JP7097187B2 - Lead-acid battery - Google Patents

Description

The present invention relates to a lead storage battery.

A lead-acid battery usually includes a plurality of electrode plates in which a positive electrode plate and a negative electrode plate housed in a bag-shaped separator are alternately laminated, and each electrode plate group is typically a negative electrode plate. The number of sheets is one more than the number of positive electrode plates. On the other hand, in recent years, for the purpose of improving the energy density and reducing the weight, it has been studied to use a group of electrode plates in which the same number of positive electrode plates and the same number of negative electrode plates are arranged (for example, Patent Document 1).

A lead-acid battery having such a configuration is used, for example, as a battery for starting an engine of a vehicle. The lead-acid battery for starting the engine of a vehicle supplies electric power to the starter motor for starting the engine and also supplies electric power to electric or electronic devices mounted on the vehicle.

JP-A-2015-144144

When a lead-acid battery is mounted on a vehicle and used, a strong vibration is applied to the lead-acid battery as the vehicle vibrates, and stress is generated at the pole column of the lead-acid battery or the connection portion between the electrode plates, thereby causing stress. The part may be damaged. According to the study by the present inventors, in a lead-acid battery having the same number of positive electrode plates and negative electrode plates in the electrode plate group, the positive electrode plate located at one end of each electrode plate group is exposed (contained in the separator). Since it is close to the inner wall surface of the battery case in the state of (not), it is easily affected by the vibration of the vehicle, and the above-mentioned damage is likely to occur.

Therefore, an object of the present invention is to provide a lead storage battery having excellent vibration resistance even when the electrode plate closest to the inner wall surface of the battery case is exposed.

One aspect of the present invention includes an electrode plate, a separator, and an electric tank for accommodating the electrode plate and the separator, and the electrode plates and the separator are alternately arranged in this order from the side close to the inner wall surface of one of the electric tanks. The electrode plate that is arranged and is in close contact with the inner wall surface is exposed to the inner wall surface, and the separator is a lead storage battery having a base portion having a thickness of 0.25 mm or more.

The lead-acid battery may include a positive electrode plate and a negative electrode plate as electrode plates, and the positive electrode plates and the negative electrode plates may be alternately arranged in this order via a separator from the side closer to the inner wall surface.

The number of positive electrode plates and the number of negative electrode plates housed in the battery case may be the same as each other.

The separator may further have a rib portion formed in a convex shape on the base portion.

The base portion may be formed of polyolefin or polyethylene terephthalate.

According to the present invention, it is possible to provide a lead storage battery having excellent vibration resistance even when the electrode plate closest to the inner wall surface of the battery case is exposed.

FIG. 1 is a perspective view showing the overall configuration and internal structure of the lead storage battery according to the embodiment. FIG. 2 is a perspective view showing an electric tank included in the lead storage battery of FIG. FIG. 3 is an exploded perspective view for explaining a main part of the lead storage battery of FIG. FIG. 4 is a diagram for explaining a separator included in the lead storage battery of FIG.

FIG. 1 is a perspective view showing the overall configuration and internal structure of the lead storage battery according to the embodiment. As shown in FIG. 1, the lead-acid battery 1 according to the embodiment has an electric tank 2 having an open upper surface, a lid 3 for closing the opening of the electric tank 2, and a plate group 4 housed in the electric tank 2. A liquid lead-acid battery comprising an electrolytic solution (not shown) such as dilute sulfuric acid and dilute sulfuric acid.

The lid 3 includes a positive electrode terminal 5, a negative electrode terminal 6, and a plurality of liquid port plugs 7 for closing the plurality of liquid injection ports provided in the lid 3. The lid 3 is made of, for example, polypropylene. The positive electrode terminal 5 is connected to one end of a positive electrode column 18 extending from the lid 3 into the electric tank 2. Similarly, the negative electrode terminal 6 is connected to one end of a negative electrode column (not shown) extending from the lid 3 into the electric tank 2.

FIG. 2 is a perspective view showing an electric tank 2 included in the lead storage battery 1 of FIG. As shown in FIG. 2, the electric tank 2 has a hollow substantially rectangular parallelepiped shape and has an opening on the upper surface. That is, the electric tank 2 is erected on a bottom wall having a rectangular planar shape, a pair of side walls (first side wall) 21 erected on the short side portion of the bottom wall, and a long side portion of the bottom wall. It is composed of a pair of side walls (second side wall) 22. The battery case 2 is made of, for example, polypropylene.

The inside of the electric tank 2 is provided with five partition walls 23 provided substantially parallel to the first side wall 21. By arranging the five partition walls 23 at predetermined intervals, the first to sixth six cell chambers 24a to 24f (hereinafter, these are collectively referred to as "cell chamber 24") inside the electric tank 2. ”) Is formed along the second side wall 22 in this order. The electrode plate group 4 is housed in each of the cell chambers 24. The electrode plate group 4 is also called a cell, and has an electromotive force of, for example, 2V.

The inner surface 21a of the first side wall 21 and the double-sided 23a of the partition wall 23 (hereinafter, collectively referred to as “inner wall surfaces 21a, 23a”) extend in a direction perpendicular to the bottom wall (opening surface of the electric tank 2). A plurality of ribs 25 are provided. The rib 25 has a function of appropriately pressurizing (compressing) the electrode plate group 4 housed in each cell chamber 24. In another embodiment, the inner wall surfaces 21a and 23a may not be provided with ribs.

Since the ribs 25 are provided on the inner wall surfaces 21a and 23a, the ribs 25 are connected to the inner wall surfaces 21a and 23a and the electrode group 4 (particularly, the positive electrode plate closest to the inner wall surfaces 21a and 23a of the electrode group 4). Since it also functions as a cushioning material between the two, the vibration resistance of the lead storage battery 1 can be further improved. The rib 25 is preferably made of polyolefin or polyethylene terephthalate, more preferably polyolefin, from the viewpoint of further improving vibration resistance. The polyolefin may be polyethylene, polypropylene or the like.

FIG. 3 is an exploded perspective view showing a first cell chamber 24a and a plate group 4 housed therein for explaining a main part of the lead storage battery 1 of FIG. As shown in FIG. 3, the electrode plate group 4 is formed by laminating a plurality of positive electrode plates 8, negative electrode plates 9 and separator 10 in a direction substantially perpendicular to the first side wall 21 of the electric tank 2.

The positive electrode plate 8 includes a positive electrode current collector 11 and a positive electrode active material 12 held by the positive electrode current collector 11. The positive electrode current collector 11 has a positive electrode ear portion 11a protruding from one end thereof toward the opening side of the electric tank 2. The negative electrode plate 9 includes a negative electrode current collector 13 and a negative electrode active material 14 held by the negative electrode current collector 13. The negative electrode current collector 13 has a negative electrode ear portion 13a protruding from one end thereof toward the opening side of the electric tank 2. In the present specification, "positive electrode active material" means a positive electrode plate from which a positive electrode current collector is removed, and "negative electrode active material" means a negative electrode plate from which a negative electrode current collector is removed.

The positive electrode current collector 11 and the negative electrode current collector 13 are formed of, for example, a lead-calcium-tin alloy, a lead-calcium alloy, a lead-antimon alloy, or the like, respectively. By forming these lead alloys in a grid pattern by a gravity casting method, an expanding method, a punching method, or the like, a positive electrode current collector 11 having a positive electrode ear portion 11a and a negative electrode current collector 13 having a negative electrode ear portion 13a are obtained, respectively. Be done.

The positive electrode active material 12 contains PbO ₂ as a Pb component, and further contains a Pb component other than PbO ₂ (for example, PbSO ₄ ) and an additive, if necessary. The negative electrode active material 14 contains a simple substance of Pb as a Pb component, and further contains a Pb component (for example, PbSO ₄ ) other than the simple substance of Pb and an additive, if necessary.

Although not shown in FIG. 3, as shown in FIG. 1, the positive electrode ears 11a are collectively welded by the positive electrode strap 15, and the negative electrode ears 13a are collectively welded by the negative electrode strap 16. The positive electrode strap 15 in the electrode plate group 4 housed in the first cell chamber 24a is connected to the positive electrode column 18 extending from the positive electrode terminal 5 into the electric tank 2 via the connecting member 17. The connecting member 17 and the positive electrode column 18 are each made of lead or a lead alloy.

When viewed from the stacking direction of the positive electrode plate 8 and the negative electrode plate 9, of the positive electrode ear portion 11a and the negative electrode ear portion 13a in each electrode plate group 4, the positive electrode ear portion 11a or the negative electrode located on the positive electrode terminal 5 and the negative electrode terminal 6 side. The ear portion 13a (for example, in the electrode plate group 4 housed in the first cell chamber 24a, the positive electrode ear portion 11a) is located inside (from the center) of the positive electrode terminal 5 and the negative electrode terminal 6. In such a case, stress is likely to be generated in the pole column due to the vibration of the lead storage battery 1, but by adopting the configuration of the lead storage battery 1 according to the present embodiment, the vibration resistance can be improved (details are as follows). Later).

In the electrode plate group 4, the positive electrode plate 8 and the negative electrode plate 9 housed in the bag-shaped separator 10 are alternately arranged in this order from the side close to the inner surface 21a of the first side wall 21 of the electric tank 2. ing. The number of positive electrode plates 8 and the number of negative electrode plates 9 are both eight. Since the positive electrode plate 8 closest to the inner surface 21a of the first side wall 21 is not housed (covered) in the separator 10, the surface of the positive electrode plate 8 facing the inner surface 21a of the first side wall 21 is the first. It is exposed to the inner surface 21a of the side wall 21 of 1.

FIG. 4 is a diagram for explaining the separator 10 included in the lead storage battery 1 of FIG. 4 (a) is a perspective view showing the separator 10, and FIG. 4 (b) is a cross-sectional view taken along the line IVb-IVb of FIG. 4 (a). The separator 10 (each of the base portion and the rib portion described later) may be formed of, for example, at least one material selected from the group consisting of glass, pulp and synthetic resin. The separator 10 may have flexibility. The separator 10 (each of the base portion and the rib portion) is preferably formed of polyolefin or polyethylene terephthalate, more preferably polyolefin, from the viewpoint of further improving vibration resistance. The polyolefin may be polyethylene, polypropylene or the like.

As shown in FIG. 4A, the separator 10 is formed from a flat plate (sheet) -shaped base portion 31 and a plurality of first ribs 32 and second ribs 33 formed on the outer surface 31a of the base portion 31. It has a ribbed part. The separator 10 is a long sheet having a base portion 31, a first rib 32, and a second rib 33, and is folded so that the first rib 32 and the second rib 33 are on the outside. It is shaped like a bag by being closed along the sides. The separator 10 may be closed by, for example, a mechanical seal, and has a mechanical seal portion 34 along a long side.

The first rib 32 and the second rib 33 are each formed in an elongated convex shape substantially parallel to each other so as to extend from the opening of the bag-shaped separator 10 to the bottom. A plurality of first ribs 32 are provided in the central portion of the base portion 31 in the direction parallel to the opening of the separator 10, at intervals of, for example, 3 to 15 mm. A plurality of second ribs 33 are provided on both end sides of the base portion 31 so as to sandwich the plurality of first ribs 32. The distance between the second ribs 33 is narrower than the distance between the first ribs 32.

The cross-sectional shape of the first rib 32 is, for example, a trapezoidal shape. The height (length in the protruding direction) H of the first rib 32 may be, for example, 0.3 mm or more, 0.4 mm or more, or 0.5 mm or more, and 1.25 mm or less, 1.0 mm or less, Alternatively, it may be 0.75 mm or less.

The width of the lower bottom of the first rib 32 (the length in the direction perpendicular to the extending direction (short direction) in the portion in contact with the base portion 31) A is, for example, 0.2 mm or more, 0.3 mm or more, or It may be 0.4 mm or more, and may be 4 mm or less, 2 mm or less, or 1 mm or less. The width of the upper bottom of the first rib 32 (the length in the direction perpendicular to the extending direction (short direction) on the upper surface of the convex shape) B may be 0.1 mm or more or 0.2 mm or more, and may be 2 mm. Hereinafter, it may be 1 mm or less, or 0.8 mm or less.

The cross-sectional shape of the second rib 33 is, for example, a semicircular shape. The height (length in the protruding direction) and width (length in the direction perpendicular to the extending direction (short direction) in the portion in contact with the base portion 31) of the second rib 33 is the height of the first rib 32. It is smaller than the width H and the width A of the lower bottom, respectively.

The thickness T of the base portion 31 is 0.25 mm or more from the viewpoint of improving vibration resistance. The thickness T of the base portion 31 is preferably 0.30 mm or more, more preferably 0.35 mm or more, still more preferably 0.40 mm or more, from the viewpoint of further improving the vibration resistance. The thickness T of the base portion 31 may be, for example, 0.50 mm or less.

Each of the second to sixth cell chambers 24b to 24f also houses the same plate group as the plate group 4 housed in the first cell chamber 24a. However, the electrode plates housed in the adjacent cell chambers (for example, the first cell chamber 24a and the second cell chamber 24b) are arranged so that the electrode plates having the same polarity face each other with the partition wall 23 in between. There is. That is, in the electrode plate group 4 housed in the first cell chamber 24a, the negative electrode plate 9 is arranged at a position closest to the partition wall 23 on the second cell chamber 24b side, and the second cell chamber 24b. In the electrode plate group housed in, the negative electrode plate is arranged at a position closest to the partition wall 23 on the first cell chamber 24a side.

In other words, in the electrode plate group housed in the second cell chamber 24b, the positive electrode plate is arranged in a state of being exposed at a position closest to the surface 23a of the partition wall 23 on the third cell chamber 24c side. .. In the electrode plate group housed in the third cell chamber 24c, the positive electrode plate is arranged in a state of being exposed at a position closest to the surface 23a of the partition wall 23 on the second cell chamber 24b side. In the electrode plate group housed in the fourth cell chamber 24d, the positive electrode plate is arranged in a state of being exposed at a position closest to the surface 23a of the partition wall 23 on the fifth cell chamber 24e side. In the electrode plate group housed in the fifth cell chamber 24e, the positive electrode plate is arranged in a state of being exposed at a position closest to the surface 23a of the partition wall 23 on the fourth cell chamber 24d side. In the electrode plate group housed in the sixth cell chamber 24f, the positive electrode plate is arranged in a state of being exposed at a position closest to the inner surface 21a of the first side wall 21 of the electric tank 2.

The lead-acid battery 1 according to the present embodiment is adjacent to the positive electrode plate 8 which is in close contact with the inner wall surfaces 21a and 23a of the electric tank 2 (the inner surface 21a of the first side wall 21 or the surface 23a of the partition wall 23) and the positive electrode plate 8. A separator 10 having a base portion 31 having a thickness T of 0.25 mm or more is provided between the negative electrode plate 9 and the negative electrode plate 9. Therefore, even when the positive electrode plate 8 closest to the inner wall surfaces 21a and 23a of the electric tank 2 is exposed to the inner wall surfaces 21a and 23a of the electric tank 2, it accompanies the vibration of the lead storage battery 1. A lead-acid battery 1 having excellent vibration resistance can be obtained by suppressing damage to the connection portion between the electrode column and the electrode plate group. The reason why such an effect is obtained when the thickness T of the base portion 31 is 0.25 mm or more is not clear, but the base portion 31 is transferred from the electric tank 2 to the inner wall surfaces 21a and 23a of the electric tank 2. It is presumed that this is because the vibration transmitted to the closest positive electrode plate 8 is buffered, and the cushioning effect is remarkably increased when the thickness T of the base portion 31 is 0.25 mm or more.

Surprisingly, for example, even if the sum of the thickness T of the base portion 31 and the thickness of the first rib 32 or the second rib 33 (rib portion) is the same, the above-mentioned effect can be obtained. Is limited to the case where the thickness T of the base portion 31 is 0.25 mm or more, and when the thickness T of the base portion 31 is less than 0.25 mm, the first rib 32 or the second rib 33 Even if the thickness of the (rib portion) is increased, the above-mentioned effect cannot be obtained.

Therefore, in another embodiment, the separator may consist only of the base portion without having the first rib and the second rib (rib portion). Even in this case, if the thickness of the base portion is 0.25 mm or more, a lead storage battery having excellent vibration resistance can be obtained.

In the above embodiment, all the electrode plates housed in each cell chamber 24 have the positive electrode plate 8 closest to the inner wall surfaces 21a and 23a of the electric tank 2 and the negative electrode plate 9 adjacent to the positive electrode plate 8. A separator 10 having a base portion 31 having a thickness T of 0.25 mm or more is provided between the two, but in another embodiment, a part of the electrode plate group housed in each cell chamber 24 is provided. Such a separator 10 may be provided.

From the viewpoint of particularly suppressing damage to the pole pillar, the first of the first cell chamber 24a and the sixth cell chamber 24f (N cell chambers (N is an integer of 3 or more) provided in the electric tank 2). And at least one (preferably both) of the electrode plates in the Nth cell chamber) is preferably provided with the separator 10 as described above. From the viewpoint of particularly suppressing damage to the connection portion between the electrode plates, the second to fifth cell chambers 24b to 24e (the second to second (N-) of the N cell chambers provided in the electric tank 2). It is preferable that at least one (preferably all) of the electrode plates in the cell chamber) of 1) is provided with the separator 10 as described above.

In the above embodiment, the electrode plate closest to the inner wall surfaces 21a and 23a of the electric tank 2 is the positive electrode plate 8, and the positive electrode plate 8 is exposed to the inner wall surfaces 21a and 23a. In the embodiment, the electrode plate closest to the inner wall surfaces 21a and 23a of the electric tank 2 may be a negative electrode plate, and the negative electrode plate may be exposed to the inner wall surfaces 21a and 23a. In this case, the positive electrode plate may be housed in the bag-shaped separator instead of the negative electrode plate. Such a lead storage battery also has excellent vibration resistance as in the above embodiment.

In the above embodiment, the number of positive electrode plates 8 and the number of negative electrode plates 9 in the electrode plate group are both the same as eight, but in another embodiment, the positive electrode plate and the negative electrode plate in the electrode plate group are the same. The number of sheets may be 6 or 7, and the number of positive electrode plates and the number of negative electrode plates may be different from each other. In other words, in the above embodiment, the number of positive electrode plates 8 and the number of negative electrode plates 9 in the lead storage battery 1 are the same as each other, but in another embodiment, the number of positive electrode plates and the number of negative electrode plates in the lead storage battery 1 are the same. And may be different from each other. Such a lead storage battery also has excellent vibration resistance as in the above embodiment.

In the above embodiment, the lead storage battery 1 is provided with a separator 10 between the positive electrode plate 8 which is in close contact with the inner wall surfaces 21a and 23a of the electric tank 2 and the negative electrode plate 9 adjacent to the positive electrode plate 8. In another embodiment, the lead-acid battery may further include a spacer between the positive electrode plate and the separator. The spacer is formed in the form of a sheet, for example, and may be a porous film (porous film) such as a non-woven fabric. The spacer may be formed of, for example, an organic fiber, an inorganic fiber, or a mixed fiber thereof. The thickness of the spacer may be, for example, 0.1 mm or more, and may be 2.0 mm or less. If the lead-acid battery is further provided with such a spacer, further excellent vibration resistance can be obtained.

In the above embodiment, the lead storage battery 1 is a liquid lead storage battery, but in another embodiment, the lead storage battery may be, for example, a control valve type lead storage battery, a closed type lead storage battery, or the like. In the above embodiment, the lead storage battery 1 is, for example, a lead storage battery for an automobile, and in order to drive the lead storage battery by boosting or stepping down the DC voltage 12V, six electrode plate groups 4 are connected in series (that is, the number of cell chambers). 6), 2V × 6 = 12V, but in another embodiment (for example, when the lead storage battery 1 is used for other purposes), the number of cell chambers does not have to be six.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention is not limited to the following examples.

(Example 1)
An expanded lattice body (current collector) was produced by subjecting a rolled sheet made of a lead alloy to an expand process. Subsequently, lead powder and lead tan (Pb ₃ O ₄ ), an additive, and water were mixed and kneaded, and further kneaded while adding dilute sulfuric acid little by little to prepare a positive electrode active material paste. Similarly, lead powder, an additive, and water were mixed and kneaded, and further kneaded while adding dilute sulfuric acid little by little to prepare a negative electrode active material paste. Next, the current collector was filled with the positive electrode active material paste and the negative electrode active material paste, respectively, and aged in an atmosphere of a temperature of 50 ° C. and a humidity of 98% for 24 hours. Then, it was dried to obtain a non-chemical positive electrode plate and a non-chemical negative electrode plate.

A bag-shaped separator made of microporous polyethylene and having a base portion having a thickness of 0.25 mm and a rib portion having a height of 0.70 mm was prepared. An unchemical negative electrode plate was housed in this separator, and eight unchemical positive electrode plates and eight unchemical negative electrode plates housed in bag-shaped separators were alternately laminated. Subsequently, the selvages of the plates having the same polarity were welded to each other by a cast-on-strap (COS) method to prepare a group of plates.

A 12V battery (corresponding to D23 size specified in JIS D 5301) was assembled by accommodating a group of electrode plates in each cell chamber of an electric tank having 6 cell chambers. At this time, in the cell chambers (first and sixth cell chambers) at both ends, the electrode plates were housed so that the positive electrode plates were arranged at positions closest to the first side wall of the battery case. An electrolytic solution (dilute sulfuric acid) was injected into this battery, and then the battery was formed in a water tank at 35 ° C. at an energization current of 18.6 A for 18 hours to obtain a liquid lead-acid battery.

(Example 2 and Comparative Examples 1 and 2)
A liquid lead-acid battery was produced in the same manner as in Example 1 except that the thickness of the base portion or the height of the rib portion of the separator was changed as shown in Table 1.

<Evaluation of vibration resistance>
The lead-acid batteries of Examples 1 and 2 and Comparative Examples 1 and 2 were vibrated in the stacking direction of the electrode plates under the following conditions. The vibration test was performed multiple times by changing the frequency.
Test device: Random vibration control system (i230 / SA2M) (trade name, manufactured by IMV Co., Ltd.)
Frequency: 24.0Hz, 37.5Hz, 39.5Hz, 45.5Hz, 51.0Hz
Vibration time at each frequency: 1200 minutes The lid of the lead-acid battery after the test was removed, and it was visually confirmed whether or not the pole column was damaged in the lead-acid battery after the test. A is the case where the pole column is not damaged at any frequency, B is the case where the pole column is cracked at any frequency, and C is the case where the pole column is broken at any frequency. And said. The results are shown in Table 1.

1 ... Lead-acid battery, 2 ... Electric tank, 8 ... Positive electrode plate, 9 ... Negative electrode plate, 10 ... Separator, 21a ... Inner surface (inner wall surface) of the first side wall.

Claims (11)

An electrode plate, a separator, and an electric tank for accommodating the electrode plate and the separator are provided.
The electrode plates and the separators are alternately arranged in this order from the side close to the inner wall surface of one of the electric tanks, and the electrode plates closest to the inner wall surface are exposed to the inner wall surface.
The separator has a base portion having a thickness of 0.25 mm or more.
A positive electrode plate and a negative electrode plate are provided as the electrode plate, and the electrode plate is provided with a positive electrode plate and a negative electrode plate.
From the side closer to the inner wall surface, the positive electrode plate and the negative electrode plate are alternately arranged in this order via the separator.
A lead-acid battery in which the number of positive electrode plates and the number of negative electrode plates housed in the battery case are the same as each other . The lead-acid battery according to claim 1 , wherein the separator further has a rib portion formed in a convex shape on the base portion. The lead-acid battery according to claim 1 or 2 , wherein the base portion is made of polyolefin or polyethylene terephthalate. The lead-acid battery according to any one of claims 1 to 3, which is a liquid type. An electrode plate, a separator, and an electric tank for accommodating the electrode plate and the separator are provided.
The electrode plates and the separators are alternately arranged in this order from the side close to the inner wall surface of one of the electric tanks, and the electrode plates closest to the inner wall surface are exposed to the inner wall surface.
The separator is a lead storage battery having a base portion having a thickness of 0.25 mm or more and a rib portion formed in a convex shape on the base portion . The lead-acid battery according to claim 5, wherein the base portion is made of polyolefin or polyethylene terephthalate. The lead-acid battery according to claim 5 or 6, which is a liquid type. An electrode plate, a separator, and an electric tank for accommodating the electrode plate and the separator are provided.
The electrode plates and the separators are alternately arranged in this order from the side close to the inner wall surface of one of the electric tanks, and the electrode plates closest to the inner wall surface are exposed to the inner wall surface.
The separator has a base portion having a thickness of 0.25 mm or more.
A lead-acid battery in which the base portion is formed of polyolefin or polyethylene terephthalate . The lead-acid battery according to claim 8, which is a liquid type. An electrode plate, a separator, and an electric tank for accommodating the electrode plate and the separator are provided.
The electrode plates and the separators are alternately arranged in this order from the side close to the inner wall surface of one of the electric tanks, and the electrode plates closest to the inner wall surface are exposed to the inner wall surface.
The separator is a liquid lead-acid battery having a base portion having a thickness of 0.25 mm or more. A positive electrode plate and a negative electrode plate are provided as the electrode plate, and the electrode plate is provided with a positive electrode plate and a negative electrode plate.
The lead-acid battery according to any one of claims 5 to 10, wherein the positive electrode plate and the negative electrode plate are alternately arranged in this order from the side close to the inner wall surface via the separator.

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