JP7818133B2 - Method for forming an electric double layer capacitor - Google Patents

Description

The present invention relates to a method for forming an electric double layer capacitor that can store electricity.

In recent years, it has been proposed to blend electrically conductive nanoporous carbon into cement, use the fluidity of water to form a nanoporous carbon network, and use the concrete as a capacitor (see, for example, Patent Document 1).

U.S. Pat. No. 1,512,022

However, Patent Document 1 only proposes storing electricity in concrete to create a capacitor, and does not propose any other applications or safety measures for actual use.

The present invention therefore aims to provide a method for forming an electric double layer capacitor using soil.

The method for forming an electric double layer capacitor according to claim 1 comprises mixing an electrically conductive material containing carbon black with soil containing ions and adding an ionic solution to form a conductive part, providing a positive electrode, a negative electrode, and a separator in the conductive part, adjusting the internal resistance of the conductive part by adjusting the amount of carbon black added and the state of contact between the soil and the carbon black by compacting the conductive part, applying a voltage between the positive electrode and the negative electrode to attract anions to the positive electrode and cations to the negative electrode.

According to the method for forming an electric double layer capacitor as set forth in claim 1, electricity can be stored using soil mixed with an electrically conductive material.

This is a cross-sectional view showing soil placed in a glass container with two copper plates inserted into the soil. This is a cross-sectional view showing a mixture of soil and carbon black placed in a glass container, with two copper plates inserted into the mixture. FIG. 1 is a schematic diagram showing the state of a capacitor during charging. FIG. 10 is a diagram showing the arrangement of a separator, a positive electrode, and a negative electrode, which are part of the capacitor configuration, on a slab. This is a partial cross-sectional view showing the mixture backfilled in the earthen floor area. FIG. 10 is a diagram showing the state of the foundation structure after compaction. FIG. 10 is a diagram showing temporary scaffolding and protective netting installed near the foundation structure. FIG. 1 is a schematic diagram showing a safety net equipped with perovskite solar cells. 9 is a cross-sectional view taken along the line AA in FIG. 8. FIG. 2 is a block diagram of a control device for controlling charging and discharging of a capacitor in the first embodiment. A figure showing the state in which a separator, a positive electrode, and a negative electrode, which are part of the capacitor configuration, are arranged on a strip foundation of the second embodiment.

(First embodiment)
The first embodiment will be described in detail below with reference to FIGS. 1 to 10. In this first embodiment, an electrically conductive material is mixed into soil to form conductive soil, and this conductive soil is used to provide a capacitor 11, which will be described later. In this first embodiment, the electrically conductive material is a material that has electronic conductivity, which allows electrons to move, and ionic conductivity, which allows ions to move. In this first embodiment, a combination of carbon black and binchotan charcoal is used as the electronically conductive material, and moist soil 2 is used as the ionic conductive material, but the present invention is not limited to this.

(Preliminary experiment to confirm the insulating properties of soil)
1 is a cross-sectional view showing a state in which soil 2 is placed in a glass container 1 and two copper plates 3 are inserted into the soil 2. The soil 2 was collected in Tsukuba City, Ibaraki Prefecture, and was placed in the glass container 1 after being sieved through a sieve with a mesh size of 4.75 mm.

A soil test of this soil 2 revealed that the density of the soil particles was 2.660 g/ ^cm3 and the natural water content was 35.7%. The particle size of Soil 2 was 4.5% gravel, 39.5% sand, 42.0% silt, and 14.0% clay. Consequently, Soil 2 was classified as sandy silt.

Sandy silt contains electrolyte substances such as calcium ions (Ca ²⁺ ) and magnesium ions (Mg ²⁺ ), so soil 2 can be used as an electrolyte. If the electrolyte substances in soil 2 are insufficient, cations with a high tendency to ionize, such as calcium ions (Ca ²⁺ ), potassium ions (K ⁺ ), magnesium ions (Mg ²⁺ ), and sodium ions (Na ⁺ ), can be added to soil 2 as electrolyte substances.

For example, cement contains calcium ions (Ca ²⁺ ), so it may be mixed with the soil 2 as soil cement.

When the tester's test leads were touched to each of the two copper plates 3, no continuity was confirmed, resulting in a non-conductive state. As a result, no continuity was confirmed in soil 2.

(Mixture of soil and electrically conductive material)
The aforementioned soil 2 was mixed with an electrically conductive material. The electrically conductive material used was a combination of carbon black and binchotan charcoal, but this is not limited to this. For example, a single carbon-derived material (e.g., binchotan or activated carbon) may also be used as the electrically conductive material. Carbon black forms a carbon network and, when mixed with soil 2, reduces the internal resistance of soil 2 and increases its charge capacity. Binchotan charcoal is a material suitable for absorbing and releasing ions. In this first embodiment, acetylene black, produced by the thermal decomposition of acetylene, was used as the carbon black. However, Ketjenblack, a registered trademark, whose primary particles have a hollow shell structure, may also be used, as may inexpensively available activated carbon. In this case, activated carbon primarily consisting of micropores or mesopores is preferred.

Binchotan charcoal, which is derived from carbon, can be crushed or commercially available powdered binchotan charcoal. It is also possible to use activated carbon with macropores instead of binchotan charcoal.

Acetylene black and binchotan charcoal are hydrophobic substances, but they become somewhat compatible with water when soaked in water for about a day. In this case, it is preferable to stir them for about 10 to 30 minutes immediately after soaking them in water. In this first embodiment, acetylene black and binchotan charcoal were each soaked in water before being mixed with soil 2. This improves the compatibility between soil 2, acetylene black, and binchotan charcoal.

The amount of acetylene black added is between 5% and less than 20% by weight of soil 2. If the amount of acetylene black added is 5% or more by weight of soil 2, a carbon network can be formed within soil 2. If the amount of acetylene black added is 20% or more by weight of soil 2, the resistance value of mixture 4, described below, will be further reduced, but in this first embodiment, the amount is set to less than 20% in consideration of the price and cost-effectiveness of acetylene black.

The amount of binchotan charcoal added is 8% or more and less than 25% by weight of soil 2. If the amount of binchotan charcoal added is 8% or more by weight of soil 2, charging using the ions of soil 2 by capacitor 11, described below, becomes possible. The amount of binchotan charcoal added can be 25% or more by weight of soil 2, but in this first embodiment, it is set to less than 25% in consideration of the price and cost-effectiveness of binchotan charcoal.

The amount of binchotan charcoal added will vary depending on the properties of soil 2, the amount of electrolyte contained in soil 2, and whether or not electrolyte is added, so the above amount should be used as a guideline. Furthermore, taking into account the performance of capacitor 11 (charge amount, charging time, etc.) described below, it is preferable to add more binchotan charcoal than acetylene black. The amount of acetylene black added may also be determined taking into account the internal resistance (several ohms to tens of ohms) when mixed with soil 2.

In this first embodiment, soil 2, acetylene black, and crushed binchotan charcoal were mixed in a mixer for several minutes (1 to 2 minutes) to create mixture 4.

(Experiment to confirm the conductivity of the mixture)
FIG. 2 is a cross-sectional view showing a state in which a mixture 4 is placed in a glass container 1 and two copper plates 3 are inserted into the mixture 4.

When the test leads of a tester were contacted with each of the two copper plates 3, the resistance was approximately 20-30 Ω, confirming conductivity of the mixture 4. This confirmed that an electrically conductive network had been formed within the soil 2 using carbon black, a carbon-derived material.

The reason for the fluctuation of about 10 Ω in the resistance value is that gas (air) was mixed into mixture 4, causing the contact state of the electrically conductive material to become unstable. For this reason, mixture 4 was manually compacted using a metal tamping rod, and the resistance value of mixture 4 was measured again.

After manual compaction, the resistance value of Mixture 4 was approximately 18-20 Ω, and it was confirmed that as the resistance value decreased, the fluctuations in the resistance value also decreased. Furthermore, this resistance value could be reduced to a few Ω by increasing the amount of carbon black added to 10-15%.

In this first embodiment, the mixture 4 is a conductive portion in which an electrically conductive carbon network is formed, and this conductive portion is used to realize the capacitor 11 as a charging device that utilizes the ions of the soil 2.

(Experiment to confirm electricity storage using a mixture)
3 shows the state of capacitor 11 during charging, and is shown as a cross-sectional view excluding power source 8. As shown in Fig. 3, after a separator 5 is attached to glass container 1, mixture 4 is placed therein, and then a positive electrode 6 and a negative electrode 7 are inserted into mixture 4 to form capacitor 11 of the first embodiment.

The separator 5 prevents direct contact between the positive electrode 6 and the negative electrode 7, which could cause a short circuit, while allowing ions in the mixture 4 to pass through through the formed carbon network. In this first embodiment, the separator 5 can be made of a polyolefin resin such as polyethylene or polypropylene, or a polyester resin such as polyethylene terephthalate or polybutylene terephthalate. Alternatively, the separator 5 can be made of cellulose-derived nonwoven fabric or paper (e.g., Japanese paper or kitchen paper). The separator 5 is fixed to the glass container 1 with insulating tape. Alternatively, the separator 5 may be sandwiched between insulating materials and then placed in the glass container 1.

The positive electrode 6 can be made of a material that does not easily react chemically with the ionic substances contained in the soil 2, such as copper, aluminum, platinum, or a carbon material. In this first embodiment, a copper plate 3 is used. The positive electrode 6 is connected to a carbon network formed from acetylene black. An electric double layer is formed near the surface of the binchotan charcoal connected to this carbon network, which attracts anions with the opposite charge to the positive electrode 6, thereby charging the electrode.

The negative electrode 7 can be made of a material that does not easily react chemically with the ionic substances contained in the soil 2, such as copper, aluminum, platinum, or a carbon material. In this first embodiment, a copper plate 3 is used. The negative electrode 7 is connected to a carbon network formed from acetylene black. An electric double layer is formed near the surface of the binchotan charcoal connected to this carbon network, which attracts cations with the opposite charge to the negative electrode 7, thereby charging the electrode.

The power supply 8 is used to charge the capacitor 11, and can be a constant voltage power supply, a constant current power supply, etc.

One end of wire 9 is connected to the positive electrode 6, and the other end is connected to the + output terminal of the power supply 8. One end of wire 10 is connected to the negative electrode 7, and the other end is connected to the - output terminal of the power supply 8.

In this first embodiment, a constant voltage power supply was used as the power supply 8, and charging was performed at a voltage of 1 V to 3 V. When the water content of the mixture 4 was high, charging was performed at 1.2 V or less to prevent hydrogen generation, and when the water content of the mixture 4 was low, i.e., when little hydrogen was generated, charging was performed at 3 V.

After charging for several minutes or 5 to 10 minutes (depending on the state of mixture 4), wires 9 and 10 were connected to a rotary motor (not shown), which then rotated. This confirmed that a carbon network was formed in soil 2 using acetylene black, and that ions were being absorbed and released by binchotan charcoal, an ion-absorbing material. In other words, it was confirmed that electricity can be stored using mixture 4.

Mixture 4 was also prepared anew using the aforementioned weight ratio, and sodium ions (Na ⁺ ) were added. Specifically, several hundred cc of 5% saline solution was added. Then, as in the previous example, it was charged at a voltage of 1.2 V for the same period of time (several minutes, or approximately 5 to 10 minutes). After that, when wires 9 and 10 were connected to a rotary motor, the rotary motor rotated longer than Mixture 4, which did not contain sodium ions (Na ⁺ ).

In this way, by adding positive ions, the charge on capacitor 11 increases, allowing it to supply more power.

In addition, in civil engineering and construction, soil has played a role as the ground and foundation, but according to this first embodiment, in addition to these, soil also plays a role in storing electricity, making it possible to realize an electric double layer capacitor using soil.

(Application of capacitors to buildings)
The following continues the description of the application of the above-described capacitor 11 to a building. Here, it is assumed that the capacitor 11 is applied to a foundation 30. In the first embodiment, the capacitor 11 is applied to the foundation 30 that is made up of a continuous footing 40 and a concrete slab 60.

Although details will be described later, the foundation structure 30 comprises a continuous footing 40, a slab 50, a mixture 4 as backfill material, and a concrete floor 60.
4 is a diagram showing a state in which a separator 5, a positive electrode 6, and a negative electrode 7, which are part of the configuration of a capacitor 11, are arranged on a continuous footing 40. Note that at an actual construction site, a plurality of continuous footings 40 are formed along the X-axis direction and the direction perpendicular to the paper surface in the figure to form a foundation structure 30. Therefore, capacitors 11 can be installed in multiple locations.

The continuous footing 40 is made of concrete with reinforcing bars, and its upper surface is formed with shear reinforcement bars 41 and main reinforcement bars 42 extending perpendicular to the plane of the paper. The inner surface 40a of the continuous footing 40 corresponds to the inner surface of the glass container 1, and is therefore coated or sprayed with an insulating agent to ensure insulation. Examples of insulating agents that can be used include, but are not limited to, alkylalkoxysilane-based insulating agents and silanesiloxane-based insulating agents.

The slab 50 is made of concrete and is installed on the ground 45 in the space surrounded by the continuous footing 40, extending perpendicular to the plane of the page. In this first embodiment, the slab 50 holds or houses the elements that make up the capacitor 11. The upper surface 50a of the slab 50 corresponds to the bottom surface of the glass container 1, and is coated or sprayed with an insulating agent to ensure insulation. Examples of insulating agents that can be used include, but are not limited to, alkylalkoxysilane-based insulating agents and silanesiloxane-based insulating agents. As described above, in this first embodiment, the opposing inner surfaces 40a of the continuous footing 40 and the upper surface 50a of the slab 50 form an insulating container.

U.S. Patent No. 11,512,022, listed in the prior art section, discloses storing electricity in concrete, but does not disclose insulating reinforcing bars when they are placed in the concrete. In contrast, in this first embodiment, insulation is ensured between the mixture 4, in which an electrically conductive substance is mixed into the soil, and the opposing inner surface 40a of the continuous footing 40 and the top surface 50a of the slab 50. Therefore, even if reinforcing bars are placed inside or on the top surface of the continuous footing 40, there is no need to insulate these reinforcing bars. Furthermore, because the earthen floor area 46 is a large space, even if the amount of charge per unit area is small, the large capacity of the mixture 4 allows for the storage of more electricity.

The slab 50 is formed with a first holding portion 51 for holding the separator 5, a second holding portion 52 for holding the positive electrode 6, and a third holding portion 53 for holding the negative electrode 7. The first holding portion 51, second holding portion 52, and third holding portion 53 have recesses, which are formed by pouring concrete into formwork that matches the respective shapes when pouring the concrete for the slab 50.

Since the first holding portion 51 is required to be insulating, it is desirable to apply or spray the aforementioned insulating agent. Furthermore, to ensure reliable retention of the separator 5, the separator 5 can be securely held using an elastically deformable, insulating resin material 54. While FIG. 4 shows resin material 54 provided on both sides of the separator 5, it is also possible to hold the separator 5 by providing resin material 54 on only one side of the separator 5. In this way, the separator 5 is fitted into the recess of the first holding portion 51 using resin material 54.

In this first embodiment, the second holding portion 52 and the third holding portion 53 have the same shape. By making the second holding portion 52 and the third holding portion 53 the same shape, a common formwork can be used, thereby reducing the cost of pouring concrete. Note that the second holding portion 52 and the third holding portion 53 may be omitted, and the positive electrode 6 and the negative electrode 7 may be held by the mixture 4.

When constructing the foundation structure 30, the soil of the ground surface 45 is excavated using heavy construction machinery such as a backhoe. This excavated soil is then used as backfill material to fill the earthen floor area 46 (described below) after the continuous footing 40 is constructed. In this first embodiment, the excavated soil is mixed with an electrically conductive material to form the mixture 4. This mixing may be performed, for example, at the construction site using the bucket of a backhoe, or by workers. The aforementioned electrolyte material may also be replenished at this time.

Here, it is preferable to place the mixture 4 produced at the construction site in the glass container 1 shown in Figure 2 and measure the resistance value of the mixture 4 produced at the construction site. It is also preferable to charge the mixture 4 produced at the construction site and measure the current value and capacitance during charging. Based on these measurement results, by further adding crushed binchotan charcoal or carbon black to the mixture 4 used as backfill material, or by supplementing it with an electrolyte substance, it is possible to realize a capacitor 11 with excellent charging performance. In this way, by producing the mixture 4 for the capacitor 11 using soil excavated at the construction site, it is possible to reduce the costs of procuring and transporting the soil.

In this first embodiment, the earthen floor area 46 is formed by the space surrounded by the continuous footing 40, the slab 50, and the deck 58 (see Figure 6), which will be described later. Figure 5 is a partial cross-sectional view showing the state in which the mixture 4 has been backfilled into this earthen floor area 46.

As shown in Figure 5, the mixture 4 is buried in the earthen floor 46 so that it does not exceed the height of the separator 5, positive electrode 6, negative electrode 7, and liner footing 40. This ensures the insulation of the capacitor 11. Note that since the mixture 4 is simply backfilled in the earthen floor 46, air exists within the mixture 4. If air exists within the mixture 4 and contact between the mixture 4 particles becomes unstable, the internal resistance value of the mixture 4 will increase and the measured internal resistance value will not be stable.

For this reason, compacting the mixture 4 backfilled in the earthen floor area 46 increases the shear resistance of the mixture 4 and reduces its internal resistance, improving its performance as a capacitor 11. Figure 6 shows the state of the foundation structure 30 after compaction. As shown in Figure 6, the height of the mixture 4 has been reduced by compaction.

6 also newly illustrates a resin sheet 55, a first pipe member 56, a second pipe member 57, a deck 58, and a concrete slab 60.
Resin sheet 55 is a sheet for preventing rainwater from getting on capacitor 11, and in the first embodiment, a polyethylene sheet is used. Note that in the first embodiment, floor concrete 60 can prevent rainwater from getting on capacitor 11. For this reason, in the first embodiment, resin sheet 55 may be omitted, or resin sheet 55 may be used until floor concrete 60 is constructed.

In this first embodiment, the first pipe member 56 is a CD pipe, a pipe member for passing the wiring 9 from the positive electrode 6. The second pipe member 57 is a CD pipe, a pipe member for passing the wiring 10 from the negative electrode 7.

In this first embodiment, it is desirable to check the operation of the capacitor 11 before pouring the concrete floor 60. To check the operation, it is desirable to charge the capacitor 11 and also discharge it. While Figure 5 and other figures show one capacitor 11, multiple capacitors 11 are installed at construction sites. When multiple capacitors 11 are connected in series, it is desirable to check the charging and discharging operation with the multiple capacitors 11 connected in series.

In addition, depending on the results of this operation check, a decision may be made as to whether or not to add the aforementioned electrolyte material. The decision regarding the addition of electrolyte material may be made by an operator, or by the control device 20 or host computer described below.

Although the deck 58 is shown simply, it is supported on the continuous footing 40 and covers the earthen floor area 46. In this first embodiment, the deck 58 is made of steel and has openings formed therein to allow the first pipe member 56 and the second pipe member 57 to pass through.

The concrete floor 60 is made of concrete. The concrete floor 60 is supported by the continuous footing 40. The concrete floor 60 has a hatch 59, which will be described later, and openings 60a and 60b formed therein.

Hatch 59 is a metal part that opens and closes openings 60a and 60b. The hatch 59 on the +X side is shown in the open state, and the hatch 59 on the -X side is shown in the closed state.

The opening 60a has an opening facing the positive electrode 6, and is an opening that allows access to the positive electrode 6, the first pipe member 56, and the second pipe member 57 through the opening in the deck 58.

Opening 60b has an opening provided opposite the negative electrode 7, and is an opening that allows access to the negative electrode 7 and second pipe member 57 through the opening in deck 58. Note that the number of openings 60a and 60b is not limited to two, and may be one, three, or more. The size and position of openings 60a and 60b can also be set as appropriate.

In this first embodiment, for example, a pipe may be provided to supply the electrolyte material to the mixture 4 via the opening 60a and the opening in the deck 58. In this case, it is preferable to supply the electrolyte material in the form of a solution, for example, by dissolving it in water.

Figure 7 shows the temporary scaffolding 61 and protective net 65 installed near the foundation structure 30.

Temporary scaffolding 61 is an external scaffolding such as, but not limited to, a bitty scaffolding.

The protective net 65 is provided on the +X side (outside) of the temporary scaffolding 61 and serves as a safety measure for nearby pedestrians to prevent tools and other objects from falling. The protective net 65 is attached to the components that make up the temporary scaffolding 61 via binding members (not shown). In this first embodiment, perovskite solar cells 70 are provided on the protective net 65.

Figure 8 is a schematic diagram showing a protective net 65 equipped with perovskite solar cells 70. As shown in Figure 8, the protective net 65 has perovskite solar cells 70 bonded in strips along the Y-axis direction to the surface of a mesh 76, which is the base material of the protective net 65. If perovskite solar cells 70 were bonded to the entire surface of the mesh 76, the breathability that is one of the protective net 65's functions would be lost. For this reason, in this first embodiment, the perovskite solar cells 70 are only partially bonded to the mesh 76. When the protective net 65 is installed on the temporary scaffolding 61, the perovskite solar cells 70 may be arranged along either the X-axis direction or the Z-axis direction.

The mesh 76 has multiple mesh openings and is made of a resin material (e.g., polyester) that is resistant to rain, heat, etc. To minimize the effects of wind, the mesh 76 preferably has a void ratio of 10% to 55%, in other words, a solidity ratio of 45% to 90%. Furthermore, to make it difficult for foreign objects to pass through, the mesh 76 can have a mesh spacing (grid spacing) of 0.5mm to 5mm, more preferably 1mm to 3mm. Note that tiny foreign objects that pass through a mesh spacing of 0.5mm or 1mm are essentially unavoidable.

In this first embodiment, the porosity of the mesh 76 may be set according to the area of the mesh 76 covered by the perovskite solar cells 70. For example, suppose the porosity of a conventional protective net without perovskite solar cells 70 is 20%. Here, if the perovskite solar cells 70 cover 50% of the area of the mesh 76, then the breathability of the entire protective net 65 can be ensured by using a mesh 76 with a porosity of 35% to 45%, preferably 40%.

The mesh 76 is also coated with a thermally conductive agent to conduct heat from the perovskite solar cell 70 to the mesh 76, forming a thermally conductive portion 77 (see Figure 9). Because the power generation efficiency of the perovskite solar cell 70 decreases when the temperature becomes too high, transferring the heat from the perovskite solar cell 70 to the mesh 76 prevents a decrease in the power generation efficiency of the perovskite solar cell 70. A thermally conductive agent such as silicone grease can be used.

Figure 9 is a cross-sectional view taken along the line A-A in Figure 8. Note that Figure 9 does not represent the actual dimensions, as it illustrates the structure of the perovskite solar cell 70 in an easily understandable manner. As shown in Figure 9, the perovskite solar cell 70 comprises a mesh 76, which is a base material, and a heat conductive portion 77, on which a first electrode 71 (positive electrode in this first embodiment), a hole transport layer 72, a perovskite layer 73, an electron transport layer 74, a second electrode 75 (negative electrode in this first embodiment), and a coating layer 78 are stacked in this order. It is preferable to provide a transparent protective layer on the surface of the second electrode 75, and it is preferable to treat this protective layer with water repellency and then form the coating layer 78.

If the proportion of the area of the perovskite solar cell 70 in the area of the mesh 76 increases, the amount of power generated by the perovskite solar cell 70 will increase, but the breathability of the mesh 76 will decrease, and there is a risk that the breathability required of the protective net 65 will no longer be met.

Therefore, in this first embodiment, the ratio of the area of the perovskite solar cells 70 to the area of the mesh 76 is set to 15% to 75%, preferably 25% to 65%, and more preferably 35% to 50%. The ratio of the area of the perovskite solar cells 70 to the area of the mesh 76 may be determined based on the power required for construction of the building protected by the protective net 65. Because the perovskite solar cells 70 generate electricity regardless of the position of the sun and even on cloudy days, they can be installed on all four sides of the building (east, west, south, and north). Furthermore, as the building becomes taller, the temporary scaffolding 61 also becomes taller, and the number of protective nets 65 used and the area of the protective nets 65 also increase. Therefore, a sufficient power generation area for the perovskite solar cells 70 can be secured in proportion to the size of the building.

Figure 10 is a block diagram of a control device 20 for controlling the charging and discharging of the capacitor 11 in this first embodiment. In this first embodiment, charging of the capacitor 11 is performed using the perovskite solar cell 70 described above, but this is not limited to this.

The control device 20 has a charging switch 12, a discharging switch 13, a communication unit 14, a memory 15, and a control unit 16.

The charging switch 12 is an on/off switch; when the switch is on, the perovskite solar cell 70 charges the capacitor 11; when the switch is off, the perovskite solar cell 70 does not charge the capacitor 11. Note that in this first embodiment, the charging switch 12 may be omitted, and the perovskite solar cell 70 may always charge the capacitor 11.

The discharge switch 13 is an on/off switch that discharges to a load when the switch is on and does not discharge to a load when the switch is off. Examples of loads include power supplies for lighting, surveillance cameras, and various sensors (such as motion sensors, sound level meters, and fire sensors). If the power supply is an AC power supply, it can be converted to AC power by an inverter.

The communication unit 14 is a wireless communication unit that accesses a wide area network such as the Internet. The communication unit 14 may also use wired communication. In this first embodiment, the communication unit 14 communicates with a remotely located host computer.

The communication unit 14 communicates, for example, the amount of charge and discharge on a daily basis to the host computer. As construction progresses from low-rise buildings to mid-rise and high-rise buildings, the number of protective nets 65 used and the area of the protective nets 65 increase, and the amount of power generated by the perovskite solar cells 70 increases. Accordingly, the amount of charge on the capacitors 11 increases, and the amount of discharge from the capacitors 11 also increases. This allows the host computer to obtain the amount of charge and discharge as construction progresses not just at one construction site, but at multiple construction sites.

Furthermore, by installing solar power generation equipment on the roof of a building or installing perovskite solar cells 70 in the windows of the building, electricity from sunlight can be charged into the capacitors 11 even after the building is completed. The communication unit 14 may be configured to communicate the daily charge and discharge amounts to the host computer even after completion. After completion, the electricity stored in the capacitors 11 can be used for various lighting purposes or as power in emergencies such as power outages. It goes without saying that perovskite solar cells installed in the windows of a building do not require the breathability required for the protective net 65.

Memory 15 is a non-volatile memory (e.g., flash memory) that stores a program for controlling the charging and discharging of capacitor 11. Memory 15 also stores, for example, the charge amount and discharge amount of capacitor 11 on a daily basis. Memory 15 may also store the charge amount and discharge amount on an hourly basis.

The control unit 16 is equipped with a CPU and controls the charging and discharging of the capacitor 11. In this first embodiment, the control unit 16 monitors the voltage of the capacitor 11, and if the voltage falls below a lower threshold, it turns off the discharge switch 13 to prevent discharging to the load. The control unit 16 may also control the charging switch 12 to turn off and prevent charging if the voltage rises above an upper threshold.

As described above, in this first embodiment, electricity generated from natural energy sources such as sunlight can be charged and used from the time of construction of a building until its completion, making it possible to realize construction work and buildings with low carbon dioxide emissions.

Second Embodiment
The second embodiment will be described below with reference to Fig. 11. The same components as those in the first embodiment are designated by the same reference numerals, and their description will be omitted or simplified. In the second embodiment, the earthen floor portion 46 is divided into two portions by a concrete partition block 63.

Figure 11 shows the arrangement of a separator 5, positive electrode 6, and negative electrode 7, which are part of the capacitor 11 configuration, on a strip foundation in the second embodiment. In this way, two capacitors 11 may be arranged in the divided earthen floor area 46. Furthermore, the number of divisions is not limited to two and can be set arbitrarily.

In this case, the capacitor 11 containing the mixture 4 may be unitized, and the unitized capacitor 11 may be placed in the earthen floor area 46. An example of a unitized capacitor is the capacitor 11 shown in Figure 3, which may have a lid member on the top surface. In this case, the lid member may have openings corresponding to the positions of the separator 5, positive electrode 6, and negative electrode 7, and may have opening/closing parts for opening and closing these openings.

The above-described embodiment is a preferred example of the present invention. However, it is not limited to this, and various modifications are possible within the scope of the gist of the present invention. For example, the unitized capacitor 11 may be installed under a concrete road. The concrete prevents it from being affected by rainwater, and since the concrete is removed during gas or sewer construction work, the capacitor 11 can be maintained and replaced, resulting in a safe and easy-to-use capacitor 11.

DESCRIPTION OF SYMBOLS 2: Soil 3: Copper plate 4: Mixture 5: Separator 6: Positive electrode 7: Negative electrode 11: Capacitor 12: Charging switch 13: Discharging switch 16: Control unit 20: Control device 30: Foundation structure 40: Strip footing 51: First holding unit 54: Resin material 45: Ground 46: Floor portion 60: Floor concrete

Claims (9)

The soil containing ions is mixed with an electrically conductive material containing carbon black, and an ionic solution is added to form a conductive portion.
The conductive part is provided with a positive electrode, a negative electrode, and a separator,
The internal resistance of the conductive portion is adjusted by adjusting the amount of carbon black added and the contact state between the soil and the carbon black by compacting the conductive portion;
A method for forming an electric double layer capacitor, comprising applying a voltage between the positive electrode and the negative electrode, thereby attracting anions to the positive electrode and cations to the negative electrode. The method for forming an electric double layer capacitor according to claim 1, wherein the applied voltage is set between 1 V and 3 V based on the amount of moisture in the conductive portion. the conductive portion, the positive electrode, the negative electrode, and the separator are provided in a container,
2. The method for forming an electric double layer capacitor according to claim 1, wherein the upper surface of the container is covered with a member. The method for forming an electric double layer capacitor according to claim 3, wherein the member covering the container has an opening corresponding to the position of the separator. The method for forming an electric double layer capacitor according to claim 3, wherein the member covering the container has an opening corresponding to the position of the positive electrode or the negative electrode. The method for forming an electric double layer capacitor according to claim 3, wherein the member covering the container has an opening for supplying an electrolyte material to the conductive portion. the conductive portion, the positive electrode, the negative electrode, and the separator are provided in a container,
2. The method for forming an electric double layer capacitor according to claim 1, wherein the positive electrode and the negative electrode are provided on the conductive portion away from the bottom of the container. The method for forming an electric double layer capacitor according to claim 1, wherein the electrically conductive material includes activated carbon. A method for forming an electric double layer capacitor according to any one of claims 1 to 8, wherein the soil contains sand.