JP6712116B1 - Lead acid battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lead storage battery capable of suppressing peeling and dropping of a positive electrode active material. A lead storage battery includes a positive electrode plate and a negative electrode plate that are alternately stacked with a separator interposed therebetween, a battery case that houses the positive electrode plate, and a positive electrode connecting body that supports an ear portion of the positive electrode plate. , Is provided. The battery case has a saddle portion provided on the bottom surface of the battery case and in contact with the positive electrode plate, and a partition wall dividing the inside of the battery case into a plurality of cell chambers. The partition wall is provided with a through hole that connects adjacent cell chambers. The positive electrode connecting body has an in-hole connecting portion located inside the through hole and an outside-hole connecting portion located outside the through hole. Ends that are part of the saddle part, the ear part, the in-hole connecting part, and the outside-hole connecting part and located on the side far from the bottom surface are located on a straight line when viewed from the stacking direction of the electrode plate group. [Selection diagram] Figure 1

Description

The present invention relates to a lead storage battery.

Among the life factors of lead-acid batteries, growth of the positive electrode substrate is known as a deterioration phenomenon caused by the positive electrode plate (see, for example, Patent Document 1). Growth is a phenomenon in which the positive electrode substrate expands due to corrosion during repeated charging and discharging, and the entire positive electrode plate expands.

JP, 2017-183278, A

Lead acid batteries are widely used for automobiles. The lead-acid battery is often installed in the bonnet, which is a place where the engine is easily exposed to the high temperature environment. A lead storage battery mounted on an automobile is usually composed of 6 cells, but especially the cells located inside are difficult to radiate heat to the outside of the lead storage battery and are likely to be in a higher temperature state. When a lead storage battery is placed in a high temperature environment, corrosion of the positive electrode substrate is likely to proceed and growth becomes remarkable. When the growth progresses, the separator may be pierced and the positive electrode plate and the negative electrode plate may be short-circuited.

Further, as the growth progresses, the lattice design of the positive electrode substrate is deformed. The positive electrode active material that cannot follow this deformation may peel off or fall off from the positive electrode substrate regardless of its deterioration. In particular, if the positive electrode active material is peeled off or dropped from the area near the ears where it is likely to contribute to the charge/discharge reaction, the lead storage battery may not be able to maintain its output when discharging a large current such as when the engine is started. ..

The present invention has been made in view of such circumstances, and an object thereof is to provide a lead storage battery capable of suppressing peeling and dropping of the positive electrode active material.

In order to solve the above problems, the lead storage battery according to one aspect of the present invention has a positive electrode plate and a negative electrode plate that are alternately stacked via a separator, and a battery case that houses the electrode plate group, A positive electrode connecting body that supports the ears of the positive electrode plate, wherein the battery case is divided into a plurality of cell chambers, and a saddle part provided on the bottom surface of the battery container and in contact with the positive electrode plate. The partition wall is provided with a through hole that connects the cell chambers adjacent to each other, and the positive electrode connecting body has a hole connecting portion located inside the through hole, and the through hole. An outside hole connecting portion located outside the hole, the outside hole connecting portion includes a strap and an intermediate pole, and the saddle portion, the ear portion, the inside hole connecting portion, and the strap. And an end located on the side far from the bottom surface of the battery case is located on a straight line when viewed from the front in the stacking direction of the electrode plates.

According to one aspect of the present invention, it is possible to provide a lead storage battery capable of suppressing peeling and falling of the positive electrode active material.

FIG. 1 is a front view showing a configuration example of a positive electrode plate according to an embodiment of the present invention. FIG. 2 is a front view showing a configuration example of the lead storage battery according to the embodiment of the present invention. FIG. 3 is a plan view showing a configuration example of the lead storage battery according to the embodiment of the present invention. FIG. 4 is a graph showing the results of evaluating the number of life cycles of the lead storage batteries manufactured in Examples 1 to 5 and Comparative Examples 1 to 3 of the present invention.

<Embodiment>
An embodiment of the present invention will be described. The embodiments and examples described below are examples of the present invention, and the present invention is not limited to the embodiments and examples. In addition, various changes or improvements can be added to the embodiments and examples, and modes in which such changes or improvements are added can also be included in the present invention.

In the following description of the drawings, the same or similar reference numerals are given to the same or similar parts. However, it should be noted that the drawings are schematic and the relationship between the thickness and the plane dimension, the ratio of the thickness of each device or each member, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. Moreover, it is needless to say that the drawings may include portions having different dimensional relationships and ratios.

In the following description of the drawings, directions may be indicated using the X-axis direction, the Y-axis direction, and the Z-axis direction. For example, the X-axis direction is the lateral direction of the positive electrode plate described later. The Y-axis direction is the thickness direction of the positive electrode plate, and is also the stacking direction of the electrode plate group described later. The Z-axis direction is the vertical direction of the positive electrode plate and also the depth direction of the battery case described later. The X-axis direction, the Y-axis direction, and the Z-axis direction are orthogonal to each other. The XYZ axes form a right-handed system.

A lead storage battery according to an embodiment of the present invention includes a conventionally known monoblock type battery case, a lid, a group of six electrode plates, and dilute sulfuric acid as an electrolytic solution. The battery case is divided into six cell chambers by partition walls. The six cell chambers are arranged along the longitudinal direction of the battery case, and the partition walls are provided with through holes that connect adjacent cell chambers. One cell group is housed in each cell chamber. Each electrode plate group includes a plurality of positive and negative electrode plates, a separator that separates the positive and negative electrode plates, a positive electrode connecting body, and a negative electrode connecting body. The positive electrode connecting body has a positive electrode strap and a positive electrode intermediate pole column or a positive electrode terminal pole column rising from the positive electrode strap. The negative electrode connecting body has a negative electrode strap and a negative electrode intermediate pole column or a negative electrode terminal pole column rising from the negative electrode strap. In the electrode plate group of the cell chambers excluding both ends of the six cell chambers, the positive electrode connected body of the electrode plate group of one cell and the negative electrode connected body of the electrode plate group of the other cell chamber adjacent to this , Are connected by the in-hole connecting portion via the through hole. In addition, in this specification, the positive electrode connecting body and the negative electrode connecting body may be replaced with the outside-hole connecting portions.

The positive electrode plate has a positive electrode substrate holding a mixture containing a positive electrode active material, and an ear protruding upward from the positive electrode substrate. The negative electrode plate has a negative electrode substrate holding a mixture containing a negative electrode active material, and ears protruding upward from the negative electrode substrate. The upper side means the side closer to the lid. The negative electrode plate and the positive electrode plate are alternately arranged with the separator interposed therebetween. The number Mn of negative electrode plates forming the electrode plate group is one more than the number Mp of positive electrode plates. The number of positive electrode plates Mp may be one more than the number of negative electrode plates Mn, or the number of negative electrode plates Mn and the number of positive electrode plates Mp may be the same.

The negative electrode plate is housed in the bag-shaped separator. Then, the bag-shaped separators accommodating the negative electrode plates and the positive electrode plates are alternately overlapped, so that the separators are arranged between the negative electrode plate and the positive electrode plate. Since the negative electrode plate is housed in the bag-shaped separator, even when the active material falls off from the lattice substrate due to the growth of the positive electrode plate and is deposited in the lower part of the battery case, the positive electrode plate and the negative electrode plate due to the deposits in the lower part of the battery case are deposited. The bag-shaped separator prevents contact, so that an internal short circuit can be prevented more reliably.

If the positive electrode plate is housed in a bag-shaped separator, the bag-shaped separator limits expansion when the positive electrode plate grows, which may promote the expansion of the positive electrode plate in the opening direction of the bag-shaped separator, that is, upward. is there. Even if it is not, there is a possibility that a part of the positive electrode grid body, which is broken due to the bending of the positive electrode plate, may break through the bag-shaped separator, and contact between the positive electrode plate and the negative electrode plate cannot be prevented, which may cause a short circuit.

FIG. 1 is a front view showing a configuration example of a positive electrode plate 1 according to an embodiment of the present invention. As shown in FIG. 1, the positive electrode plate 1 includes a positive electrode substrate 2 and a mixture 3 containing a positive electrode active material (hereinafter, referred to as positive electrode mixture) 3. The positive electrode substrate 2 includes an outer frame 21 forming a rectangular outer peripheral edge, a plurality of horizontal inner bones 22, and a plurality of vertical inner bones 23.
The outer frame 21 includes two vertical portions extending in the vertical direction (for example, the Z-axis direction) and two horizontal portions extending in the horizontal direction (for example, the X-axis direction). The lateral internal bone 22 is passed between two vertical portions facing each other in the second direction, that is, the lateral direction. The longitudinal internal bones 23 are passed between two lateral portions facing each other in the first direction, that is, the longitudinal direction. The plurality of horizontal internal bones 22 and the plurality of vertical internal bones 23 intersect each other, so that the positive electrode substrate 2 is a lattice-shaped substrate. The positive electrode mixture 3 is held on the entire openings 24 of the lattice of the positive electrode substrate 2 and the front and back surfaces of the positive electrode substrate 2.

The positive electrode plate 1 also includes an ear portion 4 protruding upward from the outer frame 21 of the positive electrode substrate 2. The positive electrode substrate 2 and the ear portion 4 are integrally formed on a substrate made of a lead alloy rolled plate. A substrate composed of a rolled plate is produced by mainly rolling an alloy containing lead to form a sheet-shaped semi-finished product, and then processing the formed semi-finished product into a lattice shape by a punching press or the like. It A substrate made of such a rolled plate of lead alloy is generally superior in mass productivity as compared to a latticed substrate made by casting, but on the other hand, crystals of the lead alloy are more likely to be oriented and the influence of elongation due to corrosion is large, so Is likely to occur.
Therefore, the embodiment of the present invention exerts a higher growth suppressing effect on the substrate made of the lead alloy rolled plate.

FIG. 2 is a front view showing a configuration example of the lead storage battery 10 according to the embodiment of the present invention, and is a front view of the lead storage battery 10 cut along an arbitrary XZ plane and viewed in the Y-axis direction. FIG. 3 is a plan view showing a configuration example of the lead storage battery 10 according to the embodiment of the present invention, and is a plan view of the lead storage battery 10 cut along an arbitrary XY plane in the Z-axis direction. 2 and 3 show the inside of the battery case 9 of the lead storage battery 10 and one cell chamber that is not located at both ends of the six cell chambers partitioned by the partition wall 94. It should be noted that FIGS. 2 and 3 only show the main parts, and the description of the configuration of the lid, the electrolytic solution and the like is omitted.

As shown in FIGS. 2 and 3, a lead storage battery 100 includes a positive electrode plate 1, a negative electrode plate accommodated in a bag-shaped separator 8, a positive electrode connector 5 supporting the positive electrode plate 1, and a negative electrode supporting the negative electrode plate. The connector 6 and the battery case 9 are provided. The positive electrode plate 1 and the negative electrode plate are laminated alternately via the bag-shaped separator 8 to form the electrode plate group 7. The cell chamber is surrounded by the side wall 92 and the partition wall 94 of the battery case 9. One electrode plate group 7 is arranged in one cell chamber. The partition wall 94 is provided with a through hole H94. Through the through hole H94, the electrode plate group 7 housed in one of the adjacent cell chambers and the electrode plate group 7 housed in the other cell chamber are connected via the partition wall 94.

The positive electrode connecting body 5 has an outside-hole connecting portion 51 arranged outside the through hole H94 and an inside-hole connecting portion (for example, resistance welding portion) 52 arranged inside the through hole H94. The resistance welding portion 52 is formed by resistance welding the positive electrode connecting body 5 arranged in one cell chamber and the negative electrode connecting body 6 arranged in the other cell chamber through the through hole H94. The extra-hole connecting portion 51 has a positive electrode strap 511 that supports the respective ears 4 of the plurality of positive electrode plates 1, and a positive electrode intermediate pole column 512 that rises from the positive electrode strap 511. The positive electrode strap 511 and the positive electrode intermediate pole column 512 are made of lead or lead alloy. The positive electrode strap 511 and the positive electrode intermediate pole column 512 are integrally molded by using a COS (cast on strap) type casting device.

The negative electrode connecting body 6 has the same shape as the positive electrode connecting body 5, has the same size as the positive electrode connecting body 5, and is made of the same material as the positive electrode connecting body 5. However, the embodiment of the present invention is not limited to this. The negative electrode connecting body 6 may have a different shape from the positive electrode connecting body 5, may have a different size from the positive electrode connecting body 5, and may be made of a material different from the positive electrode connecting body 5. It may be.

A plurality of saddle portions 93 that abut the positive electrode plate 1 are provided on the bottom portion 91 of the battery case 9 that faces the electrode plate group 7 (hereinafter referred to as the bottom surface) 91 a. Each of the plurality of saddle portions 93 extends in the stacking direction of the electrode plate group 7 (for example, the Y-axis direction) and has a linear shape in a plan view. In general, the positive electrode active material has a property of easily settling on the bottom portion 91 of the battery case 9 when it deteriorates and softens. If this precipitate diffuses into the electrolyte due to gas generation during charging of the lead storage battery, it accumulates on the upper part of the electrode plate group and on the negative electrode connecting body, causing a short circuit. In order to suppress this, the lead storage battery 10 includes a saddle portion 93 on the bottom surface 91 a of the battery case 9. As a result, in the lead storage battery 10, the precipitate is deposited below the electrode plate group 7 so that the precipitate does not easily diffuse even if gas is generated from the electrode plate group 7.

As shown in FIGS. 1 to 3, in the lead storage battery 10, one of the plurality of saddle parts 93, the ear part 4, the resistance welding part 52, and the end part 511A of the positive electrode strap 511 are arranged in the Y axis direction. Is located on a straight line SL when viewed from the front. The end portion 511A is a part of the extra-hole connecting portion 51 and is located on the side far from the bottom surface 91a. With this structure, the ear portion 4 is sandwiched and fixed by the resistance welding portion 52 and the saddle portion 93. This suppresses deformation of the portion 2A of the positive electrode substrate 2 that is connected to the ears 4 (hereinafter referred to as ears), and suppresses the positive electrode mixture 3 from peeling off from the ears 2A.

As described above, according to the lead storage battery 10 according to the embodiment of the present invention, peeling and dropping of the positive electrode mixture 3 from the vicinity 2A of the ear portion, which easily contributes to the charge/discharge reaction, are suppressed. The decrease is suppressed. As a result, the lead storage battery 10 can maintain its output even during large current discharge. The lead storage battery 10 can prevent the deformation of the vicinity 2A of the ears due to the growth even in the inner cell, which is less likely to radiate heat to the outside and tends to be in a higher temperature state, and prevents the positive electrode mixture 3 from peeling off. You can

Further, in the vicinity 2A of the ear portion, the peeling and dropping of the positive electrode mixture 3 is suppressed, so that the exposure of the base material (for example, lead alloy) is suppressed. As a result, the progress of growth is further suppressed in the vicinity 2A of the ear.
Note that the positive electrode substrate manufactured from a rolled substrate is superior to the positive electrode substrate manufactured from a cast substrate in mass productivity, but growth is likely to proceed for the above reason. According to the embodiment of the present invention, by using a rolled substrate as the positive electrode substrate, it is possible to realize both the inexpensive production of the positive electrode substrate and the suppression of the progress of growth.

Further, in the lead storage battery 10, the distance from the top 512A of the outside-hole connecting portion 51 to the center of the diameter of the inside-hole connecting portion (resistance welding portion) 52 is set to L1, and the length of the outside-hole connecting portion 51 is set in the Y-axis direction. Assuming that L2, L1 and L2 satisfy the following expression (1).
L2/L1≦4.1 (1)
As a result, as will be described in the examples below, the moment applied to the resistance welding portion 52 with the apex 512A as the fulcrum can be reduced, and the occurrence of cracks in the resistance welding portion 52 can be suppressed. As a result, it is possible to prevent the electrolytic solution from penetrating the through holes H94 from the cracks generated in the resistance welding portion 52 and causing the adjacent cell chambers to be liquid-junctioned, and the lead storage battery 10 has a long life.

Further, in the lead storage battery 10, as shown in FIG. 1, the width (that is, the length in the X-axis direction) of the saddle portion 93 in contact with the positive electrode plate 1 is Wr, and the maximum lattice spacing of the longitudinal internal bones 23 is Wi, When the maximum width of the longitudinal internal bone 23 is Ww, Wr, Wi, and Ww satisfy the following formula (2).
Wr≧Wi+Ww (2)
As a result, since the vertical inner ribs 23 are always arranged on the saddle portion 93, the structure of the positive electrode substrate 2 is strengthened. In addition, in the embodiment of the present invention, in the positive electrode substrate 2, between the end portion (hereinafter, referred to as the bottom row) 2B on the side closest to the bottom portion 91 of the battery case 9 and the other portion, the longitudinal internal bone 23 is formed. May have different lattice intervals. In this case, the maximum lattice spacing of the longitudinal internal bones 23 in the lowermost row 2B is Wi in Expression (2).

Next, examples of the present invention will be described.
<Example 1>
In Example 1, a lead storage battery having the same structure as the lead storage battery 10 according to the embodiment was manufactured by the following method. First, a Ca-based lead alloy rolled plate was processed by a punching method to integrally produce a positive electrode substrate and an ear portion. The size of the positive electrode substrate is 111 mm in the lengthwise direction (for example, the Z-axis direction), 99 mm in the horizontal direction (for example, the X-axis direction), and has a thickness (for example, the length in the Y-axis direction) of 1. It was set to 0 mm. The width Ww of the longitudinal internal bone extending in the longitudinal direction and the width of the lateral internal bone extending in the lateral direction were set to 1 mm, and the interval Wi between the longitudinal internal bones and the interval between the lateral internal bones were arranged in a lattice pattern at intervals of 5 mm. The width of the ears (hereinafter referred to as the ears width) was 10 mm. The ears were arranged such that the center of the ears was a part of the outer frame of the positive electrode substrate and was located 22 mm from the vertical frame in the vertical direction. The positive electrode substrate was filled with a positive electrode mixture made by a known method, aged and dried to obtain a positive electrode plate.
A negative electrode substrate was produced by continuous casting, and a mixture containing a negative electrode active material (hereinafter, referred to as a negative electrode mixture) was filled by a known method, aged and dried to obtain a negative electrode plate. The obtained negative electrode plate was housed in a bag-shaped separator and alternately stacked with the positive electrode plate to form an electrode plate group.

The ear of the positive electrode plate included in the electrode plate group was welded to the strap of the positive electrode connecting body using a COS type casting device. Similarly, the ears of the negative electrode plate included in the electrode plate group were welded to the strap of the negative electrode connecting body. In these welding processes, the ear part is attached to the strap so that the center position of the ear part in the width direction (for example, the X-axis direction) matches the center position of the strap in the width direction (for example, the X-axis direction). Welded.
In each of the positive electrode connecting body and the negative electrode connecting body, the strap width is 20 mm, the strap length L2 (see FIG. 3) is 28.7 mm, and the distance L1 from the top of the intermediate pole to the center of the resistance welding portion (FIG. 2). (See reference) was 7 mm. As a result, L2/L1 was set to 4.1. The diameter of the resistance weld was 8 mm.

The battery case had a size of B20, and the partition wall for partitioning between the cell chambers of the battery case was provided with through holes for connecting to adjacent cells. A saddle having a width Wr (see FIG. 3) of 6 mm and a height from the bottom of the battery case of 5 mm was provided at the bottom of the battery case located almost vertically above the through hole. The saddle portion was provided at a total of three positions, the center position, the position on the left side of the center, and the position on the right side of the center, with the center in the width direction (for example, the X-axis direction) of the battery case as a reference. The electrode plate group was inserted into the battery case provided with the saddle part, and the positive electrode intermediate pole column and the negative electrode intermediate pole column were electrically connected between the cell chambers by resistance welding. Subsequent assembly was performed by a known method, and injection and chemical formation were performed to obtain a target lead acid battery.

<Example 2>
The distance L1 from the top of the intermediate pole to the center of the resistance weld was 6 mm, and L2/L1 was 4.8. Except for this, the same procedure as in Example 1 was performed.
<Example 3>
The distance L1 from the top of the intermediate pole to the center of the resistance weld was 5 mm, and L2/L1 was 5.7. Except for this, the same as Example 1.

<Example 4>
The width Wr of the saddle portion was set to 2 mm. Except for this, the same as Example 1.
<Example 5>
The distance L1 from the top of the intermediate pole to the center of the resistance weld was 8 mm, and L2/L1 was 3.6. Except for this, the same as Example 1.

<Comparative Example 1>
In the width direction of the battery case, the position of the through hole was shifted to the outside (the battery case side) by 20 mm from Example 1. As a result, the position of the resistance welding part was set to a position deviated from the straight line passing through the saddle part and the ear part. Except for this, the same procedure as in Example 1 was performed.
<Comparative example 2>
In the width direction of the battery case, the welding position of the ear portion with respect to the strap was shifted by 5 mm from Example 1 (to the battery case side). As a result, the position of the ear portion was set to a position deviated from the straight line passing through the saddle portion and the resistance welding portion. Except for this, the same procedure as in Example 1 was performed.
<Comparative example 3>
In the width direction of the battery case, the position of the saddle portion at the bottom of the battery case was shifted to 19 mm outside (battery container side) of Example 1. As a result, the position of the saddle portion was set to a position deviated from the straight line passing through the ear portion and the resistance welding portion. Except for this, the same procedure as in Example 1 was performed.

<Evaluation method>
A light load life test was performed on each of the lead storage batteries manufactured in Examples 1 to 5 and Comparative Examples 1 to 3 in an atmosphere of 75° C. with reference to JIS D5301. One cycle is a cycle in which the lead storage battery is discharged at 25 A for 2 minutes and then continuously charged at 14.8 V (maximum current 25 A) for 10 minutes. Each time this cycle is repeated 480 times, the lead storage battery is left for 56 hours in an atmosphere of 25° C., after which the battery is continuously discharged at 280 A for 5 seconds, and the voltage after 5 seconds of discharge is measured. After measuring the voltage, charge the above under the same conditions. These operations were repeated, and the number of cycles until the discharge voltage at 5 seconds after discharge dropped to 7.2 V was defined as the life cycle number. Since the water content in the electrolytic solution decreased during the test, purified water was appropriately added. After the end of the life test, a disassembly survey was conducted.

<Evaluation result>
FIG. 4 is a graph showing the results of evaluating the number of life cycles of the lead storage batteries manufactured in Examples 1 to 5 and Comparative Examples 1 to 3 of the present invention. As shown in FIG. 4, the lead storage batteries of Examples 1 to 5 had a longer life than the lead storage batteries of Comparative Examples 1 to 3. As a result of the disassembly, in the positive electrode substrate, the deformation due to growth occurred in the part on the side opposite to the part connected to the ear part, but the deformation due to growth was suppressed in the vicinity of the ear part that most contributes to the electrochemical reaction. The fall of the positive electrode mixture was suppressed.

This is because the saddle part at the bottom of the battery case, the ear part of the positive electrode plate, the positive electrode strap, the resistance welding part, the top part of the positive electrode intermediate pole column are arranged in a straight line in a front view from the stacking direction of the electrode plate group, It is considered that this is because the area near the ears can be pressed down strongly from above and below.
In Comparative Example 1, the position of the resistance welding portion is deviated from the straight line passing through the saddle portion and the ear portion. For this reason, the positive electrode substrate was unable to suppress the growth in the vicinity of the ears and was deformed, and the positive electrode material mixture fell off. The positive electrode connecting body could not endure the upward growth of the positive electrode substrate and was deformed so as to be twisted.
In Comparative Example 2, the positions of the ears deviate more than in Comparative Example 1 from the straight line passing through the saddle portion and the resistance welding portion. For this reason, the positive electrode substrate was unable to suppress the growth in the vicinity of the ears and was deformed, and the positive electrode material mixture fell off. The positive electrode connecting body could not endure the upward growth of the positive electrode plate and was deformed so as to be twisted. The amount of deformation was larger than that of Comparative Example 1.

In Comparative Example 3, the upward growth of the positive electrode substrate was suppressed, but the downward growth of the positive electrode substrate occurred toward the gap between the saddle parts at the bottom of the battery case. The positive electrode substrate could not suppress the deformation in the vicinity of the ears, and the positive electrode mixture was dropped. This is because the saddle part at the bottom of the battery case is offset from the straight line, and the lower part of the positive electrode substrate, which is located vertically below the ear part, is floating from the bottom of the battery case. it is conceivable that. The positive electrode substrate that was pressed down above progressed downward growth so as to escape to the space between the saddle parts at the bottom of the battery case, and the corrosion near the ears, where electric currents tend to concentrate, progressed particularly It is considered that the deformation accompanied by the dropout of the agent occurred.

Although Examples 2 and 3 have a large number of life cycles and a long life as compared with Comparative Examples 1 to 3, there is room for improvement in suppressing the growth as compared with Example 1, and therefore, the resistance welded portion is below There was a crack. It is considered that this crack was generated because a moment was applied to the resistance welded portion with the top of the intermediate pole of the positive electrode as the fulcrum. This moment is greatly influenced by the length L2 of the positive electrode strap and the distance L1 from the top of the positive electrode intermediate pole column to the center of the diameter of the resistance welding portion when the stress due to growth is the same. In Example 1, since the value of L2/L1 was within the proper range, cracking did not occur, but in Examples 2 and 3, the value of L2/L1 was high, so that the moment applied to the resistance welding portion It is considered that cracking occurred because it was larger than No. 1.

In addition, in Example 4, although the number of life cycles is large and the life is long as compared with Comparative Examples 1 to 3, the lower horizontal frame (hereinafter, referred to as the lower frame) of the positive electrode substrate bites into the saddle part at the bottom of the battery case. As described above, there was room for improvement in suppressing the growth as compared with Example 1. In addition, in Example 4, the deformation in the vicinity of the ears of the positive electrode substrate was large as compared with Example 1, and there was room for improvement in suppressing the fall of the positive electrode mixture. This is because the width Wr of the saddle portion is small, so that the range which is the lower frame of the positive electrode substrate and is not connected to the longitudinal inner bone is in contact with the saddle portion.

In Example 1, the lower frame of the positive electrode substrate did not bite into the saddle portion. This is because the width Wr of the saddle portion at the bottom of the battery case, the maximum lattice spacing Wi of the lower end portion (bottom row) of the positive electrode substrate, and the maximum width Ww of the longitudinal internal bone satisfy the above formula (2). .. As a result, at least one vertical inner bone is connected to the lower frame of the positive electrode substrate in the range in which it contacts the saddle portion. For this reason, in the range where the lower frame contacts the saddle portion, the vertical inner bones are supported from the inside of the positive electrode substrate, and the positive electrode substrate has a stronger structure.

Example 5 had the longest life among Examples 1 to 5. Also in the result of disassembly, the deformation due to the growth in the vicinity of the ears of the positive electrode substrate was suppressed, and the fall of the positive electrode mixture was suppressed. It is considered that this is because the value of L2/L1 is shifted to a more appropriate range side than that of the first embodiment. It is considered that in Example 5, the moment applied to the resistance welded portion with the top of the intermediate pole of the positive electrode as the fulcrum was reduced when the growth occurred, and the growth could be suppressed more strongly.

(Other embodiments)
In the above embodiments, the positive electrode substrate is manufactured by the punching method, but the present invention is not limited to this. For example, the positive electrode substrate may be manufactured by the expanding method. The positive electrode substrate manufactured by the expanding method has a shape having a plurality of intersecting portions by intersecting the inner bones diagonally intersecting each other instead of having no vertical inner bones. Even in such a case, one of the plurality of saddles, the ear, the resistance weld, and the top of the intermediate pole may be aligned on a straight line when viewed from the stacking direction of the electrode plates. By designing the lead storage battery, it is possible to suppress the deformation of the positive electrode substrate near the ear portion, and to prevent the positive electrode mixture from falling off. When the inner bones are arranged obliquely, as in the case of the positive electrode substrate prepared by the expanding method, the maximum lattice spacing of the opening width dimension of the lattice should be set in the cut surface obtained by cutting the positive electrode substrate in parallel with the bottom surface of the battery case. Wi and the maximum width of the inner bone in the first direction is Ww.

Further, in the positive electrode substrate manufactured by the expanding method, the position of the inner bone may shift from one substrate to another depending on the cutting position of the rolled sheet. Even in such a case, by designing the lead storage battery so as to satisfy the above formula (2), the vertical inner bones can be surely arranged on the saddle part at the bottom of the battery case, and the structure of the positive electrode substrate is strengthened. can do. Furthermore, even in the case of a design in which the positive electrode substrate does not have a lower frame, when the inner bone reaches the lower end of the positive electrode substrate, only the positive electrode mixture does not come into contact with the saddle portion. It seems that the effect is great.
As described above, the present invention can make at least one of various omissions, substitutions, and changes of constituent elements without departing from the scope of the above-described embodiments and examples. Further, the effects described in the present specification are merely examples and are not limited, and other effects may be present.

DESCRIPTION OF SYMBOLS 1 Positive electrode plate 2 Positive electrode board 2A Ear vicinity 2B Bottom row 3 Positive electrode mixture 4 Ear part 5 Positive electrode connecting body 6 Negative electrode connecting body 7 Electrode plate group 8 Bag separator 9 Battery case 10 Lead acid battery 21 Outer frame 22 Horizontal inner bone 23 Vertical Inner bone 24 Opening 51 Outer hole connecting portion 52 Inner hole connecting portion (resistance welding portion)
91 Bottom 91a Bottom 92 Side wall 93 Saddle 94 Partition 100 Lead storage battery 511 Positive strap 511A End 512 Positive middle pole 512A Top H94 Through hole L1 Distance Mn Number of negative plates Mp Number of positive plates SL Straight line Wi Maximum lattice of vertical inner bones Interval Wr Saddle width Ww Maximum internal bone width

Claims (5)

A positive electrode plate and a negative electrode plate, a group of electrode plates alternately laminated via a separator,
A battery case containing the electrode plate group,
A positive electrode connecting body that supports the ear portion of the positive electrode plate,
The battery case is
A saddle portion provided on the bottom surface of the battery case and in contact with the positive electrode plate,
A partition for partitioning the inside of the battery case into a plurality of cell chambers,
The partition wall is provided with a through hole that connects the cell chambers adjacent to each other,
The positive electrode connecting body,
An in-hole connecting portion located inside the through hole,
An outer-hole connecting portion located outside the through-hole,
The outside-hole connecting portion has a strap and an intermediate pole, and is located on a side far from the bottom surface of the battery case, which is the saddle portion, the ear portion, the inside-hole connecting portion, and a part of the strap. The lead storage battery has an end portion that is located on a straight line when viewed from the front in the stacking direction of the electrode plates. In a front view from the stacking direction of the electrode plate group, a part of the intermediate pole, the length from the top located on the side far from the bottom surface of the battery case to the center of the diameter of the intra-hole connecting portion. Let L1 be
When the length of the positive electrode connecting body in the stacking direction is L2,
The lead acid battery according to claim 1, wherein L2/L1≦4.1. The positive electrode plate is
A plurality of first internal bones extending in a first direction intersecting the bottom surface and a plurality of second internal bones extending in a second direction intersecting the first direction; A lattice-shaped positive electrode substrate in which the first inner bones of a book and a plurality of second inner bones intersect each other,
The saddle portion is extended in the stacking direction,
The width of the saddle part is Wr,
The maximum lattice spacing of the first internal bone is Wi,
If the maximum width of the first internal bone is Ww,
The lead acid battery according to claim 1, wherein Wr≧Wi+Ww. The separator is a bag-shaped separator,
The lead acid battery according to any one of claims 1 to 3, wherein the negative electrode plate is housed in the bag-shaped separator. The positive electrode plate is
A plurality of first internal bones extending in a first direction intersecting the bottom surface and a plurality of second internal bones extending in a second direction intersecting the first direction; A lattice-shaped positive electrode substrate in which the first inner bones of a book and a plurality of second inner bones intersect with each other,
The lead storage battery according to any one of claims 1 to 4, wherein the positive electrode substrate is a substrate made of a rolled plate of lead alloy.

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