JP2519077B2 - Discontinuous circulation redox battery - Google Patents

Description

The present invention relates to a redox battery which is a storage battery.

(Prior Art) Electric power is easy to convert into various types of energy, easy to control, and there is no environmental pollution at the time of consumption, so the percentage of energy consumption is increasing every year. The peculiar point of power supply is that production and consumption are performed simultaneously. Within this constraint, it is a challenge of electric power technology to send high-quality electric power of a constant frequency and a constant voltage with high reliability while responding to fluctuations in power consumption. At present, it is difficult to change the output, but high-efficiency nuclear power generation and new thermal power generation are operated at the highest efficiency rating, while hydropower generation is suitable for generating power according to fluctuations in power consumption. It covers a large increase in power demand. For this reason, surplus electricity at night due to economically efficient nuclear power generation and advanced thermal power generation is stored by pumped storage power generation. However, as the location conditions for pumped storage power generation have become increasingly severe, storage methods using secondary batteries have been taken up.

In addition to conventional hydroelectric power generation, thermal power generation, and nuclear power generation, it is considered that the supply of electric power by solar power generation, wind power generation, etc. will increase in the future. However, in the case of solar power generation, wind power generation, etc., the amount of power generation depends on sunlight, wind, etc., so at least on the ground, it cannot be a sufficient power supply source alone, and some power storage equipment Only when combined with a stable power supply source.

Under the necessity of the secondary battery as described above, the lead storage battery has been widely used for solar power generation and the like, but as one of other influential secondary batteries, at least the positive electrode and the negative electrode are used. One structure is a structure in which an electrolytic solution containing an electrode active material is supplied and charging / discharging is performed by a reaction of the active material on an inactive electrode provided in advance, and the active material is a valence electrode. A redox battery, which is a substance that can be in a different number of oxidation states, is drawing attention.

Here, the outline of the principle of the redox battery is described in
This will be described with reference to FIG. 6 and FIG.

FIG. 5 shows a state during charging of the power storage system using the redox battery, and FIG. 6 shows a state during discharging.

In these figures, 1 is a power plant, 2 is substation equipment, 3
Is a load, 4 is an inverter, 5 is a redox battery, and tanks 6a, 6b, 7a and 7b, pumps 8 and 9 and a flow type electrolytic cell 10 are provided.
Consists of The flow-through type electrolytic cell 10 includes a positive electrode 11 and a negative electrode 12, and a diaphragm 13 that separates both electrodes, and a positive electrode solution 14 and a negative electrode solution 15 are contained in the left and right chambers partitioned by the diaphragm 13. The positive electrode liquid 14 is a hydrochloric acid solution containing Fe ions, and the negative electrode liquid 15
Shows an example of a hydrochloric acid solution containing Cr ions.

 Next, the operation will be described.

The electric power generated in the power plant 1 and transmitted to the substation equipment 2 is transformed into an appropriate voltage and supplied to the load 3. On the other hand, when it is nighttime and surplus power is generated, the AC / DC conversion is performed by the inverter 4, and the redox battery 5 is charged. In this case, as shown in FIG. 5, from tank 6b to 6a, tank 7a
From 7 to 7b, the positive and negative electrode liquids 14 and 15 are gradually fed by the pumps 8 and 9 to perform charging. When Fe ions are used for the positive electrode liquid 14 and Cr ions are used for the negative electrode liquid 15, the reaction that occurs in the flow-through type electrolytic cell 10 is the reaction on the charging side in the following formulas (1) to (3).

In this way, electric power is accumulated in the positive electrode liquid 14 and the negative electrode liquid 15.

On the other hand, when the supplied power is less than the demanded power, the reaction on the discharge side in the above equations (1) to (3) is performed, the orthogonal transformation is performed by the inverter 4, and the load 3 is passed through the substation equipment 2. Is powered.

(Problems to be Solved by the Invention) In the above-mentioned conventional redox battery, the charging / discharging voltage per cell is as small as about 1 V, so that an assembled battery in which single cells are stacked and electrically connected in series However, it is necessary to supply a uniform electrolytic solution to each single cell of this assembled battery at the same time. Therefore, it has a structure in which the liquid path to each cell from the common electrolytic solution supply liquid path and electrolytic solution return liquid path is branched, and through this common liquid path, from the high potential side cell to the low potential side cell. Is the leakage current in the liquid path, which is a loss of the redox battery as a current that does not contribute to charging and discharging. In particular, when the current value for charging or discharging the battery is small, the ratio of this fluid leakage current loss to the battery charge / discharge power becomes relatively large,
This is an obstacle to increasing the charge / discharge efficiency of the battery.

(Means for Solving Problems) The present invention relates to a redox battery having a structure of an assembled battery in which single cells are stacked among redox batteries, as a means for solving the problems of the conventional ones. And
At the position after branching to each cell of at least one of the electrolytic solution supply liquid path and the electrolytic solution return liquid path, made of an insulating material having a penetrating portion corresponding to the liquid path of each cell as a liquid path, or an insulating material. A covered rod-shaped valve is provided inside the assembled battery so as to pass through the entire assembled battery, and the rod-shaped valve is rotated or axially moved in synchronization with the operation and stop of the electrolyte supply pump. Provides a redox battery characterized in that the electrolyte solution passage of each cell is cut off and opened, and at least during the liquid feed stop time when the pump feeds liquid intermittently, By shutting off the liquid passage or narrowing the electrical liquid passage, it is intended to reduce the loss due to the liquid passage leakage current.

(Example) Hereinafter, an example when the present invention is applied will be described with reference to the drawings.

FIG. 1, FIG. 2 and FIG. 3 correspond to the liquid passage of each cell as a liquid passage at the branch portions of both the electrolytic solution supply side and the electrolytic solution return side to which the present invention is applied in the redox battery. It is sectional drawing which shows the structure at the time of providing the rod-shaped valve made from the insulating material which has a penetration part, or was coat | covered with the insulating material. FIG. 1 shows a state during pump operation, and FIGS. 2 and 3 show a state during pump stop. FIG. 4 is a sectional view showing the structure of a conventional redox battery to which the present invention is not applied. In each of FIG. 1, FIG. 2, FIG. 3 and FIG. 4, only the system of the positive electrode liquid is shown for the sake of convenience, but a similar system also exists for the negative electrode liquid. The present invention is applied to the side of the negative electrode liquid in the cases of FIGS. 2, 2 and 3.

In a state where the pump shown in FIG. 1 is in operation, a penetrating portion of a rod-shaped valve 26 (hereinafter, simply referred to as a rod-shaped valve 26) made of an insulating material or covered with an insulating material has a part of an electrolyte solution passage. Therefore, there is a liquid path leakage current between the cells through the common liquid paths 24 and 25. However, when the cathode fluid pump 17 is stopped at the time when the cathode fluid in each cell is sufficiently replaced, the state shown in FIG. 2 or 3 is obtained. Here, FIG. 2 shows a structure for shutting off the liquid passage by rotating the rod-shaped valve 26, and FIG. 3 shows a structure for shutting off the liquid passage by moving the rod-shaped valve 26 in the axial direction. The structure is shown. When the positive electrode liquid pump 17 shown in FIGS. 2 and 3 is stopped, the rod-shaped valve 26 electrically shuts off the liquid passage between the cells, so that the value of the liquid passage leakage current becomes extremely small. There is. On the other hand, when the present invention shown in FIG. 4 is not applied, liquid passage leakage current always flows through the common liquid passages 24 and 25 regardless of whether the positive electrode liquid pump 17 is operated or stopped.

As a result of charging and discharging both the redox battery having a structure to which the present invention is applied in FIGS. 1, 2 and 3 and the redox battery having a structure to which the present invention is not applied, shown in FIG. It was confirmed that the loss due to the leakage current in the liquid passage is smaller and the current efficiency, that is, the ratio of the discharged electricity quantity to the charged electricity quantity is higher when the method is applied.

In addition, in the present embodiment, the example in which the present invention is applied to both the electrolytic solution supply side and the electrolytic solution return side is shown, but the present invention can be applied to only one of them.

(Effects of the Invention) The present invention relates to a redox battery having a structure of an assembled battery in which single cells are stacked among redox batteries, and at least one of the electrolytic solution supply liquid path and the electrolytic solution return liquid path is connected to each cell. At the position after branching, a rod-shaped valve made of an insulating material having a penetrating portion for the liquid passage of each cell as a liquid passage, or a rod-shaped valve covered with an insulating material is provided in a shape to pass through the entire assembled battery. By rotating or moving in the axial direction, a redox battery characterized by having a structure for blocking and opening the electrolyte solution passage of each cell,
At least during the liquid feed stop time when the liquid is fed by the pump intermittently, the loss due to the liquid leak current can be reduced by cutting off the electric liquid passage or narrowing the electric liquid passage. There is an extremely great effect in practical use.

[Brief description of drawings]

FIG. 1, FIG. 2 and FIG. 3 correspond to the liquid passage of each cell as a liquid passage at the branch portions of both the electrolytic solution supply side and the electrolytic solution return side to which the present invention is applied in the redox battery. It is sectional drawing which shows the structure at the time of providing the rod-shaped valve which has a penetration part, respectively, FIG. 1 shows the state during pump operation | movement, and FIG. 2 and FIG. 3 shows the state during pump stop. Is. FIG. 4 is a sectional view showing the structure of a conventional redox battery to which the present invention is not applied. FIG. 5 and FIG. 6 are diagrams for explaining the charging and discharging states of the power storage system using the redox battery. 5 ... Redox battery, 6a, 6b, 16 ... Cathode liquid tank,
7a, 7b …… Anode liquid tank, 8, 9, 17 …… Pump, 10,
18 …… Flow type electrolyzer, 11, 19 …… Positive electrode, 12, 20 …… Negative electrode, 13, 21 …… Separator, 14, 22 …… Positive electrode solution, 15 …… Negative electrode solution, 23 …… Collection carbon plate , 24 …… common liquid path for electrolyte supply, 25
...... Electrolyte return common fluid path, 26 …… Bar valve.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yuichi Akai Yuichi Akai 11-1 Haneda Asahi-cho, Ota-ku, Tokyo Kazuhiro Itaya (56) References, Ebara Corporation Eisai Co., Ltd. References JP-A 61-269866 (JP, A) )

Claims (1)

(57) [Claims] 1. A redox battery having a structure of an assembled battery in which single cells are laminated, wherein at least one of an electrolytic solution supply liquid path and an electrolytic solution return liquid path is branched to each cell, and each of them is used as a liquid path. A rod-shaped valve made of an insulating material having a penetrating portion corresponding to the liquid passage of the cell or covered with an insulating material is provided inside the assembled battery so as to pass through the entire assembled battery, and the electrolyte supply pump is operated and stopped. A redox battery, characterized in that the rod-shaped valve is rotated or axially moved in synchronism with the above, thereby blocking and opening the electrolytic solution passage of each cell.