WO2021111497A1 - Potassium secondary cell and method for manufacturing same - Google Patents

Abstract

A potassium secondary cell 110 comprises: a positive electrode film 1, formed on a flexible transparent film substrate 4, that contains a material that is capable of potassium ion insertion and extraction; a potassium-ion-conductive transparent electrolyte 2; and a negative electrode film 3, formed on a flexible transparent film substrate 5, that contains a material that is capable of potassium dissolution and precipitation or potassium ion insertion and extraction.

Description

Potassium secondary battery and its manufacturing method

The present invention relates to a potassium secondary battery and a method for manufacturing the same.

A potassium ion secondary battery that uses a potassium ion insertion / desorption reaction is cheaper than a lithium secondary battery because it has abundant potassium resources. In addition, there are few resource constraints, so expectations are high in the future. Therefore, research and development of the electrode material and the electrolyte material are being promoted.

Recently, with the development of IT devices such as smartphones and IoT devices, secondary batteries for mobile power sources are attracting attention. Batteries for those devices may be required to have new characteristics for the purpose of differentiating each product. As new characteristics, for example, flexibility has become apparent.

As an example of a flexible secondary battery, a lithium secondary battery is reported in Non-Patent Document 1. The battery is reported to be thin, bendable, and exhibit a discharge capacity of approximately 250 μAh / g with a ^{current density of 0.1 mA / cm 2.}

Masahiko Hayashi, et al., “Preparation and electrochemical properties of pure lithium cobalt oxide films by electron cyclotron resonance sputtering”, Journal of Power Sources 189 (2009) 416-422.

In this way, with regard to lithium secondary batteries, studies are underway for batteries with new characteristics. On the other hand, regarding potassium secondary batteries, there are no reports of batteries having such new characteristics so far. As for the potassium secondary battery, if a battery having unprecedented transparency to visible light, flexibility, etc. can be realized, it is possible to greatly expand the design and the range of applications of the IoT device. However, there is a problem that such a battery does not exist yet.

The present invention has been made in view of this problem, and an object of the present invention is to provide a potassium secondary battery having both transparency and flexibility with respect to visible light and a method for manufacturing the same.

The potassium secondary battery of one aspect of the present invention comprises a positive electrode film containing a substance formed on a flexible transparent film substrate capable of inserting and removing potassium ions, and a transparent electrolyte having potassium ion conductivity. A negative electrode film containing a substance capable of dissolving and precipitating potassium or inserting and removing potassium ions formed on a flexible transparent film substrate.

The method for producing a potassium secondary battery according to one aspect of the present invention includes a positive electrode film forming step of forming a positive electrode film containing a substance capable of inserting and removing potassium ions formed on a flexible transparent film substrate. Includes an electrolyte deposition step to deposit a transparent electrolyte with potassium ion conductivity and a substance capable of dissolving and precipitating potassium formed on a flexible transparent film substrate or inserting and removing potassium ions. A negative electrode film forming step for forming a negative electrode film, and at least one of the positive electrode film forming step and the negative electrode film forming step is performed by heat treatment at 50 to 200 ° C. in an argon atmosphere after the film formation.

According to the present invention, it is possible to provide a potassium secondary battery having both transparency and flexibility to visible light and a method for producing the same.

It is a top view which shows the structure of the potassium secondary battery which concerns on this embodiment. It is a side view which shows the structure of the potassium secondary battery which concerns on this embodiment. It is a flowchart which shows the procedure of manufacturing a potassium secondary battery. It is a figure which shows an example of charge / discharge characteristics of a potassium secondary battery. It is a figure which shows an example of the charge / discharge cycle characteristic of a potassium secondary battery. It is a figure which shows an example of the light transmission characteristic of a potassium secondary battery. It is a top view which shows the apparatus which evaluates flexibility. It is a side view which shows the apparatus which evaluates flexibility. It is a figure which shows the light transmission characteristic of the potassium secondary battery of the comparative example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Structure of potassium secondary battery]
1A and 1B are schematic views showing a basic configuration of a potassium secondary battery according to the present embodiment. 1A is a plan view and FIG. 1B is a side view.

As shown in FIGS. 1A and 1B, the potassium secondary battery 100 according to the present embodiment is, for example, a rectangular flat plate, and flexible transparent film substrates 4 and 5 having visible light transmission are vertically attached to each other by a laminated film 7. It is sandwiched and the laminated films 7 are thermocompression bonded to each other. At least the positive electrode, the electrolyte, and the negative electrode are arranged in the laminated film 7. The planar shape of the potassium secondary battery 100 is not limited to a rectangle.

As shown in FIG. 1A, the positive electrode terminal 8 and the negative electrode terminal 9 having a quadrangular plan view project from both ends of one short side of the rectangular transparent films 4 and 5 to the outside of the laminated film 7. A current can be taken out from between the positive electrode terminal 8 and the negative electrode terminal 9. The positive electrode terminal 8 and the negative electrode terminal 9 may be an extension of the transparent electrode film 6 described later, or may be made of metal.

The potassium secondary battery 100 shown in FIG. 1B includes a positive electrode film 1, an electrolyte 2, a negative electrode film 3, a transparent electrode film 6, and transparent films 4 and 5. The positive electrode film 1 is formed with a substance capable of inserting and removing potassium ions having a predetermined thickness on a transparent electrode film 6 such as ITO formed on the entire surface of one surface of the flexible transparent film substrate 4. Is formed.

Similar to the positive electrode film 1, the negative electrode film 3 has potassium dissolution and precipitation or potassium ion insertion and desorption on the transparent electrode film 6 such as ITO formed on the entire surface of one surface of the transparent film substrate 5. A possible substance is formed by forming a film with a predetermined thickness. The transparent film substrates 4 and 5 are the same, and are composed of, for example, PET (Polyethylene terephthalate).

The positive electrode film 1 and the negative electrode film 3 are arranged so as to face each other with the electrolyte 2 interposed therebetween. As the electrolyte 2, an organic electrolyte containing potassium ions, an aqueous electrolyte, or the like can be used as long as it is a conventional substance having potassium ion conductivity but not having electron conductivity and having visible light transmittance.

Further, conventional solid electrolytes containing potassium ions and solid electrolytes such as polymer electrolytes can also be used as long as they transmit visible light.

A separator (not shown) may be included between the positive electrode film 1 and the negative electrode film 3. Examples of the light-transmitting separator include polyethylene (PE), polypropylene (PP), and an ion exchange membrane. When an organic electrolyte or an aqueous electrolyte is used as the electrolyte 2, for example, the separator may be impregnated with the electrolyte 2.

Further, the organic electrolyte or the aqueous electrolyte may be impregnated with the polymer electrolyte or the like. When a solid electrolyte, a polymer electrolyte, or the like is used, both electrodes of the positive electrode 1 and the negative electrode 3 may be arranged so as to be in contact with them.

As described above, the potassium secondary battery 100 of the present embodiment has a positive electrode film 1 containing a substance formed on a flexible transparent film substrate 4 capable of inserting and removing potassium ions, and potassium ion conductivity. A transparent electrolyte 2 having a potassium ion, and a negative electrode film 3 containing a substance capable of dissolving and precipitating potassium or inserting and removing potassium ions formed on a flexible transparent film substrate 5 are provided.

This makes it possible to provide a potassium secondary battery that has both visible light transmission and flexibility.

(Manufacturing method of potassium secondary battery)
FIG. 2 is a flowchart showing a procedure for manufacturing the potassium secondary battery 100 according to the present embodiment. A method for manufacturing the potassium secondary battery 100 will be described with reference to FIG.

First, the transparent film substrates 4 and 5 that serve as the substrate on which the electrode film is formed are cut into a predetermined size (step S1). The size of the transparent film substrates 4 and 5 is, for example, about 100 mm in length × 50 mm in width. The thickness is, for example, about 0.1 mm.

Next, the positive electrode film 1 is formed (step S2). In forming the positive electrode film 1, the transparent electrode film 6 is formed on the surface of the transparent film substrate 4.

The transparent electrode film 6 was coated with ITO to a thickness of 150 nm by the RF sputtering method. Sputtering was carried out using an ITO (5wt% SnO ₂ ) target with an RF output of 100 W while flowing argon (1.0 Pa).

_{Next, on the transparent electrode film 6, for example, K 4} Co ₄ [Fe (CN) ₆ ] ₃ (potassium cyano complex), which is a cyano complex, was formed as a positive electrode film 1 by an RF sputtering method to a thickness of 200 nm. For the film formation of the positive electrode film 1, _{a firing target of K 4} Co ₄ [Fe (CN) ₆ ] ₃ powder is used, the flow partial pressure ratio of argon and oxygen is 3: 1, the total gas pressure is 3.7 Pa, and RF output. It was done under the condition of 300W.

Next, the negative electrode film 3 is formed (step S3). Similar to the positive electrode film 1, the transparent electrode film 6 was first formed on the surface of the transparent film substrate 5. Next, a negative electrode film 3 was formed on the transparent electrode film 6 with a film thickness of 100 nm by the RF sputtering method in the same manner as the positive electrode film 1. Using graphite as a target, the flow voltage division ratio of argon and oxygen was 3: 1, the total gas pressure was 4.0 Pa, and the negative electrode film 3 was formed with an RF output of 300 W.

The size of the positive electrode film 1 and the negative electrode film 3 is, for example, the same size of 90 mm in length × 50 mm in width. The size of the bipolar films 1 and 3 is smaller than that of the transparent electrode film 6.

Next, the electrode terminals 8 and 9 are molded (step S4). In the transparent film substrates 4 and 5 and the transparent electrode film 6 formed as described above, there is a portion where the electrode films 1 and 3 are not formed and the transparent electrode film 6 is exposed only by 10 mm in length × 50 mm in width. Of the portion, 10 mm in length × 40 mm in width is cut out, and 10 mm in length × 10 mm in width at the end is left as a positive electrode terminal 8 or a negative electrode terminal 9.

Next, the electrolyte 2 is formed into a film (step S5). Electrolyte 2 is dispersed with polyvinyl fluoride (PVdF) powder, which is a binder, and an organic electrolyte solution in which 1 mol / L of potassium bistrifluoromethanesulfonylimide (KTFSI) is dissolved as a potassium salt in propylene carbonate (PC). A solution prepared by mixing tetrahydrofuran (THF) as a medium at a weight ratio of 1: 9: 10 was stirred at 60 ° C. for 1 hour in dry air with a dew point of -50 ° C or lower, and 50 ml of the solution was poured into a 200 mmφ chalet. Electrolyte 2 having a transparent film having a thickness of 1 μm was prepared by vacuum drying at ° C. for 12 hours.

Next, assemble the battery (step S6). The transparent film substrate 4 on which the positive electrode film 1 is formed, the transparent film substrate 5 on which the negative electrode film 3 is formed, and the electrolyte 2 are laminated so that the positive electrode film 1 and the negative electrode film 3 face each other with the electrolyte 2 interposed therebetween. Then, the positive electrode terminal 8 and the negative electrode terminal 9 are sandwiched between two laminated films 7 having a length of 110 mm, a width of 70 mm, and a thickness of 100 μm so as to be exposed to the outside, and hot-pressed at 130 ° C. The thickness of the hot-pressed battery is, for example, about 400 μm.

The potassium secondary battery 100 can be manufactured by the above process.

(Charge / discharge test)
The charge / discharge characteristics of the potassium secondary battery 100 produced by the above manufacturing method were measured. The charge / discharge test was performed using a general charge / discharge system. The charging conditions were as follows: the current density per effective area of the positive electrode film 1 was 1 μA / cm2, and the final charging voltage was 3.4 V.

The discharge conditions were a current density of 1 μA / cm2 and a discharge end voltage of 2.0 V. The charge / discharge test was performed in a constant temperature bath at 25 ° C (the atmosphere is a normal atmospheric environment).

FIG. 3 is a diagram showing the charge / discharge characteristics of the potassium secondary battery 100. The horizontal axis of FIG. 3 is the capacity [mAh], and the vertical axis is the battery voltage [V]. In FIG. 3, the broken line shows the charging characteristic and the solid line shows the discharging characteristic.

As shown in FIG. 3, the irreversible capacity, which is the difference between the charge capacity and the discharge capacity, is small. The discharge capacity was about 0.111mAh, and the average discharge voltage was about 2.5V.

FIG. 4 is a diagram showing the charge / discharge cycle characteristics of the potassium secondary battery 100. The horizontal axis of FIG. 4 is the number of charge / discharge cycles [times], and the vertical axis is the discharge capacity [mAh].

As shown in FIG. 4, the decrease in discharge capacity after 20 cycles shows only a capacity decrease of about 0.001 mAh, indicating that it has stable charge / discharge cycle characteristics.

FIG. 5 is a diagram showing the light transmission characteristics of the potassium secondary battery 100. The horizontal axis of FIG. 5 is the wavelength of light [nm], and the vertical axis is the transmittance of light [%]. In FIG. 5, the broken line indicates the light transmission characteristic of the transparent film substrate 4 including the positive electrode film 1. The alternate long and short dash line shows the light transmission characteristics of the transparent film substrate 5 including the negative electrode film 3. The solid line shows the light transmission characteristics of the entire potassium secondary battery 100.

As shown in FIG. 5, the entire potassium secondary battery 100 transmits light in the visible light wavelength range (about 380 nm to 780 nm). It transmits about 19% of light at a wavelength of 600 nm.

As described above, the potassium secondary battery 100 according to the present embodiment has stable charge / discharge cycle characteristics and light transmission characteristics.

(Experiment)
For the purpose of examining the configuration of the present embodiment described above in detail, the experiment was conducted by changing the conditions such as the film thickness of the negative electrode film 3, the film thickness of the positive electrode film 1, and the heat treatment. The results of each experiment will be described.

(Experimental Example 1)
In Experimental Example 1, the film thickness of the positive electrode film 1 was changed to 30 nm, 50 nm, 100 nm, 200 nm, 400 nm, and 500 nm to prepare a potassium secondary battery 100, and the charge / discharge characteristics were measured. As the positive electrode active material of the positive electrode film 1, the same K ₄ Co ₄ [Fe (CN) ₆ ] ₃ as in the above embodiment was used. The experimental results are shown in Table 1. The light transmittance shown in Table 1 indicates the transmittance of the entire battery at a wavelength of 600 nm.

The conditions other than the film thickness of the positive electrode film 1 are the same as those in the above embodiment. The active material of the negative electrode film 3 is graphite, and its film thickness is 100 nm.

As shown in Table 1, the film thickness of the positive electrode film 1 showed the largest discharge capacity when the film thickness was 200 nm. It is considered that this is because the amount of K ₄ Co ₄ [Fe (CN) ₆ ] ₃ which is the positive electrode active material is equal to or more than the amount of the negative electrode active material.

When the film thickness of the positive electrode film 1 whose discharge capacity decreases is 500 nm, _{the electron conductivity of K 4} Co ₄ [Fe (CN) ₆ ] ₃ itself is low, so that the space between the transparent conductive film 6 which is the current collector is reached. It is considered that this is because the resistance in the thickness direction of is increased.

From the results in Table 1, it can be seen that, for example, assuming that the discharge capacity of 0.060 mAh or more is within the allowable range, the film thickness of the positive electrode film 1 is preferably 100 nm to 400 nm. 0.060mAh or more is the capacity to use 1mW of power for about 5 minutes.

Further, the same result can be obtained by using another positive electrode active material having an electron conductivity equal to or higher than that of K ₄ Co ₄ [Fe (CN) ₆ ] _{3 for the positive electrode film 1.}

The positive electrode active material of the positive electrode film 1 is, for example, K ₄ Co ₄ [Fe (CN) ₆ ] ₃ , potassium composite oxide, potassium manganese composite oxide, potassium nickel composite oxide, potassium cobalt composite oxide, potassium chromium manganese. Composite oxide, potassium chromium nickel composite oxide, potassium chromium cobalt composite oxide, potassium nickel cobalt composite oxide, potassium manganese cobalt composite oxide, potassium manganese nickel composite oxide, potassium phosphorus oxide, potassium nickel cobalt manganese composite oxidation Contains at least one selected from the group consisting of, potassium nickel cobalt chromium composite oxide, potassium nickel manganese chromium composite oxide, potassium cobalt manganese chromium composite oxide, potassium silicon composite oxide, and potassium boron composite oxide. But it may be.

Regardless of which positive electrode active material is used, light transmission and flexibility are ensured by thinning the positive electrode film 1.

However, as shown in Table 1, if the film thickness of the positive electrode film 1 is set to 400 nm, the transmittance drops to 8.9%. For example, assuming that the transmittance is 10% or more, it can be seen from the results in Table 1 that the film thickness of the positive electrode film 1 is preferably less than 400 nm. Therefore, the film thickness of the positive electrode film 1 is more preferably 100 nm to 300 nm in consideration of the light transmittance. Within this range, it is possible to secure both a capacity of 0.060 mAh or more and a light transmittance of 10% or more.

(Experimental Example 2)
In Experimental Example 2, the thickness of the positive electrode film 1 showing the best characteristics in Experimental Example 1 was set to 200 nm, and the film thickness of the negative electrode film 3 was changed to 20 nm, 30 nm, 50 nm, 100 nm, 200 nm, and 300 nm to perform potassium secondary. A battery 100 was prepared and the charge / discharge characteristics were measured. The experimental results are shown in Table 2.

As shown in Table 2, the film thickness of the negative electrode film 3 showed a large discharge capacity when the film thickness was 100 nm or more. It is considered that this is because the amount of graphite, which is the negative electrode active material, is equal to or more than the amount of the positive electrode active material, as in Experimental Example 1.

The film thickness of the negative electrode film 3 is preferably 50 nm to 200 nm. Within this range, it is possible to secure a capacity of 0.100 mAh or more. The light transmittance is 10% or more even when the film thickness of the negative electrode film 3 is 200 nm. Therefore, the film thickness of the negative electrode film 3 is preferably 50 nm to 200 nm even in consideration of the light transmittance.

Further, the same result can be obtained by using another negative electrode active material having an electron conductivity equal to or higher than that of graphite for the negative electrode film 3.

The negative electrode active material of the negative electrode film 3 includes, for example, graphite, tin oxide, silicon oxide, titanium oxide, tungsten oxide, niobium oxide, molybdenum oxide, metal sulfide, metal nitride, metal fluoride, and It may contain at least one selected from the group consisting of metallic titanium composite oxides.

Regardless of which negative electrode active material is used, light transmission and flexibility are ensured by thinning the negative electrode film 3.

(Experimental Example 3)
It is known that the surface of the electrode film is purified and the crystallinity is enhanced by performing heat treatment after forming the electrode film. Therefore, the film thickness of the positive electrode film 1 is set to 200 nm, which shows good characteristics in Experimental Example 1, the film thickness of the negative electrode film 3 is set to 100 nm, which shows good characteristics in Experimental Example 2, and the positive electrode film 1 after film formation is set to 100 nm. A potassium secondary battery was prepared by heat-treating at each temperature of 50 ° C., 100 ° C., 200 ° C., and 300 ° C. for 12 hours in an argon atmosphere. An experiment was conducted to compare the charge / discharge cycle characteristics of each of the produced potassium secondary batteries. Table 3 shows the experimental results obtained by heat-treating only the positive electrode film 1 after the film formation.

As shown in Table 3, the battery performance was improved by performing the heat treatment. At 300 ° C., the transparent film substrate 4 was deformed and the battery could not be manufactured.

Similarly, for the negative electrode film 3, the negative electrode film 3 after film formation is heat-treated for 12 hours at each temperature of 50 ° C., 100 ° C., 200 ° C., and 300 ° C. in an argon atmosphere to prepare a potassium secondary battery. , An experiment was conducted to compare the charge / discharge cycle characteristics of each of the produced potassium secondary batteries. Table 4 shows the experimental results obtained by heat-treating only the negative electrode film 3 after the film formation.

As shown in Table 4, the same results as those of the positive electrode film 1 were obtained by performing the same heat treatment on the negative electrode film 3. When both the positive electrode film 1 and the negative electrode film 3 are heat-treated, the discharge capacity can be larger than the discharge capacities shown in Tables 3 and 4.

From the results shown in Tables 3 and 4, it was found that the battery performance was improved by performing heat treatment for 12 hours at any temperature within the temperature range of 50 ° C. to 200 ° C. after forming the electrode films 1 and 3. .. Therefore, it is advisable to perform the heat treatment after forming the electrode films 1 and 3. Both the positive electrode film 1 and the negative electrode film 3 may be heat-treated, or either the positive electrode film 1 or the negative electrode film 3 may be heat-treated.

As a result, the method for manufacturing the potassium secondary battery 100 includes a positive electrode film forming step of forming a positive electrode film 1 containing a substance capable of inserting and removing potassium ions formed on a flexible transparent film substrate 4. An electrolyte film forming step for forming a transparent electrolyte 2 having potassium ion conductivity, and a substance capable of dissolving and precipitating potassium formed on a flexible transparent film substrate 5 or inserting and removing potassium ions. Including a negative electrode film forming step of forming a negative electrode film 3 including the negative electrode film 3. At least one step of the positive electrode film forming step and the negative electrode film forming step is performed at any temperature within the temperature range of 50 to 200 ° C. in an argon atmosphere after the electrode film (positive electrode film 1, negative electrode film 3) is formed. Time heat treatment may be performed.

This makes it possible to improve the performance of the potassium secondary battery 100.

(Flexibility)
Next, the flexibility of the potassium secondary battery 100 of the present embodiment was examined.

The flexibility was evaluated by the relationship between the amount of deflection of the battery 100 and the load, with both ends of the potassium secondary battery 100 as fulcrums and a load vertically downward on the central portion of the battery 100.

6A and 6B are diagrams schematically showing an evaluation device (means) for evaluating the flexibility of a battery. FIG. 6A is a plan view of the evaluation device viewed from above, and FIG. 6B is a side view of the evaluation device viewed from the side. Metal columns 20 having a height of 15 mm are installed at intervals of 30 mm, a potassium secondary battery 100 is hung on the metal columns 20, and a metal rod 30 having a weight of 200 g and a diameter of 10 mm is placed in the center of the battery 100. The weight loaded on the metal rod 30 until the back surface of the battery 100 came into contact with the flat surface on which the metal support column 20 was placed was used as an index of flexibility.

Batteries 100 having a thickness of the laminated film 7 of 50 × 2 μm (battery thickness 431 μm), 100 × 2 μm (battery thickness 529 μm), and 150 × 2 μm (battery thickness 631 μm) were produced, and the flexibility of each battery 100 was obtained. Gender was evaluated. The evaluation results are shown in Table 5. Of the load amounts shown in Table 5, 200 g is the weight of the metal rod 30.

As shown in Table 5, as the thickness of the battery increases, the amount of load required to bend the battery by a certain amount increases. As the thickness of the battery increases in this way, the flexibility is impaired.

Assuming that the potassium secondary battery 100 of the present embodiment is mounted on the wearable device, it is considered that the flexibility is sufficient if the load of 500 g is deflected by the above amount of deflection. Therefore, it is desirable that the thickness of the potassium secondary battery 100 is 500 μm or less.

If the thickness of the potassium secondary battery 100 is set to 500 μm or less, it is possible to provide practically sufficient flexibility in addition to light transmission.

(Comparison example)
For the purpose of comparison with the above-described embodiment and experimental example, a potassium secondary battery of a comparative example was prepared by mixing (laminating) carbon, which is a conductive auxiliary agent, with a positive electrode film.

The potassium secondary battery of the comparative example was produced by forming a carbon thin film having a film thickness of 100 nm on the positive electrode film 1 of _{K 4} Co ₄ [Fe (CN) ₆ ] _{3 having a film thickness of 200 nm.} Other configurations were the same as in Experimental Example 1 above.

FIG. 7 is a diagram showing the light transmission characteristics of the comparative example. The horizontal axis of FIG. 7 is the wavelength of light [nm], and the vertical axis is the transmittance of light [%]. In FIG. 7, the broken line indicates the light transmission characteristic of the transparent film substrate 4 including the positive electrode film 1. The alternate long and short dash line shows the light transmission characteristics of the transparent film substrate 5 including the negative electrode film 3. The solid line shows the light transmission characteristics of the entire battery of the comparative example.

As shown in FIG. 7, the transmittance of the entire battery of the comparative example is about 10% lower than that of the above-described embodiment and experimental example. It is considered that the reason why the transmittance of the comparative example is low is that the carbon thin film reflects and absorbs a lot of light.

By comparing the comparative example (FIG. 7) with the potassium secondary battery 100 (FIG. 5) according to the present embodiment, it can be clearly seen that the light transmission characteristics of the present embodiment are excellent.

As described above, according to the present embodiment, it is possible to provide a potassium secondary battery having both transparency and flexibility to visible light and a method for producing the same.

The present invention is not limited to the above embodiment, and can be modified within the scope of the gist thereof.

In this embodiment, a potassium secondary battery having both visible light transmission and flexibility can be produced, and it can be used as a power source for various electronic devices.

1: Positive electrode film 2: Electrolyte 3: Negative electrode film 4, 5: Transparent film substrate 6: Transparent electrode film 7: Laminated film 8: Positive electrode terminal 9: Negative electrode terminal 100: Potassium secondary battery

Claims (4)

A positive electrode film containing a substance formed on a flexible transparent film substrate that allows insertion and desorption of potassium ions, and a positive electrode film.
A transparent electrolyte with potassium ion conductivity and
A negative electrode film formed on a flexible transparent film substrate and containing a substance capable of dissolving and precipitating potassium or inserting and removing potassium ions, and a negative electrode film.
Potassium secondary battery with. When the positive electrode film contains a potassium source,
The material of the positive electrode film is potassium composite oxide, potassium manganese composite oxide, potassium nickel composite oxide, potassium cobalt composite oxide, potassium chromium manganese composite oxide, potassium chromium nickel composite oxide, potassium chromium cobalt composite oxide. , Potassium nickel cobalt composite oxide, potassium manganese cobalt composite oxide, potassium manganese nickel composite oxide, potassium phosphorus oxide, potassium nickel cobalt manganese composite oxide, potassium nickel cobalt chromium composite oxide, potassium nickel manganese chromium composite oxide , At least one selected from the group consisting of potassium cobalt manganese chromium composite oxide, potassium silicon composite oxide, potassium cyano complex and potassium boron composite oxide.
The film thickness of the positive electrode film is 100 nm to 300 nm.
The potassium secondary battery according to claim 1. When the positive electrode film contains a potassium source,
The negative electrode film material is carbon, metallic potassium, tin oxide, silicon oxide, titanium oxide, tungsten oxide, niobium oxide, molybdenum oxide, metal sulfide, metal nitride, metal fluoride, and metal. Containing at least one selected from the group consisting of titanium composite oxides,
The film thickness of the negative electrode film is 50 nm to 200 nm.
The potassium secondary battery according to claim 1 or 2. A positive electrode film forming step of forming a positive electrode film containing a substance capable of inserting and removing potassium ions formed on a flexible transparent film substrate, and a positive electrode film forming step.
An electrolyte deposition step that deposits a transparent electrolyte with potassium ion conductivity, and
Includes a negative film formation step of forming a negative film containing a substance capable of dissolving and precipitating potassium or inserting and removing potassium ions formed on a flexible transparent film substrate.
At least one step of the positive electrode film forming step and the negative electrode film forming step is a method for manufacturing a potassium secondary battery in which heat treatment is performed at 50 to 200 ° C. in an argon atmosphere after the film formation.

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