JP2014082033A - Method for manufacturing lead-acid battery, and lead-acid battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent inorganic powder filled in a battery case from being discharged outside when an electrolyte is injected into the battery case.SOLUTION: Firstly, a filter 14 restricting inorganic powder 7 to pass through while allowing an electrolyte to pass through is attached to a liquid injection part 11 of a lid 3. Then, the inorganic powder 7 is filled from a filling part 10 of the lid 3 into a battery case 2, and, after the filling, the filling part 10 is air-tightly sealed. Then, the liquid injection part 11 of the lid 3 is connected to a vacuum pump to depressurize the inside of the battery case 2, and thereafter, an electrolyte is injected from the liquid injection part 11 into the battery case 2.

Description

  The present invention relates to a lead storage battery manufacturing method and a lead storage battery.

  In a control valve type lead-acid battery, three types of a retainer type, a gel type, and a granular type are known depending on the method of holding the electrolyte. In the retainer type, the electrolytic solution is held by a mat-like separator (glass separator) inserted between the positive electrode plate and the negative electrode plate. In the gel type, the electrolytic solution is gelled with an inorganic oxide such as silicon dioxide (silica) and held around the electrode plate. In the granular type, a granular inorganic powder such as silica is filled around the electrode plate, and the inorganic powder is impregnated with an electrolytic solution and held.

  In the above three methods, the glass separator is expensive in the retainer type. Further, when using a clad electrode plate that has better cycle life characteristics than the paste electrode plate as the positive electrode plate, the retainer type has a small contact area between the glass separator and the clad electrode plate, so that sufficient capacity can be secured. It was difficult. In contrast to the retainer type, the gel type and granule type are inexpensive, and the gel and inorganic powder holding the electrolytic solution are indefinite, so that a sufficient contact state can be maintained even with the clad electrode plate. Further, comparing the gel type and the granule type, the granule type has an advantage that the high rate discharge performance is high because the movement of the electrolyte in the inorganic powder is remarkably faster than the gel type.

  By the way, in the manufacturing process of the granular lead-acid battery, after filling the battery case containing the electrode plate with the inorganic powder, the electrolytic solution is injected into the battery case and infiltrated into the inorganic powder. In Patent Document 1, in order to quickly infiltrate the electrolyte into the inorganic powder in the battery case, the pressure in the battery case filled with the inorganic powder is reduced first, and then the electrolyte solution is put in the battery case. Injecting is disclosed. Specifically, an electrolytic solution container and a vacuum pump are connected to a liquid injection port through a three-way cock. First, the liquid inlet is connected to a vacuum pump with a three-way cock, and the inside of the battery case is decompressed by sucking the air in the battery case from the liquid inlet by the vacuum pump. After depressurization in the battery case, the three-way cock is switched to connect the liquid injection port to the electrolyte container, and the electrolyte solution is injected into the depressurized battery case.

Japanese Patent Laid-Open No. 4-363871

  As described above, in the production of the granular lead-acid battery, it is necessary to fill the battery case with inorganic powder before injecting the electrolytic solution, but after filling the battery case with inorganic powder, There is a possibility that the inorganic powder in the battery case is scattered from the electrolyte injection port to the surroundings until the subsequent injection of the electrolyte is completed. Further, as in Patent Document 1, when the pressure is reduced from the injection port in order to inject the electrolytic solution, if the vacuum pump strongly sucks, the inorganic powder is also sucked out from the injection port, so as slowly as possible. It takes time to decompress.

  An object of the present invention is to prevent the inorganic powder filled in the battery case from being discharged to the outside when the electrolytic solution is injected into the battery case.

Means for Solving the Problems and Effects of the Invention

According to a first aspect of the present invention, there is provided a lead-acid battery manufacturing method comprising: an electrode group; and a battery case that contains an inorganic powder that is filled around the electrode plate group and impregnated with an electrolyte; and A method for producing a lead-acid battery, comprising: a lid that is attached and has a filling part of the inorganic powder and an injection part of the electrolyte solution,
A filter mounting step for attaching a filter that restricts the passage of the inorganic powder while allowing the electrolyte to pass through the liquid injection part of the lid, and from the filling part of the lid to the inside of the battery case A powder filling step for filling the inorganic powder into the filling portion, a filling portion sealing step for hermetically sealing the filling portion after the powder filling step, and a pressure reducing device for the liquid injection portion of the lid And a pressure reducing step for reducing the pressure inside the battery case, and a liquid pouring step for injecting the electrolyte into the battery case from the liquid pouring part after the pressure reducing step. It is.

  In the present invention, the lid has a filling part for filling the inorganic powder and a liquid injection part for injecting the electrolytic solution. First, after attaching a filter to the injection part of the electrolytic solution, the inorganic powder is filled from the filling part. Since the filter is attached to the liquid injection part, the inorganic powder filled in the battery case is prevented from being released from the liquid injection part. When the filling of the inorganic powder is completed, the filling portion is hermetically sealed. “Sealing hermetically” means completely sealing so that not only liquid but also gas cannot pass. After sealing the filling portion, the inorganic powder is not released from the filling portion as well as the liquid injection portion.

  After sealing the filling part, the inside of the battery case is decompressed by sucking air in the battery case with a decompression device connected to the liquid injection part. After decompression, the electrolytic solution is injected into the battery case from the injection portion. Here, since the filling portion is hermetically sealed, the inside of the battery case can be surely decompressed. Moreover, since the filter is attached to the liquid injection part, the inorganic powder in the battery case is not sucked up in the pressure reducing step, so the suction force of the pressure reducing device is increased to quickly reduce the pressure in the battery case. It can be carried out. On the other hand, since the filter allows passage of the electrolytic solution, the injection of the electrolytic solution is not prevented by this filter.

  In the method for manufacturing a lead-acid battery according to the second invention, in the first invention, in the filling part sealing step, the filling part is hermetically sealed by injecting a sealing material into the filling part. It is characterized by this.

  In this invention, a filling part can be sealed easily and reliably by inject | pouring a sealing material into a filling part.

  According to a third aspect of the present invention, there is provided the method for producing a lead-acid battery according to the second aspect, wherein in the powder filling step, the filling portion is closed by attaching a closing member to the filling portion after the filling of the inorganic powder. In the filling portion sealing step, the sealing material is injected to hermetically seal the filling portion.

  In the present invention, since the sealing portion is injected after the filling portion is closed with the closing member, the filling portion is reliably sealed. In addition, when the sealing material is injected into the filling portion, the filling portion is already closed by the closing member, so that the injected sealing material is prevented from entering the battery case from the filling portion. Furthermore, after filling the inorganic powder, the filling portion is immediately closed with a closing member, so that the inorganic powder is prevented from scattering from the filling portion before the filling portion is sealed with the sealing material. it can.

  According to a fourth aspect of the present invention, there is provided a method for producing a lead-acid battery according to any one of the first to third aspects, wherein the control valve is opened in the liquid injection part in response to a pressure increase in the battery case after the liquid injection process. It is characterized by attaching.

  In the present invention, a control valve is attached to the liquid injection part, and this liquid injection part functions as an exhaust part for releasing the gas generated in the battery case after the injection of the electrolytic solution. Therefore, unlike the filling part, the liquid injection part does not need to be hermetically sealed after the electrolyte is injected.

  In the lead-acid battery manufacturing method according to a fifth aspect of the present invention, in the fourth aspect of the invention, the lid body includes a storage section in which the filling section and the liquid injection section are stored, and the control is provided in the liquid injection section. After the valve is attached, a pressing plate of the control valve is attached so as to cover the accommodating portion of the lid, and the filling portion is also covered with the pressing plate.

  In the present invention, the filling portion and the liquid injection portion are accommodated in the accommodating portion of the lid. When the control plate of the control valve is attached so as to cover the housing portion, the filling portion is also covered by the press plate. That is, since the filling part and the liquid injection part can be covered with a common member, the number of parts is reduced and the number of processes is reduced. In addition, since the filling portion is hermetically sealed in the previous filling portion sealing step, it is sufficient that the pressing plate is attached so as to cover the filling portion. The function of sealing is not necessarily required.

  A lead storage battery according to a sixth aspect of the invention is attached to the battery case, the battery case containing the electrode group, and the inorganic powder filled around the electrode group and impregnated with the electrolyte, A lead-acid battery comprising a lid having a filling part of the inorganic powder and a liquid injection part, wherein the inorganic powder is allowed to pass through the liquid injection part. A filter for restricting the passage of the body is attached, and the filling portion is hermetically sealed in a state where the inorganic powder is filled in the battery case.

  In the present invention, a filter is attached to the liquid injection part, and the filling part is hermetically sealed after filling with the inorganic powder. Therefore, the inorganic powder in which the inorganic powder is filled in the battery case is prevented from being released from the liquid injection part or the filling part.

  In the lead storage battery according to a seventh aspect based on the sixth aspect, the lid has a storage portion in which the filling portion and the liquid injection portion are stored, and the liquid injection portion of the battery case includes A control valve that opens in response to a rise in pressure in the battery case is attached, a pressure plate of the control valve is attached so as to cover the accommodating portion of the lid, and the pressure plate also covers the filling portion It is characterized by this.

  In the present invention, the filling portion and the liquid injection portion are accommodated in the accommodating portion of the lid. And a filling part is also covered by the holding plate of a control valve attached so that a storage part may be covered. That is, since the filling part and the liquid injection part are covered with a common member, the number of parts is reduced and the number of processes is also reduced.

It is a perspective view of the lead acid battery concerning a 1st embodiment. It is the II-II line vertical sectional view of FIG. It is a figure which shows the process regarding inorganic powder filling to a battery case. It is a figure which shows the process regarding injection | pouring of the electrolyte solution to a battery case. It is a figure which shows the process regarding attachment of a control valve. It is a vertical sectional view of a lead storage battery according to a second embodiment. It is a figure which shows the process regarding inorganic powder filling to a battery case, and injection | pouring of electrolyte solution of 2nd Embodiment. It is a perspective view of the lead acid battery concerning another modification.

(First embodiment)
Next, a first embodiment of the present invention will be described. FIG. 1 is a perspective view of a lead-acid battery according to the first embodiment. 2 is a vertical sectional view taken along line II-II in FIG. As shown in FIG. 1, the lead storage battery 1 includes a battery case 2, a lid 3 joined to the upper part of the battery case 2, and two terminals 4 protruding from the lid 3.

  The battery case 2 is a case made of synthetic resin with an upper portion opened. The configuration in the battery case 2 is a conventionally known configuration and detailed illustration is omitted, but as shown in FIGS. 1 and 2, the battery case 2 is alternately arranged in the direction perpendicular to the paper surface of FIG. An electrode plate group 6 composed of the two types of electrode plates 5 (the positive electrode plate 5a and the negative electrode plate 5b) is accommodated. As the positive electrode plate 5a, a so-called clad electrode plate is used in which a glass fiber is knitted into a tube shape and baked and hardened and filled with an active material. Alternatively, a so-called paste-type electrode plate in which a paste-like active material is applied to the lattice body to form an electrode plate can also be used. On the other hand, as the negative electrode plate 5b, a paste-type electrode plate is generally used.

  An inorganic powder 7 made of an inorganic material such as silica (silicon dioxide) or alumina is filled around the electrode plate group 6 in the battery case 2. The particle size of the inorganic powder 7 is about 150 to 350 μm. The inorganic powder 7 is impregnated with an electrolytic solution such as dilute sulfuric acid.

  The lid 3 is made of a synthetic resin like the battery case 2 and is joined to the upper part of the battery case 2 so as to cover the opening of the battery case 2. The lid 3 is provided with a positive terminal 4 a connected to the positive strap 8 and a negative terminal 4 b connected to the negative strap 8. The part protrudes. A sealing material such as an epoxy resin is injected between these terminals 4 and the lid 3. A label 9 for indicating the polarity of the terminal 4 is attached to the upper surface of the lid 3 so as to cover the sealing material.

  A concave accommodating portion 3a is formed on the upper surface of the lid. As shown in FIG. 2, in the accommodating part 3a, the filling part 10 for filling the inorganic powder 7 in the battery case 2, and the liquid injection part 11 for injecting the electrolyte into the battery case 2, Is arranged. Both the filling unit 10 and the liquid injection unit 11 are formed in a cylindrical shape and have a hole penetrating the lid 3 therein.

  The upper end opening of the filling part 10 is sealed with a screw-in type cap 12 (closing member). In addition, the filling portion 10 is hermetically sealed by injecting a sealing material 13 such as an epoxy resin onto the cap 12. On the other hand, a filter 14 is attached to the liquid injection part 11 by a filter press 15 so as to cover the lower end opening. As will be described later, the filter 14 is for preventing the inorganic powder 7 filled in the battery case 2 from being discharged from the liquid injection part 11 to the outside.

  Further, the liquid injection part 11 is provided with a control valve 16 made of rubber or the like so as to cover the upper end opening thereof, and also functions as an exhaust part for discharging the gas generated in the battery case 2 to the outside. The lead storage battery 1 of the present embodiment is a so-called control valve type lead storage battery, and a detailed description thereof is omitted, but is configured to absorb oxygen gas generated in the positive electrode plate 5a during charging on the negative electrode plate 5b. The battery case 2 is kept sealed by the control valve 16. However, when the pressure in the battery case 2 rises above a certain level due to an abnormality such as overcharging, the control valve 16 opens according to the pressure rise, and the gas is discharged to the outside.

  A pressing plate 17 of the control valve 16 is joined to the concave housing portion 3a formed on the lid 3 so as to cover the housing portion 3a. The holding plate 17 is arranged with a little gap from the control valve 16 and holds the control valve 16 in order to prevent the control valve 16 from dropping off when the control valve 16 is opened. The pressing plate 17 is formed of a synthetic resin as with the lid 3. Further, the pressing plate 17 extends to above the filling portion 10 and covers the sealing material 13 injected to seal the filling portion 10. That is, the filling part 10 and the liquid injection part 11 are covered with a common member (presser plate 17).

  Next, the manufacturing process of said lead acid battery 1 is demonstrated. Here, the filling of the inorganic powder 7 into the battery case 2 and the injection of the electrolytic solution will be described in particular. FIG. 3 is a diagram showing a process related to filling of the inorganic powder into the battery case, FIG. 4 is a diagram showing a process related to injection of the electrolyte into the battery case, and FIG. 5 is a diagram showing a process related to mounting the control valve. is there.

First, as shown to Fig.3 (a), the filter 14 is attached using the filter holding | suppressing 15 so that the lower end opening of the liquid injection part 11 of the cover body 3 may be covered (filter attachment process). As the filter 14, a filter having a hole smaller than the particle diameter of the inorganic powder 7 is used so as to allow passage of the electrolytic solution but restrict passage of the inorganic powder 7 filled in the battery case 2. For example, if a fiber having a diameter of 19 ± 3 μm is used and prepared with an apparent density of 0.16 ± 0.03 g / cm ³ , the electrolyte is allowed to pass through, but the inorganic powder 7 having a particle diameter of 150 to 350 μm. Can be obtained. Then, the lid 3 to which the filter 14 is attached is joined to the upper part of the battery case 2.

  Next, the inorganic powder 7 is filled into the battery case 2 from the filling portion 10 of the lid 3 (powder filling step). At this time, the liquid injection part 11 is also open, but since the filter 14 is attached to the liquid injection part 11, it was filled in the battery case 2 during and after the filling of the inorganic powder 7. The inorganic powder 7 is prevented from being released from the liquid injection part 11. When the filling of the inorganic powder 7 is completed, as shown in FIG. 3B, a screw-in type cap 12 (closing member) is attached to the filling portion 10 to temporarily seal the filling portion 10.

  Thereafter, as shown in FIG. 3 (c), a liquid sealing material 13 in an uncured state, such as an epoxy resin, is injected into the filling portion 10 (specifically, the upper portion of the cap 12 and its surroundings) The sealing material 13 is cured. Thereby, the filling part 10 is sealed airtight (filling part sealing process). As the sealing material 13, a thermosetting resin or a room temperature curable resin can be used. Further, when the sealing material 13 is injected into the filling portion 10, the same sealing material 13 is also injected around the terminal 4 (see FIG. 1), and the sealing between the terminal 4 and the lid 3 (and Curing) is performed at the same time.

  Thus, the filling part 10 can be easily and reliably sealed by injecting the sealing material 13 such as an epoxy resin. And after the filling part 10 is sealed, the inorganic powder 7 is not discharged | emitted not only from the liquid injection part 11 but from this filling part 10. FIG. In the present embodiment, after filling the inorganic powder 7, the filling portion 10 is closed with the cap 12 and then the sealing material 13 is injected, so that the filling portion 10 is reliably sealed. Further, when the sealing material 13 is injected into the filling part 10, the filling part 10 is blocked by the cap 12, so that the sealing material 13 injected into the filling part 10 may enter the battery case 2. Is prevented.

  Moreover, the sealing material 13 cannot be injected into the filling part 10 immediately after the filling of the inorganic powder 7 is completed, and an operation and time such as transporting the sealing material 13 to an injection device are required. At that time, if the filling part 10 remains open, the inorganic powder 7 may be scattered from the filling part 10 to the outside. In this regard, as described above, immediately after the filling of the inorganic powder 7, the filling portion 10 is closed with the cap 12, so that the filling portion 10 is hermetically sealed with the sealing material 13. In addition, the inorganic powder 7 can be prevented from scattering from the filling portion 10.

  When the inorganic powder 7 is filled in the battery case 2 as described above, an electrolytic solution is injected into the battery case 2. As shown to Fig.4 (a), the electrolyte container 21 and the vacuum pump 22 (pressure reduction apparatus) are connected to the liquid injection part 11 of the battery case 2 via the three-way valve 20. As shown in FIG. First, the liquid injection unit 11 and the vacuum pump 22 are communicated with each other by the three-way valve 20, and then the air in the battery case 2 is sucked by the vacuum pump 22 to reduce the pressure in the battery case 2 (decompression step). When the pressure in the battery case 2 decreases to a predetermined value or less, as shown in FIG. 4B, the three-way valve 20 is switched to allow the liquid injection part 11 and the electrolyte container 21 to communicate with each other. The liquid is injected into the battery case 2 (liquid injection process).

  Thus, after depressurizing the inside of the battery case 2, the electrolyte solution can be injected in a short time by injecting the electrolyte solution from the liquid injection part 11 into the battery case 2. Moreover, since the filling part 10 is airtightly sealed, the inside of the battery case 2 can be reliably decompressed by suction by the vacuum pump 22. Moreover, since the filter 14 is attached to the liquid injection part 11 to which the vacuum pump 22 is connected, the inorganic powder 7 in the battery case 2 is not sucked up during decompression. Therefore, the suction force (suction speed) of the vacuum pump 22 can be increased, and the pressure in the battery case 2 can be quickly reduced. On the other hand, since the filter 14 of the liquid injection part 11 allows the passage of the electrolytic solution, the injection of the electrolytic solution is not prevented by the filter 14.

  When the injection of the electrolyte is completed, the first charge is performed. After the initial charging, the control valve 16 is attached to the liquid injection part 11 as shown in FIG. Thus, since the liquid injection part 11 functions as an exhaust part for discharging the gas generated in the battery case 2 after the injection of the electrolytic solution, the liquid injection part 11 is hermetically sealed after the injection of the electrolytic solution. There is no need to stop.

  When the control valve 16 is attached, the presser plate 17 is joined to the lid 3 in a state where the presser plate 17 is arranged with a slight gap from the control valve 16 as shown in FIG. Further, the presser plate 17 is a long plate extending above the filling portion 10, and the presser plate 17 is joined to the lid 3 so as to cover almost the entire housing portion 3a (see FIG. 1). At this time, the pressing plate 17 is also joined to the upper end surface of the cylindrical filling portion 10, so that the sealing material 13 that seals the filling portion 10 is covered with the pressing plate 17. Thereby, the liquid injection part 11 (control valve 16) and the filling part 10 (sealing material 13) can be covered by the common member (pressing plate 17), and the number of parts is reduced and the number of processes is also reduced.

  In addition, since the filling part 10 is airtightly sealed by the sealing material 13 previously, it is sufficient if the pressing plate 17 is attached so as to cover the filling part 10. That is, the holding plate 17 does not need a function of hermetically sealing the filling portion 10. Therefore, it is not necessary to use a bonding method with high bonding reliability but low productivity, such as thermal welding, for bonding the pressing plate 17, and a simpler bonding method such as ultrasonic welding, for example. Can be joined.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. FIG. 6 is a vertical cross-sectional view of the lead storage battery of the second embodiment. As shown in FIG. 6, in the lead storage battery of the second embodiment, the sealing structure of the filling portion 10 of the lid 3 is different from the configuration of FIG. 2 of the first embodiment. Hereinafter, components having substantially the same configuration as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted as appropriate.

  As shown in FIG. 6, a filling portion 10 and a liquid injection portion 11 are disposed in the concave storage portion 3 a formed in the lid 3. A fitting type cap 32 (closing member) is attached to the filling unit 10, and the upper end opening of the filling unit 10 is closed by the cap 32. Further, in the second embodiment, the filling member 10 is hermetically sealed by further joining the lid member 38 on the cap 32 by heat welding or the like. As in the first embodiment, the liquid injection part 11 is provided with a filter 14 so as to cover its lower end opening, and a control valve 16 is provided so as to cover its upper end opening.

  The manufacturing process of the lead storage battery of the second embodiment will be described with reference to FIG. 7, particularly regarding the filling of the inorganic powder 7 and the injection of the electrolytic solution. First, as shown in FIG. 7A, after attaching the filter 14 to the liquid injection part 11 of the lid 3 and joining the lid 3 to the battery case 2, the inorganic powder 7 is transferred from the filling part 10 to the battery case. 2 is filled. The point that the inorganic powder 7 is prevented from being diffused from the liquid injection part 11 by the filter 14 of the liquid injection part 11 is the same as in the first embodiment.

  Next, as shown in FIG. 7B, a fitting cap 32 is attached to the filling portion 10 to temporarily seal the filling portion 10. Further, a lid member 38 is joined to the lid 3 so as to cover the filling portion 10 to hermetically seal the filling portion 10. Unlike the first embodiment in which the sealing member 13 is hermetically sealed by injection of the sealing material 13, in the second embodiment, the filling portion 10 is hermetically sealed by the lid member 38. Therefore, the lid member 38 is joined by a highly reliable joining method such as thermal welding. After sealing the filling part 10, the inside of the battery case 2 is decompressed, and then an electrolyte is injected from the liquid injection part 11.

  After the initial charging is performed by injecting the electrolytic solution, the control valve 16 is attached to the liquid injection part 11 as shown in FIG. Further, a pressing plate 37 of the control valve 16 is joined to the lid 3 by ultrasonic welding or the like so as to cover the liquid injection part 11. In the second embodiment, since the filling unit 10 is covered with the dedicated lid member 38 attached in the previous step, the pressing plate 17 covers only the liquid injection unit 11 (control valve 16). . That is, the filling part 10 and the liquid injection part 11 are respectively covered with different members (the lid member 38 and the pressing plate 37), and their attachment is also performed in a separate process.

  As mentioned above, although an example of the embodiment of the present invention has been given, the form to which the present invention can be applied is not limited to this, and various modifications can be made without departing from the spirit of the present invention as exemplified below. Is possible.

1] In the embodiment described above, after filling the inorganic powder 7 from the filling portion 10, the filling portion 10 is temporarily sealed with the cap 12 (32), and then the filling portion 10 is sealed with the sealing material 13 or the lid member 38. Although hermetically sealed (main sealing), the temporary sealing may be omitted and the main sealing may be performed immediately after completion of filling. In particular, when the filling portion 10 is hermetically sealed with the lid member 38 as in the second embodiment, unlike the case where the filling portion 10 is sealed with the sealing material 13, the filling portion 10 is open. It is not difficult to attach and seal the lid member 38.

2] The filling unit 10 and the liquid injection unit 11 do not have to be stored in the storage unit 3a formed in the lid 3, and each storage unit 3a may be individually formed in the lid 3. Good. Moreover, the accommodating part 3a does not need to be a concave shape in particular, and may be formed in the box shape which protruded from the upper surface of the cover body 3 like FIG.

DESCRIPTION OF SYMBOLS 1 Lead storage battery 2 Battery case 3 Lid 3a Housing | casing part 6 Electrode board group 7 Inorganic powder 10 Filling part 11 Injection part 12 Cap 13 Sealing material 14 Filter 16 Control valve 17 Holding plate 22 Vacuum pump 32 Cap 37 Holding plate 38 Lid member

Claims (7)

A battery case containing an electrode group, and an inorganic powder filled around the electrode group and impregnated with an electrolyte; and attached to the battery case; A method for producing a lead-acid battery, comprising a lid body having a liquid injection part.
A filter mounting step for mounting a filter that restricts the passage of the inorganic powder while allowing the electrolyte to pass through the liquid injection portion of the lid, and
From the filling part of the lid, a powder filling step of filling the inorganic powder into the battery case;
After the powder filling step, a filling portion sealing step for hermetically sealing the filling portion;
A depressurization step of depressurizing the inside of the battery case by connecting the liquid injection part of the lid to a depressurization device;
A liquid injection step of injecting the electrolytic solution from the liquid injection portion into the battery case after the pressure reducing step;
A method for producing a lead-acid battery, comprising:   2. The method for producing a lead-acid battery according to claim 1, wherein in the filling portion sealing step, the filling portion is hermetically sealed by injecting a sealing material into the filling portion.   In the powder filling step, after completion of filling of the inorganic powder, a closing member is attached to the filling portion to close the filling portion, and then the sealing material is injected in the filling portion sealing step to The lead-acid battery manufacturing method according to claim 2, wherein the filling portion is hermetically sealed.   The method for producing a lead-acid battery according to any one of claims 1 to 3, wherein a control valve that opens in response to a pressure increase in the battery case is attached to the liquid injection part after the liquid injection process. The lid has a storage part in which the filling part and the liquid injection part are stored,
The control valve is attached to the liquid injection part and then the control valve is attached so as to cover the accommodating part of the lid, and the filling part is also covered with the presser plate. 4. A method for producing a lead-acid battery according to 4. A battery case containing an electrode group, and an inorganic powder filled around the electrode group and impregnated with an electrolyte; and attached to the battery case; A lead-acid battery comprising a lid having a liquid injection part;
A filter that restricts the passage of the inorganic powder while allowing the electrolyte to pass is attached to the liquid injection part,
The lead-acid battery, wherein the filling portion is hermetically sealed in a state where the inorganic powder is filled in the battery case. The lid has a storage part in which the filling part and the liquid injection part are stored,
A control valve that opens in response to a pressure increase in the battery case is attached to the liquid injection part of the battery case,
The lead storage battery according to claim 6, wherein a pressing plate of the control valve is attached so as to cover the accommodating portion of the lid, and the pressing plate also covers the filling portion.

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