JPH08171892A - Zinc-bromine battery separator and its manufacture - Google Patents

Abstract

PURPOSE: To provide a zinc-bromine battery separator and its manufacture by which battery efficiency can be heightened by heightening the accuracy of the hole diameter control of the separator, and shortening a hole process. CONSTITUTION: An anodic oxide coating formed by anodizing aluminum is used as a zinc-bromine battery separator. Oxalic acid, sulfuric acid, or liquid formed by adding sulfosalicylic acid to the sulfuric acid is used as electrolyte in a reaction vessel 15, and an aluminum plate 17 of 0.3mm or less in thickness is soaked in a positive electrode side and a lead electrode is soaked opposite thereto in a negative electrode side. Anodizing is conducted as maintaining the temperature of the electrolyte, a power source voltage, and an electric current density at adequate values so as to form the anodic oxide coating 20 on the surface of the aluminum plate 17 to obtain the zinc-bromine battery separator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a separator which is a constituent member of an electrolytic solution circulation type laminated secondary battery, particularly a zinc-bromine battery, and a method for producing the separator.

[0002]

2. Description of the Related Art A zinc-bromine battery is a secondary battery that uses bromine as a positive electrode active material and zinc as a negative electrode active material.
It is used to store electricity at night when electricity demand is low and to release 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 form an oil-like precipitate which is returned to the storage tank, and at the time of discharging it is pumped into the unit cell. It is sent and returned. The component of the electrolytic solution is ZnBr ₂
An aqueous solution, a salt such as NH ₄ Cl for reducing resistance, Pb, Sn, quaternary ammonium salts for preventing dendrite on the negative electrode zinc side and promoting uniform electrodeposition, and a bromine complexing agent is there. A separator is inserted between the positive electrode and the negative electrode to prevent self-discharge caused by the bromine generated in the positive electrode diffusing into the negative electrode and reacting with zinc.

The chemical reaction of this zinc-bromine battery is

[0005]

[Chemical Formula 1] During charging: Positive electrode: 2Br ⁻ → Br ₂ + 2e ⁻ , Negative electrode: Zn ⁺⁺ + 2e ⁻ → Zn During discharging: Positive electrode: 2Br ⁻ ← Br ₂ + 2e ⁻ , Negative electrode: Zn ⁺⁺ + 2e ⁻ ← Zn It is represented by.

In this zinc-bromine battery, the electrodes are mainly of a bipolar type, a battery main body in which a plurality of single cells (single cells) are electrically stacked in series, an electrolytic solution storage tank, and an electrolytic solution interposed therebetween. It is composed of a pump and a piping system for circulating the liquid.

The operating principle of the zinc-bromine battery will be described based on the schematic diagram of FIG. Reference numeral 1 in the figure is a positive electrode side storage tank in which a positive electrode electrolyte solution 2 and a bromine complex compound 3 are stored. Reference numeral 4 denotes a negative electrode side storage tank, in which the negative electrode electrolyte solution 5 is stored. Then, the positive electrode electrolyte solution 2 is driven by the positive electrode side pump 6 so that the four-way valve 7
Through the positive electrode manifold 8 of the battery main body through the positive electrode chamber 8 and flow back to the positive electrode side storage tank 1 while the negative electrode electrolytic solution 5 is driven by the negative electrode side pump 9 From the negative electrode manifold 10 of the main body to the separator 1
It circulates in the negative electrode chamber separated by 1 and is returned to the negative electrode side storage tank 4. Reference numeral 12 is an intermediate electrode, and 13 is a collector electrode.

As the electrode material of the collector electrode 13, a carbon plastic electrode material is used which is formed by melting and mixing carbon black and graphite for imparting conductivity with polyethylene as a binder at an appropriate ratio and then forming a sheet. The positive electrode is laminated with a sheet made of carbon cloth or carbon fiber with a resin binder in order to reduce the reaction overvoltage of bromine.

The separator 11 is usually a relatively hard polyethylene resin made of silica and dioctyl phthalate (D).
A microporous film obtained by extrusion molding means after melt-mixing OP), extracting DOP with a solvent to make it porous, is used. The average pore size of this microporous membrane is about 0.1 μm.
It is about (1000Å).

In the above zinc-bromine battery, bromine generated on the positive electrode side during charging reacts with a bromine complexing agent (quaternary ammonium salt) contained in the electrolytic solution to form an oily bromine complex at the bottom of the positive electrode side tank. The bromine stored in the solution is converted into Br ₃ ⁻ ions and dissolved in the electrolytic solution, and zinc is electrodeposited on the carbon plastic electrode.

The zinc-bromine battery thus constructed is
It has been confirmed that the battery efficiency of a 50 KW class battery is about 80% and the total energy efficiency is about 70%.

[0012]

The efficiency of such a zinc-bromine battery for electric power storage is required to improve the overall efficiency including the inverter efficiency, but one of the factors that hinders the efficiency is the separator. There is a problem of pore size control. As described above, the separator is a porous film and contains Zn ⁺⁺ ions and B
It is necessary that the bromine and the bromine complex compound do not permeate even though the r ⁻ ion permeates. In particular, if the pore size is too large, a large amount of bromine molecules (Br ₂ ) or bromine complex compound (QBr ₃ ) will also penetrate, and the efficiency of the battery will decrease.

However, the pore size of the separator often changes depending on the molding conditions, and it is difficult to control the fine pore size by the method of extrusion molding after melt-mixing silica with DOP in a usual polyethylene resin, and it is difficult to control the pore size at a constant level. The problem that the shape of the hole penetrating linearly cannot be obtained remains, and it is difficult to obtain the separator having good selective permeability as described above.

Usually, the average pore diameter of the separator made of polyethylene resin is 0.1 μm (1000 Å), but it is estimated that about 200 to 500 Å is actually suitable. Further, since the holes penetrate between the front and back surfaces of the separator plate in a complicated path so as to sew between voids, the actual stroke of the holes is usually considerably longer than the plate thickness. Furthermore, since the thickness of the separator plate is about 1 mm, the swelling of the electrolytic solution in the battery tends to occur.

The present invention has been made in view of the above points, and improves the accuracy of the hole diameter control of the separator, and shortens the actual process by forming the holes in a straight line to improve the battery efficiency. It is an object of the present invention to provide a zinc-bromine battery separator and a method for producing the same.

[0016]

In order to achieve the above object, the present invention forms a single cell by stacking a separator on an intermediate electrode to form a single cell, and constructs a battery main body by laminating a plurality of the single cells. A pair of zinc electrodes, in which a pair of current collecting electrodes and a tightening end plate are arranged at both ends of the battery body so as to be integrally laminated and fixed.
In the bromine battery, an alumite film formed by anodizing aluminum is used as the separator.

As a second aspect, oxalic acid having a concentration of 3 to 4% is put into the reaction tank as an electrolytic solution, and the plate thickness is 0.3 m on the anode side.
Immerse an aluminum plate of m or less and a lead electrode facing the cathode so that the positive side of the power source is connected to aluminum and the negative side of the power source is connected to the lead electrode. Provided is a method for producing a zinc-bromine battery separator in which an anodizing film is formed on the surface of an aluminum plate by performing anodization while maintaining the current density at an appropriate value.

According to the third aspect, the alumite coating formed on the aluminum plate is separated from immediately above the barrier layer by the reverse electropeeling method to obtain a porous alumite coating having hexagonal cells penetrating a large number of pores. This anodized film is exposed to air at a temperature of 850 ° C or higher, preferably about 9 ° C.
A method of heat treatment at 00 ° C. for 1 hour is provided.

Further, a fourth aspect provides a method using sulfuric acid containing aluminum sulfate as an electrolytic solution, and a fifth aspect provides a method using a solution obtained by adding sulfosalicylic acid to sulfuric acid as the electrolytic solution.

According to a sixth aspect of the present invention, a mask having a large number of round holes opened is fixed to a surface of an aluminum plate to be anodized, and the aluminum is not covered with the mask by anodizing in an electrolytic solution. An alumite coating is formed on the surface of the plate, and an alumite coating is formed on the entire surface of the aluminum plate in the opposite direction to the surface on which the alumite coating is formed.The alumite coating is connected to the alumite coating and covered with a mask. The unreacted aluminum plate remaining in the exposed part was dissolved and removed with an acid, two flat plates were connected back to back using two of the obtained members, and electrode plates were fixed on both surfaces to obtain zinc. -Providing a method for manufacturing a separator for a bromine battery.

[0021]

According to such a separator, a porous alumite film is formed by anodizing an aluminum plate, which is separated from the aluminum plate side immediately above the barrier layer by a reverse electrolysis method or the like to reduce the plate thickness. A porous alumite coating having a large number of pores uniformly dispersed in the direction is obtained. Since the pore size is determined by the voltage applied to the film during the anodization, the pore size can be easily controlled.

The anodized film as anodized is Al ₂ O ₃ in an amorphous state, and it is transformed into a crystal structure of δ-Al ₂ O ₃ by heating after anodization and is transformed into a strongly acidic electrolytic solution. Corrosion resistance is greatly improved.

In this alumite coating, the pores penetrate linearly in the plate thickness direction, and the stroke of the holes is considerably shorter than the ordinary porous polyethylene film even with the same plate thickness. Moreover, the thickness of the alumite coating can be significantly reduced.

Further, by using the method according to claim 6, the separator itself can be made compact and a membrane having good selective permeability can be obtained, which is easier to manufacture than the conventional kneading operation of polyethylene resin. A zinc-bromine battery separator can be obtained.

[0025]

EXAMPLES Various specific examples of the zinc-bromine battery separator and the method for producing the same according to the present invention will be described below. The feature of this embodiment is that an alumite film formed by anodizing aluminum is used as a separator having selective permeability.

FIG. 2 shows an example of an anodizing apparatus for aluminum adopted in the first embodiment of the present invention. As shown in the figure, oxalic acid 16 is put into a reaction tank 15 as an electrolytic solution, and an aluminum plate 17 is placed on the anode side. , The lead electrode 18 is dipped facing the cathode side, the positive side of the power source 19 is connected to the aluminum plate 17, and the negative side of the power source 19 is connected to the lead electrode 18, and the reaction is performed while maintaining an appropriate temperature and voltage. By carrying out the above, an anodized film on the surface of the aluminum plate 17,
That is, the alumite coating 20 is formed.

In this embodiment, as the film forming conditions for the porous alumite film 20 by the oxalic acid method, the aluminum plate 17 has a chemical composition of Al 99.99% or more and a plate thickness of 0.3.
mm or less, the concentration of oxalic acid 16 is 3 to 4%, the temperature of the electrolytic solution is 20 ° C to 30 ° C, and the voltage of the power source 19 is 25V (DC).
Or 80V (AC), current density 100 (A / m ² , D
C) or 50 (A / m ² , AC).

The alumite film 20 obtained was transparent at a DC voltage, but exhibited a pale yellow to brown color at an AC voltage.

FIG. 1 shows the obtained porous alumite coating 2
It is a schematic diagram showing the structure of 0, by separating the alumite film 20 formed on the aluminum plate 17 from the aluminum plate 17 side by the dotted line portion 22 immediately above the barrier layer 21 by the reverse electrolysis peeling method, thereby forming the upper and lower pores. The thickness t having the hexagonal cell 24 through which 23 and 23 penetrate is 80 μm (maximum 400
μm), and a porous alumite film having a pore diameter of 40 nm (400 Å) was obtained. This alumite film 20 is 90
It heat-processed at 0 degreeC for 1 hour.

Therefore, in the first embodiment, it is possible to grow the porous alumite film 20 to a maximum thickness of 400 μm by anodizing the aluminum plate 17 by the oxalic acid method. By separating from the aluminum plate 17 side directly above the barrier layer 21 by a method or the like, a porous alumite coating 20 having a large number of pores 23, 23 penetrating in the plate thickness direction is obtained.

The size of the hexagonal cells 24 and the sizes of the pores 23, 23 are determined by the voltage applied to the film during the anodizing treatment. When the voltage is V, the size diameter D _C (2R) of the hexagonal cell 24 is D _C = 23 × V (Å), and the size diameter D _P (2r) of the pores 23 and 23 is D _P =
It is D _C / 3 (Å).

The alumite film 20 obtained in this example was immersed in an electrolyte solution for a strongly acidic battery having a pH of 1, and the original shape was retained without being dissolved even after 1500 hours (about 2 months) had elapsed.

FIGS. 3 (A) and 3 (B) are spectra showing the analysis results by X-ray diffraction of the alumite coating 20 obtained in this Example. B)
Is heat treated at 900 ° C. for 1 hour in the atmosphere.
From FIG. 3, it was found that the anodized aluminum film 20 as it was anodized was amorphous Al ₂ O ₃ and was transformed into a crystal structure of δ-Al ₂ O ₃ by heating after the anodization.

FIG. 4 is a spectrum showing the result of thermogravimetric measurement (TG) of the alumite coating 20. From the same figure, it is recognized that the weight gradually decreases due to the release of the water adsorbed on the coating surface as the temperature rises, and it is 850 ° C. In the vicinity, a significant weight reduction was recognized, which is considered to correspond to the transformation from the amorphous state to the δ-Al ₂ O ₃ crystal. This is the decomposition and release of water of crystallization from hydrates and the OH from Al (OH) ₃ which is contained in trace amounts.
It is believed that this is due to the decomposition and release of the group.

That is, by adsorbing water, Al _{2 in} an amorphous state containing a part of crystal water or Al (OH) ₃
Anodized aluminum film 20 made of O ₃ is transformed into the [delta]-Al ₂ O ₃ crystal by a high-temperature heat treatment at 900 ° C., it was found that also greatly improved corrosion resistance in a strongly acidic electrolyte.

Compared with the average pore size of the present porous polyethylene membrane separator of 0.1 μm (1000 Å), the alumite coating by the oxalic acid method has a pore size of about 200 Å to 500 Å depending on the applied voltage. It is possible to control, and it becomes easy to control the pore size. The obtained pore size is also small, and the pores are uniformly dispersed.

Further, since the pores of the alumite coating formed by the oxalic acid method penetrate linearly in the plate thickness direction, the current porous polyethylene membrane, that is, a large number of voids are sewn together in a complicated route to form a fine line. The stroke of the hole is considerably shorter than that of the film through which the hole penetrates even if the plate thickness is the same.

Further, the oxalic acid alumite coating can make the plate thickness much thinner than the porous polyethylene coating.
The thickness of the polyethylene film at present is about 1 mm, whereas the thickness of the oxalic acid alumite film of this embodiment is about 30-40.
Any film can be formed within the range of 0 μm.

The alumite film formed according to the first embodiment easily adsorbs water, and water of crystallization or Al (OH) ₃
Al ₂ O ₃ in an amorphous state containing a part of it dissolves in a strongly acidic electrolyte in a short time of a few days, but 850
High-temperature heat treatment at a temperature of not less than 0 ° C., preferably 900 ° C. for 1 hour transforms into a δ-Al ₂ O ₃ crystal, and the corrosion resistance can be greatly improved. However, it is difficult to increase the area with a single alumite coating, and the limit is usually about 5 × 5 cm.

Next, a second embodiment of the present invention will be described. The second embodiment is characterized in that sulfuric acid is used instead of oxalic acid as the electrolytic solution used when forming the alumite film in the first embodiment. The aluminum anodizing apparatus shown in FIG. 2 is the same except that the oxalic acid 16 was changed to sulfuric acid. This sulfuric acid contains a predetermined amount of aluminum sulfate.

As a film forming condition for the porous alumite film 20 by the sulfuric acid method, the chemical composition of the aluminum plate 17 is Al 99.99% or more and the plate thickness is 0.3 mm or less,
The concentration of sulfuric acid as the electrolyte is 5 to 25%, aluminum sulfate is 1 to 50 (kg / m ³ ), and the temperature of the electrolyte is 15 ° C.
-25 degreeC, the power supply voltage was 15-20V (DC), and the current density was 80-300 (A / m < ² >). The alumite film 20 obtained by this sulfuric acid method was colorless and transparent.

The structure of the porous alumite coating 20 obtained in the second embodiment is the same as that shown in FIG. 1, and the aluminum plate 17 is formed at the dotted line portion 22 immediately above the barrier layer 21 by the reverse electropeeling method.
By separating from the side, the thickness t having the hexagonal cells 24 through which the pores 23, 23 penetrate vertically is 30 μm to 300 μm.
A porous alumite film having a diameter of 100 μm and a pore size of 100 Å to 250 Å was obtained. This alumite coating 20 was heat-treated in the atmosphere at 900 ° C. for 1 hour.

The size of the hexagonal cells 24 and the sizes of the pores 23, 23 are determined by the voltage applied to the film during the anodizing process, as in the case of Example 1 described above. The original shape was retained without being dissolved even after 1500 hours (about 2 months) after being immersed in the electrolytic solution for a strongly acidic battery.

Looking at the analysis result of the alumite coating 20 obtained in the second embodiment by X-ray diffraction, the alumite coating 20 as anodized is in the amorphous state A.
It was 1 ₂ O ₃ and was found to be transformed into the crystal structure of δ-Al ₂ O ₃ by performing a heat treatment after the anodizing treatment. Further, according to the spectrum showing the result of thermogravimetric measurement (TG), the weight gradually decreased due to the release of the moisture adsorbed on the coating surface with the temperature rise, and the amorphous state was changed from δ-Al ₂ O ₃ to about 890 ° C. A significant weight loss, which is considered to correspond to the transformation into crystals, was observed.

Next, a third embodiment of the present invention will be described. The third embodiment is characterized in that the cal-color method is used when forming the alumite film. In this Calcar method, a solution obtained by adding sulfosalicylic acid 100 (kg / m ³ ) to sulfuric acid 50 (kg / m ³ ) is used as an electrolytic solution.
The temperature of the electrolytic solution is 22 ° C to 25 ° C, and the power supply voltage is 25 to 70.
V (DC), current density is 200 to 3200 (A / m ² )
And The alumite coating 20 obtained by the Kull color method exhibited bronze to black.

The aluminum anodic oxidation apparatus shown in FIG. 2 is the same except for the electrolytic solution.
As a film forming condition of the porous alumite coating film 20 by this Kalcolor method, the chemical composition of the aluminum plate 17 was Al 99.99% or more and the plate thickness was 0.3 mm or less.

The structure of the obtained porous alumite coating 20 is the same as that shown in FIG.
A porous alumite coating having a hexagonal cell 24 having pores 23, 23 penetrating vertically and having a thickness t of 30 μm to 400 μm and a pore diameter of 200 Å to 600 Å by separating from the aluminum plate 17 side by a dotted line portion 22 immediately above 1. Got This alumite coating 20 was heat-treated in the atmosphere at 900 ° C. for 1 hour.

The size of the hexagonal cells 24 and the sizes of the pores 23, 23 are determined by the voltage applied to the film during the anodizing process, as in the case of Example 1 described above. The original shape was retained without being dissolved even after 1500 hours (about 2 months) after being immersed in the electrolytic solution for a strongly acidic battery.

Looking at the analysis result of the alumite coating 20 obtained in the third embodiment by X-ray diffraction, the alumite coating 20 as it was anodized was A in an amorphous state.
It was 1 ₂ O ₃ and was found to be transformed into the crystal structure of δ-Al ₂ O ₃ by performing a heat treatment after the anodizing treatment. Further, according to the spectrum showing the result of thermogravimetry (TG), the weight gradually decreased due to the release of the water adsorbed on the coating surface with the temperature rise, and the amorphous state was changed from δ-Al ₂ O ₃ to about 860 ° C. A significant weight loss, which is considered to correspond to the transformation into crystals, was observed.

FIG. 5 shows a fifth embodiment of the present invention,
This example is the alumite coating 2 described in the above examples.
The specific example which manufactured the separator 11 for zinc-bromine batteries using the formation method of 0 is shown.

Explaining in the order of steps, the aluminum plate 17 having a thickness of 0.8 mm is first shown in FIG.
A mask 25 having a large number of round holes opened is fixed to the surface to be anodized, and the surface to which the mask 25 is fixed is set as the inside at the bottom of the reaction tank 15 as an anode. In addition, the lead electrode 18 is arranged to face the cathode side, the positive side of the power source 19 is connected to the aluminum 17, and the negative side of the power source 19 is connected to the lead electrode 18. Then, when the anodic oxidation reaction is performed while maintaining the temperature, voltage and current density disclosed in the first embodiment, the alumite coatings 20, 20 are formed on the surface portion of the aluminum plate 17 not covered by the mask 25. .
The thickness of the alumite coatings 20, 20 is 0.4 mm.
And

Next, as shown in FIG. 7B, the aluminum plate 17 is turned upside down to form the alumite coating 20.
The alumite coating 20a is formed on the entire surface from the opposite direction to the surface on which the is formed by the same operation. The thickness of the alumite coating 20a is 0.4 mm as described above.

By this step, the alumite film 20 and the alumite film 20a are connected from above and below, and the mask 25
Unreacted aluminum islands 17a, 1
Since 7a remains, the whole unreacted aluminum plate 17 is dissolved and removed by immersing the whole in a container 28 filled with hydrochloric acid 27 as shown in FIG. Reference numeral 26 is a portion where aluminum is removed, and the portion mainly composed of the alumite coatings 20 and 20a remains in the hydrochloric acid 27 without being dissolved. After this, the barrier layer is removed by immersing in a sodium hydroxide solution.

FIGS. 5D and 5E show the structure of the separator 11 formed of the obtained alumite coating, and the alumite coatings 20 and 2 obtained as described above are shown.
Two members composed of 0a are used, the flat surfaces of both members are connected back to back, and the electrode plates 29, 29 are fixed to both left and right sides to complete the process. At this time, the hole 30 serves as a flow path for the electrolytic solution.

According to the fifth embodiment, the separator 11
(EN) A zinc-bromine battery separator that is compact in itself and that can obtain a membrane having good selective permeability, and that the process itself is simplified compared to conventional kneading work of polyethylene resin and that is easy to manufacture. You can

[0056]

As described in detail above, according to the zinc-bromine battery separator of the present invention, a separator made of a porous alumite film obtained by anodizing an aluminum plate is used. As a result, the size of the pores is determined by the voltage applied to the film during anodic oxidation, making it easier to control the pore size and finer separators that have been one of the factors that have hindered battery efficiency. The accuracy of the hole diameter control is improved, a hole shape that penetrates straightly with a constant hole diameter is obtained, and a separator having good selective permeability and enhancing battery efficiency can be obtained.

Since the above-mentioned pores are uniformly dispersed in the plate thickness direction and penetrate straightly, the stroke of the hole becomes considerably shorter than the ordinary porous polyethylene membrane even with the same plate thickness. In addition, the thickness of the alumite coating can be significantly reduced.

Further, by using the method according to claim 6, a separator for a zinc-bromine battery can be obtained in which the separator itself is made compact and the production thereof is easy as compared with the conventional kneading operation of a polyethylene resin. .

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the structure of a porous alumite coating obtained in this example.

FIG. 2 is a schematic cross-sectional view showing an example of an aluminum anodic oxidation apparatus adopted in this example.

FIG. 3 is a spectrum showing the analysis result by X-ray diffraction of the alumite film obtained in this example.

FIG. 4 is a spectrum showing the result of thermogravimetric measurement (TG) of the alumite film obtained in this example.

FIG. 5 is a schematic view showing a specific example in which a zinc-bromine battery separator is manufactured by using the method for forming an alumite film according to this example.

FIG. 6 is a schematic diagram illustrating the operating principle of a zinc-bromine battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Positive electrode side storage tank 2 ... Positive electrode electrolytic solution 3 ... Bromine complex compound 4 ... Negative electrode side storage tank 5 ... Negative electrode electrolytic solution 6 ... Positive electrode side pump 7 ... Four-way valve 8 ... Positive electrode manifold 9 ... Negative electrode manifold 11 ... Separator 12 ... Intermediate Electrode 13 ... Current collecting electrode 15 ... Reaction tank 16 ... Oxalic acid 17 ... Aluminum plate 18 ... Lead electrode 19 ... Power source 20 ... Alumite film 21 ... Barrier layer 23 ... Pore 24 ... Hexagonal cell 25 ... Mask 29 ... Electrode plate

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location C25D 11/10 11/18 313 H01M 2/18 R 12/08 C (72) Inventor Shinichi Fujie Tokyo 2-1-1-17 Osaki, Shinagawa-ku, Tokyo Stock Company Meidensha

Claims (6)

[Claims] 1. A single cell is formed by stacking a separator on an intermediate electrode, and a plurality of the single cells are laminated to form a battery main body, and a pair of current collecting electrodes and a tightening end are provided at both ends of the battery main body. In a zinc-bromine battery in which plates are arranged and integrally laminated and fixed, a zinc-bromine battery characterized by using an alumite coating formed by anodizing aluminum as the separator Separator. 2. The concentration of the electrolytic solution in the reaction tank is 3 to 4%.
Oxalic acid, and immerse an aluminum plate with a thickness of 0.3 mm or less on the anode side and a lead electrode facing the cathode side, so that the positive side of the power source is connected to aluminum and the negative side of the power source is lead. Connected to the electrode, the temperature of the electrolyte is 20 ℃ ~ 30 ℃, the power supply voltage is 25V (DC) or 8
Zinc characterized by forming an alumite film on the surface of an aluminum plate by anodizing at 0 V (AC) and a current density of 100 (A / m ² , DC) or 50 (A / m ² , AC). Method for manufacturing bromine battery separator. 3. A porous alumite coating having hexagonal cells with a large number of pores penetrating is obtained by separating the alumite coating formed on the aluminum plate from immediately above the barrier layer by a reverse electrolysis method. The method for producing a zinc-bromine battery separator according to claim 2, wherein the alumite coating is heat-treated in the air at 850 ° C or higher for about 1 hour. 4. A sulfuric acid containing aluminum sulfate is used as an electrolytic solution, and the concentration of this sulfuric acid is 5 to 25.
%, Aluminum sulfate 1 to 50 (kg / m ³ ), temperature 15 to 25 ° C., power supply voltage 15 to 20 V (DC),
A method for producing a zinc-bromine battery separator, characterized in that anodizing is performed at a current density of 80 to 300 (A / m ² ) to form an alumite coating on the surface of an aluminum plate. 5. A solution obtained by adding sulfosalicylic acid to sulfuric acid is used as the electrolytic solution, and the temperature of the electrolytic solution is 22 ° C. to 2 ° C.
5 ℃, power supply voltage 25 ~ 70V (DC), current density 2
A method for producing a separator for a zinc-bromine battery, characterized in that anodizing is performed as 00 to 3200 (A / m ² ) to form an alumite coating on the surface of an aluminum plate. 6. A mask having a large number of round holes opened is fixed to the surface of the aluminum plate to be anodized, and the surface of the aluminum plate not covered with the mask is anodized in an electrolytic solution. An alumite film is formed, and an alumite film is formed on the entire surface of the aluminum plate in the opposite direction to the surface on which the alumite film is formed. The alumite film is connected to the alumite film and remains in the portion covered with the mask. An unreacted aluminum plate was dissolved and removed with an acid, two flat plates were connected back to back using two obtained members, and electrode plates were fixed on both surfaces to obtain zinc. -A method for manufacturing a bromine battery separator.