JP7569285B2 - Electricity storage units and structures - Google Patents

Description

The present invention relates to an electricity storage unit and an electricity storage structure that uses this electricity storage unit.

Demand for renewable energy is increasing with the aim of reducing greenhouse gas emissions. Renewable energy sources include, for example, solar power generation, wind power generation, hydroelectric power generation, geothermal power generation, and biomass power generation.
Electricity generated by renewable energy sources etc. can be stored in energy storage facilities to ensure a stable supply. To ensure a stable supply of electricity, energy storage facilities capable of storing the necessary amount of electricity are required, but building large-scale energy storage facilities requires a large amount of land.
Concrete is used in a variety of structures, including those with large areas and volumes. For this reason, the applicant came up with the idea of giving the concrete that constitutes the structure a storage function, thereby using the structure itself as a storage battery.
Here, Patent Document 1 discloses a battery that uses water in fresh concrete as an electrolyte. However, the invention described in Patent Document 1 relates to fresh concrete before hardening, and does not relate to a hardened body having a predetermined strength as a part of a structure.

JP 2007-263735 A

The objective of the present invention is to propose a power storage unit that enables the construction of a structure with power storage capabilities, and a power storage structure that uses this power storage unit.

In order to solve the above problems, the electric storage body of the present invention comprises a hardened body of a geopolymer composition and a pair of positive and negative electrodes implanted in the hardened body. The geopolymer composition contains an aqueous solution of an alkali silicate. The aqueous solution of an alkali silicate is, for example, an aqueous solution of potassium silicate, an aqueous solution of sodium silicate, or an aqueous solution of lithium silicate, and may contain two or more types of aqueous solutions of an alkali silicate, or may be water glass (a concentrated aqueous solution of an alkali silicate) whose main component is an alkali silicate.
The electricity storage structure of the present invention is constructed by connecting a plurality of the electricity storage units in series.
The geopolymer composition preferably contains an activated powder consisting of fly ash and blast furnace slag. The mass ratio of the content of the activated powder to the content of the alkali silicate aqueous solution is preferably 1:0.3 to 0.8. The mass ratio of the content of the fly ash to the content of the blast furnace slag is preferably 1:0.04 to 0.06.
This type of electricity storage unit is highly durable because it is mainly made of geopolymer materials. In addition, by adjusting the composition of each material, the strength required for the structure can be achieved. Therefore, electricity storage units can be used as building materials, and by connecting them together, a large-area electricity storage structure can be constructed.
Furthermore, if a recess is formed on the surface of the hardened body opposite the surface on which the electrode is implanted, into which another electrode to be connected to the electrode can be inserted, it will be possible to connect multiple storage batteries to construct a large-scale storage facility.

The electricity storage unit of the present invention and the electricity storage structure using this electricity storage unit make it possible to build a structure that ensures a large-area, large-volume electricity storage area.

1 is a diagram showing an example of an electricity storage structure according to an embodiment of the present invention; 1A is a perspective view of a power storage unit, FIG. 1B is a cross-sectional plan view, and FIG. 1C is a cross-sectional view. FIG. 4 is a front view showing an overview of the power storage area. 1 is a graph showing the discharge characteristics of a power storage unit.

In this embodiment, a case where a large-area and large-volume storage area 3 is secured by using a storage battery 2 in a structure constituting at least a part of a road structure (storage structure) 1 is exemplified. In this embodiment, a case where the power required for road ancillary equipment is supplied from the storage area 3 is described. FIG. 1 shows the road structure 1 of this embodiment. As shown in FIG. 1, a storage area 3 is secured inside the road structure 1. A power generation facility (solar panel) 4 is provided in the road structure 1, and the power generated by the power generation facility 4 is stored in the storage area 3. The power stored in the storage area 3 is supplied to, for example, lighting 11 and IoT sensors 12 provided on the road. The storage area 3 is configured by connecting (combining) multiple storage batteries 2, 2, .... FIG. 2 shows the storage battery 2.

The electric storage body 2 is mainly composed of a hardened body 5 of a geopolymer composition, and has a block shape as shown in FIG. 2(a). A pair of positive and negative electrodes 6, 6 are implanted in the hardened body 5. The electric storage body 2 of this embodiment is a rectangular parallelepiped, and a pair of electrodes 6, 6 are provided on each of two side surfaces that are continuous through a corner (ridge line). The tip of the electrode 6 protrudes from the hardened body 5, and the other part of the electrode 6 is embedded in the hardened body 5. In addition, as shown in FIGS. 2(b) and (c), a recess 7 is formed on the surface (opposite the surface on which the electrode 6 protrudes) facing the side surface on which the electrodes 6, 6 are implanted, among the six surfaces of the hardened body 5. The recess 7 can insert another electrode 6 (the electrode 6 of another electric storage body 2) connected to the electrode 6. The recess 7 of this embodiment is a slit-shaped groove according to the shape of the electrode 6. The other end of the electrode 6 embedded in the power storage unit 2 is exposed at the bottom of the recess 7 so as to be able to come into contact with the electrode 6 inserted into the recess 7 .
The geopolymer composition of this embodiment contains an active powder and an aqueous alkali silicate solution. The mass ratio of the content of the active powder to the content of the aqueous alkali silicate solution is 1:0.3 to 0.8.
The aqueous alkali silicate solution is, for example, an aqueous potassium silicate solution, an aqueous sodium silicate solution, or an aqueous lithium silicate solution. The aqueous alkali silicate solution may contain two or more types of aqueous alkali silicate solutions, or may be water glass containing an alkali silicate as the main component (a concentrated aqueous solution of an alkali silicate).
The activated powder is composed of fly ash and blast furnace slag, and the mass ratio of the fly ash content to the blast furnace slag content in the activated powder is 1:0.04 to 0.06.
As shown in FIG. 3, the electricity storage area 3 is formed by arranging electricity storage bodies 2 in a row in the front-rear and left-right directions.

According to the electric storage unit 2 of the present embodiment, since it is mainly made of a geopolymer material, it has high durability. Therefore, it is possible to maintain a maintenance-free state for a long period of time. In addition, it is not necessary to cover (package) the electric storage unit 2 with a protective material, and it is possible to use it outdoors.
In addition, by adjusting the composition of each material, the necessary strength as a structure is achieved. Therefore, the electricity storage units 2 can be used as building materials, and by connecting them together, it is possible to construct an electricity storage region 3 with a large area and volume that is not possible with ordinary electronic devices.

Next, the results of an experiment to confirm the performance of the electricity storage unit 2 of this embodiment will be described. In this experiment, the tendency of materials with different compositions to solidify when manufacturing the electricity storage unit 2 and the discharge characteristics when electricity is consumed were confirmed. Table 1 shows the compositions (mass ratios) of each sample (cases A to E). Table 2 also shows the compressive strength of cases A to E at an age of 28 days. Furthermore, Figure 4 shows the discharge characteristics of cases A to E.

As shown in Table 2, it was confirmed that Cases D and E exhibited greater compressive strength than Cases A and C. It was also confirmed that Case B exhibited early strength development.
4, in cases A, C, and E, the voltage did not drop suddenly when power was consumed, and was discharged smoothly over time, compared to cases B and D. Therefore, it was confirmed that cases A, C, and E have better charge storage capacity than cases B and D.
From the above results, cases A and C were excellent in electricity storage, but had low strength as a structure. Cases B and D exhibited high compressive strength, but had low electricity storage. On the other hand, it was confirmed that the blend of case E (where the mass ratio of the fly ash content to the blast furnace slag content was in the range of 1:0.04 to 0.06) was superior in electricity storage and strength development compared to the other blends.

Although an embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and each of the above-described components can be appropriately modified without departing from the spirit of the present invention.
In this embodiment, the hardened body 5 is formed using only the geopolymer composition, but the hardened body 5 may also be formed by kneading the geopolymer composition with fine aggregate, coarse aggregate, synthetic resin fibers, foam beads, etc.
In the above embodiment, the electrodes 6 protrude from the power storage units 2 in two directions, and the power storage units 2 are connected vertically and horizontally. However, the electrodes 6 protrude from the power storage units 2 in only one direction. In this case, the power storage units 2 are connected in one direction. Note that the power storage region 3 does not necessarily need to be formed by connecting a plurality of power storage units 2, and may be formed by connecting a single power storage unit 2.
It may be composed of only
In the above embodiment, the hardened body 5 is block-shaped (rectangular), but the shape of the hardened body 5 is not limited to this and may be, for example, cylindrical, or may be determined as appropriate depending on the shape of the energy storage structure to be used.
In the above embodiment, the end faces of the electrodes 6 are butted against each other within the recess 7 , but the ends of the electrodes 6 may overlap each other within the recess 7 to be in surface contact with each other.
In the above embodiment, one pair of positive and negative electrodes 6, 6 is provided on each surface, but two or more pairs of electrodes 6, 6 may be provided on one surface.
The electrode 6 may be processed to increase the contact area with the geopolymer composition. For example, the electrode 6 may be processed by forming projections and recesses on the surface or by drilling a plurality of holes.

1 Road structures (electricity storage structures)
2 Electricity storage body 3 Electricity storage area 4 Power generation equipment 5 Hardened body 6 Electrode 7 Recess

Claims (6)

A storage battery comprising a hardened body of a geopolymer composition and a pair of positive and negative electrodes implanted in the hardened body,
The geopolymer composition is characterized in that it contains an aqueous alkali silicate solution. The storage battery according to claim 1, characterized in that the geopolymer composition contains an activated powder made of fly ash and blast furnace slag. The electricity storage unit according to claim 2, characterized in that the mass ratio of the content of the active powder to the content of the alkali silicate aqueous solution is 1:0.3 to 0.8. The electric storage unit according to claim 2 or 3, characterized in that the mass ratio of the fly ash content to the blast furnace slag content is 1:0.04 to 0.06. The electric storage unit according to any one of claims 1 to 4, characterized in that a recess is formed on the surface of the hardened body opposite the surface on which the electrode is implanted, into which another electrode to be connected to the electrode can be inserted. An electricity storage structure comprising a plurality of electricity storage units according to any one of claims 1 to 5 arranged in series.

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