CN115291450A - Method for printing electrolyte layer, electrochromic device and preparation method thereof - Google Patents

Abstract

The invention discloses a method for printing an electrolyte layer, an electrochromic device and a preparation method thereof, wherein the method for printing the electrolyte layer comprises the following steps: obtaining electrolyte slurry, and mixing the electrolyte slurry with a diluent to obtain an electrolyte diluent with the viscosity of 4000-40000mPa & s; printing the electrolyte diluent on the base material by adopting a screen printing mode to form a printing layer on the base material; removing the diluent in the printing layer to obtain a prefabricated layer; and curing the prefabricated layer to obtain the electrolyte layer. The method for printing the electrolyte layer can ensure that the viscosity of the electrolyte slurry meets the requirement of screen printing and can also keep the shape of the uncured electrolyte layer in the assembling process of the electrochromic device.

Description

Method for printing electrolyte layer, electrochromic device and manufacturing method thereof

technical field

The invention relates to the technical field of printed electronics, in particular to a method for printing an electrolyte layer, an electrochromic device and a preparation method thereof.

Background technique

One of the challenges in the industrial application of electrochromic devices lies in the preparation of large-area green processes, and one of the main problems is the printing preparation of large-area electrolytes. Traditional methods of grouting and scraping cannot achieve very accurate preparation of the electrolyte layer, and secondly, the smoothness and uniformity of the electrolyte film layer cannot be reliably guaranteed. The preparation of the electrolyte layer by screen printing can solve the above problems, but in the assembly process of the electrochromic device, when the viscosity of the electrolyte paste formulation is too small, the shape retention of the electrochromic device is poor during the assembly process; the electrolyte paste formulation When the viscosity is too high, the penetration of the slurry screen is poor, and the corresponding pattern cannot be printed.

The information disclosed in this Background section is only for enhancing the understanding of the general background of the present invention and should not be taken as an acknowledgment or any form of suggestion that the information constitutes the prior art that is already known to those skilled in the art.

Contents of the invention

The purpose of the present invention is to provide a method for printing an electrolyte layer, which can not only make the viscosity of the electrolyte slurry meet the requirements of screen printing, but also maintain the shape of the uncured electrolyte layer during the assembly process of the electrochromic device.

Another object of the present invention is to provide an electrochromic device and a preparation method thereof.

To achieve the above object, an embodiment of the present invention provides a method for printing an electrolyte layer, comprising the following steps:

Obtain the electrolyte slurry and mix it with the diluent to obtain an electrolyte diluent with a viscosity of 4000-40000mPa·s;

Printing the electrolyte diluent on the substrate by screen printing to form a printing layer on the substrate;

removing the diluent from the printed layer to obtain a prefabricated layer; and

The prefabricated layer is cured to obtain the electrolyte layer.

In one or more embodiments of the present invention, the viscosity of the prefabricated layer is greater than or equal to 80000 mPa·s.

In one or more embodiments of the present invention, the step of removing the diluent in the printing layer comprises:

Heat the printed layer to remove the diluent in the printed layer.

In one or more embodiments of the present invention, the curing treatment is photocuring treatment or thermal curing treatment.

In one or more embodiments of the present invention, the diluent includes at least one of ethyl acetate, ethanol, and water.

In one or more embodiments of the present invention, the electrolyte slurry includes a polymer host, a plasticizer, a lithium salt, a photoinitiator, and a crosslinking agent.

In one or more embodiments of the present invention, the crosslinking agent is one of polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, and trimethylolpropane acrylate; and/ or,

The polymer body includes at least one of polymethyl methacrylate, polyvinyl fluoride and polyurethane.

In one or more embodiments of the present invention, the lithium salt is at least one of lithium perchlorate and lithium bistrifluoromethanesulfonylimide; and/or,

The plasticizer includes at least one of polycarbonate, dimethyl carbonate, ethylene carbonate and water.

Embodiments of the present invention also provide a method for preparing an electrochromic device, comprising the following steps:

Obtain the electrolyte slurry and mix it with the diluent to obtain an electrolyte diluent with a viscosity of 4000-40000mPa·s;

Printing the electrolyte diluent on the first electrode by screen printing to form a printing layer on the first electrode;

Remove the diluent in the printing layer to obtain the prefabricated layer;

bonding the prefabricated layer on the first electrode to the second electrode; and

The prefabricated layer is cured to obtain an electrochromic device.

An embodiment of the present invention provides an electrochromic device, which is manufactured by the above-mentioned preparation method of the electrochromic device.

Compared with the prior art, according to the method of printing the electrolyte layer according to the embodiment of the present invention, by mixing the electrolyte slurry with the diluent, the viscosity of the electrolyte diluent meets the requirements of screen printing, and after the screen printing, the printing layer is removed The diluent in the medium increases the viscosity of the printing layer, and the printing layer is in an incompletely cured state, so that the printing layer has a certain rigidity and a certain wettability, and can maintain its own shape to suppress the extension phenomenon during the bonding process, and can ensure The uncured electrolyte layer can be in close contact with other functional layers.

Description of drawings

1 is a flowchart of a method for printing an electrolyte layer according to an embodiment of the present invention;

2 is a schematic diagram of an electrochromic device according to an embodiment of the present invention;

Fig. 3 is the schematic diagram of the electrochromic device in the embodiment 1 in the faded transparent state;

Fig. 4 is the schematic diagram of the electrochromic device in embodiment 1 in colored state;

Fig. 5 is a state diagram of printing electrolyte slurry on a substrate in the conventional screen printing method for printing an electrolyte layer.

Detailed ways

The specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

As shown in Figure 1, the method for printing an electrolyte layer according to a preferred embodiment of the present invention includes the following steps:

S11. Obtain the electrolyte slurry and mix it with the diluent to obtain an electrolyte dilute material with a viscosity of 4000-40000 mPa·s.

Wherein, the electrolyte slurry may include a polymer host, a plasticizer, a lithium salt, a photoinitiator, and a crosslinking agent. Specifically, the crosslinking agent is polyethylene glycol diacrylate. The polymer host may include at least one of polymethyl methacrylate and polyvinyl fluoride. The lithium salt is at least one of lithium perchlorate and lithium bistrifluoromethanesulfonimide. The plasticizer includes at least one of polycarbonate, dimethyl carbonate, ethylene carbonate and water. The viscosity of the electrolyte slurry may be greater than or equal to 80000 mPa·s.

Specifically, the diluent includes at least one of ethyl acetate, ethanol, and water. The function of the diluent is to dilute the electrolyte slurry, so that the viscosity of the mixed electrolyte dilute material is 4000-40000mPa·s. To meet the requirements of screen printing. The boiling point of the diluent is lower than the boiling point of the plasticizer. If the diluent is removed by heating in the later stage, the diluent can be removed as much as possible, and at the same time, the amount of plasticizer in the electrolyte slurry can be prevented or avoided as much as possible. .

It should be noted that the choice of diluent should meet the following conditions:

First, after removing the diluent in the later stage, try to make the components in the prefabricated layer and the electrolyte slurry basically the same. Basically the same can be understood as the components and the corresponding contents are basically the same.

Secondly, the diluent itself will not affect the performance of the electrolyte slurry or the final electrolyte layer to a certain extent.

S12. Print the electrolyte dilution material on the substrate by screen printing, so as to form a printing layer on the substrate.

S13, removing the diluent in the printing layer to obtain a prefabricated layer.

Specifically, the step of removing the diluent in the printing layer may include:

Heat the printed layer to remove the diluent in the printed layer. Wherein, the heating temperature can be adjusted according to the selection of the diluent and the selection of components in the electrolyte slurry. The temperature of heating may be at or about the boiling temperature of the diluent. In addition, the heating temperature is preferably to avoid volatilization of other substances in the electrolyte slurry.

Wherein, the viscosity of the prefabricated layer is greater than or equal to 80000mPa·s. The prefabricated layer has a certain degree of rigidity, and can maintain its own shape to suppress the extension phenomenon in the bonding process.

It should be noted that the composition of the prefabricated layer and the composition of the electrolyte slurry can be considered to be basically the same or approximately the same.

S14, curing the prefabricated layer to obtain an electrolyte layer.

Specifically, the curing treatment is photocuring or thermal curing. For example, when the electrolyte slurry contains polymers such as a photoinitiator and PEG-DA, the prefabricated layer can be cured in the way of ultraviolet curing. When the electrolyte slurry contains other components such as maleimide, the prefabricated layer can be cured by heat curing.

It should be noted that during the preparation process of the electrolyte layer, there are three states, that is, a low viscosity state, a high viscosity state and a solid state. Among them, the low-viscosity state corresponds to the state of the electrolyte diluent, which mainly serves to meet the viscosity requirements of screen printing. The high-viscosity state corresponds to the state of the prefabricated layer, which serves to inhibit the extension phenomenon during the bonding process and provide a certain rigidity for the prefabricated layer. High viscous state can be understood as an incompletely cured state, which has a certain wettability to ensure that the prefabricated layer can be in close contact with other functional layers. The solid state is the state of the final electrolyte layer, which plays the role of connecting different substrates (or laminates).

An embodiment of the present invention provides an electrochromic device. In a specific embodiment, the electrochromic device may include a first transparent electrode, a first electrode, an electrolyte layer, a second electrode, and a second transparent electrode stacked in sequence .

Wherein, the first electrode can be considered as a counter electrode or an ion storage layer. The second electrode can be considered a working electrode. The materials of the first transparent electrode and the second transparent electrode can be selected from ITO, IZO or Ag mesh and the like. The material of the first electrode may be a functional material capable of electrochromic reaction such as thiophene and its variants. The material of the second electrode can be slurry of thiophene and its derivatives, TiO ₂ , MCCP and the like.

In a specific embodiment, the present invention also provides a method for preparing the above-mentioned electrochromic device, comprising the following steps:

S21. Obtain the electrolyte slurry and mix it with the diluent to obtain an electrolyte dilute material with a viscosity of 4000-40000 mPa·s.

Wherein, the electrolyte slurry may include a polymer host, a plasticizer, a lithium salt, a photoinitiator, and a crosslinking agent. Specifically, the crosslinking agent is polyethylene glycol diacrylate. The polymer host may include at least one of polymethyl methacrylate and polyvinyl fluoride. The lithium salt is at least one of lithium perchlorate and lithium bistrifluoromethanesulfonimide. The plasticizer includes at least one of polycarbonate, dimethyl carbonate, ethylene carbonate and water. The viscosity of the electrolyte slurry may be greater than or equal to 80000 mPa·s. The photoinitiator may be 2,2-dimethoxy-2-phenylacetophenone.

Specifically, the diluent includes at least one of ethyl acetate, ethanol, and water. The function of the diluent is to dilute the electrolyte slurry, so that the viscosity of the mixed electrolyte dilute material is 4000-40000mPa·s. To meet the requirements of screen printing.

It should be noted that the choice of diluent should meet the following conditions:

First, after removing the diluent in the later stage, try to make the components in the prefabricated layer and the electrolyte slurry basically the same. Basically the same can be understood as the components and the corresponding contents are basically the same.

Secondly, the diluent itself will not affect the performance of the electrolyte slurry or the final electrolyte layer to a certain extent.

S22. Print the electrolyte diluent on the first electrode by screen printing, so as to form a printing layer on the first electrode.

S23, removing the diluent in the printing layer to obtain a prefabricated layer.

Specifically, the step of removing the diluent in the printing layer may include:

Heat the printed layer to remove the diluent in the printed layer. Wherein, the heating temperature can be adjusted according to the selection of the diluent and the selection of components in the electrolyte slurry.

Wherein, the viscosity of the prefabricated layer is greater than or equal to 80000mPa·s. The prefabricated layer has a certain degree of rigidity, and can maintain its own shape to suppress the extension phenomenon in the bonding process.

It should be noted that the composition of the prefabricated layer and the composition of the electrolyte slurry can be considered to be basically the same or approximately the same.

S24, bonding the prefabricated layer on the first electrode to the second electrode.

In step S24, the prefabricated layer on the first electrode is bonded to the second electrode to form a semi-finished product. During the bonding process, due to the high viscosity of the prefabricated layer, that is, greater than or equal to 80000mPa·s, the prefabricated layer has It must be rigid and can maintain its own shape to suppress the extrusion force generated by the first electrode and the second electrode during the bonding process and avoid the extension of the prefabricated layer.

It should be noted that the first electrode can be considered as the counter electrode or ion storage layer in the electrochromic device, and its formation method can be printing. The second electrode can be regarded as a working electrode, and its formation method can be inkjet printing/spin coating/screen printing and the like.

S25, curing the prefabricated layer to obtain an electrochromic device.

Specifically, the curing treatment is photocuring or thermal curing. For example, when the electrolyte slurry contains polymers such as a photoinitiator and PEG-DA, the prefabricated layer can be cured in the way of ultraviolet curing. When the electrolyte slurry contains other components such as maleimide, the prefabricated layer can be cured by heat curing.

The main electrochromic region of the electrochromic device prepared by the present invention may be greater than or equal to 10 cm*10 cm. The pixel size of the electrochromic device prepared based on this design method can reach 0.5 mm*0.5 mm. The electrochromic device based on this process can also print a large area of 10 cm*10 cm (electrochromic area) device. The maximum wavelength transmittance difference: 30~40%; at -0.6V, 0.8V driving voltage, the response transmittance of fading and coloring (change to 90% of the maximum transmittance difference) the response of fading and coloring Time: both ~0.5s; coloring and fading state maintenance time>5h.

As shown in Figure 2, in a specific embodiment, the electrochromic device (being the darker part in Fig. 2) of the ITO/PEDOT/electrolyte/PProDOT/ITO that adopts preparation method of the present invention to obtain, its area size It can be from 1.5mm*1.5mm to 10cm*10cm. 550nm is the maximum light modulation wavelength, the maximum wavelength transmittance difference: 30~40%; under the driving voltage of -0.6V, 0.8V, the response time of fading and coloring: ~0.5s; coloring and fading state maintenance time >5h. The thickness of the electrolyte layer is 50 μm, and the electrolyte formula is PMMA/PC/PEGDA/water/LiTFSi/2,2-dimethoxy-2-phenylacetophenone.

In another specific embodiment, in the electrochromic device prepared by the preparation method of the present invention, only a part of the area may be an electrochromic area, and the electrochromic area at this time may be patterned (such as an animal shape, a smiling face, etc.) class, graphics (triangle, square, etc.) or other graphics), the way to form the pattern is to print the electrolyte layer by screen printing only at the position that needs to be discolored. Since the screen printing is used, the formed The pattern can be formed by several points, that is, the electrolyte layer can be considered to be formed by several spaced points.

In other embodiments, the patterned electrochromic region may also be a layered electrolyte layer (non-spotted) formed after the electrolyte slurry is cured. Moreover, the electrolyte layer is a flat film that can be observed by the naked eye, rather than having obvious problems such as residual mesh marks.

As shown in FIG. 5 , FIG. 5 is a picture of an electrolyte layer printed by an existing screen printing method. Since no diluent is added between the printed electrolyte layers, the viscosity of the electrolyte slurry is relatively low, which reduces the problems of web marks and stringing when printing on the substrate.

In addition, when the electrolyte layer is printed by the existing screen printing method, since the viscosity of the electrolyte layer before curing is not adjusted after printing, when the uncured electrolyte layer is bonded to other devices, the rigidity is not enough, and it may not be possible to maintain the The desired pattern will cause the pattern formed by the electrochromic region of the final electrochromic device to be deformed and become a defective product.

The method for printing the electrolyte layer, the electrochromic device and the preparation method thereof of the present invention will be described in detail below in conjunction with specific examples.

Example 1

The ITO material is screen printed to form the first transparent electrode, and the PEDOT is screen printed on the first transparent electrode to form the first electrode. In addition, an ITO material is selected to form a second transparent electrode by screen printing, and PProDOT is spin-coated to form a second electrode on the second transparent electrode.

Weigh 3g of PMMA (polymethyl methacrylate), 5g of PC (polycarbonate), 5g of PEG-DA (polyethylene glycol diacrylate), 2.8g of LiTFSi and 15mg of 2,2- Dimethoxy-2-phenylacetophenone was stirred evenly to obtain an electrolyte slurry with a viscosity of 88000 mPa·s. 0.8 g of water and 3 g of ethyl acetate were weighed and mixed with the electrolyte slurry to obtain an electrolyte dilution material with a viscosity of 4000 mPa·s.

The electrolyte diluent is printed on the first electrode by screen printing to obtain a printing layer. The printing layer is heated, the heating temperature is 60° C., and the heating time is 5 minutes. Get the prefab layer.

The second electrode was bonded to the prefabricated layer and cured under UV conditions to obtain an electrochromic device as shown in Figure 3 and Figure 4, wherein the thickness of the electrolyte layer was 50 μm.

Wherein, FIG. 3 is a schematic diagram of the electrochromic device in embodiment 1 in a faded transparent state, and FIG. 4 is a schematic diagram of the electrochromic device in embodiment 1 in a colored state. As can be seen from Figures 3 and 4, the color-changing pattern in the electrochromic device in Example 1 is in the shape of a smiling face, and the shape of the dielectric layer in the electrochromic device is a smiling face made of dots, so that in the electrochromic device The color-changing pattern of is in the shape of a smiley face.

Example 2

The ITO material is screen printed to form the first transparent electrode, and the PEDOT is screen printed on the first transparent electrode to form the first electrode. In addition, the silver paste material was selected to form the second transparent electrode by screen printing, and the PProDOT was spin-coated on the second transparent electrode to form the second electrode.

Weigh respectively 4g of PMMA, 3g of EC (ethylene carbonate), 5g of PEG-DA, 2.8g of LiTFSi and 15mg of 2,2-dimethoxy-2-phenylacetophenone, stir evenly to obtain The electrolyte slurry has a viscosity of 90000mPa·s. Then 0.8 g of water and 4.5 g of ethyl acetate were weighed and mixed with the electrolyte slurry to obtain an electrolyte dilution material with a viscosity of 4000 mPa·s.

The electrolyte diluent is printed on the first electrode by screen printing to obtain a printing layer. The printing layer is heated, the heating temperature is 60° C., and the heating time is 5 minutes. Get the prefab layer.

The second electrode is attached to the prefabricated layer and cured under UV conditions to obtain an electrochromic device, wherein the thickness of the electrolyte layer is 45 μm. The performance of the electrochromic device obtained in this example is basically the same as that of the electrochromic device obtained in Example 1.

Example 3

The ITO material is screen printed to form the first transparent electrode, and the PEDOT is screen printed on the first transparent electrode to form the first electrode. In addition, an ITO material is selected to form a second transparent electrode by screen printing, and PProDOT is spin-coated to form a second electrode on the second transparent electrode.

Weigh 3g of PVDF (polyvinylidene fluoride), 5g of DEC (diethyl carbonate), 5g of PEG-DA, 2.8g of lithium perchlorate and 15mg of 2,2-dimethoxy-2 - Phenylacetophenone, stir evenly to obtain electrolyte slurry, the viscosity of which is 70000mPa·s. 0.8 g of water and 3 g of ethyl acetate were weighed and mixed with the electrolyte slurry to obtain an electrolyte dilution material with a viscosity of 4000 mPa·s.

The electrolyte diluent is printed on the first electrode by screen printing to obtain a printing layer. The printing layer is heated, the heating temperature is 60° C., and the heating time is 5 minutes. Get the prefab layer.

The second electrode is attached to the prefabricated layer, and cured under UV conditions to obtain an electrochromic device, wherein the thickness of the electrolyte layer is 40 μm.

The performance of the electrochromic device obtained in this example is basically the same as that of the electrochromic device obtained in Example 1.

In summary, the beneficial effects of the preparation method of the electrochromic device of the present invention are:

(1) The electrolyte slurry can meet the viscosity requirements of screen printing through the diluent, and the diluent is removed through subsequent steps to increase the viscosity of the electrolyte layer before curing, so that the electrolyte layer has a certain viscosity before curing. Rigid, can maintain its own shape to suppress the extension phenomenon in the bonding process.

(2) To achieve the effect of stable and efficient large-area printing electrolyte layer, the film thickness is uniform, the repeatability is good, and the film thickness is very thin, which can further improve the performance of the electrochromic device.

(3) By increasing the diluent, the film thickness of the printed electrolyte layer can be effectively adjusted.

(4) The electrochromic device structure of the present invention has the advantages of fast response and stable cycle.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. These descriptions are not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling others skilled in the art to make and use various exemplary embodiments of the invention, as well as various Choose and change. It is intended that the scope of the invention be defined by the claims and their equivalents.

Claims (10)

1. A method for printing electrolyte layer, is characterized in that, comprises the following steps: Obtain the electrolyte slurry and mix it with the diluent to obtain an electrolyte diluent with a viscosity of 4000-40000mPa·s; Printing the electrolyte diluent on the substrate by screen printing to form a printing layer on the substrate; removing the diluent from the printed layer to obtain a prefabricated layer; and The prefabricated layer is cured to obtain the electrolyte layer. 2. The method for printing an electrolyte layer according to claim 1, wherein the viscosity of the prefabricated layer is greater than or equal to 80000 mPa·s. 3. The method for printing an electrolyte layer as claimed in claim 1, wherein the step of removing the diluent in the printing layer comprises: Heat the printed layer to remove the diluent in the printed layer. 4 . The method for printing an electrolyte layer according to claim 1 , wherein the curing treatment is photocuring or thermal curing. 5. The method for printing an electrolyte layer according to claim 1, wherein the diluent comprises at least one of ethyl acetate, ethanol, and water. 6. The method for printing an electrolyte layer as claimed in claim 5, wherein the electrolyte slurry comprises a polymer body, a plasticizer, a lithium salt, a photoinitiator and a crosslinking agent, wherein the diluent The boiling point is lower than that of the plasticizer. 7. the method for printing electrolyte layer as claimed in claim 6 is characterized in that, described crosslinking agent is polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, trimethylol propane acrylate one of; and/or, The polymer body includes at least one of polymethyl methacrylate, polyvinyl fluoride and polyurethane. 8. The method for printing an electrolyte layer according to claim 6, wherein the lithium salt is at least one of lithium perchlorate and lithium bistrifluoromethanesulfonylimide; and/or, The plasticizer includes at least one of polycarbonate, dimethyl carbonate, diethyl carbonate, ethylene carbonate and water. 9. A method for preparing an electrochromic device, comprising the following steps: Obtain the electrolyte slurry and mix it with the diluent to obtain an electrolyte diluent with a viscosity of 4000-40000mPa·s; Printing the electrolyte diluent on the first electrode by screen printing to form a printing layer on the first electrode; Remove the diluent in the printing layer to obtain the prefabricated layer; bonding the prefabricated layer on the first electrode to the second electrode; and The prefabricated layer is cured to obtain an electrochromic device. 10. An electrochromic device, characterized in that it is produced by the method for preparing an electrochromic device as claimed in claim 9.

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