KR20170039926A

KR20170039926A - Electrolyte nanofiber for efficient windows applications and manufacturing method of the same

Info

Publication number: KR20170039926A
Application number: KR1020150139118A
Authority: KR
Inventors: 김헌; 마크 푸구안 존
Original assignee: 명지대학교 산학협력단
Priority date: 2015-10-02
Filing date: 2015-10-02
Publication date: 2017-04-12
Also published as: KR101801234B1

Abstract

The present invention relates to an electrolyte suitable for an energy efficient window, comprising a base of a copolymer material of PVdF; An ion source including lithium ions; And a ZrO ₂ nano powder as a nanofiller, and is in the form of a nanofiber.
The present invention has the effect of providing a nanofiber type electrolyte capable of forming a mat of porous structure while adding ZrO ₂ nanopillar to improve ionic conductivity.
Further, the present invention has an effect of improving the light transmittance of the electrolyte nanofibers by uniformly dispersing the ZrO ₂ nanofiller using a dispersant.
Further, by improving the ionic conductivity and the light transmittance of the electrolyte, it is possible to provide an electrolyte nanofiber suitable for an energy efficiency window.

Description

ELECTROLYTE NANOFIBER FOR EFFICIENT WINDOWS APPLICATIONS AND MANUFACTURING METHOD OF THE SAME <br> <br> <br> Patents - stay tuned to the technology ELECTROLYTE NANOFIBER FOR EFFICIENT WINDOWS APPLICATIONS AND MANUFACTURING METHOD OF THE SAME

The present invention relates to a polymer electrolyte, and more particularly, to an electrolyte nanofiber suitable for an energy-efficient window.

Generally, energy efficient windows, called smart windows, control the amount of light passing through the panel to enhance energy efficiency and provide room comfort. Electricity, which uses electricity to change color, An energy-efficient window using a color-changing element is put into practical use.

An electrochromic device (ECD) refers to a device in which the color of an electrochromic material is changed by an electric oxidation-reduction reaction according to the application of an electric field, thereby changing a light transmission characteristic. The most successful products utilizing the above-described electrochromic devices include a rearview mirror for automatically controlling the glare of light at the rear at night, a smart window (smart window, which can be automatically controlled according to the intensity of light) window. The smart window has a characteristic that it changes into a darker color tone in order to reduce the amount of light when the amount of solar radiation is large and the energy saving efficiency is changed by changing to a bright color tone on a cloudy day. In addition, development is being continuously carried out for applications such as electric sign boards and e-book displays.

The electrochromic layer constituting the electrochromic device is divided into a reducing coloring material and an oxidizing coloring material. Reducing coloring material is a substance that tends to be colored when an electron is obtained. Typically, tungsten oxide is being studied. On the contrary, the oxidation coloring material is a substance which is colored when the electron is lost, and typical examples thereof include nickel oxide and cobalt oxide. In addition, typical electrochromic materials include inorganic metal oxides such as V ₂ O ₅ , Ir (OH) _x , NiO _x H _y , TiO ₂ and MoO ₃ , and PEDOT (poly-3,4-ethylenedioxythiophene), polypyrrole, There are conductive polymers such as polyazulene, polythiophene, polypyridine, polyindole, polycarbazole, polyazine, polyquinone, and organic coloring materials such as biologen, anthraquinone, phenothiazine and the like.

The electrolyte maintains electrical contact between the electrochromic material and the electrode through the flow of ions and ion exchange, and is an essential component of the electrochromic device. Electrolytes can be classified into liquid electrolytes, ceramic electrolytes, inorganic solid electrolytes, and polymer electrolytes. Recently, there is a great interest in polymer electrolytes having workability, mechanical strength, and operating temperature suitable for electrochromic devices.

Also, the polymer electrolyte can be classified into a solid polymer electrolyte, a gel polymer electrolyte, a polyelectrolyte, and a hybrid electrolyte, and exhibits a higher ionic conductivity than a remainder electrolyte in a hybrid electrolyte. Recently, materials of interest as polymer bases for hybrid electrolytes include polyethylene oxide (PEO), polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), and polyvinylidene fluoride , And PVDF). In particular, PVDF has a high dielectric constant to aid ionisation of the salt, which can increase the charge density with high mechanical strength, so it is of interest as a base constituting the electrolyte. However, PVDF exhibits semi-crystalline characteristics and is difficult to work with lithium ions.

Korean Patent No. 10-0718444

It is an object of the present invention to provide an electrolyte nanofiber suitable for an energy efficiency window.

In order to achieve the above object, the electrolyte nanofiber according to the present invention is a PVdF copolymer material; An ion source including lithium ions; And a ZrO ₂ nano powder as a nanofiller, and is in the form of a nanofiber.

In order to enhance the flow of lithium ions, ZrO ₂ nanoparticles, which are nanofillers, are used in a PVdF copolymer base. To compensate for changes in the microstructure of the matrix from a porous structure to a dense structure, The electrolyte was constituted. As a result, the ion conductivity can be improved and the advantage of the porous structure can be obtained.

At this time, it is preferable that ZrO ₂ is contained in the range of 0.5 to 3 wt%. If the amount is less than this range, the effect of increasing the ion conductivity is decreased. If the amount is larger than this range, the transmittance is worse, it's difficult. In addition, it is preferable that the size of the ZrO ₂ nano powder is in the range of 5 to 20 nm, and if it is smaller, the manufacturing cost is increased. If it is larger, the effect as the nanofiller is reduced.

It is preferable that the copolymer of PVDF has a -CF 3 pendant group, and in particular, PVdF-HFP copolymer is preferable.

The ion source is preferably LiCF ₃ SO ₃ for supplying lithium ions. PVdF was not smoothly flowed with lithium ions due to its semi-crystallinity, but the present invention is suitable for an ion source providing lithium ions by adding a nanofiller at the same time as using a PVdF-HFP copolymer.

It is preferable that the ion source is added in the range of 5 to 20 wt%. If the amount is less than the above range, ions are insufficient as a carrier to lower the conductivity, and if the amount is larger than the above range, the mechanical properties are deteriorated.

In this case, the plasticizer is preferably contained in the range of 10 to 20 wt%, and it is particularly preferable to include propylene carbonate.

Furthermore, it is preferable that the present invention is such that ZrO ₂ is uniformly dispersed by a dispersant containing a vinyl group and is covalently bonded to a matrix. By using the dispersant in this way, agglomeration of the nanofiller is prevented, and the transparency of the electrolyte nanofiber is improved.

At this time, it is preferable to use MPS (3- (trimethoxysilyl) propyl methacrylate) as the dispersant.

The method for producing the electrolyte nanofiber of the present invention comprises the steps of: dissolving a plasticizer, an ion source and a copolymer of PVDF in a solvent; Adding and mixing ZrO ₂ nanoparticles into the solution; Molding the mixed solution into a nanofiber form; And drying the nanofibers to remove a solvent and moisture.

At this time, it is preferable to further add a vinyl group-containing ligand as a dispersant. The dispersant may be MPS (3- (trimethoxysilyl) propyl methacrylate), and the molar ratio of the dispersant ligand to the ZrO ₂ is preferably in the range of 0.01: 1 to 0.1: 1. At this ratio, the efficiency of the dispersant is the highest, and when the dispersant is used in a larger amount, the characteristics of the electrolyte deteriorate.

It is preferable that the step of forming into a nanofiber shape is performed by an electrospinning process, and it is preferable that the nanofiber is collected in the form of a nanofiber mat in a process of collecting nanofibers according to an electrospinning process. Further, a process of immersing in propylene carbonate may be further performed to improve film stability and ionic conductivity.

The energy-efficient window of the present invention comprises two electrodes facing each other; An electrochromic composition layer disposed between the electrodes; And an electrolyte layer that transfers electricity between the electrochromic composition layer and the electrode, and a nanofiber mat composed of the electrolyte nanofibers including the ZrO ₂ nanopiller described above is used for the electrolyte layer . Since the energy efficiency window of the present invention can be applied to all energy-efficient windows except for using a nanofiber mat composed of electrolyte nanofibers, a detailed description will be omitted.

At this time, if the thickness of the electrolyte is made thin, the transmittance range suitable for the electrochromic device can be maintained despite the decrease in the light transmittance due to the addition of the nanofiller, and the thickness of the electrolyte can be controlled within the range of 3 to 15 μm .

On the other hand, when the electrolyte is formed to have a thickness smaller than this range, there is a problem that the function of the electrolyte deteriorates. Furthermore, it may be a structure in which propylene carbonate is filled in the pores of the nanofiber mat constituting the electrolyte layer in order to improve film stability and ionic conductivity.

The present invention constructed as described above has an effect of providing a nanofiber-shaped electrolyte capable of forming a mat having a porous structure by adding ZrO ₂ nanofiller to improve ionic conductivity.

Further, the present invention has an effect of improving the light transmittance of the electrolyte nanofibers by uniformly dispersing the ZrO ₂ nanofiller using a dispersant.

Further, by improving the ionic conductivity and the light transmittance of the electrolyte, it is possible to provide an electrolyte nanofiber suitable for an energy efficiency window.

FIG. 1 shows XRD analysis results of ZrO ₂ produced according to this embodiment.
Figure 2 shows the particle size distribution of ZrO ₂ powder.
3 is an FT-IR spectrum of ZrO ₂ produced according to this embodiment.
4 is a graph showing the ion conductivity of the hybrid electrolyte according to the addition amount of the ion source.
5 is a graph showing the ionic conductivity of the hybrid electrolyte according to the addition amount of the plasticizer.
6 shows the ionic conductivity of the hybrid electrolyte according to the addition amount of the nanofiller.
Fig. 7 shows XRD analysis results of PVdF-HFP used in the production of the hybrid electrolyte.
8 shows XRD analysis results with addition of a plasticizer.
9 shows XRD analysis results according to the addition amount of the plasticizer.
10 shows XRD analysis results with addition of nanofiller.
11 to 13 show the result of EDX analysis on the hybrid electrolyte.
14 shows the results of evaluating the light transmittance of the hybrid electrolyte.
15 is a result of evaluating the light transmittance of the hybrid electrolyte according to the addition of the dispersant.
Figure 16 shows the FT-IR spectrum of ZrO ₂ functionalized with MPS.
FIG. 17 shows the results of measurement of change in ion conductivity of a hybrid electrolyte according to addition of MPS.
18 shows the results of XRD analysis according to MPS addition.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the accompanying drawings, embodiments of the present invention will be described in detail.

The electrolyte nanofibers of this example were prepared by the following procedure.

First, a ZrO ₂ nano powder to be used as a nanofiller of an electrolyte was prepared. At this time, ZrO ₂ is composed of nanocrystalline, and nanocrystals are minute nanocrystals of grown crystals. Nanocrystalline ZrO ₂ nanoparticles were prepared and used because the higher the crystallinity and the smaller the crystal size, the higher the permeability.

Specifically, 5 g of zirconium (IV) isopropoxide (purity 99.9%) and 75 ml of benzyl alcohol (98% or more) were mixed in a stainless steel reactor and sealed in a bench top supercritical reactor system And the mixture was heated at 210 DEG C for 3 days with stirring at 200 rpm. The liquid in which the white substance obtained by cooling the reactor was cooled was centrifuged in a high speed centrifuge at a speed of 15000 rpm for 30 minutes to separate benzyl alcohol. In order to remove excess solvent contained in the sediment, ultrasonic treatment and centrifugation were performed twice with anhydrous ethanol added. The obtained ZrO ₂ nano powder was dried in a vacuum state at a temperature of 80 ° C for 24 hours and stored in a dryer.

N, N-dimethylformamide (DMF), and acetone (DMF), which are solvents, were mixed with propylene carbonate (PC) as a plasticizer and LiCF ₃ SO ₃ as an ion supplying agent and MPS And stirred for 15 minutes. Adding a ZrO ₂ prepared in this solution, which was stirred for 3 days. The homogenized solution was obtained by continuously stirring for 24 hours while gradually adding PVdF-HFP (polyvinylidene fluoride-co-hexafluoropropylene). Ultrasonic treatment was performed for 1 hour to prepare a suspension in which ZrO ₂ was uniformly dispersed Respectively.

The suspension prepared by the above process was applied as a spinning solution to prepare an electrolyte nanofiber through an electrospinning process. The spinning solution was injected at 0.5 ml / min and a direct current of 15 kV was applied using a GA-27 metal nozzle. The collecting part was wrapped with aluminum foil on the surface of a stainless steel rotary drum and rotated at 800 rpm. The interval between the collecting part and the nozzle tip was 15 cm. In the process of collecting the electrolytic nanofibers, the nanofiber mat was directly formed and the collected nanofiber mat was dried in a vacuum state at 130 ° C for 4 hours.

Table 1 shows the composition of the electrolyte nanofiber prepared by the above-mentioned method. Each figure is weight (in g).

Membrane PVdF-HFP PC LiCF ₃ SO ₃ ZrO ₂ MPS DMF Acetone NF0 1.20 0.376 0.512 0 0 3.60 2.40 NF1 1.20 0.376 0.512 0.0705 0.014 3.60 2.40 NF2 1.20 0.376 0.512 0.1704 0.034 3.60 2.40 NF3 1.20 0.376 0.512 0.300 0.0707 3.60 2.40 NF4 1.20 0.376 0.512 0.477 0.100 3.60 2.40 no MPS (NF2) 1.20 0.376 0.512 0.1704 0 3.60 2.40

At this time, the dispersant MPS was adjusted to an appropriate amount according to the amount of ZrO ₂ added.

FIG. 1 shows the XRD analysis results of ZrO ₂ prepared according to the present embodiment, and FIG. 2 shows the particle size distribution of the ZrO ₂ powder.

As shown, the produced nanopowder can be confirmed to be pure ZrO ₂ in accordance with JCPDS 37-1484 standard data. In addition, the size of crystal grains based on the Scherrer equation corresponding to the (111) reflection is confirmed to be 11.66 nm, and it can be confirmed that it is a nanocrystal state. The average crystal size according to dynamic light scattering (DLS) analysis is measured as 11.04 nm And it was in agreement with the XRD analysis result.

Further, as shown in FIG. 2, it can be seen that the particles of the ZrO ₂ nano powder prepared in this example exhibit a very narrow particle size distribution.

3 is an FT-IR spectrum of ZrO ₂ produced according to this embodiment.

As shown, two strong absorption bands appeared at frequencies of 1,536 cm ^-1 and 1424.8 cm ^-1 , but this phenomenon disappeared after firing at 600 ° C for 6 hours.

1,536cm ^- peak of 1424.8 cm ^-1 and ¹ is similar to the symmetric and asymmetric vibration peak vibration of each carboxylate group. And 718.9cm ^- peak at 3061.9 cm ^-1 and ¹ correspond to the out-of-plane vibrations of the CH and CH stretching vibration of the phenyl group and phenyl group, respectively, indicating that the phenyl group-containing paper with an organic chemical bond to the surface of the nanopowder. This indicates the presence of benzoate molecules adsorbed on the surface of the nano powder.

The very broad peak observed at 3.370 cm ^-1 is attributed to the surface of the hydroxyl group, which also disappeared after firing.

FIGS. 4 to 8 are SEM photographs of the electrolyte nanofibers produced according to the present embodiment, and FIG. 9 is a graph comparing diameters of the produced electrolyte nanofibers.

Figs. 4 to 8 are photographs for NF0 to NF4, respectively. As illustrated, in the case of a low ratio of ZrO ₂ NF1 shows a fibrous one In analogy to the NF0 ZrO ₂ is not added uniformly. However, due to the influence of the addition of ZrO ₂ , it can be seen that the diameter of the nanofiber of NF 1 is 292 nm, which is thinner than 314 nm of NF 0. The NF2 and NF3 the nanofiber diameter was reduced according to the ZrO ₂ addition amount increased. This reduction in diameter is a result of the ZrO ₂ nanofiller affecting the stretching action of the fiber. This is not consistent with the general conclusion that increasing the viscosity of the solution increases the diameter of the electrospun nanofibers, and is thought to be the dominant influence on the reduction of the surface tension rather than the viscosity. Specifically, ZrO ₂ can induce ionization of the lithium salt causing an increase in the conductivity of the solution, so that an electrostatic repulsion sufficiently high enough to overcome the surface tension can be obtained. On the other hand, beads were formed in the NF ₄ containing 5.5 wt% of ZrO ₂ as the diameter increased. When therefrom ZrO ₂ is added enough to decrease the mobility of PVdF-HFP in a solvent under the influence of the viscosity becomes thicker the thickness of the nanofiber, the aggregation Excessive addition of ZrO ₂ can be seen to form a bead.

10 to 13 show the results of EDX analysis on the electrolyte nanofibers.

Was the amount of the nano filler of ZrO ₂ performing EDX analysis of the different NF1 to NF4, showed a ratio (at%) of key elements in Table II.

Element NF1 NF2 NF3 NF4 C 66.83 62.6 61.76 58.91 O 4.75 4.88 5.96 7.60 F 29.51 30.34 29.06 29.21 Zr 1.91 2.19 3.22 4.28

It can be confirmed that the atomic ratio of Zr and O increases with an increase in the amount of ZrO ₂ nano powder added.

14 and 15 are XRD analysis results of the electrolyte nanofibers.

In FIG. 14, peaks of 2θ = 18.4 ° and 20.6 ° corresponding to the reflection of the (100) plane and the (020) plane of PVdF α were observed, indicating that the spherulites grown dominantly in the polymer were dominant . In addition, it shows amorphous nature besides the main peak, and it can be confirmed that PVdF-HFP has semi-crystalline characteristics as a whole. However, the ZrO ₂ to the intensity of the two peaks in the addition of 0.86wt% and 2.05wt% of NF1 with NF2 was added showed a reduction look to decrease the crystallinity, in particular, the (020) was reduced to a comparable peak surface significantly.

NF3 Figure 15 is ZrO ₂ added was 3.54wt% in the peak indicating crystallinity of PVdF is substantially reduced and, 2θ = 14.08 °, a strong peak appeared of 16.94 ° and 25.6 °, which the ion shown in Figure 16 source is a characteristic peak of LiCF ₃ SO _3. On the other hand, in NF4 added with 5.5 wt% ZrO ₂ , the peak of LiCF ₃ SO ₃ was greatly decreased. On the other hand, no characteristic peak of ZrO ₂ was observed in all of the electrolyte nanofibers, indicating that ZrO ₂ was completely compounded in the polymer matrix.

17 shows the impedance spectrum according to the addition amount of the nanofiller of the electrolyte nanofiber, and FIG. 18 shows the ion conductivity according to the addition amount of the nanofiller of the electrolyte nanofiber.

Bulk resistance was extracted from the spectral graph and applied to the calculation of ionic conductivity. The bulk ion conductivity was calculated by the equation σ = 1 / Rb A, where l is the distance between the working electrode and the sensing electrode, Rb is the bulk resistance and A is the cross-sectional area of the membrane perpendicular to the flow of ions.

The ionic conductivity increased with the addition of ZrO ₂ , and the maximum value was found in NF ₂ added with 20.5 wt%. There are two reasons for this increase in ion conductivity. First, ZrO ₂ acts as a nanofiller to inhibit the crystallization of the PVdF-HFP matrix, which interferes with the flow of ions. As will be seen later, due to the addition of nanofillers, the PVdF-HFP matrix has enhanced amorphous properties and ionic conductivity is improved due to the smooth flow of ions. The second reason for the increased ionic conductivity is the result of the enhanced ionization of the ion source by the high dielectric constant of ZrO ₂ . By adding ZrO ₂ having a high dielectric constant, the density of ions is increased, and consequently ion conductivity is improved.

On the other hand, the content of ZrO ₂ number of NF3 and NF4 NF2 rather than the symptoms the ionic conductivity is lowered occurred. In the early days when the amount of nanofiller is increased, the ion conductivity increases because the nanofiller maintains a gap so that the high conductivity regions near the particle surface are mutually connected, allowing the ions to move along the easy-to-travel region. However, when the amount of nanofiller is further increased, the nanofiller is located too close to the ionic conductivity because the blocking effect or the geometrically constrained component is strengthened.

FIG. 19 shows the impedance spectrum according to the temperature of the electrolyte nanofiber, and FIG. 20 shows the ionic conductivity according to the temperature of the electrolyte nanofiber.

In the same way as above, the ion conductivity was calculated from the spectrum according to temperature, and the ion conductivity was increased with increasing temperature. This can be explained by the free volume model. As the temperature increases, the polymer electrolyte expands to form a free volume that can increase the mobility of ions and solvated molecules or polymer fragments, resulting in increased ionic conductivity.

21 is a graph showing Arrhenius plots for NF0 and NF2.

Result of comparing the NF2 containing the that do not contain NF0 and nanofiller a nanofiller, by lowering the activation energy of the electrolyte by the addition of ZrO ₂ nano filler, it can be inferred that this can increase the amount of lithium ions.

From another experiment, it was confirmed that the addition of ZrO ₂ nano powder as a nanofiller increases the ion conductivity of the hybrid electrolyte, but the lower the permeability becomes, the higher the ZrO ₂ content is.

The dispersant MPS used in this example was introduced to improve the dispersibility of ZrO ₂ to prevent agglomeration of nano powder and to increase the permeability.

Figure 22 shows the FT-IR spectrum of ZrO ₂ functionalized with MPS.

As shown, a new band appeared in the range of 790 to 1100 cm ^-1, which was not seen in the spectra of ZrO ₂ and MPS. This is due to Si-O-Zr bonding, replacing the peaks of 1081 cm ^-1 and 814 cm ^-1 corresponding to the asymmetric stretching vibration and symmetric stretching vibration of Si-O-CH 3 of MPS. On the other hand, the 1,424 cm ^-1 and 1,536 cm ^-1 peaks identified in ZrO ₂ remain after functionalization. Thus, a dispersant containing a vinyl group provides stabilization of the nanopowder in the organism, allowing the nanoparticles to react in the polymerization process, allowing the nanoparticles to covalently bond to the polymer matrix through the carbon-carbon double bond. These covalent bonds stabilize the nanoparticles on the polymer matrix and prevent separation of the nanopowder and the polymer.

23 shows the ionic conductivity and the light transmittance according to the addition amount of the nanofiller of the electrolyte nanofiber.

An electrolyte nanofiber mat was formed to a thickness of 16 탆 on the surface of a 2.5 × 2.5 cm ITO-PET substrate, and the light transmittance was evaluated by UV-VIS spectroscopy after immersion in propylene carbonate in order to improve film stability and ionic conductivity .

As shown, both the ionic conductivity and the light transmittance show the same tendency to increase and then decrease with the addition of ZrO ₂ . However, the ionic conductivity of NF2 increased to the maximum, while the light transmittance decreased greatly, indicating that there was a difference at the point of decrease.

24 is a graph showing the light transmittance according to the thickness of the electrolyte nanofiber mat.

As shown in the figure, it can be seen that the light transmittance is greatly improved when the electrolyte nanofiber mat is formed to a thickness of 5 to 12 μm, compared with a case where the electrolyte nanofiber mat is formed to a thickness of 16 μm. The reason why the light transmittance changes as described above is that the light transmittance due to the pores formed in the porous structure of the electrolyte nanofiber mat decreases as the thickness becomes thicker and because of the change in permeability due to the structural characteristics, Change. From this, it can be confirmed that the ion conductivity and light transmittance of the electrolyte nanofiber mat can be optimally controlled by adjusting the content and thickness of the nanofiller.

25 is a graph showing the light transmittance according to the addition of the dispersing agent in the electrolyte nanofiber mat.

It can be confirmed that the light transmittance is increased when MPS is added as the dispersant in the same nanofiller content and thickness of the electrolyte nanofiber mat. From this, it can be seen that the light transmission characteristics of the electrolyte nanofiber containing nanofiller can be controlled by using a dispersant.

While the present invention has been particularly shown and described with reference to preferred embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Those skilled in the art will understand. Therefore, the scope of protection of the present invention should be construed not only in the specific embodiments but also in the scope of claims, and all technical ideas within the scope of the same shall be construed as being included in the scope of the present invention.

Claims

A base which is a copolymer of PVDF;
An ion source including lithium ions; And
And a ZrO ₂ nano powder as a nanofiller,
Wherein the electrolyte nanofiber is in the form of a nanofiber.

The method according to claim 1,
And the ZrO ₂ is contained in a range of 0.5 to 3 wt%.

The method according to claim 1,
Wherein the ZrO ₂ nano powder has a size of 5 to 20 nm.

The method according to claim 1,
Wherein the copolymer of PVDF has a -CF3 pendant group.

The method of claim 4,
Wherein the copolymer of PVDF is a PVdF-HFP copolymer.

The method according to claim 1,
Wherein the ion source is LiCF ₃ SO ₃ .

The method according to claim 1,
Wherein the ion source is added in an amount of 5 to 20 wt%.

The method according to claim 1,
The electrolyte nanofiber according to claim 1, further comprising a plasticizer.

The method of claim 8,
Wherein the plasticizer is propylene carbonate.

The method of claim 8,
Wherein the plasticizer is added in an amount of 10 to 20 wt%.

The method according to claim 1,
Wherein the ZrO ₂ is dispersed evenly by a dispersing agent containing a vinyl group and is covalently bonded to the matrix.

The method of claim 11,
Wherein the dispersant is MPS (3- (trimethoxysilyl) propyl methacrylate).

Dissolving a copolymer of a plasticizer and an ion source and PVdF in a solvent;
Adding ZrO ₂ nanopowder to the prepared solution and mixing them;
Molding the mixed solution into a nanofiber form; And
And drying the nanofibers to remove a solvent and moisture.

14. The method of claim 13,
Wherein a ligand containing a vinyl group is further added to the solution as a dispersant.

15. The method of claim 14,
Wherein the dispersant is MPS (3- (trimethoxysilyl) propyl methacrylate).

15. The method of claim 14,
Wherein the molar ratio of the dispersant ligand to the ZrO ₂ ranges from 0.01: 1 to 0.1: 1.

14. The method of claim 13,
Wherein the forming step is performed in an electrospinning process.

18. The method of claim 17,
Wherein the nanofibers are collected in the form of a nanofiber mat in the electrospinning process.

19. The method of claim 18,
Wherein the nanofibers are collected in the form of a nanofiber mat and then immersed in propylene carbonate.

Two electrodes facing each other;
An electrochromic composition layer disposed between the electrodes; And
And an electrolyte layer for transferring electricity between the electrochromic composition layer and the electrode,
Wherein the electrolyte layer is a nanofiber mat composed of the electrolyte nanofiber of any one of claims 1 to 12.

The method of claim 20,
Wherein the electrolyte layer has a thickness of 3 to 15 占 퐉.

The method of claim 20,
Wherein the pores of the nanofiber mat are filled with propylene carbonate.