JP2024021849A - Energy storage device and method for manufacturing the energy storage device - Google Patents

Abstract

The present invention provides an energy storage device that has an energy storage function and can be used underwater, and an electronic device that can be used underwater by using the energy storage device. An electronic device (1) includes an energy storage device (2) and an electronic element (3). The energy storage device 2 includes a base body 4 and an energy storage element 5 , and the electronic element 3 inside the base body 4 is connected to the energy storage element 5 . When used while immersed in liquid L, a gas region A is generated above the water-repellent surface 6 of the substrate 4. As the energy storage element 5, an electric double layer capacitor 5d (FIG. 14) using a hollow structure 15 (FIG. 15) can be used. [Selection diagram] Figure 1

Description

The present invention relates to an energy storage device used as a power source, a method of manufacturing the same, and an electronic device using the energy storage device, and particularly relates to a small energy storage device and electronic device that can be used underwater. be.

In the age of IoT (Internet of Things), where everything is connected to the internet, there is a need to install sensors, which are electronic devices for obtaining data, everywhere. A power source is required to operate the sensors, but connecting small sensors individually to electrical outlets or providing batteries for each sensor that require periodic replacement means that the number of sensors is enormous. Considering this, it cannot be said to be realistic. Therefore, the inventor of the present invention came up with the idea of using an energy storage element to supply power to a large number of small sensors. An energy storage element is an element that converts energy stored in various forms into electricity and supplies it as needed. For example, a power storage element that stores electricity and a heat storage element that stores heat are known. However, the inventors of this application are not aware of any examples that specifically present useful techniques regarding the structure and manufacturing method necessary for using a small energy storage device underwater.

Therefore, the inventor of the present application conducted a multifaceted study on means and methods for stably supplying electric power to underwater electronic devices (for example, sensors, etc.) using energy storage elements. As a result, the inventor of the present application has discovered that there are various ways to extract electric power through an energy harvesting method, for example, a power generation method that utilizes an environmentally conductive liquid such as seawater, and to store that electric power with an energy storage element. We have come to believe that this is a promising technical problem that is useful in various applications. However, since no such technology was known to be practical, the researchers continued to pursue further research.

The present invention has been made based on the knowledge and research of the inventor as described above, and includes an energy storage device that can be used underwater and has energy storage functions such as electricity storage and heat storage, and an energy storage device that can be used underwater. The purpose is to provide electronic devices etc. that can be used in

The energy storage device according to claim 1 includes:
a base in which a gas region is formed in a part of the surface that is in contact with an electrically conductive liquid;
an energy storage element disposed on the base body inside the gas region;
It is characterized by having the following.

The energy storage device according to claim 2 is the energy storage device according to claim 1, comprising:
The surface of the substrate on which the gas region is formed is a water-repellent surface.

The energy storage device according to claim 3 is the energy storage device according to claim 2, comprising:
The energy storage element is
At least one of a power storage element group including a chemical battery and an electric double layer capacitor, a heat storage element group including a latent heat heat storage element, a chemical heat storage element, a thermoelectric heat storage element, a temperature difference heat storage element, a photochemical heat storage element, and a sensible heat heat storage element. It is characterized in that it is one or more elements selected from the group.

The energy storage device according to claim 4 is the energy storage device according to claim 3, comprising:
The energy storage element is
a hollow portion formed on the surface of the base body inside the gas region;
an electrode provided on the inner surface of the hollow part;
a connection part that electrically connects the electrode in the hollow part and the electrode in the adjacent hollow part;
an electrolytic solution filled inside the hollow part;
The electric double layer capacitor is characterized in that the electric double layer capacitor has the following characteristics.

The energy storage device according to claim 5 is the energy storage device according to claim 3,
In the energy storage element,
An environment in which two metals of different types are arranged on the base body so as to span both the gas region and the liquid, and electric power is generated by a potential difference generated between the two metals in the gas region. It is characterized by a power generation element connected to it.

The energy storage device according to claim 6 is the energy storage device according to claim 3, comprising:
A thermoelectric conversion element is connected to the elements of the heat storage element group.

The method for manufacturing an energy storage device according to claim 7 is the method for manufacturing the energy storage device according to claim 4, comprising:
The manufacturing process of the electric double layer capacitor includes:
irradiating electromagnetic waves to a plurality of microscopic bodies arranged at intervals on the surface of the base body to form a protuberance on the base body below the microscopic bodies to which the microscopic bodies are fixed;
forming the electrode on the surface of the microscopic body facing the adjacent microscopic body;
irradiating the microscopic body with electromagnetic waves to form the hollow portion that is continuous with the raised portion and covering the microscopic body and the electrode;
removing the microscopic body leaving the hollow part and the electrode;
forming the connection portion that connects the electrode located inside the hollow portion and the electrode located inside the adjacent hollow portion;
filling the inside of the hollow part with the electrolytic solution;
It is characterized by including.

The electronic device according to claim 8 includes:
It is characterized by comprising an electronic element that functions with electric power supplied from the energy storage device according to any one of claims 1 to 6.

The hollow structure according to claim 9 includes:
a raised part formed by raising a part of the base;
a hollow part formed continuously in the raised part;
It is characterized by having the following.

The method for manufacturing a hollow structure according to claim 10 includes:
irradiating electromagnetic waves to a plurality of microscopic bodies arranged at intervals on the surface of the base body to form a protrusion on the base body below the microscopic bodies to which the microscopic bodies are fixed;
irradiating the microscopic body with electromagnetic waves to form the hollow portion that is continuous with the raised portion and covering the microscopic body;
removing the microscopic body leaving the hollow part;
It is characterized by having the following.

According to the energy storage device according to the first aspect, it can be used as a power source for operating electronic elements such as sensors placed underwater.

According to the energy storage device according to claim 2, when the energy storage device is placed in water, a gas region is formed on the water-repellent surface of the base, so that the energy storage element can be prevented from getting wet. .

According to the energy storage device according to the third aspect, an appropriate element can be selected as the energy storage element from the power storage element group and the heat storage element group according to the purpose, application, etc.

According to the energy storage device described in claim 4, the surface of the base body in which the minute hollow portions are formed becomes a water-repellent surface to create a gas region in water, and the electric double layer formed by the hollow portions etc. A capacitor can supply electricity to the electronic device.

According to the energy storage device described in claim 5, the energy harvesting element can generate electric power underwater, and the energy storage element can store electricity, so that the supply of electric power to the electronic elements is stabilized.

According to the energy storage device described in claim 6, heat supplied from the elements of the heat storage element group can be converted into electricity by the thermoelectric conversion element and supplied to the electronic element.

According to the method for manufacturing an energy storage device according to claim 7, the protrusion and the hollow body formed on the surface of the base, the electrode provided on the inner surface of the hollow body, and the electrode of the adjacent hollow body are connected. An electric double layer capacitor having a connecting portion and an electrolytic solution filled inside a hollow portion can be reliably manufactured through a simple process.

According to the electronic device described in claim 8, power can be supplied from the energy storage device to the electronic element to make it function underwater.

According to the hollow structure described in claim 9, the hollow part is reliably held on the surface of the base by the raised part, and a structure according to the use or purpose can be built inside the hollow part. It can be used as a stable container to store necessary substances.

According to the method for manufacturing a hollow structure described in claim 10, a large number of hollow structures can be manufactured with a necessary and uniform size by using microscopic bodies of a size according to the use or purpose and electromagnetic waves of appropriate energy. They can be formed on the surface of the substrate by arranging them in an orderly manner.

Part (a) is a front view of the electronic device of the first embodiment, and part (b) is a plan view thereof. Part (a) is a front view of the electronic device of the second embodiment, and part (b) is a plan view thereof. Part (a) is a front view of the electronic device of the third embodiment, and part (b) is a plan view thereof. FIG. 7 is a front view of an electronic device according to a fourth embodiment. It is a front view which shows the microsphere alignment process in the manufacturing process of the electric double layer capacitor of 5th Embodiment. It is a front view which shows the pre-etching process in the manufacturing process of the electric double layer capacitor of 5th Embodiment. It is a front view which shows the pre-laser irradiation process in the manufacturing process of the electric double layer capacitor of 5th Embodiment. It is a front view which shows the electrode formation process in the manufacturing process of the electric double layer capacitor of 5th Embodiment. It is a front view which shows the hollow part formation process in the manufacturing process of the electric double layer capacitor of 5th Embodiment. It is a front view which shows the microsphere removal process in the manufacturing process of the electric double layer capacitor of 5th Embodiment. It is a front view which shows the electrolyte solution filling process in the manufacturing process of the electric double layer capacitor of 5th Embodiment. It is a front view which shows another example of the electrolyte solution filling process in the manufacturing process of the electric double layer capacitor of 5th Embodiment. It is a front view which shows the connection part formation process in the manufacturing process of the electric double layer capacitor of 5th Embodiment. FIG. 7 is a front view showing how an electronic device having an electric double layer capacitor according to a fifth embodiment is used underwater. It is a figure which shows the electron micrograph of a hollow structure.

Embodiments of the present invention will be described below with reference to FIGS. 1 to 15.
FIG. 1 is a diagram schematically showing an electronic device 1 according to a first embodiment having the basic structure of the present invention. The basic structure of this electronic device 1 is common to multiple embodiments. That is, this electronic device 1 includes an energy storage device 2 and an electronic element 3. The energy storage device 2 includes a base 4 and an energy storage element 5 provided on the surface of the base, and an electronic element 3 is provided inside the base 4 and connected to the energy storage element 5. has been done. As shown in FIG. 1, this electronic device 1 can be used by being immersed in a liquid L having electrical conductivity. In the figure, the liquid L portion is shown in light black (gray coloring).

The base body 4 is a rectangular plate made of a material that is insulating and transparent to radio waves so that the electronic element 3 provided therein can communicate with the outside by radio waves. A part of the upper surface of the base body 4 has a water-repellent surface 6 which is an elliptical area treated to be water-repellent, so if the base body 4 is submerged in the liquid L, a sphere will appear above the water-repellent surface 6. Alternatively, a gas region A, which is a bubble shaped like a spheroid divided into two, is generated. The energy storage element 5 is attached to the water-repellent surface 6, and even if the electronic device 1 is submerged in water, the energy storage element 5 will not get wet because it is inside the gas region A.

As the insulating material constituting the base 4, for example, silicone rubber, which is a solid compound containing Si--O--Si bonds, can be used. In order to form a water-repellent surface 6 on a part of the upper surface of the base 4 made of silicone rubber, a large number of silica glass microspheres are arranged on the surface of the base 4, irradiated with a laser beam, and the laser beam is concentrated. A method of deforming the surface of the base 4 can be adopted. In this method, the energy of the laser beam is concentrated at many points on the surface of the substrate 4 by the lens effect of the microspheres, and photocleavage of the main chain structure of the silicone rubber is induced at each point, thereby converting the low molecular weight silicone into microspheres. This is a photochemical method that forms a microstructure consisting of many ridges and hollows by depositing along the surface.

Note that such a photochemical method can be similarly applied to polymer materials other than the silicone rubber mentioned above. Further, the material of the substrate 4 is not limited to a polymer material, as long as a fine structure can be created on the surface of the substrate 4 by a method other than a photochemical method. For example, a similar fine structure can be created on the surface of the metal base 4 using a 3D printer (laser additive manufacturing).

When the silicone rubber substrate 4 processed by the photochemical method described above is placed in water, a gas (air) region A with a thickness of about 0.5 to 5 mm is formed only on the water-repellent surface 6 where a microstructure is formed. was found to be formed. That is, it has been found that if the base body 4 is immersed in the liquid L, the gas region A can be reliably generated. In addition, in surface engineering, the term "super water repellency" is generally used when the contact angle is 150 degrees or more, so the water repellency required to generate the gas region A required in the present invention is super water repellent. It includes water repellency and also includes a certain range that does not fall under super water repellency.

Note that the photochemical method described above is a method for forming a water-repellent surface 6 on a part of the upper surface of the substrate 4, and at the same time, it is a method for forming a water-repellent surface 6 on a part of the upper surface of the substrate 4. It can also be part of the manufacturing process for one type of electric double layer capacitor. Therefore, the details of the photochemical method described above will be explained in detail with reference to FIGS. 5 to 15 in the description of the energy storage device and electronic device of the fifth embodiment having an electric double layer capacitor. Note that the photochemical method for forming the microstructure described above is an example of a method for forming the water-repellent surface 6, and the water-repellent surface 6 may be provided on the surface of the substrate 4 by other methods, means, or structures. You can.

As the energy storage element 5, an electricity storage element and a heat storage element can be used. As the power storage element, a chemical battery or an electric double layer capacitor can be used. As the heat storage element, a latent heat heat storage element, a chemical heat storage element, a thermoelectric heat storage element, a temperature difference heat storage element, a photochemical heat storage element, a sensible heat heat storage element, etc. can be used. Note that the heat storage element can supply electric power by combining with a thermoelectric conversion element. The size of the storage energy element may be within the size of the gas region A formed on the surface of the base 4, and is typically assumed to be about 5×5×5 (mm ³ ).

The electronic element 3 provided inside the base 4 has a sensor that detects the external state of the electronic device 1 and a communication means that transmits information detected by the sensor to the outside. According to this electronic element 3, information in the environment can be detected by the sensor and immediately transmitted by the communication means, so that the information can be acquired at a remote location. However, if the premise is to recover the electronic device 1 placed in the environment, even if the electronic device 3 is only a sensor with a certain memory function, it will be inconvenient to collect information.

According to the electronic device 1 of the first embodiment, since the gas region A is formed on the water-repellent surface 6 of the base 4 when placed in water, the energy storage element 5 does not get wet and malfunction occurs, and the sensor It is possible to operate the electronic device 3 stably. Further, as the energy storage element 5, an appropriate element can be selected from the power storage element group and the heat storage element group depending on the purpose, application, etc.

FIG. 2 is a diagram schematically showing an electronic device 1a according to the second embodiment. Components that are the same as those in the first embodiment are given the same reference numerals as in FIG. 1, and the description of the first embodiment is used. This electronic device 1a includes an energy storage device 2a and an electronic element 3. The energy storage device 2a includes a base 4, a solar cell 7 as an energy harvesting element provided on the surface of the base 4, and an electricity storage element as an energy storage element provided on the surface of the base 4 and connected to the solar cell 7. 5a. The electronic element 3 is provided inside the base 4 and connected to the energy storage element 5a. As shown in FIG. 2, this electronic device 1a can be used by being immersed in a liquid L having electrical conductivity.

According to the electronic device 1a of the second embodiment, even when placed underwater, the solar cell 7 generates power as long as sunlight reaches it, and the power generated by the solar cell 7 is transferred to the storage element. Since the power can be stored in 5a, the supply of power to the electronic device 3 is stabilized.

FIG. 3 is a diagram schematically showing an electronic device 1b according to the third embodiment. Components that are the same as those in the first embodiment are given the same reference numerals as in FIG. 1, and the description of the first embodiment is used. This electronic device 1b includes an energy storage device 2b and an electronic element 3. The energy storage device 2b includes a base 4, an energy harvesting element 8 provided on the surface of the base 4, and an energy storage element 5b as an energy storage element provided on the surface of the base 4 and connected to the energy harvesting element 8. are doing. Electronic element 3 is provided inside base 4 and connected to power storage element 5b. As shown in FIG. 3, this electronic device 1b can be used by being immersed in a liquid L having electrical conductivity.

As shown in FIG. 3(b), the energy harvesting element 8 includes a first electrode 8a and a second electrode 8b of different types, which are arranged so as to span both the gas region A and the liquid L. As the different types of metals, for example, aluminum and copper can be used. Specifically, thin wires of aluminum and copper are placed on the top surface of the base 4 so as to span the inside and outside of the water-repellent surface 6 . When this energy harvesting element 8 was immersed in an aqueous NaCl solution with a concentration of 3 wt%, a gas region A was formed on the water-repellent surface 6. Here, the thin wire-shaped aluminum and copper are arranged so as to span both the NaCl aqueous solution and the gas region A, so there is a voltage of about 800 mV between one end of the aluminum and one end of the copper in the gas region A. A voltage was generated electrochemically. Power is stored in the power storage element 5b provided between one end of aluminum and one end of copper in the gas region A, and power is supplied to the electronic element 3 connected to the power storage element 5b. 3 can operate and function.

The two different types of metals constituting the electrode mean that the electrode potentials, which are physical property values specific to each metal, are different. The electrode potential is generally expressed as a V value indicating the ± difference from the standard electrode potential of hydrogen. For example, measurement results have been obtained regarding the value of electrode potential when immersed in seawater, and this generally agrees with the ionization tendency.

According to the electronic device 1 of the third embodiment, a potential difference occurs between the two metals between the liquid L and the gas region A, so in an environment in the liquid L (underwater) where the solar cell 7 cannot generate electric power. Even if the electronic device 1a of the second embodiment is used, power can be obtained and the power can also be stored by the power storage element 5b, so the power supply is more stable than in the electronic device 1a of the second embodiment.

FIG. 4 is a diagram schematically showing an electronic device 1c according to the fourth embodiment. Components that are the same as those in the first embodiment are given the same reference numerals as in FIG. 1, and the description of the first embodiment is used. This electronic device 1c includes an energy storage device 2c and an electronic element 3. The energy storage device 2c includes a base 4, a heat storage element 5c provided on the surface of the base 4, and an electromagnetic wave absorber 9 attached to the surface of the heat storage element 5c. The electronic element 3 is provided inside the base 4 and connected to the heat storage element 5c. Although not shown, the heat storage element 5c includes a thermoelectric conversion element. In this electronic device 1c, when heat is supplied to the heat storage element 5c, the electromagnetic wave absorber 9 is irradiated with electromagnetic waves (including lasers) E to absorb energy, which is stored in the heat storage element 5c. The heat accumulated in the heat storage element 5c is supplied as electricity to the electronic element 3 via the thermoelectric conversion element. As shown in FIG. 4, this electronic device 1 can be used by being immersed in a liquid L having electrical conductivity.

According to the electronic device 1c of the fourth embodiment, even in an environment where the solar cell 7 cannot generate electric power, the electronic device 1c to which energy is to be supplied can be selectively irradiated with electromagnetic waves E of appropriate intensity. By doing so, energy can be stored and power can be supplied to the electronic element 3.

The electronic device 1d of the fifth embodiment and its manufacturing method will be described with reference to the schematic diagrams of FIGS. 5 to 15.
This electronic device 1d uses the photochemical method of manufacturing the fine structure described in the first embodiment, that is, the step of manufacturing a hollow structure 15, which is a fine structure, on the surface of the base 4 to form the water-repellent surface 6. At least a part of the hollow structure 15 of the water-repellent surface 6 formed thereby is also used as the structure of the electric double layer capacitor 5d which is an energy storage element.

Note that an electric double layer capacitor is a special type of capacitor that has characteristics intermediate between a normal capacitor and a battery (secondary battery). While batteries store charge through chemical reactions, electric double layer capacitors store charge by adsorbing ions to the surface of electrodes immersed in electrolyte to form an electric double layer. For this reason, charging that takes several hours with a battery is completed in a few seconds with an electric double layer capacitor. Also, unlike a battery, which has a limited number of charges, an electric double layer capacitor can be charged an unlimited number of times in principle.

1. Microsphere Alignment Step As shown in FIG. 5, microspheres 10, which are microscopic bodies made of silica glass and having a diameter of 2.5 μm, are aligned in a single layer on the surface of a base 4 made of silicone rubber (thickness: 2 mm). In this state, the microspheres 10 are in contact with each other. In order to obtain such a structure, microspheres 10, which are microscopic objects made of silica glass with a diameter of 2.5 μm, are dispersed in ethanol, and this is dropped onto the surface of the substrate 4 and air-dried to form a partially multilayer structure. The microspheres 10 may be arranged in a single layer on the substrate 4 by removing the microspheres 10 by any means, such as physical means such as lightly rubbing with paper.

2. Microsphere dissolution process by pre-etching As shown in FIG. 6, in order to create a gap between the microspheres 10 arranged in a single layer, the surface of the microspheres 10 is uniformly removed to create Perform an operation to make it smaller. The method is arbitrary, but for example, a sample in which microspheres 10 are arranged in a single layer is fixed to the upper part of a closed container containing an HF aqueous solution with a concentration of 46 to 48%, as shown by the downward arrow in FIG. Thus, a method can be adopted in which the surface of the microsphere 10 is chemically dissolved by exposure to HF gas and chemically etched until the diameter becomes about 2 μm.

3. Protuberance formation process by pre-laser irradiation (microsphere bonding process)
As shown by the downward arrow in FIG. 7, irradiation is performed with an ArF excimer laser having a wavelength of 193 nm at a single pulse fluence of 30 mJ/cm ² , a pulse repetition frequency of 1 Hz, and a number of shots of 100 (irradiation time 100 s). A laser beam is focused on the substrate 4 directly below each microsphere 10, and the main chain structure (Si--O--Si bonds) constituting the silicone rubber of the substrate 4 is photochemically cleaved. As a result, the portion of the substrate 4 on which the laser beam is focused has a lower molecular weight, volume expansion occurs, and the raised portion 11 begins to be formed. At this time, the base 4 and the microspheres 10 are weakly bonded. Therefore, the microspheres 10 will not move and come off the raised portions 11 during laser irradiation in subsequent steps. Note that in this step, the laser is uniformly irradiated onto a square area of 10 mm x 10 mm. Since the laser beam is not focused in the gap between the microspheres 10, the base 4 will not be damaged in this area.

4. Electrode formation process by vacuum evaporation As shown in FIG. 8, a sample is placed in a vacuum evaporation apparatus, and on the surface of each microsphere 10, a downward arrow in the figure is placed at each position on both side surfaces facing the adjacent microspheres 10. As shown in , metal vapor deposition is performed to form a metal thin film electrode 12 . Specifically, a fine mesh mask of an appropriate size on which the pattern of the electrode 12 to be created is formed is placed above the microspheres 10, and the adjacent electrodes 12 are placed at each position of each microsphere 10. Each electrode 12 is formed so that the electrode 12 is not electrically conductive.

5. Hollow part formation process by laser irradiation ^As shown by the downward arrow in FIG. 30 min). Through this step, the raised portions 11 grow further to reach the maximum height, and the low molecular weight silicone inside the structure of the raised portions 11 is further reduced in molecular weight by laser irradiation, and is formed along the surface of the microsphere 10. As the particles are deposited, a capsule-shaped hollow portion 13 that follows the outer shape of the microsphere 10 is formed.

6. Microsphere removal (dissolution) process by etching As shown in Figure 10, the sample after laser irradiation is fixed at the top of a closed container containing an HF aqueous solution with a concentration of 46 to 48%. As shown, only the microspheres 10 are removed by chemical etching upon exposure to HF gas. Through this process, a capsule-shaped hollow part 13 supported by the raised part 11 and a hollow structure 15 in which the electrodes 12 remain in close contact with both sides of the inner surface of the hollow part 13 are obtained. Note that in this step, it was difficult to remove the microspheres 10 when an HF aqueous solution was used under atmospheric pressure, but as described above, the microspheres 10 could be removed by chemical etching using HF gas. did it. Therefore, the microspheres 10 are considered to be porous, having pores that are not large enough to allow water to enter under atmospheric pressure, but are large enough to allow gas to pass through. In this way, it is preferable to use gas for etching the microspheres 10. This is because if it is a gas, it can enter the interior through the porous pores of the hollow portion 13 and dissolve the microspheres 10. In addition, during this HF gas exposure, since the electrodes 12 are on the inside of the parts where the hollow parts 13 are lined up and close to each other, the side parts of the hollow parts 13 may come closer to each other and come into contact. It is considered that the film thickness of the hollow portion 13 becomes thinner in that portion. Therefore, during this HF gas exposure, it is thought that at the same time as the microspheres 10 are removed, a minute hole is formed in the side surface of the hollow part 13 by chemical etching, so that the electrode 12 becomes visible from the outside.

It was confirmed by X-ray photoelectron spectroscopy that the hollow portion 13 was made of silicone rubber. In addition, as for whether the microspheres 10 are included in the hollow part 13 as shown in FIG. 9, or whether the microspheres 10 are removed from the hollow part 13 by chemical etching as shown in FIG. They can be clearly distinguished by the peak position of the Si2p peak determined by spectroscopic analysis. That is, when the microspheres 10 are included, both peaks of 103.5 eV (peak position of silica) and 102.0 eV (peak position of silicone) are observed, and the microspheres 10 are removed and the hollow part When the inside of 13 is a cavity, only a peak of 102.0 eV is detected.

7. Electrolyte Filling Step As shown in FIG. 11, an electrolyte (ionic liquid) 16 is dropped onto the surface of the silicone rubber base 4, and a vacuum state is maintained in a vacuum chamber for 30 minutes. The electrolytic solution 16 is infiltrated and filled into the inside. As described above, since the hollow part 13 is porous, it is considered that the electrolytic solution 16 permeates through the pores and fills the hollow part 13 under vacuum.

As shown by the upward arrow in Figure 12, after the ArF excimer laser irradiation, a femtosecond laser with a wavelength of 520 nm was irradiated from the back side of the silicone rubber with an output of 300 to 350 mW, a pulse repetition frequency of 20 kHz, and an irradiation time of 5 to 10 s. Then, micro-sized pores larger than the porous pores are generated at the top of the hollow portion 13, so that the electrolytic solution 16 can more easily penetrate into the interior through the pores. In the case of the example shown in FIG. 12, since a larger hole is formed at the top of the hollow portion 13, a solid electrolyte may be filled instead of the electrolytic solution 16. Note that in this step, the laser is uniformly irradiated onto a square area of 10 mm x 10 mm. Since the laser beam is not focused in the gap between the microspheres 10, the base 4 will not be damaged in this area.

8. Connection part (microconductor) forming process As shown in FIG. 13, using laser 3D printer (laser additive manufacturing) technology, in the two adjacent hollow parts 13, 13, the gap between the two opposing sides is By melting the metal powder with a laser while supplying it, a connecting portion 17 is formed that connects the opposing electrodes 12, 12 of two adjacent hollow portions 13, 13 to each other. This completes the structure of the electric double layer capacitor 5d. Note that after the step of removing (dissolving) the microspheres 10 by etching (see FIG. 10), the step of forming the connection portion 17 (see FIG. 13) is performed, and then the step of filling the electrolyte 16 (see FIG. 11) is performed. You may do so.

Next, an electronic device 1d according to a fifth embodiment having an electric double layer capacitor 5d formed through the above steps will be described with reference to FIG. 14.
The electronic device 1d shown in FIG. 14 includes an energy storage device 2d and an electronic element 3 (not shown). The energy storage device 2d includes a base 4, an energy harvesting element 8 provided on the surface of the base 4, and an electric double layer capacitor 5d as an energy storage element provided on the surface of the base 4 and connected to the energy harvesting element 8. have. The configuration of the energy harvesting element 8 is similar to that of the third embodiment shown in FIG. An electronic element 3 (not shown) is provided inside the base 4 and connected to the electric double layer capacitor 5d. In this electronic device 1d, the portion on which the electric double layer capacitor 5d is formed has a microstructured water-repellent surface 6, and when immersed in the electrically conductive liquid L, the electric double layer capacitor 5d is accommodated. Since the gas region A is formed on the base 4, the electric double layer capacitor 5d can be used without getting wet with the liquid L.

According to the electronic device 1d of the fifth embodiment, energy harvesting can be performed in the electrically conductive liquid L, typified by seawater, so that the incorporated electronic device 3 (sensor and communication device) is free from external interference. Even without power supply or batteries, information can be collected stably in real time over a long period of time in the presence of liquid L, and the collected information can be transmitted. Energy can also be stored in the electric double layer capacitor 5d in the gas region A. Such an electronic device 1d is very useful as an IoT device. Furthermore, the hollow structure (fine raised structure) that realizes the electric double layer capacitor 5d in this electronic device 1d can be widely applied to basic technology for manufacturing devices in the field of electrical and electronic engineering, as explained in the following Embodiment 6. Therefore, its uses can be extended to all fields.

Next, a hollow structure 15 according to a sixth embodiment will be described.
The sixth embodiment is an example in which the fine structure of the hollow structure 15 formed on the surface of the base 4 of the fifth embodiment and the method of manufacturing the same according to the fifth embodiment are applied to other uses. The sixth embodiment will be described below with reference to FIGS. 5 to 7, 9, and 10 of the fifth embodiment, and the description of the specification regarding these figures, and further with reference to FIG. 15.

The steps in FIGS. 5 to 7 are the same as in the fifth embodiment.
After the process shown in FIG. 7, in the fifth embodiment, the process shown in FIG. 9 is performed without manufacturing the manufactured electrode 12. That is, irradiation is performed with an ArF excimer laser having a wavelength of 193 nm under the same conditions as in the fifth embodiment. Through this step, the raised portion 11 grows further and becomes the largest in height, and the low molecular weight silicone rubber inside the structure of the raised portion 11 is further reduced in molecular weight by laser irradiation and stretches along the surface of the microsphere 10. As a result, a capsule-shaped hollow portion 13 that follows the outer shape of the microsphere 10 is formed.

As shown in FIG. 10, the sample after laser irradiation is fixed at the top of a closed container containing an HF aqueous solution with a concentration of 46 to 48%, and only the microspheres 10 are removed by chemical etching by exposure to HF gas. Through this process, a hollow structure 15 having a raised part 11 and a capsule-shaped hollow part 13 supported by the raised part 11 is obtained. Although the electrode 12 is shown in FIGS. 9 and 10, this is the structure of the fifth embodiment, and the hollow structure 15 of the sixth embodiment excludes the electrode 12 from FIGS. 9 and 10. The structure is as follows.

FIG. 15 shows an electron micrograph of the hollow structure 15 of the sixth embodiment. The imaging equipment was Phenomworld's Pro, and the imaging conditions were an electron beam acceleration voltage of 10 kV and a magnification of 20,000 times. A scale representing a scale of 3 μm is shown in the photograph of the figure. As can be understood from this photograph, on the surface of the base 4, there is a raised part 11 with a diameter of about 1.5 μm and a height of about 1 μm, which is a raised part of the base 4, and a diameter continuous with the raised part 11. Hollow structures 15 having hollow portions 13 of about 2 μm are formed in a substantially uniform size and lined up at intervals of about 2.5 μm. This photograph corresponds to FIG. 10 in the diagram used to explain the manufacturing process of the fifth and sixth embodiments. However, the electrode 12 is not formed on the inner surface of the hollow part 13.

The hollow structure 15 of the sixth embodiment can be suitably applied to, for example, a "drug delivery system". For example, a medicine is encapsulated in the hollow part 13 of these hollow structures 15, and the hollow structure 15 moves inside the body of a patient who takes the medicine, so that a desired amount of medicine is released at a desired place (affected area). Configure. For example, each hollow part 13 may contain different types of drugs, such as drug A, drug B, drug C, drug D, etc., and drug A and C are released in one affected area, and drug B is released in the next affected area. Medicine and C medicine are released, and then medicines B and D are released in the next affected area, so that the medicinal effects can be obtained according to the condition of each affected area. In order to do this, small pumps are provided in each hollow part 13 using the technique of creating the electrode 12 inside the hollow part 13 in the fifth embodiment or the laser 3D printer technology, and each pump is activated at the required timing. The device may be configured to operate in such a way as to supply the necessary medicine to the target affected area.

A latent heat storage element can also be constructed using the hollow structure 15 of the sixth embodiment. If a latent heat storage material such as paraffin is sealed in the hollow part 13 of the hollow structure 15, a microcapsule-shaped material that absorbs heat when solid paraffin becomes liquid L and radiates heat when paraffin in liquid L becomes solid can be formed. A latent heat storage element is obtained. If such microcapsule-shaped latent heat storage elements are printed and fixed on textile products such as bed mattresses, they will increase comfort during use, and if mixed into building materials, they can be used as materials for energy-saving houses. can. Additionally, by mixing it with various resin materials, it can be used as an energy-saving material in a variety of industries.

1, 1a, 1b, 1c, 1d...Electronic device 2, 2a, 2b, 2c, 2d...Energy storage device 3...Electronic element 4...Base 5...Energy storage element 5a, 5b...Energy storage element as an energy storage element 5c... Heat storage element as an energy storage element 5d... Electric double layer capacitor as an energy storage element 6... Water repellent surface 7... Solar cell as an energy harvesting element 8... Energy harvesting element 9... Electromagnetic wave absorber 10... Microsphere as a microscopic body 11... Protuberance 12... Electrode 13... Hollow part 15... Hollow structure 16... Electrolyte 17... Connection part A... Gas region L... Liquid E... Electromagnetic wave

The present invention relates to an energy storage device used as a power source and a method of manufacturing the same, and particularly to a small-sized energy storage device that can be used underwater and a method of manufacturing the same .

The present invention has been made based on the knowledge and research of the inventor described above, and provides an energy storage device that can be used underwater and has energy storage functions such as electricity storage and heat storage, and a method for manufacturing the same . The purpose is to

The energy storage device according to claim 1 includes:
A base body having a gas region formed in a part of the surface in contact with an electrically conductive liquid, and an energy storage element disposed on the base body inside the gas region , the gas region being formed. The surface of the base body is a water-repellent surface, the energy storage device comprising:
The energy storage element is
a hollow portion formed on the surface of the base body inside the gas region;
an electrode provided on the inner surface of the hollow part;
a connection part that electrically connects the electrode in the hollow part and the electrode in the adjacent hollow part;
an electrolytic solution filled inside the hollow part;
The electric double layer capacitor is characterized in that the electric double layer capacitor has the following characteristics.

The method for manufacturing the energy storage device according to claim 2 is the method for manufacturing the energy storage device according to claim 1 , comprising:
The manufacturing process of the electric double layer capacitor includes:
irradiating electromagnetic waves to a plurality of microscopic bodies arranged at intervals on the surface of the base body to form a protuberance on the base body below the microscopic bodies to which the microscopic bodies are fixed;
forming the electrode on the surface of the microscopic body facing the adjacent microscopic body;
irradiating the microscopic body with electromagnetic waves to form the hollow portion that is continuous with the raised portion and covering the microscopic body and the electrode;
removing the microscopic body leaving the hollow part and the electrode;
forming the connection portion that connects the electrode located inside the hollow portion and the electrode located inside the adjacent hollow portion;
filling the inside of the hollow part with the electrolytic solution;
It is characterized by including.

According to the energy storage device according to the first aspect, it can be used as a power source for operating electronic elements such as sensors placed underwater. Further, when the energy storage device is placed in water, a gas region is formed on the water-repellent surface of the base, so that the energy storage element can be prevented from getting wet. In addition, the surface of the substrate with minute hollow parts formed therein becomes a water-repellent surface, creating a gas region in water, and an electric double layer capacitor formed by these hollow parts can supply electricity to electronic devices. .

According to the method for manufacturing an energy storage device according to claim 2 , the protrusion and the hollow body formed on the surface of the base, the electrode provided on the inner surface of the hollow body, and the electrode of the adjacent hollow body are connected. An electric double layer capacitor having a connecting portion and an electrolytic solution filled inside a hollow portion can be reliably manufactured through a simple process.

Claims (10)

a base in which a gas region is formed in a part of the surface that is in contact with an electrically conductive liquid;
an energy storage element disposed on the base body inside the gas region;
An energy storage device characterized by having. The energy storage device according to claim 1, wherein the surface of the base on which the gas region is formed is a water-repellent surface. The energy storage element is
At least one of a power storage element group including a chemical battery and an electric double layer capacitor, a heat storage element group including a latent heat heat storage element, a chemical heat storage element, a thermoelectric heat storage element, a temperature difference heat storage element, a photochemical heat storage element, and a sensible heat heat storage element. The energy storage device according to claim 2, characterized in that the energy storage device is one or more elements selected from the group. The energy storage element is
a hollow portion formed on the surface of the base body inside the gas region;
an electrode provided on the inner surface of the hollow part;
a connection part that electrically connects the electrode in the hollow part and the electrode in the adjacent hollow part;
an electrolytic solution filled inside the hollow part;
The energy storage device according to claim 3, wherein the electric double layer capacitor has: In the energy storage element,
An environment in which two metals of different types are arranged on the base body so as to span both the gas region and the liquid, and electric power is generated by a potential difference generated between the two metals in the gas region. The energy storage device according to claim 3, characterized in that a power generation element is connected. The energy storage device according to claim 3, wherein a thermoelectric conversion element is connected to the elements of the heat storage element group. The manufacturing process of the electric double layer capacitor includes:
irradiating electromagnetic waves to a plurality of microscopic bodies arranged at intervals on the surface of the base body to form a protuberance on the base body below the microscopic bodies to which the microscopic bodies are fixed;
forming the electrode on the surface of the microscopic body facing the adjacent microscopic body;
irradiating the microscopic body with electromagnetic waves to form the hollow portion that is continuous with the raised portion and covering the microscopic body and the electrode;
removing the microscopic body leaving the hollow part and the electrode;
forming the connection portion that connects the electrode located inside the hollow portion and the electrode located inside the adjacent hollow portion;
filling the inside of the hollow part with the electrolytic solution;
The method for manufacturing the energy storage device according to claim 4, further comprising: An electronic device comprising an electronic element that functions with electric power supplied from the energy storage device according to any one of claims 1 to 6. a raised part formed by raising a part of the base;
a hollow part formed continuously in the raised part;
A hollow structure characterized by having. irradiating electromagnetic waves to a plurality of microscopic bodies arranged at intervals on the surface of the base body to form a protrusion on the base body below the microscopic bodies to which the microscopic bodies are fixed;
irradiating the microscopic body with electromagnetic waves to form the hollow portion that is continuous with the raised portion and covering the microscopic body;
removing the microscopic body leaving the hollow part;
A method for manufacturing a hollow structure, comprising:

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