Ionic Gel Film Encapsulation Method for Perovskite Solar Cells

Abstract

The present invention discloses a method for encapsulating an ion gel film of a perovskite solar cell, comprising: sequentially depositing an electron transport layer, a perovskite light-absorbing layer, and a hole transport layer of the perovskite solar cell from bottom to top on an FTO glass layer, using evaporation deposition of Au as a metal electrode, and arranging a metal electrode at the edge of the hole transport layer and the FTO glass layer, thereby preparing a perovskite solar cell; sequentially covering a thin film encapsulation layer, an ion gel encapsulation layer, and an upper transparent glass layer on the prepared perovskite solar cell, and using a laminator to heat and press to melt the thin film encapsulation layer so as to isolate the perovskite solar cell from the external environment; at the same time, sealing the two side edges of the perovskite solar cell with butyl sealant. The process of the present invention is simple, the encapsulation efficiency is high, and the ability to isolate water, oxygen, etc. is far higher than that of conventional encapsulation methods. The perovskite solar cell device can maintain the efficiency basically stable for a long time, thereby greatly improving the stability of the perovskite solar cell device.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar cells, and more specifically, the present invention relates to a method for encapsulating an ion gel film of a perovskite battery. Background Art

[0002] Professor Riki Miyasaka and his colleagues at the University of Tsukuba, Yokohama, Japan, first reported the photovoltaic properties of organic-inorganic calcium halide perovskites. In 2009, they further increased the efficiency to 3.8% by replacing bromine with iodine. Due to its excellent performance, low cost, and great commercial value, perovskite batteries have since shone brightly, and their energy conversion efficiency has increased from 3.8% to 25.2% in just ten years. Since 2020, perovskite solar cells have made great progress, attracting extensive attention from researchers and industrialists, and are considered to be outstanding representatives of the new generation of low-cost solar cell technologies, with very promising commercial prospects.

[0003] The patent with the patent number CN108183169 A provides a method for encapsulating a perovskite solar cell, using a thin and lightweight polyethylene terephthalate (PET) covering film with good plasticity and a transparent AB glue that has little impact on perovskite materials to encapsulate the perovskite battery. In the conventional single-layer glue film encapsulation method, trace amounts of water vapor will still enter the perovskite battery device during long-term use, resulting in the degradation of perovskite materials and the attenuation of battery efficiency, making it difficult to meet the usage requirements of solar cells for more than twenty years. In the patent with the patent number CN106981574A, an Al2O3 thin film is grown on a transparent electrode using atomic layer deposition technology, and then an Al or Ag reflective electrode layer is thermally evaporated on the Al2O3 thin film, which improves the device life and stability while also increasing the energy conversion efficiency. However, using the atomic layer deposition method to directly prepare Al2O3 on perovskite solar cells requires solving the negative impacts caused by solvents and precursors on perovskite solar cell devices during the atomic deposition process.

[0004] In summary, the stability and encapsulation problems of perovskite solar cells are still the key issues restricting the development and widespread application of perovskite batteries. However, the existing encapsulation technologies have relatively weak water and oxygen isolation capabilities, resulting in a rapid attenuation of the efficiency of perovskite battery devices over time and being unable to meet the commercialization requirements. Therefore, it is very important to develop an encapsulation technology method with high stability and high water and oxygen isolation capabilities. Summary of the Invention

[0005] An object of the present invention is to solve at least the above problems and / or defects and provide at least the advantages described hereinafter.

[0006] To achieve these and other advantages in accordance with the present invention, a method for encapsulating an ion gel film of a perovskite battery is provided, including the following steps:

[0007] The electron transport layer, perovskite light-absorbing layer, and hole transport layer of the perovskite solar cell are sequentially deposited on the FTO glass layer from bottom to top. Evaporation of Au is used as the metal electrode, and a metal electrode is provided at the edge of the hole transport layer and the FTO glass layer, thereby obtaining a perovskite solar cell;

[0008] A thin film encapsulation layer, an ion gel encapsulation layer, and an upper transparent glass layer are sequentially covered on the prepared perovskite solar cell, and the layer press is used to heat and pressurize to melt the thin film encapsulation layer, thereby isolating the perovskite solar cell from the external environment;

[0009] At the same time, butyl sealant is used to seal both side edges of the perovskite solar cell.

[0010] Preferably, the material of the perovskite light-absorbing layer is polycrystalline or single-crystalline organic-inorganic hybrid ABX3, where the A site is MA + , FA + , Cs + , Rb + organic-inorganic cations, the B site is Pb 2+ , Sn 2+ metal cations, and the X site is Cl - , Br - , I - halide anions.

[0011] Preferably, the thin film encapsulation layer is a non-crosslinked polyolefin POE thin film material.

[0012] Preferably, the thickness of the thin film encapsulation layer is 450 - 650 μm, and its water vapor transmission rate ≤ 5.0 g / (m 2 ·24 h).

[0013] Preferably, the ion gel encapsulation layer is a polyacrylic acid-polyacrylamide hydrophobically modified ion gel film.

[0014] Preferably, the preparation steps of the polyacrylic acid-polyacrylamide hydrophobically modified ion gel film are as follows:

[0015] S1. Mix acrylamide monomer and acrylic acid monomer according to a weight ratio of 2:5 to 2:9, with a stirring speed of 130 rpm and a stirring time of 25 min to obtain a mixed polymer monomer;

[0016] S2. In the polymer monomer mixed in S1, add a covalent crosslinking agent of N,N'-methylenebisacrylamide and a thermal initiator of azobisisobutyronitrile, each equivalent to 0.5% wt of the mixed polymer monomer, to obtain a solution;

[0017] S3. Weigh the ionic liquid of dimethyl phosphate methyltributylphosphonium salt, which accounts for 130% of the mass fraction of the mixed polymer monomers, and add the ionic liquid of dimethyl phosphate methyltributylphosphonium salt to the solution in S2.

[0018] S4. Add the hydrophobic modifier octadecyltrichlorosilane according to 3 - 8% of the mass fraction of the mixed polymer monomers. After adding, stir at a speed of 130 rpm and stir thoroughly for 120 min to obtain a uniformly mixed liquid.

[0019] S5. Add the uniformly mixed liquid obtained in S4 to a designed mold, and heat it to 80 °C under the protection of an inert gas and keep this temperature for 30 min to obtain a transparent ion gel film with hydrophobic modification of polyacrylic acid - polyacrylamide.

[0020] Preferably, the thickness of the ion gel film with hydrophobic modification of polyacrylic acid - polyacrylamide is 200 - 300 μm, and there are no bubbles on its surface, its water vapor transmission rate ≤ 10 -7 g / (m 2 ·24 h), and its Young's modulus is 60 - 80 MPa.

[0021] Preferably, the butyl sealant is the Edge Sealant SET LP03 butyl adhesive integrated with a desiccant.

[0022] Preferably, the FTO glass layer includes a lower transparent glass layer and an FTO layer on the lower transparent glass layer.

[0023] Preferably, the metal electrode includes Metal Electrode Ⅰ and Metal Electrode Ⅱ. The cross - section of Metal Electrode Ⅰ is in an L - shaped structure, with a part of it disposed on the upper surface of the hole - transporting layer and another part closely attached to the side surfaces of the electron - transporting layer, the perovskite light - absorbing layer, and the hole - transporting layer; Metal Electrode Ⅱ is respectively disposed at the two side edge positions close to the FTO glass layer.

[0024] The present invention has at least the following beneficial effects:

[0025] (1) The present invention adopts a double - layer encapsulation structure of a thin - film encapsulation material and an ion gel film of polyacrylic acid - polyacrylamide with a special formula design, and hydrophobic modification is carried out on the ion gel film of polyacrylic acid - polyacrylamide. There are adverse effects if no hydrophobic modifier is used; the weight ratio of acrylamide monomer and acrylic acid monomer is 2:5 - 2:9, and there are adverse effects if the dosage is too much or too little. Thus, the ability to isolate water and oxygen is much higher than that of conventional encapsulation methods, and the device can maintain the efficiency basically stable for a long time, thereby greatly improving the stability of the perovskite solar cell device.

[0026] (2) The present invention simultaneously uses a butyl sealant integrated with a desiccant to seal the edge part of the perovskite battery, further increasing the isolation ability of water, oxygen, etc., and can further improve the stability of the perovskite battery device.

[0027] (3) The present invention does not use solvents, avoiding the problem of damage to the perovskite solar cell device caused by solvents that must be faced in the solution method for preparing the protective layer;

[0028] (4) The present invention has the advantages of simple process, high encapsulation efficiency, and very good encapsulation effect on large-area perovskite batteries.

[0029] Other advantages, objectives, and features of the present invention will be partially reflected by the following description, and partially will also be understood by those skilled in the art through the research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the encapsulation structure of the perovskite battery device encapsulated by using the ionic gel film encapsulation method of the perovskite battery provided by the present invention for Examples 1 - 4 and Example 6;

[0031] Figure 2 Schematic diagram of the encapsulation structure of the perovskite battery device encapsulated by using the traditional encapsulation method for Example 5;

[0032] Figure 3 I - V curve diagram of the perovskite battery after encapsulation for Examples 1 - 6.

[0033] The corresponding reference numerals for each structure in the figure are as follows: lower transparent glass layer 1, FTO layer 2, electron transport layer 3, perovskite light - absorbing layer 4, hole transport layer 5, metal electrode 6, metal electrode I 61, metal electrode II 62, thin - film encapsulation layer 7, ionic gel encapsulation layer 8, butyl sealant 9, upper glass layer 10. DETAILED DESCRIPTION OF THE INVENTION

[0034] The following further describes the present invention in detail with reference to the drawings, so that those skilled in the art can implement it according to the description in the specification.

[0035] It should be understood that the terms such as "having", "comprising", and "including" used herein do not exclude the presence or addition of one or more other elements or their combinations.

[0036] In each embodiment, the raw materials are commercially available. Among them, the polyolefin (POE) encapsulation films in Embodiments 1-6 are respectively purchased from Changzhou Baijiadaindai, with the model number B606. The butyl sealant in Embodiments 1-5 is purchased from QUANEX, with the model number SolarGain SET LP03. The ordinary sealant in Embodiment 6 is purchased from 3M Company. The acrylamide and acrylic acid monomers are purchased from Dow Chemical. N,N'-methylenebisacrylamide and dimethyl methyltributylphosphonium phosphate are purchased from Sigma-Aldrich. Octadecyltrichlorosilane is purchased from Aladdin Reagent Co., Ltd.

[0037] Embodiment 1

[0038] This embodiment provides a method for encapsulating an ion gel film of a perovskite solar cell, including:

[0039] On the FTO glass layer formed by the lower transparent glass layer 1 and the FTO layer 2, the electron transport layer 3, the perovskite light-absorbing layer 4, and the hole transport layer 5 of the perovskite solar cell are sequentially deposited from bottom to top. Evaporation of Au is used as the metal electrode 6. The metal electrode includes a metal electrode I 61 and a metal electrode II 62. The cross-section of the metal electrode I 61 is in an L-shaped structure. A part of it is disposed on the upper surface of the hole transport layer 5, and the other part is closely attached to the sides of the electron transport layer 3, the perovskite light-absorbing layer 4, and the hole transport layer 5. The metal electrode II 62 is respectively disposed at the two side edge positions close to the FTO glass layer, thereby preparing a perovskite solar cell;

[0040] On the prepared perovskite solar cell, a thin film encapsulation layer 7, an ion gel encapsulation layer 8, and an upper transparent glass layer 10 are sequentially covered. The layer press is used to heat and pressurize to melt the thin film encapsulation layer 7, thereby isolating the perovskite solar cell from the external environment;

[0041] At the same time, the two side edges of the perovskite solar cell are sealed with a butyl sealant 9. The butyl sealant is an Edge Sealant SET LP03 butyl adhesive integrated with a desiccant. The encapsulation schematic diagram of the perovskite solar cell obtained in this embodiment is as Figure 1 shown.

[0042] The material of the perovskite light-absorbing layer is polycrystalline or single-crystalline organic-inorganic hybrid ABX3, where the A site is MA + , FA + , Cs + , Rb + organic-inorganic cations, the B site is Pb 2+ , Sn 2+ metal cations, and the X site is Cl - , Br - , I - halogen anions, which is MAPbI3 in this embodiment.

[0043] Among them, the thin film encapsulation layer is a non-crosslinked polyolefin POE thin film material, and the thickness of the thin film encapsulation layer is 450 μm, and its water vapor transmission rate ≤ 5.0 g / (m 2 ·24 h); the ion gel encapsulation layer 8 is an ion gel film hydrophobically modified with polyacrylic acid - polyacrylamide, and the preparation steps of the ion gel film hydrophobically modified with polyacrylic acid - polyacrylamide are as follows:

[0044] S1. Mix 200 g of acrylamide monomer and 600 g of acrylic acid monomer, with a stirring speed of 130 rpm and a stirring time of 25 min to obtain a mixed polymer monomer;

[0045] S2. In the polymer monomer mixed in S1, add 4 g of N,N'-methylenebisacrylamide covalent crosslinking agent and 4 g of azobisisobutyronitrile thermal initiator respectively to obtain a solution;

[0046] S3. Add 1040 g of methyltributylphosphonium dimethylphosphate ionic liquid to the solution in S2;

[0047] S4. Add 40 g of hydrophobic modifier octadecyltrichlorosilane, and after adding, stir at a stirring speed of 130 rpm and stir thoroughly for 120 min to obtain a uniformly mixed liquid;

[0048] S5. Add the uniformly mixed liquid in S4 into a designed mold. The size of the mold can be changed according to the specific actual situation, which does not affect the performance of the final ion gel film. Control the thickness of the final ion gel film by controlling the weight of the added liquid. In this example, a 500 mm * 500 mm mold is used, pour 100 g of the above-mentioned uniformly mixed liquid, and heat it to 80 °C under inert gas protection and keep this temperature for 30 min to obtain a transparent ion gel film hydrophobically modified with polyacrylic acid - polyacrylamide.

[0049] The thickness of the ion gel film hydrophobically modified with polyacrylic acid - polyacrylamide prepared in this example is 200 μm, and there are no bubbles on its surface, and its water vapor transmission rate ≤ 10 -7 g / (m 2 ·24 h), and its Young's modulus is 60 MPa.

[0050] Example 2

[0051] In the ion gel film encapsulation method of the perovskite battery in this example, it is the same as that in Example 1. The difference is that in the preparation steps of the ion gel film hydrophobically modified with polyacrylic acid - polyacrylamide, step S4 is removed, that is, the hydrophobic modifier octadecyltrichlorosilane is not added, and the rest of the process is the same as that in Example 1.

[0052] Example 3

[0053] The method for encapsulating the perovskite solar cell with an ion gel film in this embodiment is the same as that in Embodiment 1. The difference is that in the preparation steps of the polyacrylic acid-polyacrylamide hydrophobically modified ion gel film, the dosage of acrylamide monomer in S1 is 320 g, and the dosage of acrylic acid monomer is 480 g, and the remaining processes are the same as those in Embodiment 1.

[0054] Embodiment 4

[0055] The method for encapsulating the perovskite solar cell with an ion gel film in this embodiment is the same as that in Embodiment 1. The difference is that in the preparation steps of the polyacrylic acid-polyacrylamide hydrophobically modified ion gel film, the dosage of acrylamide monomer in S1 is 115 g, and the dosage of acrylic acid monomer is 685 g, and the remaining processes are the same as those in Embodiment 1.

[0056] Embodiment 5

[0057] Compared with Embodiment 1, the method for encapsulating the perovskite solar cell with an ion gel film in this embodiment removes the ion gel encapsulation layer 8 and only uses a polyolefin (POE) encapsulation film. The polyolefin (POE) encapsulation film is purchased from Changzhou Baijia Niandai, with the model number B606. Other encapsulation methods are the same as those in Embodiment 1, and the obtained encapsulation structure is as Figure 2 shown;

[0058] The preparation steps of the polyacrylic acid-polyacrylamide hydrophobically modified ion gel film in this embodiment are the same as those in Embodiment 1.

[0059] Embodiment 6

[0060] Compared with Embodiment 1, the method for encapsulating the perovskite solar cell with an ion gel film in this embodiment removes the butyl sealant 9 and uses a common sealant to replace the butyl sealant 9. The common sealant is purchased from 3M and its color is black. Other encapsulation methods are the same as those in Embodiment 1;

[0061] The preparation steps of the polyacrylic acid-polyacrylamide hydrophobically modified ion gel film in this embodiment are the same as those in Embodiment 1.

[0062] The perovskite solar cells encapsulated in Embodiments 1-6 are taken respectively to test the J-V curves and their performance parameters. The results are as follows:

[0063] As Figure 3As shown, from the comparison of Examples 1-6, it can be seen that in Example 1, the encapsulation technology method of the present invention has the lowest efficiency decay after long-term use, and the perovskite battery device has higher stability; the perovskite battery devices prepared by Examples 2-4 by changing the composition of the ion gel film are basically the same as Example 1 during short-term use, and the power decay during long-term use is still higher than that of Example 1; in Example 5, the ion gel encapsulation layer is removed, and the power decay amplitude of the perovskite battery device is much higher than that of Examples 1-4 after use for a period of time, indicating that this ion gel encapsulation layer plays a very important role in the sealing of the perovskite battery device; in Example 6, the butyl sealant is removed, and although it still shows very good stability; but it is still slightly worse than Example 1, and it can also be seen that the butyl sealant integrated with the desiccant does have a very good sealing effect on the edge part of the perovskite battery device.

[0064] The equipment quantities and processing scales described herein are used to simplify the description of the present invention. Applications, modifications, and variations of the present invention will be apparent to those skilled in the art.

[0065] Although the embodiments of the present invention have been disclosed as above, they are not limited to only the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily achieved. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the illustrated and described examples here.

Claims

1. An encapsulation method for an ion gel film of a perovskite battery, characterized in that, It includes the following steps: Deposit the electron transport layer, perovskite light-absorbing layer, and hole transport layer of the perovskite cell in sequence from bottom to top on the FTO glass layer. Use evaporation of Au as the metal electrode, and set the metal electrode at the edges of the hole transport layer and the FTO glass layer, thereby preparing the perovskite cell; Cover the prepared perovskite cell with a thin-film encapsulation layer, an ion gel encapsulation layer, and an upper transparent glass layer in sequence, and use a laminator to heat and pressurize to melt the thin-film encapsulation layer to isolate the perovskite cell from the external environment; At the same time, seal the two side edges of the perovskite cell with butyl sealant; The ion gel encapsulation layer is an ion gel film hydrophobically modified with polyacrylic acid-polyacrylamide. The preparation steps of the polyacrylic acid-polyacrylamide hydrophobically modified ion gel film are as follows: S1. Mix acrylamide monomer and acrylic acid monomer according to a weight ratio of 2:5 to 2:9, with a stirring speed of 130 rpm and a stirring time of 25 min to obtain a mixed polymer monomer; S2. In the polymer monomer mixed in S1, add a covalent cross-linking agent of N,N'-methylenebisacrylamide and a thermal initiator of azobisisobutyronitrile, each equivalent to 0.5%wt of the mixed polymer monomer, to obtain a solution; S3. Weigh an ionic liquid of methyltributylphosphonium dimethylphosphate salt accounting for 130% of the mass fraction of the mixed polymer monomer, and add the ionic liquid of methyltributylphosphonium dimethylphosphate salt to the solution in S2; S4. Add a hydrophobic modifier of octadecyltrichlorosilane according to 3-8% of the mass fraction of the mixed polymer monomer. After adding, stir at a stirring speed of 130 rpm and stir thoroughly for 120 min to obtain a uniformly mixed liquid; S5. Add the uniformly mixed liquid obtained in S4 to a designed mold, and heat it to 80 °C under inert gas protection and keep this temperature for 30 min to obtain a transparent polyacrylic acid-polyacrylamide hydrophobically modified ion gel film.

2. The ion gel film encapsulation method of the perovskite battery according to claim 1, characterized in that, The material of the perovskite light-absorbing layer is polycrystalline or single-crystalline organic-inorganic hybrid ABX3, where the A site is MA + , FA + , Cs + , Rb + organic or inorganic cations, the B site is Pb 2+ , Sn 2+ metal cations, and the X site is Cl - , Br - , I - halide anions.

3. The ion gel film encapsulation method of the perovskite battery according to claim 1, characterized in that The thin-film encapsulation layer is a non-crosslinked polyolefin POE thin-film material.

4. The ion gel film encapsulation method of the perovskite battery according to claim 1, characterized in that, The thickness of the thin film encapsulation layer is 450 - 650 μm, and its water vapor transmission rate ≤ 5.0 g / (m 2 ·24 h).

5. The ion gel film encapsulation method of the perovskite battery according to claim 1, wherein The thickness of the polyacrylic acid-polyacrylamide hydrophobically modified ion gel membrane is 200-300 μm, and its surface has no bubbles. Its water vapor transmission rate ≤ 10 -7 g / (m 2 ·24 h), and its Young's modulus is 60-80 MPa.

6. The ion gel film encapsulation method of the perovskite battery according to claim 1, wherein The butyl sealant is a butyl adhesive integrated with a desiccant.

7. The ion gel film encapsulation method of the perovskite battery according to claim 1, wherein The FTO glass layer includes a lower transparent glass layer and an FTO layer on the lower transparent glass layer.

8. The ion gel film encapsulation method of the perovskite battery according to claim 1, characterized in that, The metal electrode includes metal electrode I and metal electrode II. The cross-section of metal electrode I is in an L-shaped structure, with a part disposed on the upper surface of the hole transport layer and another part closely attached to the sides of the electron transport layer, perovskite light-absorbing layer, and hole transport layer; Metal electrode II is respectively disposed at positions close to the two side edges of the FTO glass layer.

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