Power generation system, power storage device, power generation device, and power generation method

Abstract

To provide a power generation system that can suppress electrode deterioration without reducing power generation efficiency.SOLUTION: A power generation system 1 includes a power generation layer 10 and an electrode 11. The power generation system generates electricity as droplets 16 move on the power generation layer, and extracts the generated electrical energy from the electrode. The electrode is disposed downstream of the power generation layer in the direction of droplet movement, and includes a covered portion 13 whose surface is covered with a protective film 19 and an exposed portion 14 whose surface is not covered with the protective film, and the droplets that move on the power generation layer come into contact with the electrode at the exposed portion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power generation system, a power storage device, a power generation device, and a power generation method. [Background technology]

[0002] TriboElectric Nano Generators (TENGs) are attracting attention due to their high potential and diverse applications, as they can absorb mechanical and thermal energy from various microscopic physical phenomena and convert it into electricity. Generally, TENGs are devices that convert external mechanical energy into electrical energy by combining the triboelectric effect and electrostatic induction. Among TENGs, those that use the sliding behavior of water for friction are called W-TENGs (water droplet power generation), and have attracted attention in recent years as a technology with the highest conversion efficiency among TENGs. In a TENG, the movement of discrete droplets or other liquid masses causes electrostatic induction, which transfers electric charges, thereby allowing electrical energy to be extracted.

[0003] For example, Patent Document 1 describes a generator that obtains power from the sliding behavior of droplets when they are dropped onto a layer of polytetrafluoroethylene (PTFE). However, since water droplet power generation is expected to be used with rainwater or irrigation channels, etc., it is likely to be exposed outdoors for long periods of time. Therefore, in Patent Document 1, the upper electrode, which is made of metal, is completely exposed, raising concerns about deterioration due to rust, etc.

[0004] On the other hand, if the metal is coated with a non-conductive material such as a fluorine-containing resin, deterioration of the metal can be suppressed. For example, Patent Document 2 describes a method for providing a chemical conversion plated steel sheet that is excellent in weather resistance, water resistance, blackening resistance, film adhesion, and anti-glare properties by forming a phosphate film on a hot-dip Zn-Al-Mg alloy plated steel sheet and then forming a chemical conversion coating on the phosphate film, in which a high-molecular-weight fluorine-containing resin having a hydrophilic functional group introduced therein is crosslinked with a Group 4A metal compound. Summary of the Invention [Problem to be solved by the invention]

[0005] However, in a triboelectric nanoengineer (TENG), if the electrodes that come into contact with the droplets are coated with a non-conductive material to prevent deterioration of the metal electrodes, it is thought that power generation will be almost nonexistent and power generation efficiency will decrease. An object of one embodiment of the present invention is to provide a power generation system that can suppress electrode deterioration without reducing power generation efficiency. [Means for solving the problem]

[0006] In order to solve the above problem, one embodiment of the present invention is The solar cell includes a power generation layer and an electrode, A power generation system in which electricity is generated by the movement of droplets on the power generation layer, and the generated electrical energy is extracted from the electrode, the electrode is disposed downstream of the power generation layer in the direction of movement of the droplets, The electrode has a covered portion whose surface is covered with a protective film and an exposed portion whose surface is not covered with the protective film, and the droplets that move on the power generation layer come into contact with the electrode at the exposed portion. [Effects of the Invention]

[0007] According to one embodiment of the present invention, it is possible to provide a power generation system that can suppress electrode deterioration without reducing power generation efficiency. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an enlarged schematic view of an example of a power generation system according to an embodiment of the present invention. [Figure 2] 1 is an example of how a power generation layer is charged by friction with droplets in a power generation system according to an embodiment of the present invention. [Figure 3]1 is an example of a flow of charges moving due to the movement of droplets in a power generation system according to an embodiment of the present invention. [Figure 4] 1 is a schematic diagram of an example of a power generation system according to an embodiment of the present invention. [Figure 5] 1 is a schematic diagram of an example of a power generation system according to an embodiment of the present invention. [Figure 6] 6 is a schematic diagram showing an example of a state in which droplets are moved onto the power generation layer of the power generation system of FIG. 5. FIG. [Figure 7] 6 is a schematic diagram showing an example of a state in which droplets are moved onto the power generation layer of the power generation system of FIG. 5. FIG. [Figure 8] 1 is a schematic diagram of an example of a power generation system according to an embodiment of the present invention. [Figure 9] 9 is a schematic diagram showing an example of droplets landing on the power generation layer of the power generation system of FIG. 8. FIG. [Figure 10] 1 is a schematic diagram showing an example of a plan view of droplets moving after landing on a power generation layer of an example of a power generation system according to an embodiment of the present invention. FIG. [Figure 11] 1 is a schematic diagram showing an example of a plan view of droplets moving after landing on a power generation layer of an example of a power generation system according to an embodiment of the present invention. FIG. [Figure 12] FIG. 1 is a schematic diagram of an example of a power generation system prepared in an example. [Figure 13A] FIG. 2 is an enlarged schematic view of a part of the power generation system prepared in the examples. [Figure 13B] FIG. 10 is a voltage waveform diagram of an electromotive voltage generated by moving water droplets in the power generation system fabricated in the example. [Figure 13C] 10 is a graph showing values ​​of electromotive voltage and charge quantity generated by moving water droplets in the power generation system fabricated in the example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described in detail.

[0010] (Power generation system and power generation method) The power generation system of the present invention comprises: The solar cell includes a power generation layer and an electrode, A power generation system in which electricity is generated by the movement of droplets on the power generation layer, and the generated electrical energy is extracted from the electrode, the electrode is disposed downstream of the power generation layer in the direction of movement of the droplets, The electrode has a covered portion whose surface is covered with a protective film and an exposed portion whose surface is not covered with the protective film, and the droplets that move on the power generation layer come into contact with the electrode at the exposed portion, making this a power generation system.

[0011] According to the power generation system of the present invention, the exposed area of ​​the electrode can be reduced, thereby significantly reducing the contact area with the droplets. Therefore, according to the power generation system of the present invention, by reducing the exposed area of ​​the electrode and the area in contact with the droplets, a power generation system can be provided that can suppress electrode deterioration without reducing power generation efficiency.

[0012] The power generation system of the present invention is not particularly limited as long as it satisfies the above-described configuration, and may be a power generation element that satisfies the configuration of the power generation system. The power generation system preferably further comprises another electrode. With such a power generation system, it is possible to provide a power generation system with good power generation efficiency. The power generation system may further include other components as necessary.

[0013] The power generation method of the present invention comprises: A power generation method comprising: supplying droplets to a power generation layer having electrodes; and moving the droplets on an upper surface of the power generation layer to extract electrical energy from the electrodes, the method comprising: the electrode has an exposed surface portion and a surface portion covered with a protective film, In this power generation method, the exposed surface portion of the electrode is in electrical contact with the droplet. According to the power generation method of the present invention, deterioration of the electrodes can be suppressed without reducing the power generation efficiency.

[0014] In the power generation method, it is preferable that electrical energy is extracted by electrostatic induction of the electrodes. The electrostatic induction is preferably caused by moving charged droplets on the upper surface of the power generation layer, causing droplets polarized by the charge on the upper surface of the power generation layer to come into contact with the exposed surface of the electrode or the stagnant liquid.

[0015] The power generation method further comprises: It is preferable that the electrode is arranged below the power generation layer, and the exposed surface portion of the electrode is a portion exposed through an opening in the power generation layer and is a portion that is in electrical contact with the droplet through the retained liquid retained in the opening. Such a power generation method allows for more efficient power generation and suppresses electrode deterioration without reducing power generation efficiency.

[0016] The power generation method further comprises: It is preferable that the electrode is arranged on the upper surface of the power generation layer, and the exposed surface portion of the electrode is a part of the surface of the electrode that faces the direction in which the droplet moves, and is a part that makes electrical contact with the droplet via the retained liquid that retains in the exposed surface portion of the electrode. Such a power generation method allows for more efficient power generation and suppresses electrode deterioration without reducing power generation efficiency.

[0017] <Droplet> The liquid droplets are not particularly limited, but from the viewpoint of practicality and ease of use in the renewable energy field, examples include liquid droplets of water, an aqueous solution, a colloidal solution, or oil.

[0018] The water includes rainwater, tap water, distilled water, ion-exchanged water, ultrafiltered water, reverse osmosis water, pure water, highly pure water, ultrapure water, etc., and these may be used alone or in combination of two or more types. Examples of the aqueous solution include NaCl solution, seawater, and sewage. Examples of the colloidal solution include milk and sewage.

[0019] The amount of droplets to be supplied to the power generation system of the present invention is not particularly limited as long as it can extract electrical energy from the electrodes, and the shape, size, volume, and mass of the droplets are not particularly limited and can be selected appropriately depending on the purpose, but it is preferably 5 to 150 μl.

[0020] <Power generation layer> The power generation layer is not particularly limited in material, shape, size, thickness, or structure, as long as it is an insulator that is charged by friction with the droplets, and can be appropriately selected depending on the purpose.

[0021] Examples of materials for the power generation layer include polymer materials and rubber.

[0022] Examples of the polymeric material include polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride, polyimide, polyamide, fluororesin, acrylic resin, polydimethylsiloxane, and cellulose.

[0023] Examples of the rubber include silicone rubber, acrylic rubber, chloroprene rubber, polysulfide rubber, urethane rubber, butyl rubber, natural rubber, ethylene-propylene rubber, nitrile rubber, fluororubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, ethylene-propylene-diene rubber, chlorosulfonated polyethylene rubber, and polyisobutylene.

[0024] The power generation layer is preferably made of an electret material. A PET material is a material that provides an electric field to the surrounding area by stably maintaining static electricity for a long period of time. means. If the power generation layer is made of an electret material, it can retain electric charge semi-permanently. Therefore, the power generation layer does not need to be charged to saturation by friction with the droplets. Examples of the electret material include CYTOP (manufactured by AGC Corporation) and polytetrafluoroethylene. Examples include fluororesins such as PTFE (polytetrafluoroethylene), and porous polypropylene. can be.

[0025] <Electrode> The electrodes are electrically conductive and can move droplets to extract electrical energy. There are no particular restrictions on the material, shape, size, structure, or location, and it is sufficient to use it according to the purpose. It can be selected appropriately depending on the situation. The electrode preferably has a large surface free energy relative to the droplets, since if the surface free energy relative to the droplets is large, the liquid in the droplets that flows into the exposed portion is likely to remain.

[0026] The shape of the electrode may be, for example, a plate, a rod, a wire, a film, or a combination thereof. Examples include:

[0027] The power generation system may include a single electrode or multiple electrodes. When there are a plurality of electrodes, the materials, shapes, sizes, and structures of the electrodes may be the same or different. In addition, when there is a single electrode, in order for the charge to move, an object that corresponds to another electrode connected to the electrode is required, so the object at one end connected to the electrode can be considered as the other electrode, and the ground connected to the electrode can be considered as the other electrode.

[0028] The power generation system may have the electrodes on the upper and / or lower surfaces of the power generation layer, and from the viewpoint of extracting higher electrical energy, it is preferable to have the electrodes on the upper and lower surfaces of the power generation layer. Furthermore, since it is preferable that the length of the lower electrode in the direction in which the droplets flow is approximately the same as the diameter of the droplets, a large amount of power can be generated, it is preferable that the length of the lower electrode in the direction in which the water flows is 1 mm to 10 mm.

[0029] If the power generation system has the electrodes only on the upper surface of the power generation layer, when a droplet comes into contact with the saturated power generation layer, the charge in the droplet is polarized. When the polarized droplet moves and comes into contact with the electrode on the upper surface of the power generation layer, the charge balance in the power generation system is disrupted, electrostatic induction is induced, and the charge is transferred via the ground or the like. When the droplet then flows down from the power generation layer, the charge balance in the power generation system is again disrupted, electrostatic induction is induced, and the charge is transferred via the electrode on the upper surface of the power generation layer.

[0030] In the case where the power generation system has the electrodes only on the underside of the power generation layer, when a droplet comes into contact with the saturated power generation layer, the charge in the droplet is polarized, which disrupts the balance of charges in the power generation system, causing electrostatic induction and transferring charges through the electrodes on the underside of the power generation layer. When the droplet then flows down from the power generation layer, the balance of charges in the power generation system is disrupted, causing electrostatic induction and transferring charges via the ground or the like.

[0031] When the power generation system has the electrodes on the upper and lower surfaces of the power generation layer, when a droplet comes into contact with the saturated power generation layer, the charge in the droplet becomes polarized, disrupting the charge balance in the power generation system, causing electrostatic induction, and charge transfer through the electrode on the lower surface of the power generation layer. Next, when the polarized droplet moves and contacts the electrode on the upper surface of the power generation layer, the charge balance in the power generation system is disrupted, causing electrostatic induction, and charge transfer through the ground or the like. Then, when the droplet flows down from the power generation layer, the charge balance in the power generation system is disrupted, causing electrostatic induction, and charge transfer through the electrode on the upper surface of the power generation layer.

[0032] Examples of materials for the electrodes include metals, conductive polymers, and conductive rubber compositions.

[0033] Examples of the metal include gold, silver, copper, aluminum, stainless steel, tantalum, nickel, phosphor bronze, and indium tin oxide.

[0034] Examples of the conductive polymer include polythiophene, polyacetylene, and polyaniline.

[0035] The conductive rubber composition may be, for example, a composition containing a conductive filler and rubber.

[0036] Examples of the conductive filler include carbon materials (e.g., ketjen black, acetylene black, graphite, carbon fiber, carbon nanofiber, carbon nanotube, graphene, etc.), metals (e.g., gold, silver, platinum, copper, iron, aluminum, nickel, etc.), conductive polymers (e.g., derivatives of at least one of polythiophene, polyacetylene, polyaniline, polypyrrole, polyparaphenylene, and polyparaphenylenevinylene, or derivatives of these derivatives to which a dopant typified by an anion or a cation has been added), and ionic liquids.

[0037] Examples of rubber contained in the conductive rubber composition include silicone rubber, modified silicone rubber, acrylic rubber, chloroprene rubber, polysulfide rubber, urethane rubber, isobutyl rubber, fluorosilicone rubber, ethylene rubber, and natural rubber (latex).

[0038] In the power generation system, the electrode may be formed on the surface of the power generation layer along which the droplets move, or may be formed on the surface of the power generation layer opposite to the surface along which the droplets move. The electrode may be formed so that the thickness direction of the electrode and the thickness direction of the power generation layer are the same, and the electrode and the power generation layer are arranged side by side without overlapping. When the electrode is arranged in this manner, it can be said that the electrode is formed on the surface of the power generation layer along which the droplets move.

[0039] <Coated part> The covering portion is a portion of the electrode that comes into contact with the droplets in the power generation system of the present invention, the surface of which is covered with the protective film. By providing the covering portion to the electrode, the electrode is less likely to come into contact with the outside air, and deterioration of the electrode due to blackening or oxidation, etc. can be suppressed.

[0040] <<Protective film>> The protective film has the function of insulating the electrode from the outside air and is formed on a part of the electrode. Examples of materials for the protective film include polymeric materials, and materials with high dielectric constant, durability, and water repellency, such as fluorine-based resins, are preferred. The protective film may be made of a porous sheet, a fiber sheet, or a woven fabric, as long as it has the effect of improving durability.

[0041] In the power generation system, the protective film is preferably a dielectric film. In such a power generation system, the droplets come into contact with the electrodes via the protective film, causing electrostatic induction, making it possible to generate electricity through the sliding behavior of the droplets even in areas other than the exposed areas.

[0042] -Dielectric- Examples of the dielectric material include polymeric materials such as fluorine-based resins, silicone resins, and rubber, and inorganic materials such as alumina.

[0043] <Exposed part> The exposed portion is a portion of the electrode that comes into contact with the liquid droplets in the power generation system of the present invention, where the surface is exposed and not covered with the protective film. The exposed portion is a portion that is in electrical contact with the droplet.

[0044] In the power generation system, the exposed portion is preferably formed so that the droplets that come into contact with the electrode remain there. In such a power generation system, the exposed portion that comes into contact with the droplets is covered with retained liquid from droplets that have already come into contact with the exposed portion, reducing the exposure of the exposed portion to the outside air. Furthermore, when newly arriving droplets come into contact with the retained liquid, charge transfer occurs. Because the droplets can make electrical contact with the retained liquid, electrode deterioration can be suppressed without reducing power generation efficiency.

[0045] In this specification, the region on the power generation layer directly above the upstream side of the electrode where the fallen droplets can spread the most is referred to as the “effective power generation region.” The amount of charge on the droplets in this region contributes most to power generation. The electromotive voltage generated when power is generated by the power generation system of the present invention is proportional to the contact area between the power generation layer and the exposed portion of the electrode or the retained liquid at the moment the droplets come into contact with the exposed portion of the electrode or the retained liquid.

[0046] In the power generation system, the exposed portion may be formed on the upstream side of the electrode in the direction of droplet movement, in the center, or on the downstream side, but is preferably formed on the upstream side. When the exposed portion is located upstream of the protective film, the droplets are more likely to enter the exposed portion because the distance from the droplets to the exposed portion is shorter. Also, the droplets can come into contact with the electrode surface or the retained liquid in the exposed portion before the liquid is scraped off from the droplets due to the droplets' movement on the power generation layer or contact between the protective film and the droplets, preventing a decrease in the contact area between the droplets and the exposed portion of the electrode or the retained liquid. Therefore, if the exposed portion is located on the upstream side of the protective film, a power generation system with good power generation efficiency can be provided.

[0047] Furthermore, it is particularly preferable that the droplets fall into the effective power generation area and flatten out, and then come into contact with the surface of the electrode or the stagnant liquid in the exposed portion, and therefore it is particularly preferable that the exposed portion be formed so as to include a portion of the most upstream end of the protective film.

[0048] In the power generation system, it is preferable that the electrode is formed on the surface of the power generation layer opposite to the surface on which the droplets move, and the exposed portion is formed by opening a portion of the power generation layer in the area where the electrode and the power generation layer overlap. In such a power generation system, the patterns of the laminated members can be easily formed, and the system is easy to manufacture.

[0049] In the power generation system, the electrode may be formed on the upper surface of the power generation layer, and the exposed portion may be a part of a surface of the electrode that faces the direction in which the droplets move. Such a power generation system can be easily modified from a conventional power generation system.

[0050] The exposed portion is not particularly limited in shape, thickness, or structure as long as it is formed so as to expose a part of the electrode in order to prevent a decrease in power generation efficiency, and can be appropriately selected depending on the purpose. The size of the exposed portion is not particularly limited as long as it is large enough for the droplets to penetrate therein, and can be appropriately selected depending on the purpose.

[0051] <Other materials> Examples of the other members include a substrate and an adhesive. The substrate may be any insulating material that can form the power generation system, and there are no particular restrictions on the material, shape, size, thickness, or structure, which may be selected appropriately depending on the purpose.

[0052] Examples of the material for the substrate include polymeric materials, rubber, paper, minerals, glass, ceramics, and combinations thereof.

[0053] The shape of the substrate may be, for example, a plate, a rod, a wire, a film, or a combination thereof.

[0054] Examples of the adhesive include double-sided tape and combinations thereof.

[0055] The method for manufacturing the power generation system of the present invention may be any method for stacking a power generation layer, an electrode, and a protective film, and an appropriate method can be selected depending on the purpose. For example, the power generation system of the present invention can be manufactured by producing a power generation element in which a power generation layer, an electrode, and a protective film are stacked by inkjet printing, screen printing, lamination, vacuum deposition, sputtering, or a combination of these.

[0056] (power generation equipment) The power generation device of the present invention includes the power generation system and an electric circuit, and may further include other components as required.

[0057] <Electrical Circuit> The electric circuit in the power generating device of the present invention is not particularly limited as long as it is a circuit that extracts the electric power generated by the power generating system, and can be appropriately selected depending on the purpose.

[0058] <<Other materials>> Examples of the other components in the power generating device of the present invention include a ground, a resistor, a rectifier circuit, and the like.

[0059] (Electricity storage device) The electricity storage device of the present invention includes the power generation system, and may further include other components as necessary.

[0060] <Other materials> Examples of the other components in the electricity storage device of the present invention include an electric circuit for extracting the electric power generated from the power generation system, an electric circuit for storing the extracted electric power, and the like.

[0061] <<Electrical Circuits>> The electric circuit in the electricity storage device of the present invention is not particularly limited as long as it is a circuit for extracting or storing the electric power generated by the power generation system, and can be appropriately selected depending on the purpose.

[0062] (sensor) The power generation system can be used as a sensor by extracting, as an electrical signal, the movement of charges caused by contact between the droplets and the electrodes or the movement of the droplets on the upper surface of the power generation layer. Examples of the sensor include a water level sensor, a flow meter, a water leakage sensor, and a rain gauge.

[0063] The fields in which the power generation device, the power storage device, and the sensor are used are not particularly limited as long as they are fields that use a configuration in which droplets are brought into contact with a power generation layer and / or an electrode when extracting electrical energy, and can be selected appropriately depending on the purpose. However, it is preferable to use them in fields that utilize renewable energy, more preferably in fields that generate electricity using natural energy such as solar, wave, hydropower, and wind power, or in fields that combine these, and it is even more preferable to use them to complement these power generation methods.

[0064] Here, an example of the power generation system according to the present invention will be described with reference to FIGS. In each drawing, the same components are denoted by the same reference numerals, and redundant explanations may be omitted. Furthermore, the number, position, shape, etc. of the following components are not limited to these embodiments, and may be any number, position, shape, etc. that is preferable for implementing the present invention.

[0065] FIG. 1 is an enlarged schematic view of an example of a power generation system according to an embodiment of the present invention. 1 has an electrode 11 on a portion of the upper surface of a power generation layer 10, which is the surface along which droplets 16 move, and an electrode 12 on the lower surface of the power generation layer 10. The electrode 11 has a covered portion 13, where part of the surface of the electrode 11 is covered with a protective film 19, and an exposed portion 14 that is not covered with the protective film 19. The exposed portion 14 is disposed opposite the direction in which the droplets 16 move, and comes into electrical contact with the droplets 16 that have moved from upstream. After that, a portion of the droplets 16 remains as retained liquid 17 in the area surrounded by the surface of the power generation layer 10, the exposed portion 14, and the end of the protective film 19. Then, the droplets 16 that have moved from upstream come into contact with the retained liquid 17. This contact between the droplets 16 and the retained liquid 17 causes a charge transfer similar to that occurring when the droplets 16 and the electrode 11 come into electrical contact. Electrode 11 and electrode 12 are connected to ground via a resistor, and ground is one end connected to electrode 11 and electrode 12. Since charge moves through ground, in the power generation system 1 of Figure 1, ground can be considered as another electrode connected to electrode 11 and electrode 12.

[0066] Next, an example of the power generation method of the present invention will be described with reference to FIGS.

[0067] FIG. 2 shows an example of how the power generation layer is charged by friction with droplets in a power generation system according to an embodiment of the present invention.

[0068] The droplet 16 initially falls onto the uncharged upper surface of the power generation layer 10 (FIG. 2(a)), and as it moves in contact with the upper surface of the power generation layer 10, friction occurs, and a negative charge is transferred from the droplet 16 to the upper surface of the power generation layer 10 (FIG. 2(b)). At this time, the electrode 12 on the lower surface of the power generation layer 10 is positively charged by electrostatic induction.

[0069] A second droplet 16 falls onto the upper surface of the power generation layer 10, to which a negative charge has been transferred by the falling of the first droplet 16 (FIG. 2(c)), and moves in contact with the upper surface of the power generation layer 10, causing friction, and a negative charge is transferred from the droplet 16 to the upper surface of the power generation layer 10 (FIG. 2(d)). At this time, the electrode 12 on the lower surface of the power generation layer 10 is further charged with a positive charge due to electrostatic induction.

[0070] The third droplet 16 falls on the upper surface of the power generation layer 10 (FIG. 2(e)), and similarly to the case where the second droplet 16 fell, a negative charge is transferred from the droplet 16 to the upper surface of the power generation layer 10. At this time, the electrode 12 on the lower surface of the power generation layer 10 is further charged with a positive charge due to electrostatic induction, similarly to the case where the second droplet 16 fell.

[0071] The droplets 16 continue to fall onto the upper surface of the power generation layer 10, repeating the cycle of (c) and (d) in FIG.

[0072] The droplets 16 are allowed to fall until no negative charge is transferred to the upper surface of the power generation layer 10 even when the droplets 16 fall, and the cycle of (c) and (d) in Figure 2 is repeated to charge the power generation layer 10 to a saturated state, so that subsequent falls of the droplets 16 will result in stable output due to charge transfer.

[0073] Furthermore, since the droplets 16 are liquid, the actual contact area with the object they come into contact with is large, so the power generation layer 10 can be charged to a saturated state quickly. In the power generation system 1, when the power generation layer 10 is charged by friction of the droplets 16, the droplets 16 act as a frictional charging partner to the power generation layer 10, exchanging charges with each other.

[0074] When the power generation layer 10 is made of an electret material, the power generation layer 10 can retain an electric charge semi-permanently, so it is not necessary to drop, contact, and move a liquid droplet 16 onto the upper surface of the power generation layer 10, which is initially uncharged, as shown in Figure 2, to charge the power generation layer 10 through friction.

[0075] FIG. 3 shows an example of the flow of charges transferred by the movement of droplets in a power generation system according to an embodiment of the present invention.

[0076] A droplet 16 falls onto the upper surface of the power generation layer 10 of the power generation system 1, which is sufficiently negatively charged and in a charge-balanced state (FIG. 3(a)).

[0077] When the fallen droplet 16 comes into contact with the upper surface of the power generation layer 10 and moves, the positive charge of the droplet 16 is attracted to the side of the power generation layer 10 because the upper surface of the power generation layer 10 is negatively charged, and the negative charge of the droplet 16 is induced to the opposite side of the power generation layer 10, resulting in a polarized state (FIG. 3(b)). At this time, because the droplet 16 and the power generation system 1 are in contact with each other, the power generation system 1 in contact with the droplet 16 loses its charge balance, and the positively charged electrode 12 releases excess positive charge (FIG. 3(b)).

[0078] When the polarized droplet 16 moves over the top surface of the power generation layer 10 and comes into contact with the exposed portion 14 of the electrode 11, the negative charge polarized in the droplet 16 moves to the exposed portion 14, which is the interface with the electrode 11 (Figure 3(c)).

[0079] In the power generation system 1, the state of charge balance is disrupted, and electrostatic induction is caused to form an electric double layer with the negative charge of the droplet 16 that has moved to the interface with the electrode 11, and a positive charge moves from the ground 22 through the resistor 21 to the exposed portion 14, which is the interface with the electrode 11 (Figure 3 (d)).

[0080] When a positive charge is electrostatically induced on the electrode 11, the power generation system 1 in contact with the droplet 16 is brought into a charge-balanced state (FIG. 3(e)), and the transfer of charge stops.

[0081] Thereafter, when the droplet 16 flows down beyond the electrode 11, the amount of liquid in the droplet 16 decreases, and the amount of negative charge in the droplet 16 also decreases, causing the charge balance in the power generation system 1 in contact with the droplet 16 to be lost, and excess positive charge is released from the electrode 11 by electrostatic induction (Figure 3(f)). This electrostatic induction causes the charge to move, and electrical energy can be extracted as the droplets 16 flow down from the power generation system 1. The direction in which the charge moves at this time is opposite to the direction in which the charge moves when a positive charge is electrostatically induced from the ground 22 through the resistor 21 to the electrode 11, as shown in (d) of FIG.

[0082] By continuing to drop the droplets 16 and repeating the cycle from (a) to (f) in Figure 3, electrostatic induction is induced many times, and charge transfer occurs each time, allowing electrical energy to be extracted efficiently.

[0083] When a droplet 16 is dropped onto the upper surface of the power generation layer 10 of the power generation system 1, in which the power generation layer 10 has been sufficiently charged to a state close to saturation and the charges are balanced, and the droplet 16 comes into contact with the upper surface of the power generation layer 10, moves to the electrode 11, and comes into contact with the exposed portion 14 to extract electrical energy, the droplet 16 acts as a dielectric to bridge the power generation layer 10 and the electrode 11 to form a closed circuit.

[0084] FIG. 4 is a schematic diagram of an example of a power generation system according to an embodiment of the present invention. Fig. 4(a) is a schematic plan view of an example of a power generation system according to an embodiment of the present invention, and Fig. 4(b) is a schematic cross-sectional view of the power generation system 1 taken along the dotted line X1 in Fig. 4(a) in the Y direction. FIG. 4(c) is a schematic cross-sectional view of the power generation system 1 taken along the dotted line Y1 in FIG. 4(a) in the X direction. 4, the electrode 11 is formed on the surface of the power generation layer 10 opposite to the surface on which the droplets 16 move, and the exposed portion 14 is formed by opening a part of the power generation layer 10 in the area where the electrode 11 and the power generation layer 10 overlap. Of the power generation layer 10 on the upper surface of the electrode 11, the part that overlaps with the electrode serves as a protective film for the electrode 11, and the part of the electrode 11 covered by the power generation layer 10 serves as a covered portion 13. The electrode 11 has a predetermined width in the direction in which the droplet 16 moves, and the exposed portion 14 is located at the center of the electrode 11 in the width direction relative to the direction in which the droplet 16 moves.

[0085] FIG. 5 is a schematic diagram of an example of a power generation system according to an embodiment of the present invention. Fig. 5(a) is a schematic plan view of an example of a power generation system according to an embodiment of the present invention, and Fig. 5(b) is a schematic cross-sectional view of the power generation system 1 taken along the dotted line X2 in Fig. 5(a) in the Y direction. Fig. 5(c) is a schematic cross-sectional view of the power generation system 1 taken along the dotted line Y2 in Fig. 5(a) in the X direction. 5, electrode 11 is sandwiched between power generation layers 10 in an arrangement in which an end of electrode 11 and an end of power generation layer 10 are in contact with each other, and the surface of the electrode on power generation layer 10 along which droplets 16 move is arranged at approximately the same height as the surface of the electrode. Therefore, electrode 11 can be said to be formed on the surface along which droplets 16 move on power generation layer 10. A portion of the surface of electrode 11 is covered with protective film 19, and the surface of electrode 11 includes a covered portion 13 covered with protective film 19 and an exposed portion 14 that is not covered with protective film 19. Exposed portion 14 is formed by opening a portion of protective film 19 in the region where electrode 11 and protective film 19 overlap, and is formed as an opening in the center of protective film 19.

[0086] The electrode 11 has a predetermined width in the direction in which the droplet 16 moves, and the exposed portion 14 is located at the center of the electrode 11 in the width direction relative to the direction in which the droplet 16 moves. The protective film 19 may be made of the same material as the power generation layer 10 . The electrode 11 has a predetermined width in the direction in which the droplet 16 moves, and the exposed portion 14 is located at the center of the electrode 11 in the width direction relative to the direction in which the droplet 16 moves.

[0087] FIG. 6 is a schematic diagram of an example of a state in which droplets are moved onto the power generation layer of the power generation system of FIG. Fig. 6(a) is a schematic plan view of an example of a state in which droplets are moved onto the power generation layer of the power generation system of Fig. 5. Fig. 6(b) is a schematic cross-sectional view of the power generation system 1 taken along the dotted line X3 in Fig. 6(a) in the Y direction. In Figure 6, droplets 16 move from upstream in the direction of the arrow (Figure 6(a)), and some of the droplets 16 remain as retained liquid 17 in exposed portion 14 formed by an opening in the center of protective film 19 (Figure 6(b)).

[0088] FIG. 7 is a schematic diagram of an example of a state in which droplets are moved onto the power generation layer of the power generation system of FIG. Fig. 7(a) is a schematic plan view of an example of a state in which droplets are moved onto the power generation layer of the power generation system of Fig. 5. Fig. 7(b) is a schematic cross-sectional view of the power generation system 1 taken in the Y direction from the dotted line X4 in Fig. 7(a). Electrodes 11 and 12 are connected to ground via a resistor, and ground is one end connected to electrodes 11 and 12. Since charge moves through ground, in the power generation system 1 of Figure 7, ground can be considered as another electrode connected to electrodes 11 and 12. 7, droplets 16 move from upstream in the direction of the arrow (FIG. 7(a)), and come into contact with retained liquid 17 that has accumulated in exposed portion 14 formed by an opening in the center of protective film 19 (FIGS. 7(a) and 7(b)). This contact between droplets 16 and retained liquid 17 causes charge transfer in power generation system 1.

[0089] FIG. 8 is a schematic diagram of an example of a power generation system according to an embodiment of the present invention. Fig. 8(a) is a schematic plan view of an example of a power generation system according to an embodiment of the present invention. Fig. 8(b) is a schematic cross-sectional view of the power generation system 1 taken along the Y direction from the dotted line X5 in Fig. 8(a). Fig. 8(c) is a schematic cross-sectional view of the power generation system 1 taken along the Y direction from the dotted line X6 in Fig. 8(a). Fig. 8(d) is a schematic cross-sectional view of the power generation system 1 taken along the X direction from the dotted line Y3 in Fig. 8(a). 8, electrode 11 is sandwiched between power generation layers 10 in an arrangement in which an end of electrode 11 and an end of power generation layer 10 are in contact, and the surface of electrode 11 on power generation layer 10 along which droplets 16 move is arranged side by side at approximately the same height as the surface of electrode 11, so that electrode 11 can be said to be formed on the surface along which droplets 16 move on power generation layer 10. A portion of the surface of electrode 11 is covered with protective film 19, and the surface of electrode 11 has covered portion 13 covered by protective film 19 and exposed portion 14, and exposed portion 14 is formed by opening part of protective film 19 in the region where electrode 11 and protective film 19 overlap, and is formed on the upstream side of protective film 19 in the direction of droplet movement. The protective film 19 may be made of the same material as the power generation layer 10 .

[0090] FIG. 9 is a schematic diagram of an example of droplets landing on the power generation layer of the power generation system of FIG. Fig. 9(a) is a schematic plan view of an example of droplets landing on the power generation layer of the power generation system of Fig. 8. Fig. 9(b) is a schematic cross-sectional view of the power generation system 1 taken along the Y direction from the dotted line X7 in Fig. 9(a). Fig. 9(c) is a schematic cross-sectional view of the power generation system 1 taken along the Y direction from the dotted line X8 in Fig. 9(a). Fig. 9(d) is a schematic cross-sectional view of the power generation system 1 taken along the X direction from the dotted line Y4 in Fig. 9(a). In the region where the electrode 11 and the protective film 19 overlap, the retained liquid 17 is retained in the exposed portion 14 formed by opening a part of the protective film 19 (FIGS. 9(a), (b), and (d)). When the droplets land on the power generation layer 10 at a high speed, such as by free fall, they become flattened landing droplets 18 (FIGS. 9(a) and (d)).

[0091] FIG. 10 is a schematic plan view of an example of how droplets move after landing on a power generation layer of an example of a power generation system according to an embodiment of the present invention. Electrodes 11 and 12 are connected to ground via a resistor, and ground is one end connected to electrodes 11 and 12. Since electric charges move through ground, in the power generation system 1 of Figure 10, ground can be considered as another electrode connected to electrodes 11 and 12.

[0092] In the region where the electrode 11 and the protective film 19 overlap, a part of the upstream side of the protective film 19 is opened to form an exposed portion, where the retained liquid 17 is retained. A droplet lands on the power generation effective area 20 of the power generation system 1 and becomes a flattened droplet 18 (FIG. 10(a)), which gradually shrinks from its flat state (FIG. 10(b)), slides down in the direction of the arrow, and comes into contact with the retained liquid 17 (FIG. 10(c)). From the time the droplet lands on the power generation effective area 20 until it comes into contact with the retained liquid 17, friction between the power generation layer 10 and the droplet charges the power generation layer 10, and contact between the droplet 16 and the retained liquid 17 causes a transfer of charge in the power generation system 1. Depending on the surface condition of the power generation layer 10, when the impacted droplet 18 shrinks from a flat state and slides down, the interface of the droplet 16 forms an edge with a complex shape, and the droplet 16 slides down at high speed, thereby efficiently rubbing the surface of the power generation layer 10.

[0093] FIG. 11 is a schematic plan view of an example of how droplets move after landing on a power generation layer of an example of a power generation system according to an embodiment of the present invention. Electrodes 11 and 12 are connected to ground via a resistor, and ground is one end connected to electrodes 11 and 12. Since charge moves through ground, in the power generation system 1 of Figure 11, ground can be considered as another electrode connected to electrodes 11 and 12.

[0094] In the area where the electrode 11 and the protective film 19 overlap, a portion of the protective film 19 on the downstream side is opened to form an exposed portion, where the retained liquid 17 is retained. A droplet lands on the power generation effective area 20 of the power generation system 1 and becomes a flattened landing droplet 18 (FIG. 11(a)). The droplet gradually shrinks from its flat state (FIG. 11(b)), slides down in the direction of the arrow, and comes into contact with the retained liquid 17 (FIG. 11(c)). Friction between the power generation layer 10 and the droplet from the time the droplet lands on the power generation effective area 20 until it comes into contact with the retained liquid 17 causes the power generation layer 10 to become charged, and contact between the droplet 16 and the retained liquid 17 causes a transfer of charge in the power generation system 1. When the exposed portion is formed by opening a part of the downstream side of the protective film, the friction between the droplets and the power generation layer in the power generation effective region tends to be sufficient. [Example]

[0095] The present invention will be described in more detail below with reference to examples and comparative examples. However, the present invention is not limited to the above.

[0096] <Fabrication of the power generation element that is the power generation system> As shown in Figure 12, a copper foil tape (CU-35C, manufactured by 3M) serving as an electrode, a polytetrafluoroethylene (PTFE) tape (Scotch5480, manufactured by 3M: 80mm x 50mm) serving as a power generation layer, and another copper foil tape (CU-35C, manufactured by 3M) serving as an electrode were laminated in this order on an acrylic plate (Kanaselite, manufactured by Kanase Co., Ltd.: 80mm x 150mm x 5mm thick) serving as a base material, to produce a power generation element with the laminated structure shown in Figure 13A(a). This was used as the power generation element of the reference example. 13A(a) was completely covered with PTFE tape, which served as a protective film 19, to produce a power generating element having a laminated structure as shown in FIG. 13A(b). This was used as the power generating element of the comparative example. Furthermore, the top electrode 11 in Fig. 13A(a) was partially covered with PTFE tape, which served as a protective film 19, to produce a power generating element with a laminated structure as shown in Fig. 13A(c). This was used as the power generating element of the example.

[0097] The power generating elements of the reference example, comparative example, and example were tilted at an angle of 45°, and water droplets were supplied as liquid droplets. The electromotive force and the amount of charge generated when the water droplets were continuously supplied to the upper electrode portion under the measurement conditions below were measured. For the power generating element of the example, water droplets were supplied so that the exposed portion 14 came into contact with the water droplets.

[0098] <Measurement conditions> Measuring equipment: Oscilloscope WaveSurfer3024 (LeCroy) Probe resistance: 10MΩ Load resistance: 1 [MΩ] Recording time: 12 seconds Sampling rate: 50 kHz Nozzle diameter for water droplets: φ1.6 [mm] Water droplet flow rate: 0.3 [ml / s]

[0099] The voltage waveform of the reference example is shown in FIG. 13B(a), the voltage waveform of the comparative example is shown in FIG. 13B(b), and the voltage waveform of the example is shown in FIG. 13B(c). The values ​​of the electromotive force and charge amount for the reference example are shown in the bar graph of FIG. 13C(a), those for the comparative example are shown in the bar graph of FIG. 13C(b), and those for the working example are shown in the bar graph of FIG. 13C(c). In each bar graph in FIG. 13C, V represents electromotive voltage (V) and Q represents charge amount (nC).

[0100] When water droplets were supplied to the power generating element of the reference example, a certain voltage and charge amount were generated (FIG. 13B(a), FIG. 13C(a)).

[0101] When water droplets were supplied to the power generating element of the comparative example, almost no voltage or charge was generated compared to the reference example (FIG. 13B(b), FIG. 13C(b)).

[0102] When water droplets were supplied to the power generating element of the example, a certain voltage and charge amount were generated (FIG. 13B(c), FIG. 13C(c)). The voltage and charge amount generated by the power generating element of the example and the power generating element of the reference example were almost the same.

[0103] Therefore, it was shown that in a power generation system that satisfies the configuration of the present invention, the power generation efficiency does not decrease even if the exposed area of ​​the electrode is reduced to decrease the area in contact with the droplets.

[0104] From the above, it has been shown that a power generation system satisfying the configuration of the present invention can provide a power generation system that can suppress electrode deterioration without reducing power generation efficiency.

[0105] The above describes preferred embodiments of the present invention, but the present invention is not limited to such specific embodiments, and unless otherwise specifically limited in the above description, various modifications and changes are possible within the scope of the spirit of the present invention described in the claims. The effects described in the embodiments of the present invention are merely examples of the most preferable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the embodiments of the present invention.

[0106] The present invention includes, for example, the following aspects. <1> a power generation layer and an electrode, A power generation system in which electricity is generated by the movement of droplets on the power generation layer, and the generated electrical energy is extracted from the electrode, the electrode is disposed downstream of the power generation layer in the direction of movement of the droplets, The electrode has a covered portion whose surface is covered with a protective film and an exposed portion whose surface is not covered with the protective film, and the droplets that move on the power generation layer come into contact with the electrode at the exposed portion. <2> the electrode is formed on the surface of the power generation layer on which the droplets move; <1> The power generation system according to claim 1. <3> the electrode is formed on a surface of the power generation layer opposite to a surface on which the droplet moves, and the exposed portion is formed by opening a part of the power generation layer in a region where the electrode and the power generation layer overlap; <1> The power generation system according to claim 1. <4> the exposed portion is formed on the upstream side of the electrode in the moving direction of the droplet; <1> , <2> , <3> The power generation system according to any one of the preceding claims. <5> the exposed portion is formed so that the droplets that come into contact with the electrode remain thereon; <1> , <2> , <3> , <4> The power generation system according to any one of the preceding claims. <6> The protective film is a dielectric. <1> , <2> , <3> , <4> , <5> The power generation system according to any one of the preceding claims. <7> Further, the other electrode is provided. <1> , <2> , <3> , <4> , <5> , <6> The power generation system according to any one of the preceding claims. <8> The aforementioned <1> , <2> , <3> , <4> , <5> , <6> , <7> 10. A power storage device comprising the power generation system according to claim 19. <9> The aforementioned <1> , <2> , <3> , <4> , <5> , <6> , <7> A power generation device comprising the power generation system according to any one of the preceding claims. <10> A power generation method comprising: supplying droplets to a power generation layer having electrodes; and moving the droplets on an upper surface of the power generation layer to extract electrical energy from the electrodes, the method comprising: the electrode has an exposed surface portion and a surface portion covered with a protective film, The power generating method, wherein the exposed surface portion of the electrode is in electrical contact with the droplet. <11> the electrode is disposed below the power generation layer, and the exposed surface of the electrode is exposed through an opening in the power generation layer and is in electrical contact with the droplet through the retained liquid retained in the opening; <10> The power generation method according to claim 1. <12> the electrode is disposed on the upper surface of the power generation layer, and the exposed surface portion of the electrode is a part of the surface of the electrode that faces the direction in which the droplet moves and is in electrical contact with the droplet via retained liquid retained in the exposed surface portion of the electrode; <10> The power generation method according to claim 1.

[0107] the above <1> from <7> Any of the power generation systems listed above <8> The above-mentioned storage device <9> The power generation device <10> from <12> According to any one of the power generation methods, the various problems in the prior art can be solved and the object of the present invention can be achieved. [Explanation of symbols]

[0108] 1. Power generation system 10 Power Generation Layer 11 electrodes 12 electrodes 13 Covering part 14 Exposed part 15 Base material 16 droplets 17 Retained liquid 18 Droplets 19 Protective film 20 Effective power generation area 21 Resistance 22 Grand [Prior art documents] [Patent documents]

[0109] [Patent Document 1] U.S. Patent No. 11,239,768 [Patent Document 2] Patent No. 5469556

Claims

1. The solar cell includes a power generation layer and an electrode, A power generation system in which electricity is generated by the movement of droplets on the power generation layer, and the generated electrical energy is extracted from the electrode, the electrode is disposed downstream of the power generation layer in the direction of movement of the droplets, The electrode has a covered portion whose surface is covered with a protective film and an exposed portion whose surface is not covered with the protective film, and the droplets that move on the power generation layer come into contact with the electrode at the exposed portion.

2. The power generation system according to claim 1 , wherein the electrode is formed on a surface of the power generation layer on which the droplets move.

3. 2. The power generation system according to claim 1, wherein the electrode is formed on a surface of the power generation layer opposite to a surface along which the droplets move, and the exposed portion is formed by opening a portion of the power generation layer in an area where the electrode and the power generation layer overlap.

4. The power generation system according to claim 1 , wherein the exposed portion is formed on an upstream side of the electrode in the direction of movement of the droplets.

5. The power generation system according to claim 1 , wherein the exposed portion is formed so that the droplets that come into contact with the electrode remain thereon.

6. The power generation system according to claim 1 or 2, wherein the protective film is a dielectric.

7. The power generation system according to claim 1 or 2, further comprising another electrode.

8. A power storage device comprising the power generation system according to claim 1 or 2.

9. A power generation device comprising the power generation system according to claim 1 or 2.

10. A power generation method comprising: supplying droplets to a power generation layer having electrodes; and moving the droplets on an upper surface of the power generation layer to extract electrical energy from the electrodes, the method comprising: the electrode has an exposed surface portion and a surface portion covered with a protective film, The power generating method, wherein the exposed surface portion of the electrode is in electrical contact with the droplet.

11. 11. The power generation method according to claim 10, wherein the electrode is disposed below the power generation layer, and the exposed surface portion of the electrode is exposed through an opening in the power generation layer and is in electrical contact with the droplet through the retained liquid retained in the opening.

12. 11. The power generation method according to claim 10, wherein the electrode is disposed on the upper surface of the power generation layer, and the exposed surface portion of the electrode is a part of the surface of the electrode that faces the direction in which the droplet moves and is in electrical contact with the droplet via retained liquid retained in the exposed surface portion of the electrode.

Images