Power generation sheet

Abstract

To realizes a power generation sheet that is easy to install and has a large power generation capacity.SOLUTION: A power generation sheet (1) includes a sheet (10) having a first main surface (11) that covers the soil, a negative electrode (20) provided on the first main surface (11) and extracting electrons released when microorganisms contained in a soil decompose organic matter contained in the soil, and a positive electrode (30) provided on the first main surface (11) and reducing oxygen. The negative electrode (20) and the positive electrode (30) protrude from the first main surface (11).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power generating sheet that utilizes microorganisms contained in soil. [Background technology]

[0002] Conventionally, techniques for generating electricity using microorganisms contained in soil have been known. For example, Patent Document 1 discloses a microbial fuel cell that generates electricity using current-generating bacteria supplied from soil or mud as a catalyst. The microbial fuel cell disclosed in Patent Document 1 includes an anode electrode that oxidizes organic fuel supplied from the soil or mud, a cathode electrode that reduces oxygen supplied from the air and water, and an oxygen permeation-limiting layer between the anode electrode and the cathode electrode. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-54106 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology described in Patent Document 1 requires that the anode electrode and the oxygen permeation limiting layer be buried in the soil, which makes installation difficult and also makes it impossible to generate electricity on a large scale.

[0005] An object of one aspect of the present invention is to provide a power generating sheet that is easy to install and allows for a large-scale power generation. [Means for solving the problem]

[0006] In order to solve the above problems, a power-generating sheet according to one embodiment of the present invention comprises a sheet having a first main surface that covers the soil, a negative electrode provided on the first main surface that extracts electrons released when microorganisms contained in the soil decompose organic matter contained in the soil, and a positive electrode provided on the first main surface that reduces oxygen, wherein the negative electrode and the positive electrode protrude from the first main surface. [Effects of the Invention]

[0007] According to one aspect of the present invention, the power generation scale can be increased. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view of a power generating sheet according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing the power generating sheet installed in soil. [Figure 3] FIG. 2 is a perspective view showing an example of the configuration of a negative electrode provided in the power generating sheet. [Figure 4] FIG. 3 is a circuit diagram showing a part of the circuitry of the power generating sheet. [Figure 5] FIG. 10 is a perspective view of a power generating sheet according to a second embodiment of the present invention. [Figure 6] FIG. 2 is a cross-sectional view of the power generating sheet. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Embodiment 1] An embodiment of the present invention will be described in detail below. FIG. 1 is a perspective view of a power generating sheet 1 in this embodiment. FIG. 2 is a diagram showing the power generating sheet 1 placed in soil S. The power generating sheet 1 is a sheet that generates electricity when placed in soil S. In this embodiment, as shown in FIG. 2, an example will be described in which the power generating sheet 1 is placed to cover ridges formed in soil S on agricultural land such as a field. However, the object on which the power generating sheet 1 is placed is not limited to ridges. The power generating sheet 1 may be placed and used to cover soil S, or it may be placed and used to cover soil S other than agricultural land.

[0010] As shown in FIGS. 1 and 2, the power generating sheet 1 includes a sheet 10, a negative electrode 20, a positive electrode 30, a negative electrode tab 40, and a positive electrode tab 50.

[0011] The sheet 10 covers the soil S when the power generating sheet 1 is installed. In this embodiment, the sheet 10 is a mulch sheet that covers ridges formed in a field. The sheet 10 has a first main surface 11 that faces the soil S when the power generating sheet 1 is installed on the soil S, and a second main surface 12 that is the surface opposite to the first main surface 11. The first main surface 11 is the surface that covers the soil S when the power generating sheet 1 is installed on the soil S. There are no particular limitations on the material that makes up the sheet 10, as long as it is a non-conductive material, and for example, polyethylene or the like can be used.

[0012] The second main surface 12 may be configured to reflect only light with a wavelength of 600 to 700 nm. This allows the second main surface 12 to reflect light with a wavelength of 600 to 700 nm and irradiate it onto plants planted in the ridges. As a result, photosynthesis in plants can be promoted and carbon dioxide in the atmosphere can be reduced. For example, by applying a structural color treatment to the second main surface 12, the second main surface 12 can be configured to reflect only light with a wavelength of 600 to 700 nm.

[0013] A plurality of negative electrodes 20 and a plurality of positive electrodes 30 are provided on the first main surface 11 of the sheet 10. The negative electrodes 20 are electrodes that extract electrons that are released when microorganisms contained in the soil S decompose organic matter contained in the soil S. The positive electrodes 30 are electrodes that reduce oxygen in the air using the electrons extracted by the negative electrodes 20.

[0014] In the power generating sheet 1 of this embodiment, the negative electrode 20 and the positive electrode 30 have the same configuration. Therefore, only the structure of the negative electrode 20 will be described here. Note that the negative electrode 20 and the positive electrode 30 may have different configurations. In FIG. 1, the negative electrode 20 is shown hatched to distinguish between the negative electrode 20 and the positive electrode 30.

[0015] The negative electrode 20 is formed so as to protrude from the first main surface 11. In the power generating sheet 1 of this embodiment, as shown in FIGS. 1 and 2, the negative electrode 20 has a truncated cone shape. However, the negative electrode 20 and the positive electrode 30 are not limited to a truncated cone shape and may have other shapes as long as they protrude from the first main surface 11. The negative electrode 20 may be, for example, a rectangular parallelepiped, a cone, or a cylinder. The length by which the negative electrode 20 and the positive electrode 30 protrude from the first main surface 11 is not particularly limited, but may be, for example, 10 to 30 mm.

[0016] FIG. 3 is a perspective view showing an example of the configuration of the negative electrode 20. As shown in FIG. 3, the negative electrode 20 may be composed of a first material 21 that expands upon absorbing water and a second material 22 that contains the first material 21 and is conductive and water-permeable. When the power generating sheet 1 is laid on soil S, the first material 21 absorbs moisture contained in the soil S and permeates through the second material 22, causing the first material 21 to expand. As a result, the negative electrode 20 protrudes more from the first main surface 11, making it easier to bring the negative electrode 20 into contact with the soil S. This mechanism also applies to the positive electrode 30. Furthermore, since the negative electrode 20 and the positive electrode 30 can be made smaller before laying the power generating sheet 1, the power generating sheet 1 can be easily rolled. The first material 21 is not particularly limited as long as it expands upon absorbing water; for example, a water-absorbent polymer can be used. The second material 22 is not particularly limited as long as it is a material that is conductive and water permeable, and for example, carbon felt can be used.

[0017] The negative electrode 20 and the positive electrode 30 are not limited to the configuration shown in Fig. 3 and may have other configurations. For example, the negative electrode 20 and the positive electrode 30 may be made of only a conductive material. Examples of conductive materials include metals such as platinum, gold, and stainless steel, and carbon.

[0018] As shown in FIG. 1 , holes 60 are formed in the sheet 10 near each of the multiple positive electrodes 30. In other words, the sheet 10 has multiple holes 60 formed in a plan view that are closer to the positive electrodes 30 than the negative electrodes 20. By forming the holes 60 in positions closer to the positive electrodes 30 than the negative electrodes 20, air is sent from the second main surface 12 to the first main surface 11 through the holes 60, and oxygen is supplied to the positive electrodes 30 located in the vicinity of the holes 60. The positive electrodes 30 function as positive electrodes by reducing the oxygen supplied through the holes 60. In other words, the electrodes in the vicinity of the holes 60 function as positive electrodes 30 when the sheet 10 is viewed in a plan view.

[0019] Next, the arrangement of the negative electrodes 20 and the positive electrodes 30 on the first main surface 11 will be described. As shown in FIG. 1, the negative electrodes 20 and the positive electrodes 30 are alternately arranged in multiple rows. As shown in FIG. 1, the power generating sheet 1 includes multiple cells 70, each of which is formed by connecting the negative electrodes 20 and the positive electrodes 30. FIG. 4 is a circuit diagram showing a portion of the circuit included in the power generating sheet 1. As shown in FIG. 4, some of the multiple cells 70 are connected in series. In the following description, a structure in which the cells 70 are connected in series is referred to as a series structure 71. The power generating sheet 1 includes the series structures 71, which enable it to increase its power generation voltage. As shown in FIG. 4, the power generating sheet 1 includes multiple series structures 71, and at least two of the series structures 71 are connected in parallel. This allows electrons to be transferred via the series structure 71 connected in parallel to the series structure 71 including the failed cell 70 if a malfunction occurs in one of the cells 70 included in the parallel-connected series structure 71. This reduces the likelihood that the power generating sheet 1 will be unable to generate power.

[0020] As shown in FIG. 1 , a portion of the negative electrode 20 is electrically connected to a conductive negative electrode tab 40. The negative electrode tab 40 is connected to an external circuit (not shown) and transfers electrons extracted by the negative electrode 20 to the external circuit. The external circuit generates electricity using the electrons transferred by the negative electrode tab 40. In addition, a portion of the positive electrode 30 is electrically connected to a positive electrode tab 50. The positive electrode tab 50 is connected to the external circuit and transfers electrons extracted by the negative electrode 20 from the external circuit to the positive electrode 30. There are no particular limitations on the materials constituting the negative electrode tab 40 and the positive electrode tab 50 as long as they are conductive, and for example, carbon, metal, etc. can be used.

[0021] As described above, in the power generating sheet 1, the negative electrode 20 and the positive electrode 30 protrude from the first main surface 11. Therefore, as shown in Fig. 2, the negative electrode 20 and the positive electrode 30 can be brought into contact with the soil S to generate electricity without burying the negative electrode 20 and the positive electrode 30 in the soil S. This makes it easier to lay (install) the power generating sheet 1, and allows the power generating sheet 1 to be laid over a large area, thereby increasing the scale of power generation.

[0022] [Embodiment 2] Other embodiments of the present invention will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0023] Fig. 5 is a perspective view of the power generating sheet 1A of this embodiment. Fig. 6 is a cross-sectional view of the power generating sheet 1A. As shown in Figs. 5 and 6, the power generating sheet 1A includes a sheet 10A instead of the sheet 10 of embodiment 1. In addition to the configuration of the sheet 10 of embodiment 1, the sheet 10A includes a plurality of protrusions 80 and a gelatin layer 90.

[0024] As shown in FIGS. 5 and 6, the protrusions 80 protrude from the second main surface 12 of the sheet 10A. Providing the protrusions 80 on the second main surface 12 increases the surface area of ​​the sheet 10A on the second main surface 12 side. This allows moisture in the air to be collected on the second main surface 12 side. The protrusions 80 protrude from the second main surface 12 by a length of, for example, 10 to 30 mm. In this embodiment, the protrusions 80 have a substantially rectangular shape when the power generating sheet 1A is viewed from above. However, the shape of the protrusions 80 is not limited to this and may be other shapes.

[0025] Grooves 81 are formed between the protrusions 80. The width of the grooves 81 is 1 to 100 nm. In other words, in the power generating sheet 1A, the multiple protrusions 80 are arranged so that the width of the grooves 81 formed between adjacent protrusions 80 is 1 to 100 nm. The grooves 81 are connected to any of the holes 60 formed in the sheet 10A. This allows water collected by the protrusions 80 to be transported to the holes 60 by capillary action. The water transported to the holes 60 by the grooves 81 moves through the holes 60 toward the first main surface 11. This increases the number of electron transfer paths in the oxidation-reduction reaction occurring in the negative electrode 20 and the positive electrode 30 provided on the first main surface 11. This reduces the decrease in power generation efficiency, for example, even in barren land where the soil S has little moisture.

[0026] The gelatin layer 90 is a layer containing gelatin. As shown in FIG. 6, the gelatin layer 90 is laminated on the first main surface 11 of the sheet 10A. The gelatin layer 90 covers the negative electrode 20 and the positive electrode 30. The gelatin layer 90 contains gelatin, which allows microorganisms to be cultured. For example, the gelatin layer 90 can be used to culture microorganisms (power-generating microorganisms) that decompose organic matter contained in the soil S, thereby improving power generation efficiency. As another example, the gelatin layer 90 can be used to culture microorganisms that promote plant growth and / or microorganisms that produce nitrogen fertilizer, thereby promoting plant growth.

[0027] 〔summary〕 The power-generating sheet according to aspect 1 of the present disclosure comprises a sheet having a first main surface that covers the soil, a negative electrode provided on the first main surface that extracts electrons released when microorganisms contained in the soil decompose organic matter contained in the soil, and a positive electrode provided on the first main surface that reduces oxygen, wherein the negative electrode and the positive electrode protrude from the first main surface.

[0028] A power generating sheet according to a second aspect of the present disclosure is the same as that of the first aspect, but the sheet may have holes formed therein that are located closer to the positive electrode than to the negative electrode when viewed in plan.

[0029] In the power generating sheet according to aspect 3 of the present disclosure, in the above aspect 1 or 2, the negative electrode and the positive electrode may comprise a first material that expands upon absorbing water, and a second material that contains the first material and has electrical conductivity and water permeability.

[0030] A fourth aspect of the present disclosure provides a power generating sheet according to the third aspect, wherein the first material is a water-absorbing polymer.

[0031] A fifth aspect of the present disclosure provides a power generating sheet according to the third or fourth aspect, wherein the second material is carbon felt.

[0032] A power generating sheet according to a sixth aspect of the present disclosure is any one of the first to fifth aspects, wherein a second main surface of the sheet, which is the surface opposite to the first main surface, has a plurality of protrusions formed thereon that protrude from the second main surface, a plurality of holes formed in the sheet, the plurality of protrusions being arranged such that the width of a groove formed between adjacent protrusions is 1 to 100 nm, and the groove may be connected to at least one of the plurality of holes.

[0033] A power generating sheet according to a seventh aspect of the present disclosure is the power generating sheet of any one of the first to sixth aspects, wherein the sheet may have a gelatin layer containing gelatin on the first main surface, covering the negative electrode and the positive electrode.

[0034] The power generating sheet according to aspect 8 of the present disclosure is any one of aspects 1 to 7 above, wherein the second main surface of the sheet, which is the surface opposite to the first main surface, may be configured to reflect only light with a wavelength of 600 to 700 nm.

[0035] The power generating sheet according to aspect 9 of the present disclosure may be any of aspects 1 to 8 above, and may include a plurality of cells in which the negative electrode and the positive electrode are connected, and the plurality of cells may be connected in series.

[0036] The power generating sheet according to aspect 10 of the present disclosure is the same as in aspect 9 above, but has a plurality of series structures in which the cells are connected in series, and at least two of the series structures may be connected in parallel.

[0037] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0038] 1. 1A power generation sheet 10, 10A sheets 11 First main surface 12 Second main surface 20 negative electrode 21 First material 22 Second material 30 Positive electrode 60 holes 70 cells 71 Serial Structure 80 Protrusion 81 Groove 90 gelatin layer

Claims

1. a sheet having a first main surface that covers the soil; a negative electrode provided on the first main surface, for extracting electrons emitted when microorganisms contained in the soil decompose organic matter contained in the soil; a positive electrode provided on the first main surface and configured to reduce oxygen; the negative electrode and the positive electrode protrude from the first main surface, The power generating sheet has holes formed in the sheet that are located closer to the positive electrode than to the negative electrode when viewed from above.

2. A sheet having a first main surface that covers soil; a negative electrode provided on the first main surface, for extracting electrons emitted when microorganisms contained in the soil decompose organic matter contained in the soil; a positive electrode provided on the first main surface and configured to reduce oxygen; the negative electrode and the positive electrode protrude from the first main surface, The negative electrode and the positive electrode are a first material that expands upon absorbing water; a second material containing the first material and having electrical conductivity and water permeability.

3. The power generating sheet according to claim 2 , wherein the first material is a water-absorbing polymer.

4. The power generating sheet according to claim 2 , wherein the second material is carbon felt.

5. A sheet having a first main surface that covers soil; a negative electrode provided on the first main surface, for extracting electrons emitted when microorganisms contained in the soil decompose organic matter contained in the soil; a positive electrode provided on the first main surface and configured to reduce oxygen; the negative electrode and the positive electrode protrude from the first main surface, a second main surface of the sheet, which is a surface opposite to the first main surface, has a plurality of protruding portions formed thereon, the protruding portions protruding from the second main surface; The sheet has a plurality of holes formed therein, the plurality of protrusions are arranged so that a groove formed between adjacent protrusions has a width of 1 to 100 nm; The power generating sheet, wherein the groove is connected to at least one of the plurality of holes.

6. A sheet having a first main surface that covers soil; a negative electrode provided on the first main surface, for extracting electrons emitted when microorganisms contained in the soil decompose organic matter contained in the soil; a positive electrode provided on the first main surface and configured to reduce oxygen; the negative electrode and the positive electrode protrude from the first main surface, The power generating sheet has a gelatin layer on the first main surface, the gelatin layer covering the negative electrode and the positive electrode.

7. A sheet having a first main surface that covers soil; a negative electrode provided on the first main surface, for extracting electrons emitted when microorganisms contained in the soil decompose organic matter contained in the soil; a positive electrode provided on the first main surface and configured to reduce oxygen; the negative electrode and the positive electrode protrude from the first main surface, The power generating sheet has a second main surface opposite to the first main surface, which reflects only light with a wavelength of 600 to 700 nm.

8. a plurality of cells in which the negative electrode and the positive electrode are connected; The power generating sheet according to claim 1 , wherein a plurality of the cells are connected in series.

9. The cell has a plurality of serial structures connected in series, The power generating sheet according to claim 8 , wherein at least two of the series structures are connected in parallel.

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