-sensitized solar cell according to an embodiment of the present invention.
Figure 2 shows a process for manufacturing a dye-sensitized solar cell based on a glass substrate according to an embodiment of the present invention.
FIG. 3 is a photograph observing the manufacturing process of a dye-sensitized solar cell based on a glass substrate according to an embodiment of the present invention.
4 is a graph showing current-voltage and conversion efficiency of a dye-sensitized solar cell based on a glass substrate according to an embodiment of the present invention.
5 shows a process for manufacturing a dye-sensitized solar cell based on a flexible substrate according to an embodiment of the present invention.
6 is a photograph observing the manufacturing process of a dye-sensitized solar cell based on a flexible substrate according to an embodiment of the present invention.
7 is a graph showing current-voltage and conversion efficiency of a dye-sensitized solar cell based on a flexible substrate according to an embodiment of the present invention.

The present invention relates to a semi-solid electrolyte for a dye-sensitized solar cell and a method for manufacturing a dye-sensitized solar cell using the same, which will be described in detail below with reference to the drawings.

First, the semi-solid electrolyte of the present invention comprises an iodine-based non-volatile liquid electrolyte and inorganic nanoparticles, and the iodine-based non-volatile liquid electrolyte is made based on Succinonitrile (SN) of a plastic crystaline phase, and 1-ethyl-3- Methylimidazolium iodide (1-ethyl-3-methylimidazolium iodid, EMII) and Succinonitrile are included in a weight ratio of 1:2 to 3, and inorganic nanoparticles are included in a weight ratio of 0.01 to 0.03 compared to Succinonitrile.

Preferably, the inorganic nanoparticles may be 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, more preferably 7 It may be composed of SiO ₂ having a size of ~ 50 nm.

[Example 1] Preparation of semi-solid electrolyte

First, Succinonitrile was dissolved in a liquid state at 70 ℃. SiO ₂ inorganic nanoparticles with a size of 7 to 50 nm were mixed with liquefied Succinonitrile at a ratio of 0.01 to 0.03 compared to Succinonitrile, and mixed to form a semi-solid state.

1-ethyl-3-methylimidazolium iodide (EMII) 1.35M, iodine(I ₂ ) 0.07M, guanidine thiocyanate 0.13M, 4-tert-butylpyridine 0.85M and lithium in the semi-solid Succinonitrile and SiO ₂ inorganic nanoparticle mixture iodideLiI) Iodide electrolyte ion composed of 0.7M was added, but the weight ratio of EMII and Succinonitrile was 1:3. Thereafter, the mixture was stirred at 45° C. for 6 hours to prepare a semi-solid electrolyte.

As can be seen in Figure 1, it was confirmed that the semi-solid electrolyte prepared by this has a high viscosity and thus does not flow into a semi-solid state. This means that unlike the conventional semi-solid electrolyte for a fuel-sensitized solar cell, the semi-solid electrolyte of the present invention has an appropriate viscosity and is capable of uniform coating on the entire surface of the substrate.

Therefore, the semi-solid electrolyte according to the present invention is formed to be able to print by any one or more of doctor blade printing (doctor blade printing) and screen printing (screen printing), has uniformity and uniform thickness even when screen printing The printing can be maintained, and the doctor blade printing method, which is a method in which an ink solution is transferred to a substrate, can also be applied.

Next, a method of manufacturing the dye-sensitized solar cell of the present invention will be described in detail.

2 shows a process for manufacturing a dye-sensitized solar cell based on a glass substrate according to the present invention. As shown in FIG. 2, the solar cell of the present invention uses the above-described semi-solid electrolyte of the present invention as the electrolyte layer 40 to prepare the first electrode and the second electrode, and then the first electrode and the second electrode. It is manufactured by attaching and pressing an electrode.

Specifically, step (1) is a step of manufacturing a first electrode, the first glass substrate 11, the photoelectrode layer 20 formed on one surface of the first glass substrate 11 and the top surface of the photoelectrode layer 20 It is manufactured to be made of the electrolyte layer 40 to be formed.

Next (2) is a step of manufacturing a second electrode, the second glass substrate 13, the counter electrode layer 30 formed on one surface of the second glass substrate 13 and the upper surface of the counter electrode layer 30 It is manufactured to be made of the electrolyte layer 40 to be formed.

At this time, between the photoelectrode layer 20 and the counter electrode layer 30 and each electrolyte layer 40, one or several layers of the electrolyte layer 40 are applied, but there is no space between them. At this time, in the process of applying the electrolyte layer 40, the printing method using the semi-solid electrolyte of the present invention as a coating solution may be applied, and preferably, a doctor blade printing or screen printing method may be applied.

Finally, step (3) is a step of attaching and compressing the first electrode and the second electrode, attaching the first electrode and the second electrode so that the electrolyte layers of the first electrode and the second electrode face each other, and then pressing and dyeing the dye. Prepare a sensitized solar cell.

Here, the edge portion of the first glass substrate 11 and the second glass substrate 13 may be sealed, and preferably a UV curing bond between the first glass substrate 11 and the second glass substrate 13 Can be injected.

[Example 2] Manufacturing a dye-sensitized solar cell based on a glass substrate

A glass substrate on which a photoelectrode layer was formed and another glass substrate on which a counter electrode was formed were prepared, and the semi-solid electrolyte prepared according to the above-described [Example 1] was used as a coating solution, respectively, on the photoelectrode layer and the counter electrode by a doctor blade printing method. A 50 micro-thick electrolyte layer was formed.

Subsequently, each glass substrate was attached so that the formed electrolyte layer faced each other, and then pressed with a press, and a UV curing bond was injected between the glass substrates to seal the rim.

Through FIG. 3, it can be seen that the solar cell is manufactured accordingly.

As shown in FIG. 4, the solar cell manufactured as described above was higher than the efficiency of a solar cell using a conventional solid electrolyte with an efficiency of about 6.5%, and accordingly, the ion conductivity characteristics close to the liquid electrolyte without a separate high-temperature process. It was confirmed that the show.

Next, another manufacturing method of the dye-sensitized solar cell of the present invention will be described.

5 shows a process for manufacturing a dye-sensitized solar cell based on a flexible substrate according to the present invention. As shown in FIG. 5, the solar cell of the present invention uses the above-described semi-solid electrolyte of the present invention as the electrolyte layer 40 to prepare a first electrode and a second electrode, and then a first electrode and a second electrode It is manufactured through the steps of attaching, forming a film layer on both sides, and then pressing.

Specifically, step (a) is a step of manufacturing the first electrode and the second electrode, the first flexible substrate 15, the photoelectrode layer 20 and the first flexible substrate formed on one surface of the first flexible substrate 15 The first electrode made of the electrolyte layer 40 formed on the other surface of (15) and (b) the second flexible substrate 17, the counter electrode layer 30 and the counter electrode layer formed on one surface of the second flexible substrate 17 A second electrode made of the electrolyte layer 40 formed on the upper surface of 30 is manufactured.

In this case, as described above, one layer or several layers of the electrolyte layer 40 may be applied, and in this case, the printing method using the semi-solid electrolyte of the present invention as a coating solution in the process of applying the electrolyte layer 40 is applied. It is possible, and preferably, a doctor blade printing or screen printing method can be used.

Next, step (c) is a step of attaching the first electrode and the second electrode, and attaching the first electrode and the second electrode so that the electrolyte layers 40 of each of the first electrode and the second electrode face each other, and then the unit electrode. To prepare. At this time, the electrolyte layer 40 prevents shorts between the two electrodes. At this time, in order to prevent a short circuit from occurring when the first flexible substrate 15 and the second flexible substrate 17 are in direct contact, a portion of the flexible substrate where the electrolyte layer 40 is not formed is attached or ( In steps a) and (b), it may be cut before forming the electrolyte layer 40 on each flexible substrate.

Finally, step (d) is a step of forming a film layer on both sides and then compressing the film, forming a film layer on both sides of the unit electrode, and then thermocompressing to manufacture a dye-sensitized solar cell based on a flexible substrate. As the film layer, an EVA film can be used and can be sealed by a thermocompression method, so that mass production using a roll-to-roll process is possible.

[Example 3] Fabrication of a dye-sensitized solar cell based on a flexible substrate

A flexible substrate on which a photoelectrode layer was formed and another flexible substrate on which a counter electrode was formed were prepared, and the semi-solid electrolyte prepared according to the above [Example 1] was used as a coating solution, and the other side of the flexible substrate and the upper side of the counter electrode by a doctor blade printing method Each of the 50 micro-thick electrolyte layers was formed. In this embodiment, a flexible substrate was used as a metal mesh.

Subsequently, after each flexible substrate was cut so as not to overlap each other, each glass substrate was attached so that the formed electrolyte layer faced each other. This was put on top of a PET-EVA film and the top was covered with another PET-EVA film.

And between the two PET-EVA film was sealed using a coating machine.

Through FIG. 6, it can be seen that the solar cell is manufactured accordingly.

As shown in FIG. 7, the solar cell thus manufactured showed an efficiency of about 3.6%, which was higher than that of a conventional solar cell using a solid electrolyte. This means that it is possible to introduce a roll-to-roll method in the production of dye-sensitized solar cells.

As described above, the preferred embodiments according to the present invention have been examined, and the fact that the present invention can be embodied in other specific forms without departing from the spirit or scope of the embodiments described above has ordinary knowledge in the art. It is obvious to them. Therefore, the above-described embodiments are to be regarded as illustrative rather than restrictive, and accordingly, the present invention is not limited to the above description and may be changed within the scope of the appended claims and their equivalents.

11: first glass substrate 13: second glass substrate
15: first flexible substrate 17: second flexible substrate
20: photoelectrode layer 30: counter electrode layer
40: electrolyte layer 50: film layer

Claims (5)

Iodine-based non-volatile liquid electrolyte and inorganic nanoparticles,
The liquid electrolyte is 1-ethyl-3-methylimidazolium iodide (1-ethyl-3-methylimidazolium iodid) and succinonitrile (Succinonitrile) is included in a weight ratio of 1:2 to 3,
The nanoparticles are characterized in that contained in a weight ratio of 0.01 to 0.03 compared to the succinonitrile, dye-sensitized semi-solid electrolyte for solar cells. According to claim 1,
The nanoparticles are characterized in that 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, for dye-sensitized solar cells Solid electrolyte. According to claim 1,
The semi-solid electrolyte is formed in a printable form,
Semi-solid electrolyte for dye-sensitized solar cells, characterized in that it can be printed by any one or more of doctor blade printing and screen printing. (1) manufacturing a first electrode comprising a first glass substrate, a photoelectrode layer formed on one surface of the first glass substrate, and an electrolyte layer formed on an upper surface of the photoelectrode layer;
(2) manufacturing a second electrode comprising a second glass substrate, a counter electrode layer formed on one surface of the second glass substrate, and an electrolyte layer formed on an upper surface of the counter electrode layer; And
(3) comprising the steps of attaching the first electrode and the second electrode so that the electrolyte layers of each of the first electrode and the second electrode face each other, and then compressing to prepare a unit cell,
The electrolyte layer of each of the first electrode and the second electrode is formed of a semi-solid electrolyte according to any one of claims 1 to 3, a dye-sensitized solar system based on a glass substrate using a semi-solid electrolyte Battery manufacturing method. (a) manufacturing a first electrode comprising a first flexible substrate, a photoelectrode layer formed on one surface of the first flexible substrate, and an electrolyte layer formed on the other surface of the first flexible substrate;
(b) manufacturing a second electrode comprising a second flexible substrate, a counter electrode layer formed on one surface of the second flexible substrate, and an electrolyte layer formed on an upper surface of the counter electrode layer;
(c) manufacturing a unit electrode by attaching a first electrode and a second electrode so that the electrolyte layers of the first electrode and the second electrode face each other; And
(d) forming a film layer on both sides of the unit electrode subjected to the step (c), followed by thermocompression to produce a unit cell,
The electrolyte layer of each of the first electrode and the second electrode is formed of a semi-solid electrolyte according to any one of claims 1 to 3, a dye-sensitized solar system based on a flexible substrate using a semi-solid electrolyte Battery manufacturing method.

Images