JPH0660055U - Current collector for zinc-bromine battery - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide a current collecting electrode for a zinc-bromine battery which has improved flatness and which does not cause destruction of components due to excessive bolt tightening stress. [Structure] A carbon plastic electrode 15a is incorporated into a hole 17 formed in a sheet-like insulating frame member 16b, and the carbon plastic electrode 15a and the insulating frame member 16 are formed.
A conductor 19 having rigidity is arranged on the back side a of b,
The carbon plastic electrode 15a and the insulating frame member 16b
Provided is a current collecting electrode for a zinc-bromine battery in which and are welded to the liquid contact side b of the conductor 19. A large number of protrusions 20, 20 are formed in advance on the surface of the rigid conductor 19 on the liquid contact side b to enhance the welding strength.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a collecting electrode which is a constituent member of an electrolyte circulating type laminated secondary battery, particularly a zinc-bromine battery.

[0002]

[Prior art]

 Zinc-bromine batteries are secondary batteries that use bromine as the positive electrode active material and zinc as the negative electrode active material. For example, this battery is used at night when power demand is low to solve the imbalance between day and night. It is used to store electricity and discharge it in the daytime.

Bromine generated on the positive electrode side at the time of charging reacts with the bromine complexing agent added to the electrolytic solution to be returned as an oily precipitate to the storage tank, and at the time of discharging it is pumped into the unit cell. It is sent and returned. The components of the electrolytic solution are a ZnBr ₂ aqueous solution, a salt such as NH ₄ Cl for reducing the resistance, and Pb, Sn, and quaternary ammonium salts for preventing dendrite on the negative electrode zinc side and promoting uniform electrodeposition. , With a bromine complexing agent. A separator is inserted between the positive electrode and the negative electrode to prevent self-discharge due to the bromine generated in the positive electrode diffusing into the negative electrode and reacting with zinc.

This zinc-bromine battery mainly has a bipolar type electrode, a battery body in which a plurality of cells (cells) are electrically stacked in series, an electrolytic solution storage tank, and an electrolytic solution storage tank between them. It consists of a pump and a piping system that circulates the electrolyte.

FIG. 5 is an exploded perspective view showing an example of a battery main body that constitutes the zinc-bromine battery, in which an insulating frame 1b is arranged on the outer periphery of an electrode portion 1a of a bipolar plate-shaped intermediate electrode 1 having a rectangular flat plate shape. Similarly, in the separator plate 2 having a rectangular flat plate shape, the frame body 2 a is formed on the outer periphery of the separator 3. The separator plate 2 and, if necessary, the packing 4 and the spacer mesh 5 are stacked on the intermediate electrode 1 to form a single cell, and a plurality of the single cells are laminated to form a battery body.

A collector electrode 7 having a collector mesh 6, a pair of tightening end plates 8 and a stacking end plate 9 for pressing, which is located inside the collector electrodes 7, are provided at both ends of the stacked battery bodies. It is arranged. Then, a bolt (not shown) is passed between both the tightening end plates 8 and 8 to fasten the bolt to form a battery body integrally laminated and fixed.

In each unit cell of the battery main body configured as described above, the positive electrode manifold 10 formed at the upper and lower two corners of the frame 2 a of each intermediate electrode 1 and the separator plate 2, The electrolyte solution flows in and out from the negative electrode manifold 11 through the channels 12 and the microchannels 13 provided in the frame body 2a of the separator plate 2, respectively.

It has been confirmed that the zinc-bromine battery configured as described above has a battery efficiency of about 80% and a total energy efficiency of about 70% in a 50 KW class battery.

As shown in the exploded cross-sectional view of FIG. 6, the current collecting electrode 7 has a sheet-like insulating frame member 16a having a thickness of about 1 mm, and the hole 17 having the same thickness as the insulating frame member 16a has a frame shape. A plurality of hollowed out insulating frame members 16b are laminated on each other, and a carbon plastic electrode 15a having a thickness of about 1 mm, a current collecting mesh 6 made of brass and a carbon plastic electrode having a thickness of about 3 mm are stacked in the hole 17. 15b and 15b are sequentially assembled in a sandwich form, and are integrally manufactured using a die (not shown) based on heat press means under predetermined temperature and pressure conditions.

In addition, the terminal piece 6a for extracting electric power, which is led out from the current collecting mesh 6, is led out to the outside through the slit 14 formed in the carbon plastic electrode 15a and the insulating frame member 16a, It is connected to the collector bus bar.

[0011]

[Problems to be solved by the device]

 However, in the case of the current collecting electrode 7 used in such a conventional zinc-bromine battery, a difference in thermal contraction rate occurs due to a difference in material between the back side a and the liquid contact side b with respect to the electrolytic solution. This is unavoidable, and especially when the temperature drops, the flatness of the collector electrode may drop due to the difference in the heat shrinkage ratio.

When the flatness of the current collecting electrode is lowered, when a bolt is tightened by passing bolts between the tightening end plates 8 and 8 constituting the battery main body as described with reference to FIG. 5, liquid is collected from the interface of the current collecting electrode 7. Leakage is likely to occur, which causes a problem that the stored electric power is lost. If the tightening force of the bolt is increased in order to eliminate this liquid leakage, there is a problem in that the stress concentrating at the interface causes destruction of the component members.

The present invention has been made in view of the above points, and prevents the flatness from being deteriorated due to the difference in the heat shrinkage ratio, and prevents the component members from being broken by the stress due to excessive bolt tightening. The purpose of the present invention is to provide a collector electrode that does not occur.

[0014]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention forms a single cell by stacking a separator plate on a rectangular flat plate-shaped intermediate electrode, and stacks a plurality of the single cells to form a battery main body. A sheet of zinc-bromine battery current collecting electrodes, in which a pair of current collecting electrodes and a tightening end plate are arranged at both ends, and the two tightening end plates are bolted together to be integrally laminated and fixed. A carbon plastic electrode is installed in the hollowed-out hole of a rectangular insulating frame material, and a conductor having rigidity is arranged on the back side of the carbon plastic electrode and the insulating frame material. The present invention provides a current collecting electrode for a zinc-bromine battery, in which a material is welded to the liquid contact side of a conductor.

According to a second aspect of the invention, there is provided a current collecting electrode in which a large number of convex portions are formed on the liquid contact side surface of the rigid conductor.

[0016]

[Action]

 With such a collector electrode, the flatness of the collector electrode is extremely well maintained due to the rigidity of the conductor, so that the tightening force of the bolt between the tightening end plates that are the constituent members of the battery body is strong. It is possible to prevent the destruction of the constituent members due to the tightening stress and to prevent the liquid leakage from the interface of the current collecting electrode. Further, it becomes possible to replace the electric conductor with a current collecting mesh which is provided integrally with a conventional current collecting electrode.

Further, by forming a large number of protrusions on the liquid contact side surface of the conductor, the welding strength between the carbon plastic electrode and the insulating frame member and the conductor is maintained large.

[0018]

【Example】

 An embodiment of a current collecting electrode of a zinc-bromine battery according to the present invention will be described below in detail with reference to the drawings, in which the same reference numerals are given to the same components as the conventional components.

FIG. 1A is an exploded cross-sectional view for schematically explaining the structure of the current collecting electrode in this embodiment, in which 15a is a carbon plastic electrode and 16b is a sheet-like insulating frame material. Therefore, the carbon plastic electrode 15a is incorporated in the frame-shaped hollow portion 17 of the insulating frame member 16b.

On the other hand, 19 is a rigid conductor, and this conductor 19 is arranged on the back side a of the carbon plastic electrode 15a and the insulating frame member 16b. A large number of convex portions 20, 20 are formed on the surface of the conductor 19 on the liquid contact side b. The material of the conductor 19 is not particularly limited, and steel or special steel or other metal body can be used.

Then, as shown in FIG. 1B, the carbon plastic electrode 15a and the sheet-shaped insulating frame member 16b are welded to the surface of the conductor 19 on the liquid contact side b to form a main body. The collector electrode 7 according to the example is obtained.

According to the configuration of the current collecting electrode 7, since the flatness of the current collecting electrode itself is favorably maintained by the conductor 19 having rigidity, the tightening end plates 8 and 8 which are constituent members of the battery main body. (Refer to Fig. 5) It is not necessary to make the tightening force of the bolt between them particularly strong, and it is possible to prevent the structural members from being broken by the bolt and to prevent the liquid leakage from the interface of the collector electrode 7. To be Moreover, the presence of the conductor 19 eliminates the need for the current collecting mesh 6 (see FIG. 5) integrally provided with the conventional current collecting electrode. That is, in this embodiment, the conductor 19 can be replaced with the current collecting mesh 6.

Further, since a large number of protrusions 20 and 20 are formed on the surface of the conductor 19 on the liquid contact side b, the carbon plastic electrode 15a, the insulating frame member 16b and the conductor 19 are formed by the protrusions 20 and 20. The welding strength between them can be increased.

2 to 4 show a method of processing the manifold portion of the current collecting electrode 7 in the present embodiment. Since the electrolyte solution flows through the manifold portion, liquid tightness and insulation are high. Must be maintained at. Therefore, first, as shown in FIGS. 2A and 2B, from above the conductor 19 in which the hole portion 19a for the manifold is preliminarily opened, as shown in FIGS. A small-diameter hole portion 16c penetrating 16b is formed so that the central axis thereof coincides with that of the above-mentioned hole portion 19a.

Next, as shown in FIG. 4, a hole 8a for a manifold is preliminarily opened in the tightening end plate 8, and a manifold joint member 21 is fitted into this hole 8a. While the center axes of the holes 19a and 16c are aligned with the hold joint member 21, an O-ring 22 is interposed between the insulating frame member 16b and the manifold joint member 21 to connect the tightening end plate 8 and the collector electrode 7 to each other. Then, by tightening the tightening bolts 23 inserted between the pair of tightening end plates 8, the current collecting electrode 7 and the tightening end plates 8 are sealed in a liquid-tight manner. In addition, 25 of FIG. 4 has shown the laminated cell.

By such a method of processing the manifold portion, the liquid tightness and the insulating property with respect to the electrolytic solution are highly maintained.

[0027]

As described above in detail, according to the current collecting electrode of the zinc-bromine battery of the present invention, the carbon plastic electrode and the insulating frame material are welded to the liquid contact side of the rigid conductor. As a result, the flatness of the collector electrode can be maintained satisfactorily due to the rigidity of this conductor, and the liquid tightness can be improved without increasing the tightening force of the bolt between the tightening end plates. It is possible to improve battery performance and life.

In particular, it is possible to prevent the flatness of the current collecting electrode itself from being deteriorated due to the difference in heat shrinkage and to prevent the structural members from being broken by the stress caused by excessive bolt tightening. .

Further, by effectively utilizing the current collecting action of the above-mentioned electric conductor, it becomes possible to substitute this electric conductor for a current collecting mesh provided integrally with a conventional current collecting electrode.

Further, by forming a large number of protrusions on the liquid contact side surface of the conductor, the welding strength between the carbon plastic electrode and the insulating frame member and the conductor can be largely maintained, and the current collection can be performed. The reliability as an electrode can be improved.

[Brief description of drawings]

FIG. 1A is an exploded cross-sectional view for schematically explaining the structure of a current collecting electrode of the present invention. Figure 1 (B) is Figure 1 (A)
Sectional drawing which shows the state which assembled each member of FIG.

FIG. 2A is a partial plan view showing a main part of this embodiment. FIG. 2B is a cross-sectional view taken along the line AA of FIG.

FIG. 3A is a partial plan view showing a state in the middle of the process of this example. FIG. 3B is a cross-sectional view taken along the line BB of FIG.

FIG. 4 is a cross-sectional view of a main part showing an assembled state in the present embodiment.

FIG. 5 is an exploded perspective view of essential parts showing a battery body of a zinc bromine battery.

FIG. 6 is a cross-sectional view of an essential part showing the structure of a conventional collector electrode.

[Explanation of symbols]

 7 ... Current collecting electrode 8 ... Tightening end plate 15a ... Carbon plastic electrode 16b ... Insulating frame material 16b ... Insulating frame material 8a, 16c, 17 ... Hole portion 19 ... (Rigid) conductor 20 ... Convex portion 21 ... Manifold Joint member 22 ... O-ring 23 ... Tightening bolt

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Hosono 2-1-1-17 Osaki, Shinagawa-ku, Tokyo Stock Company Shameidensha

Claims (2)

[Scope of utility model registration request] 1. A rectangular flat plate-shaped intermediate electrode is laminated with a separator plate to form a single cell, and a plurality of the single cells are laminated to form a battery main body, and a pair of collectors are provided at both ends of the battery main body. In the current collecting electrode of the zinc-bromine battery, in which the electrode and the clamping end plate are arranged, and the clamping end plates are bolted together, the electrodes are laminated and fixed integrally. A carbon plastic electrode is incorporated in the removed hole, a conductor having rigidity is arranged on the back side of the carbon plastic electrode and the insulating frame member, and the carbon plastic electrode and the insulating frame member are wetted by the conductor. A current collecting electrode for a zinc-bromine battery, which is welded to the side surface. 2. The current collecting electrode for a zinc-bromine battery according to claim 1, wherein a large number of protrusions are formed on the surface of the rigid conductor which is in contact with liquid.