Lead-acid battery

Abstract

To suppress the occurrence of damage to a pole column due to vibration applied to a lead-acid battery.SOLUTION: The lead-acid battery includes an electric tank having a cell chamber and an opening on the top surface, a lid closing the opening, an electrode plate group having a plurality of electrode plates and housed in the cell chamber, and an electrode pole. In the lead-acid battery (except for a lead-acid battery in which a downward depression is formed in the upper-end portion of the positive electrode pole), the ratio of the mass of the electrode plate group to the smallest diameter of the electrode pole is 220 g / mm or less, and the height of the electrode column is 85 mm or less.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to lead-acid batteries. [Background technology]

[0002] Lead-acid batteries are used for various purposes, such as starting vehicle engines and as backup power sources. In particular, lead-acid batteries for starting vehicle engines supply power to the engine starter motor as well as to various electric and electronic devices mounted on the vehicle. In recent years, as an effort to protect the environment and improve fuel efficiency, the application of lead-acid batteries to micro-hybrid vehicles, such as idling stop vehicles (hereinafter referred to as "ISS vehicles") that reduce the operating time of the engine and power generation control vehicles that reduce the power generation of the alternator by the power of the engine, has been considered.

[0003] However, when a lead-acid battery is mounted on a vehicle, the lead-acid battery may be subjected to strong vibrations due to the vibrations of the vehicle. In this case, a pole, which is one of the components of the lead-acid battery, is directly subjected to stress, and the pole may be damaged. In response to this, Patent Document 1 proposes that a cylindrical body having a lower electrical resistance than the pole base material is provided inside the pole made of a lead alloy, thereby suppressing the occurrence of damage to the pole due to the vibrations. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-252625 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technology of Patent Document 1 requires a change in the material of the pole, which leads to an increase in manufacturing costs, and therefore there is a need to develop a new technology that can suppress the occurrence of pole breakage without changing the pole material. In addition, as has become clear from the investigations of the present inventors, when vibration is applied to a lead-acid battery in the stacking direction of the electrode plates, the poles are likely to be damaged, and the technology of Patent Document 1 cannot sufficiently suppress the occurrence of pole breakage.

[0006] SUMMARY OF THE PRESENT EMBODIMENTS Accordingly, an object of the present invention is to suppress the occurrence of damage to poles of a lead-acid battery due to vibration being applied thereto. [Means for solving the problem]

[0007] A lead-acid battery according to one aspect of the present invention includes a battery case having a cell chamber and an open top, a lid for closing the opening, a plate group having a plurality of electrode plates and housed in the cell chamber, and a pole, in which the ratio of the mass of the plate group to the minimum diameter of the pole is 220 g / mm or less.

[0008] According to the above-described lead-acid battery, it is possible to suppress the occurrence of damage to the poles due to vibration being applied to the lead-acid battery.

[0009] The ratio of the mass of the electrode plate assembly to the minimum diameter of the electrode post may be 200 g / mm or more, which tends to suppress the occurrence of breakage of the electrode post and increase the discharge capacity (discharge duration).

[0010] The base diameter of the electrode post may be 10.0 mm or more. In a lead-acid battery, Joule heat may be generated in the electrode post during high current discharge, etc. If the base diameter of the electrode post is 10.0 mm or more, even if Joule heat is generated, the electrode post is unlikely to melt.

[0011] The volume of the pole is 5723 mm 3 In this case, the resistance of the electrode post can be made sufficiently small, and the generation of Joule heat in the electrode post can be suppressed. As a result, melting of the electrode post due to Joule heat can be easily prevented.

[0012] The height of the pole may be 85 mm or less, which makes it easier to prevent the pole from melting down due to Joule heat.

[0013] The area of ​​the pole tip on the battery case side is 100 mm 2 In this case, it becomes easier to prevent the electrode posts from melting down due to Joule heat. Effect of the Invention

[0014] According to the present invention, it is possible to suppress the occurrence of damage to poles of a lead-acid battery caused by vibrations being applied thereto. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view showing the overall configuration and internal structure of a lead-acid battery according to one embodiment. [Diagram 2] FIG. 2 is a perspective view showing a battery case used in the lead-acid battery of FIG. [Diagram 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is an exploded perspective view for explaining an electrode plate group included in the lead-acid battery of FIG. [Diagram 5] 5(a) and 5(b) are front views showing an example of a current collector (positive electrode current collector or negative electrode current collector). [Figure 6] FIG. 6 is a partial cross-sectional view taken along line VV in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] <Lead acid battery> Fig. 1 is a perspective view showing the overall configuration and internal structure of a lead-acid battery according to an embodiment. As shown in Fig. 1, the lead-acid battery 1 according to an embodiment is a flooded lead-acid battery including a battery case 2 with an open top, a lid 3 for closing the opening of the battery case 2, a plate group 4 and an electrolyte such as dilute sulfuric acid (not shown) housed in the battery case 2, a positive pole (not shown) and a negative pole 5 (hereinafter, these are also collectively referred to as "pole 6"). The lead-acid battery according to an embodiment may be in a state before the electrolyte is poured. That is, the lead-acid battery does not need to include an electrolyte.

[0017] The lid 3 includes a positive electrode terminal 7 and a negative electrode terminal 8 (hereinafter, collectively referred to as "electrode terminals 9"), and a plurality of liquid inlet plugs 10 that close a plurality of liquid inlet holes provided in the lid 3. The lid 3 is formed of, for example, polypropylene. The positive electrode terminal 7 is connected to one end of the positive electrode pole. Similarly, the negative electrode terminal 8 is connected to one end of the negative electrode pole 5.

[0018] Fig. 2 is a perspective view showing the battery case 2 included in the lead-acid battery 1 of Fig. 1. As shown in Fig. 2, the battery case 2 has a hollow, generally rectangular parallelepiped shape and is composed of a bottom wall having a rectangular planar shape, a pair of side walls (first side walls) 21 erected on the short sides of the bottom wall, and a pair of side walls (second side walls) 22 erected on the long sides of the bottom wall. The battery case 2 is made of, for example, polypropylene.

[0019] The interior of the battery case 2 is provided with five partition walls 23 arranged approximately parallel to the first side wall 21. The five partition walls 23 are arranged at predetermined intervals, so that inside the battery case 2, six cell chambers, numbered first to sixth 24a to 24f (hereinafter collectively referred to as "cell chambers 24") are formed in this order along the second side wall 22. Each of the cell chambers 24 contains an electrode plate group 4. The electrode plate group 4 is also called a single cell, and has an electromotive force of, for example, 2V.

[0020] A plurality of ribs 25 extending in a direction perpendicular to the bottom wall (the opening surface of the battery case 2) are provided on the inner surface 21a of the first side wall 21 and on both surfaces 23a of the partition wall 23. The ribs 25 have the function of appropriately pressurizing (compressing) the electrode plate groups 4 housed in each cell chamber 24. In another embodiment, the inner surface 21a of the first side wall 21 and on both surfaces 23a of the partition wall 23 may not be provided with ribs.

[0021] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. The width X of the cell chamber 24 (the length in the stacking direction of the electrode plates) is not particularly limited, and can be adjusted by the height of the rib 25, etc. The widths of the cell chambers may be the same or different. In this specification, the width X of the cell chamber 24 is defined as the shortest distance between the first side wall 21 and the partition wall 23, or the shortest distance between the opposing partition walls 23 (hereinafter referred to as "wall-to-wall distance Xa"), when the first side wall 21 and the partition wall 23 do not have the rib 25. When the first side wall 21 and / or the partition wall 23 have a rib, the width X of the cell chamber is defined as the value obtained by subtracting the height Ha of the highest rib from the wall-to-wall distance Xa (see FIG. 3). For example, when the rib height Ha of the two opposing partition walls 23 is the same, the width X of the cell chamber is [wall-to-wall distance Xa]-(2×[rib height Ha]).

[0022] Fig. 4 is an exploded perspective view for explaining an electrode plate group included in the lead-acid battery of Fig. 1. As shown in Fig. 4, the electrode plate group 4 is formed by stacking a plurality of positive electrode plates 11, negative electrode plates 12, and separators 13 in a direction approximately perpendicular to the first side wall 21 of the battery case 2.

[0023] The positive electrode plate 11 includes a positive electrode current collector 14 and a positive electrode active material 15 held by the positive electrode current collector 14. The negative electrode plate 12 includes a negative electrode current collector 16 and a negative electrode active material 17 held by the negative electrode current collector 16. In this specification, the "positive electrode active material" refers to the positive electrode plate excluding the positive electrode current collector, and the "negative electrode active material" refers to the negative electrode plate excluding the negative electrode current collector.

[0024] 5(a) and 5(b) are front views showing a current collector (positive electrode current collector 14 or negative electrode current collector 16). In FIG. 5(a) and FIG. 5(b), the reference numerals in parentheses indicate the configuration of the negative electrode current collector. As shown in FIG. 5(a), the positive electrode current collector 14 has a positive electrode active material support portion 14a filled with a positive electrode active material, an upper frame portion (upper peripheral portion) 14b formed in a strip shape on the upper side of the positive electrode active material support portion 14a, and a positive electrode ear portion 14c provided so as to partially protrude upward from the upper frame portion 14b. The positive electrode ear portion 14c is located toward the center of the positive electrode plate 11 when viewed from the stacking direction of the positive electrode plate 11. The outer shape of the positive electrode active material support portion 14a is, for example, rectangular (rectangle or square) and is formed in a lattice shape. The positive electrode active material support portion 14a may have a shape in which the lower corner is cut off, as shown in FIG. 5(b). Similarly, the negative electrode current collector 16 has a negative electrode active material support portion 16a filled with a negative electrode active material, an upper frame portion (upper peripheral portion) 16b formed in a strip shape on the upper side of the negative electrode active material support portion 16a, and a negative electrode ear portion 16c provided so as to partially protrude upward from the upper frame portion 16b. The negative electrode ear portion 16c is located toward the center of the negative electrode plate 12 when viewed from the stacking direction of the negative electrode plate 12. The negative electrode active material support portion 16a has an outer shape of, for example, a rectangle (rectangle or square) and is formed in a lattice shape. The negative electrode active material support portion 16a may have a shape in which a lower corner is cut off, as shown in FIG. 5(b).

[0025] The positive electrode current collector 14 and the negative electrode current collector 16 are each formed of, for example, a lead-calcium-tin alloy, a lead-calcium alloy, a lead-antimony alloy, etc. By forming these lead alloys into a lattice shape by gravity casting, expanding, punching, etc., the positive electrode current collector 14 having the positive electrode ears 14c and the negative electrode current collector 16 having the negative electrode ears 16c are obtained, respectively.

[0026] The positive electrode active material 15 contains PbO2 as a Pb component, and further contains a Pb component other than PbO2 (e.g., PbSO4) and an additive as necessary. The negative electrode active material 17 contains simple Pb as a Pb component, and further contains a Pb component other than simple Pb (e.g., PbSO4) and an additive as necessary.

[0027] Although not shown in FIG. 4, as shown in FIG. 1, the positive electrode ears 14c are welded together with a positive electrode strap 18. Similarly, the negative electrode ears 16c are welded together with a negative electrode strap 19. The negative electrode strap 19 in the electrode plate group 4 housed in the first cell chamber 24a is connected to the negative electrode pole 5 extending from the negative electrode terminal 8 into the battery case 2 via a connection member 20. Although not shown, like the negative electrode strap 19 in the electrode plate group 4 housed in the first cell chamber 24a, the positive electrode strap 18 in the electrode plate group 4 housed in the sixth cell chamber 24f is connected to the positive electrode pole extending from the positive electrode terminal 7 into the battery case 2 via a connection member. The straps (positive electrode strap 18 and negative electrode strap 19) and the connection member 20 are each made of lead, a lead alloy (for example, an alloy containing Pb, Sb, As, etc.), or the like. In another embodiment, the connection member 20 may not be provided. That is, the positive poles may be directly connected (eg, welded) to the positive straps 18 , and the negative poles 5 may be directly connected (eg, welded) to the negative straps 19 .

[0028] 4, the number of electrode plates (positive electrode plates 11 and negative electrode plates 12) in the electrode plate group 4 is 7 positive electrode plates and 8 negative electrode plates, but is not limited to this. For example, the number of electrode plates may be 5 positive electrode plates and 6 negative electrode plates, or 6 positive electrode plates and 7 negative electrode plates.

[0029] The thickness Y of the electrode plate group 4 is not particularly limited and can be adjusted by the thickness of the electrode plates, the thickness of the separator 13, the thickness of the spacer, etc. In this specification, the thickness Y of the electrode plate group 4 means the thickness of the electrode plate group in a state where no compressive force is applied to the electrode plate group 4 from the battery case 2, and means the thickness of the electrode plate group after chemical formation.

[0030] The thickness Y of the electrode plate group 4 is defined as the average value of the thicknesses of the electrode plate group 4 measured at three points, one at the center in the longitudinal direction of the electrode plate group 4, one at an arbitrary position to the right of the center, and one at an arbitrary position to the left of the center, in a range of ±3 mm in the short direction (the direction in which the lug extends among the directions perpendicular to the lamination direction) from the lower end (the boundary between the region filled with the electrode active material and the upper frame part of the current collector) of the electrode plate (negative electrode plate 12 in FIG. 4) located at the outermost part of the electrode plate group 4. Here, in the case of a configuration in which a separator 13 is arranged at the outermost part of the electrode plate group 4 as shown in FIG. 4, the height of the rib 13b of the separator 13 is not included in the thickness of the electrode plate group 4. That is, in the case of a configuration in which a separator 13 is arranged at the outermost part of the electrode plate group 4, the thickness of the electrode plate group 4 is measured at the position of the part (base part) 13a supporting the rib 13b of the separator 13. However, in cases where the first side wall 21 of the battery case 2 does not have a rib 25, for example, and the rib 13b of the separator arranged on the outermost side of the plate group contacts the first side wall 21 or the partition wall 23 of the battery case 2, the height of the rib 13b is included in the thickness of the plate group. The thickness Y of the plate group 4 in a lead-acid battery after chemical formation can be measured, for example, by taking out the plate group 4 after chemical formation, washing it with water for one hour, and then thoroughly drying the plate group 4 from which the sulfuric acid has been removed in a system free of oxygen.

[0031] The difference (clearance: XY) between the width X (unit: mm) of the cell chamber 24 in the battery case 2 and the thickness Y (unit: mm) of the electrode plate group 4 may be 2.0 mm or less, 1.8 mm or less, 1.7 mm or less, or 1.6 mm or less, or 1.2 mm or more, 1.4 mm or more, 1.5 mm or more, or 1.6 mm or more. The above upper and lower limit values ​​can be arbitrarily combined. That is, the clearance (XY) may be, for example, 1.2 to 2.0 mm, 1.4 to 1.8 mm, or 1.5 to 1.7 mm. In the following similar descriptions, the upper and lower limit values ​​individually described can be arbitrarily combined.

[0032] Next, the electrode column 6 will be described in detail with reference to FIG. 6. FIG. 6 is a partial cross-sectional view taken along the line VV in FIG. 1. The electrode column 6 shown in FIG. 6 is a negative electrode column 5, but the positive electrode column has a similar (for example, identical) structure to the negative electrode column. The negative electrode column 5 (electrode column 6) extends from the lid 3 into the battery case 2. More specifically, the negative electrode column 5 is formed in a truncated cone shape extending from a negative electrode terminal 8 provided on the lid 3. The negative electrode column 5 has an upper base 5a (6a) and a lower base 5b (6b). The end of the negative electrode column 5 on the upper base 5a side is welded to the negative electrode terminal 8, and a welded portion 30 is formed at the connection portion between the negative electrode column 5 and the negative electrode terminal 8. On the other hand, the end of the negative electrode column 5 on the lower base 5b side is welded to the connection member 20. With the above configuration, the negative electrode column 5 electrically connects the electrode plate group 4 to the negative electrode terminal 8. In another embodiment, the negative electrode column 5 may be cylindrical. In another embodiment, the shape of the cross section perpendicular to the extension direction of the negative electrode pillar 5 does not have to be circular, and may be, for example, rectangular. In another embodiment, the positive electrode pillar and the negative electrode pillar may have different structures.

[0033] The height h of the electrode post 6 (the length in the extending direction of the electrode post 6) is preferably 85 mm or less, and more preferably 84 mm or less, from the viewpoint of further suppressing the occurrence of breakage of the electrode post. The height h of the electrode post 6 may be 46 mm or more or 63 mm or more, from the viewpoint of easily suppressing the overflow of the electrolyte even when the liquid level of the electrolyte is raised, and of being able to electrically connect the electrode plate group 4 and the electrode terminal 9. From these viewpoints, the height h of the electrode post 6 may be 46 to 85 mm, 63 to 85 mm, or 63 to 84 mm. The height h of the electrode post 6 is the shortest distance from the tip of the electrode post 6 on the battery case 2 side to the tip of the electrode post 6 on the lid 3 side, as shown in FIG. 6. The height h of the pole 6 can be obtained, for example, by cutting the electrode terminal 9 portion of the lead-acid battery as shown in Figure 6 and observing it, and measuring the shortest distance from the boundary of the welded portion between the connection member 20 and the pole 6 (the tip of the pole 6 on the battery case 2 side) to the boundary of the welded portion between the welded portion 30 and the pole 6 (the tip of the pole 6 on the lid 3 side).

[0034] The base diameter R of the electrode post 6 (diameter of the end on the battery case 2 side) may be 9.5 mm or more, 9.6 mm or more, or 9.8 mm or more. From the viewpoint of easily suppressing meltdown of the electrode post, the base diameter R of the electrode post 6 is preferably 10.0 mm or more, more preferably 11.2 mm or more, and even more preferably 12.5 mm or more. From the viewpoint of advantageously reducing the weight of the lead-acid battery, the base diameter R may be 13.0 mm or less or 12.5 mm or less. From these viewpoints, the base diameter R may be 9.5 to 13.0 mm, 9.6 to 13.0 mm, 9.8 to 13.0 mm, 10.0 to 13.0 mm, 10.0 to 12.5 mm, 11.2 to 13.0 mm, 11.2 to 12.5 mm, or 12.5 to 13.0 mm. 6, the root diameter R of the electrode post 6 means the length in a direction perpendicular to the height direction of the electrode post 6 at the tip of the electrode post 6 on the battery case 2 side (for example, the boundary of the weld between the connection member 20 and the electrode post 6). If the shape of the cross section perpendicular to the height direction of the electrode post 6 is circular, the root diameter R of the electrode post 6 means the diameter of the circle, and if the shape of the cross section perpendicular to the height direction of the electrode post 6 is a shape other than circular (for example, polygonal), the root diameter R of the electrode post 6 means the diameter of the inscribed circle.

[0035] The minimum diameter r of the electrode post 6 is preferably 6.8 mm or more, more preferably 7.0 mm or more, from the viewpoint of further suppressing the occurrence of breakage of the electrode post. The minimum diameter r may be 7.2 mm or less or 7.1 mm or less, from the viewpoint of advantageously reducing the weight of the lead-acid battery. From these viewpoints, the minimum diameter r may be 6.8 to 7.2 mm, 6.8 to 7.1 mm, 7.0 to 7.2 mm, or 7.0 to 7.1 mm. The minimum diameter r of the electrode post 6 is the minimum value of the length in the direction perpendicular to the height direction of the electrode post 6. In this embodiment, as shown in FIG. 6, the length in the direction perpendicular to the height direction of the electrode post 6 at the tip of the electrode post 6 on the lid 3 side (the boundary of the weld between the welded portion 30 and the electrode post 6) is the minimum diameter r.

[0036] The area S of the tip surface of the pole 6 on the battery case 2 side (for example, the surface where the pole 6 and the connecting member 20 contact) is 71 mm 2 That's it, 72mm 2 or more than 75mm 2The area S is preferably 100 mm2 or more from the viewpoint of easily suppressing meltdown of the pole. 2 More preferably, 123 mm or more. 2 The area S is set to 133 mm from the viewpoint of reducing the weight of the lead-acid battery. 2 Less than or equal to 123mm 2 From these viewpoints, the area S may be 71 to 133 mm 2 , 72~133mm 2 , 75~133mm 2 , 100~133mm 2 , 100~123mm 2 Or 123~133mm 2 It may be.

[0037] The volume V of the pole 6 is set to 6855 mm from the viewpoint of reducing the weight of the lead-acid battery. 3 Less than or equal to 6831mm 3 The volume V of the pole 6 may be 4400 mm 3 or more than 4610mm 3 The volume V of the electrode post 6 is preferably 5723 mm from the viewpoint of making the resistance of the electrode post sufficiently small and easily suppressing the generation of Joule heat in the electrode post and thus preventing the electrode post from melting. 3 More preferably, 6276 mm 3 More preferably, 6831 mm 3 From these viewpoints, the volume V of the pole 6 is 4400 to 6855 mm 3 , 4610~6855mm 3 , 5723~6855mm 3 , 6276~6855mm 3 , 6276~6831mm 3 Or 6831~6855mm 3 The volume V of the pole 6 can be calculated by measuring the dimensions of the pole.

[0038] The composition of the electrode posts 6 (positive electrode posts and negative electrode posts 5) may be the same as that of the straps (positive electrode straps 18 and negative electrode straps 19) and the connecting members 20. For example, the electrode posts 6 may be made of a Pb—Sb based alloy.

[0039] The separator 13 includes a flat (sheet) base portion 13a, and a plurality of ribs 13b and a plurality of mini ribs 13c formed on the outer surface of the base portion 13a. The separator 13 is formed in a bag shape and accommodates the negative electrode plate 12. Specifically, a long sheet including the base portion 13a, the plurality of ribs 13b and the plurality of mini ribs 13c is folded back so that the ribs 13b and the mini ribs 13c are on the outside, and closed along the long side to form a bag shape. In another embodiment, the separator 13 may accommodate the positive electrode plate 11. Furthermore, the separator 13 does not have to be formed in a bag shape.

[0040] The separator 13 includes at least one material selected from the group consisting of glass, pulp, and synthetic resin, for example. The separator 13 may be a flexible separator, and may be a separator made of a synthetic resin from the viewpoint of further suppressing short circuits and of facilitating compression of the electrode plate group 4 due to its flexibility. Among synthetic resins, polyolefins (e.g., polyethylene and polypropylene) are particularly preferably used.

[0041] Although not shown in FIG. 4, a spacer may be provided between the positive electrode plate 11 and the negative electrode plate 12. The spacer may be provided between the positive electrode plate 11 and the separator 13, or between the negative electrode plate 12 and the separator 13. In this embodiment, since the electrode plate group 4 includes the spacer, the maximum acceleration of the electrode pole when the lead-acid battery is vibrated can be reduced, and the occurrence of breakage of the electrode pole can be further suppressed. The spacer is formed, for example, in a sheet shape. The spacer is, for example, a porous film (porous film), for example, a nonwoven fabric.

[0042] The spacer is not particularly limited in terms of its constituent material, so long as it is resistant to the electrolyte. Specific examples of the spacer constituent material include organic fibers, inorganic fibers, pulp, and inorganic oxide powder. The spacer may be made of a mixed fiber containing inorganic fibers and pulp, or an organic-inorganic mixed fiber containing organic fibers and inorganic fibers. Examples of organic fibers include polyolefin fibers (polyethylene fibers, polypropylene fibers, etc.), and polyethylene terephthalate fibers. Examples of inorganic fibers include glass fibers.

[0043] From the viewpoint of reducing the maximum acceleration of the poles and further suppressing the occurrence of breakage of the poles, the spacer is preferably a glass mat formed by processing glass fibers into a felt-like material. Examples of glass fibers include chopped strands and milled fibers. The glass mat may be made of glass fibers alone, or may contain materials other than glass fibers (such as the above-mentioned organic fibers).

[0044] In this embodiment, the ratio (M / r) of the mass M (unit: g) of the electrode plate group 4 to the minimum diameter r (unit: mm) of the electrode post 6 is 220 g / mm or less. By setting the ratio (M / r) to 220 g / mm or less, the occurrence of damage to the electrode posts due to vibration applied to the lead-acid battery is suppressed. The ratio (M / r) may be 215 g / mm or less or 212 g / mm or less. From the viewpoints of suppressing the occurrence of damage to the electrode posts and increasing the discharge capacity (discharge duration), the ratio (M / r) may be 200 g / mm or more. From these viewpoints, the ratio (M / r) may be 200 to 220 g / mm, 200 to 215 g / mm, or 200 to 212 g / mm. In this embodiment, it is sufficient that at least one of the ratio (M / r1) of the mass M (unit: g) of the plate group 4 to the minimum diameter r1 (unit: mm) of the positive electrode column and the ratio (M / r2) of the mass M (unit: g) of the plate group 4 to the minimum diameter r2 (unit: mm) of the negative electrode column 5 satisfies the range of the above ratio (M / r), and it is preferable that both the ratio (M / r1) and the ratio (M / r2) satisfy the range of the above ratio (M / r).

[0045] The mass M of the plate group 4 is the mass after formation. The mass of the strap (positive electrode strap 18 or negative electrode strap 19) and the connecting member 20 is not included in the mass M of the plate group 4. The mass M of the plate group 4 in the lead-acid battery after formation can be measured, for example, by the following method. First, the plate group 4 housed in the cell chamber (e.g., the first cell chamber 24a or the sixth cell chamber 24f) in which the pole of the lead-acid battery 1 after formation is located is removed from the battery case 2. Next, the plate group 4 and the strap are separated at the boundary between the lug of the electrode plate of the plate group 4 and the strap. The obtained electrode plate group 4 is washed with water for 1 hour, and the washed electrode plate group 4 is thoroughly dried in an oxygen-free system (for example, dried at 50°C for 24 hours). Next, the mass of the electrode plate group 4 is measured (if any electrode active materials have fallen off from the electrode plate group 4 during the washing and drying process, they are collected and included in the mass of the electrode plate group 4 before the mass of the electrode plate group 4 is measured). This gives the mass M of the electrode plate group 4.

[0046] From the viewpoint of further suppressing the occurrence of breakage of the electrode columns, the mass M of the electrode plate group 4 is preferably 1550g or less, more preferably 1530g or less, and even more preferably 1510g or less. From the viewpoint of suppressing the occurrence of breakage of the electrode columns and increasing the discharge capacity (discharge duration), the mass M of the electrode plate group 4 may be 1000g or more, 1200g or more, or 1400g or more. From these viewpoints, the mass M of the electrode plate group 4 may be 1000 to 1550g, 1200 to 1530g, or 1400 to 1510g.

[0047] The lead-acid battery 1 having the above configuration can suppress the occurrence of damage to the poles when subjected to vibration. In particular, compared to conventional lead-acid batteries, there is a tendency for the occurrence of damage to the poles when vibration is applied in the stacking direction of the electrode plates to be suppressed.

[0048] The manufacturing method for the lead-acid battery described above includes, for example, a step of accommodating the plate group 4 in the cell chamber 24 of the battery case 2 (accommodating step), a step of electrically connecting the straps (positive electrode strap 18 and negative electrode strap 19) of the plate group 4 to the electrode terminals 9 (positive electrode terminal 7 and negative electrode terminal 8) via the poles 6 (positive electrode pole and negative electrode pole 5) (connecting step), a step of supplying an electrolyte into the battery case 2 (supplying step), and a step of forming the unformed battery after the electrolyte has been supplied (formation step).

[0049] The electrode plate group 4 may be obtained, for example, by an electrode plate manufacturing process for obtaining unformed electrode plates (unformed positive electrode plates and unformed negative electrode plates), and a process for stacking a bag-shaped separator 13 with the unformed negative electrode plates obtained in the electrode plate manufacturing process disposed therein, a spacer, and an unformed positive electrode plate in this order, and connecting (such as welding) the ears of the electrode plates of the same polarity with a strap (positive electrode strap 18 or negative electrode strap 19) to obtain the electrode plate group 4. In the electrode plate manufacturing process, for example, an electrode active material paste (positive electrode active material paste and negative electrode active material paste) is filled into a current collector (for example, a current collector grid such as a cast grid or an expanded grid), and then aging and drying are performed to obtain an unformed electrode plate.

[0050] The electrode active material paste contains, for example, the raw material of the electrode active material (such as lead powder) and may further contain other additives. The electrode active material paste can be obtained, for example, by adding additives (such as short reinforcing fibers) and water to the raw material of the electrode active material, adding dilute sulfuric acid, and kneading the mixture.

[0051] In the connection step, the pole 6 is electrically connected via the connection member 20 to a strap that connects the lug of the electrode terminal 9 to which the pole 6 is connected and that has the same polarity.

[0052] In the supplying step, the opening of the battery container 2 of the unformed battery obtained through the above-mentioned accommodation step and connection step is closed with the lid 3, and then the electrolyte is supplied (injected) into the battery container 2.

[0053] The formation step may be, for example, a step of supplying an electrolyte solution and then passing a direct current to form a battery container. After formation, the specific gravity of the electrolyte solution may be adjusted to an appropriate specific gravity. In this way, a formed lead-acid battery (flooded lead-acid battery) 1 is obtained.

[0054] The chemical formation conditions and the specific gravity of sulfuric acid can be adjusted according to the properties of the electrode active material. In addition, the chemical formation is not limited to being performed after obtaining an unformed battery, but may be performed after aging and drying in the electrode plate manufacturing process (tank chemical formation).

[0055] Although one embodiment of the lead acid battery and the manufacturing method thereof according to the present invention has been described above, the present invention is not limited to the above embodiment.

[0056] In the above embodiment, the lead-acid battery 1 is a flooded lead-acid battery, but in another embodiment, the lead-acid battery may be, for example, a valve-regulated lead-acid battery, a sealed lead-acid battery, etc. In the above embodiment, the lead-acid battery 1 is, for example, an automotive lead-acid battery, and six electrode plate groups 4 are connected in series to drive the battery by stepping up or stepping down a DC voltage of 12 V. That is, the number of cell chambers is six, and 2 V x 6 = 12 V. When the lead-acid battery 1 is used for another purpose, the number of cell chambers does not have to be six. EXAMPLES

[0057] The present invention will be specifically described below with reference to examples, although the present invention is not limited to the following examples.

[0058] Example 1 An expanded grid (current collector) was produced by subjecting a rolled sheet made of a lead alloy to an expanding process. Then, lead powder, red lead (Pb3O4), additives, and water were mixed and kneaded, and dilute sulfuric acid was added little by little while kneading further to produce a positive electrode active material paste. Similarly, lead powder, additives, and water were mixed and kneaded, and dilute sulfuric acid was added little by little while kneading further to produce a negative electrode active material paste. Next, the positive electrode active material paste and the negative electrode active material paste were each filled into a current collector, and aged for 24 hours in an atmosphere at a temperature of 50°C and a humidity of 98%. Then, they were dried to obtain an unformed positive electrode plate and an unformed negative electrode plate.

[0059] A pouch-shaped separator made of microporous polyethylene with a base part 0.25 mm thick and a rib part 0.70 mm high was prepared. Unformed negative plates were housed in this separator, and five unformed positive plates and six unformed negative plates housed in the pouch-shaped separator were alternately stacked. Next, the ears of the plates of the same polarity were welded together using the cast-on-strap (COS) method to create an electrode plate group.

[0060] A 12V battery was assembled by housing the electrode plates in each cell chamber of a battery case having six cell chambers. At this time, in the cell chambers at both ends (the first and sixth cell chambers), the plate groups were housed in the cell chambers, and the straps and the poles (positive poles or negative poles) were electrically connected via connecting members. The clearance (cell chamber width X--plate group thickness Y) was adjusted to be 1.6 mm. When housing the plate groups in the cell chambers, the pressure F applied to the plate groups in a direction perpendicular to the opening of the battery case was 3.5 N. The poles (positive poles and negative poles) had a height h of 84 mm, a minimum diameter r of 7.0 mm, a base diameter R of the poles of 9.6 mm, and a volume V of 4449.8 mm. 3 The area S of the lower end (the area of ​​the surface in contact with the connecting member) is 72 mm 2 The lead alloy was an alloy of lead and antimony (Sb), and the content of antimony in the lead alloy was 2.9 mass % based on the total mass of the lead alloy.

[0061] Next, an electrolyte (dilute sulfuric acid) was poured into the battery container. After that, the electrolyte was formed in a water tank at 35° C. for 18 hours at a current of 18.6 A to obtain a flooded lead-acid battery. The mass M of the electrode plate group after the formation was 1476 g.

[0062] Example 2 A lead-acid battery was produced in the same manner as in Example 1, except that the configuration of the electrode pillars was changed as shown in Table 1, and the configuration of the electrode plate group was changed so that the mass M of the electrode plate group was the value shown in Table 1. The mass M of the electrode plate group was adjusted by changing the amount of electrode active material filled and by forming the electrode plate group by alternately stacking six unformed positive electrode plates and seven unformed negative electrode plates each housed in a bag-shaped separator.

[0063] Example 3 A lead-acid battery was produced in the same manner as in Example 1, except that the configuration of the electrode pillars was changed as shown in Table 1, and the configuration of the electrode plate group was changed so that the mass M of the electrode plate group was the value shown in Table 1. The mass M of the electrode plate group was adjusted by changing the amount of electrode active material filled and by forming the electrode plate group by alternately stacking seven unformed positive electrode plates and eight unformed negative electrode plates each housed in a bag-shaped separator.

[0064] Example 4 A lead-acid battery was produced in the same manner as in Example 3, except that the configuration of the electrode plate group was changed so that the mass M of the electrode plate group had the value shown in Table 1. The mass M of the electrode plate group was adjusted by the amount of electrode active material filled.

[0065] Comparative Example 1 A lead-acid battery was produced in the same manner as in Example 3, except that the configuration of the electrode plate group was changed so that the mass M of the electrode plate group had the value shown in Table 1. The mass M of the electrode plate group was adjusted by the amount of electrode active material filled.

[0066] <Vibration test> A vibration test was carried out on the lead-acid batteries of the examples and the comparative examples. Specifically, the lead-acid batteries were vibrated in the stacking direction of the electrode plates under the following conditions. The vibration test was carried out multiple times by changing the vibration frequency. [conditions] Test equipment: Random vibration control system (i230 / SA2M) (product name, manufactured by IMV Corporation) Frequency: 24.0Hz, 37.5Hz, 39.5Hz, 45.5Hz, 51.0Hz Vibration time at each frequency: 1200 minutes

[0067] After the test, the lid of the lead-acid battery was removed, and the presence or absence of damage to the poles of the lead-acid battery after the test was visually confirmed. If no damage occurred to the poles at any frequency, it was rated as A, if cracks occurred in the poles at any frequency, it was rated as B, and if the poles broke at any frequency, it was rated as C. The results are shown in Table 1.

[0068] <Fusing test> A meltdown test was conducted on the lead-acid batteries of the examples and comparative examples. Specifically, the lead-acid batteries were first left in a water tank at 40°C for 16 hours or more, then fully charged, and discharged at a constant current of 400A for 1 minute. At this time, the electrolyte level was set to a height (Lower Level) at which the top of the strap was immersed in the electrolyte. If the voltage reached 6V within 1 minute, the test was terminated.

[0069] After the test, the lid of the lead-acid battery was removed, and the presence or absence of melting of the poles in the lead-acid battery after the test was visually confirmed. If the poles were not melted, it was rated as A, and if the poles were melted, it was rated as B. The results are shown in Table 1.

[0070] [Table 1] [Explanation of symbols]

[0071] Reference Signs List 1...lead-acid battery, 2...case, 3...lid, 4...plate group, 5...negative electrode column, 6...electrode column, 7...positive electrode terminal, 8...negative electrode terminal, 9...electrode terminal, 10...liquid outlet plug, 11...positive electrode plate, 12...negative electrode plate, 13...separator, 14...positive electrode collector, 14c...positive electrode lug, 15...positive electrode active material, 16...negative electrode collector, 16c...negative electrode lug, 17...negative electrode active material, 18...positive electrode strap, 19...negative electrode strap, 20...connecting member, 24...cell chamber, 30...welded portion, r...minimum diameter, R...root diameter.

Claims

1. A battery case having a cell chamber and an open top; A lid for closing the opening; an electrode plate group having a plurality of electrode plates and accommodated in the cell chamber; A pole and a The ratio of the mass of the electrode plate group to the minimum diameter of the electrode post is 220 g / mm or less, A lead-acid battery in which the height of the pole is 85 mm or less (excluding lead-acid batteries in which a downward recess is formed at the upper end portion of the positive pole).

2. 2. The lead-acid battery according to claim 1, wherein the base diameter of the electrode post is 10.0 mm or more.

3. 3. The lead-acid battery according to claim 1, wherein the base diameter of the electrode post is 12.5 mm or less.

4. The lead-acid battery according to any one of claims 1 to 3, wherein the pole pillar is frustum-shaped.

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