JP2018092959A - Lead acid battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve long life by restraining short circuit at the upper part of an electrode plate group due to dropped active material.SOLUTION: In a lead acid battery 1 including an electrode plate group 11 where a positive electrode plate 12 and a negative electrode plate 13 are laminated alternately via a separator, and the current collector 22 of the positive electrode plate 12 and the current collector 32 of the negative electrode plate 13 are welded collectively to the positive electrode strap 15 and the negative electrode strap 16 for each polarity, the positive electrode plate 12 and negative electrode plate 13 have filling parts 24, 34 filled with an active material, respectively, alloy composition of the positive electrode strap 15 and the negative electrode strap 16 is lead-antimony-based, and S/V is 3.95-4.00 cm, where S is the total surface area of the filling part 24 of the positive electrode plate 12, and V is the apparent volume of the filling part 24 of the positive electrode plate 12 and the filling part 34 of the negative electrode plate 13.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a lead-acid battery.

  Lead storage batteries are widely used for industrial use and consumer use because of their reliability and low price. In particular, there is a great demand for lead storage batteries for automobiles (so-called batteries).

  Conventionally, in lead-acid batteries for automobiles, a paste-type electrode plate in which a predetermined amount of active material paste is filled in a lead alloy lattice is used. There are a positive electrode plate and a negative electrode plate in the electrode plate of a lead storage battery (hereinafter also simply referred to as a battery). Each of the positive electrode plate and the negative electrode plate has a current collector (ear part). Then, the positive electrode plate and the negative electrode plate are alternately laminated via the separator, and the current collecting portions of the positive electrode plate and the negative electrode plate are collectively welded to the strap for each polarity, and the inter-cell connection portion or the pole column is connected to the strap. The electrode plate group is configured.

  As the separator, a so-called bag separator is used in which a microporous sheet made of a synthetic resin is folded in two and both sides thereof are sealed to form a bag. By inserting the electrode plate into the bag separator, the positive electrode plate and the negative electrode plate can be reliably separated. The electrode plate to be inserted into the bag separator may be either a positive electrode plate or a negative electrode plate. There are both types of batteries in which the positive electrode plate is inserted into the bag separator and the negative electrode plate is inserted into the bag separator. . A battery of the type in which a positive electrode plate is inserted into a bag separator may break through the bag separator due to corrosion and deformation of the positive electrode plate when used at a high temperature. For this reason, a battery of a type in which a negative electrode plate is inserted into the separator is usually employed from the viewpoint of preventing breakage of the separator.

  By the way, in recent automobiles, since the number of electrical components has increased, the load on the battery has increased. As a result, the discharge amount of the battery is increased. As an index of the discharge amount of the battery, there is a discharge depth DOD (Depthof Discharge). The discharge depth DOD indicates that the discharge amount increases as the value increases.

  When the battery is charged / discharged under a condition where the DOD is large, a softening phenomenon in which the connection between the active materials weakens in the positive electrode plate, and the active material gradually drops from the lattice. The dropped active material floats in the electrolytic solution (dilute sulfuric acid) and eventually settles at the bottom of the battery. The active material precipitated at the bottom of the battery is lifted up to the upper part of the electrode plate group by the gas generated by charging the battery, and adheres and deposits on the upper part of the positive electrode plate and the negative electrode plate. As a result, when charging / discharging of the battery was repeated, there was a problem that the active material caused a short circuit in the upper part of the electrode plate group, resulting in a short battery life.

  Therefore, in order to solve such a problem, Patent Document 1 discloses a lead storage battery including an electrode plate group in which a positive electrode plate and a negative electrode plate accommodated in a bag separator are alternately stacked. It is disclosed that an electrode member for capturing a fallen active material electrically connected to a negative electrode plate is provided on the outside. As a result, the active material that has fallen off the positive electrode plate can be captured by the electrode member for capturing the dropped active material.

JP-A-8-130030

  However, the force that is lifted by the gas generated by the dropped active material is greater than the force by which the negative electrode plate captures the dropped positive electrode active material. For this reason, even if the electrode member for capturing the fallen active material described in Patent Document 1 is provided, the fallen active material may be captured and leaked. Thereby, the fallen active material may adhere and accumulate also on the negative electrode plate accommodated in the bag separator, and a short circuit may occur in the upper part of the electrode plate group.

  Then, an object of this invention is to provide the lead acid battery which can aim at the lifetime improvement by suppressing the short circuit in the electrode group upper part by the dropped active material.

A lead-acid battery according to one aspect of the present invention includes an electrode plate group in which positive and negative electrode plates are alternately stacked via separators, and current collectors of the positive and negative electrode plates are collectively welded to straps for each polarity. The positive electrode plate and the negative electrode plate each have a filling portion filled with an active material, the total surface area of the filling portion of the positive electrode plate is S, the filling portion of the positive electrode plate and the filling portion of the negative electrode plate When the apparent volume is V, S / V is 3.95 cm ⁻¹ or more. Here, the apparent volume of the filling portion of the positive electrode plate and the filling portion of the negative electrode plate is a volume of a region surrounded by the filling portion of the positive electrode plate and the filling portion of the negative electrode plate, and a gap between adjacent filling portions. It is an apparent volume including The total surface area of the filling portion of the positive electrode plate is the total surface area of the portions contributing to power generation of the positive electrode plate. That is, it is an area obtained by multiplying the total surface area of the front and back surfaces of the filling portion by the number of positive electrode plates constituting the electrode plate group.

By setting S / V to 3.95 cm ⁻¹ or more, the progress of softening of the active material of the positive electrode plate is suppressed in the charge / discharge cycle of the lead storage battery as compared with the case where S / V is less than 3.95 cm ^−1. It is thought. For this reason, in the lead acid battery which concerns on ¹ side of this invention, since the short circuit in the electrode group upper part by the dropped active material is suppressed compared with the case where S / V is less than 3.95 cm < ^-1 >, charging / discharging The number of possible times increases, and the life of the lead-acid battery can be extended.

In the above lead storage battery, S / V may be 4.20 cm ⁻¹ or more. Since it is considered that the progress of softening of the active material of the positive electrode plate is further suppressed in the charge / discharge cycle of the lead storage battery by setting S / V to 4.20 cm ⁻¹ or more, the life of the lead storage battery is further extended. Can be planned.

  In the lead storage battery, the alloy composition of the strap may be a lead-antimony system. By making the alloy composition of the strap lead-antimony, the charge characteristics of the lead-acid battery are improved as compared with the case where the alloy composition of the strap is lead-tin.

  According to the present invention, a short circuit at the upper part of the electrode plate group due to the dropped active material can be suppressed, and the life can be extended.

It is a perspective view of a lead acid battery concerning an embodiment. It is a figure which shows the internal structure of the lead acid battery shown in FIG. It is a perspective view which shows an electrode group. It is a front view which shows a positive electrode plate (negative electrode plate). It is sectional drawing in the VV line of FIG. It is a front view which shows the lattice body of lead alloy. It is a front view which shows a microporous polyethylene sheet. It is a figure which shows the state which puts a negative electrode plate in a bag separator. It is a perspective view which shows a battery case. It is a table | surface which shows the experimental result of an Example.

  Hereinafter, with reference to drawings, a suitable embodiment of a lead acid battery concerning one side of the present invention is described in detail. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

  FIG. 1 is a perspective view of a lead-acid battery according to an embodiment. FIG. 2 is a diagram showing an internal structure of the lead storage battery shown in FIG. As shown in FIGS. 1 and 2, the lead storage battery 1 according to this embodiment includes a battery case 2 in which an upper surface is opened and a plurality of electrode plate groups 11 are accommodated, and a lid 3 that closes the opening of the battery case 2. It is equipped with. The lid 3 is made of, for example, polypropylene, and includes a positive electrode terminal 4, a negative electrode terminal 5, and a liquid port plug 6 that closes a liquid injection port provided in the lid 3.

  FIG. 3 is a perspective view showing the electrode plate group. As shown in FIGS. 2 and 3, the electrode plate group 11 includes a positive electrode plate 12, a negative electrode plate 13, a bag separator 14, a positive electrode side strap 15, a negative electrode side strap 16, an inter-cell connection portion 17 or an electrode. And a pillar 18.

(Positive electrode plate)
FIG. 4 is a front view showing a positive electrode plate (negative electrode plate). 5 is a cross-sectional view taken along line VV in FIG. FIG. 6 is a front view showing a lead alloy lattice. 4 to 6, the reference numerals in parentheses indicate the reference numerals of the negative electrode plates. As shown in FIGS. 4 to 6, the positive electrode plate 12 includes a lead alloy lattice body 21, a current collector 22 connected to an upper portion of the lattice body 21 and called an ear portion, and an active material filled in the lattice body 21. And a substance 23. The active material 23 of the positive electrode plate 12 is also referred to as a positive electrode active material.

  The lattice body 21 is formed in a lattice shape in order to hold the active material 23 to be filled. As the lattice body 21, for example, an expanded lattice body in which a slit is formed in a lead alloy sheet and the slit is expanded so as to be expanded, or a lattice body manufactured by a casting method can be used. In the drawing, an expanded lattice body 21 is shown. The lattice body 21 of the expanded lattice body includes a lattice-shaped bone portion 21a and an upper frame bone 21b that is positioned above the bone portion 21a and extends linearly. In this case, the active material 23 is filled in the bone part 21a. Examples of the lead alloy used for the lattice body 21 of the expanded lattice body include a lead-calcium-tin alloy. Examples of the lead alloy used for the lattice body 21 manufactured by the casting method include a lead-calcium-tin system or a lead-antimony-arsenic system. The width W1 of the lattice body 21 can be set to, for example, 145 mm. The height H1 of the lattice body 21 can be set to 115 mm, for example. The thickness of the lattice body 21 can be 1.5 mm, for example.

  The active material 23 is composed of lead dioxide. Although the production method of the active material 23 is not particularly limited, for example, it can be produced by the following method. First, an active material paste is prepared by adding a slurry prepared by reacting lead oxide with dilute sulfuric acid, water and dilute sulfuric acid in advance to 70% oxidation degree lead powder produced by a ball mill method, and kneading them. . Subsequently, the produced active material paste is filled in the lattice body 21, and is aged and dried by a conventional method. Thereby, the unformed active material 23 with which the lattice body 21 was filled is obtained.

  And the part with which the active material 23 was filled among the positive electrode plates 12 becomes the filling part 24 (dotted part (part hatched in sandy shape) of FIG. 4). The filling portion 24 is formed on the front and back surfaces of the positive electrode plate 12. Usually, the entire surface of the lattice body 21 is filled with an active material. However, the lattice body 21 does not necessarily need to be filled with an active material, and the active material 23 is not partially filled with the active material 23. There may be parts. In this case, only the portion of the lattice body 21 that is filled with the active material 23 becomes the filling portion 24, and the portion of the lattice body 21 that is not filled with the active material 23 is excluded from the filling portion 24.

(Negative electrode plate)
Similarly to the positive electrode plate 12, the negative electrode plate 13 includes a lead alloy lattice 31, a current collector 32 connected to the upper portion of the lattice 31 and called an ear portion, and an active material 33 filled in the lattice 31. It is equipped with. The active material 33 of the negative electrode plate 13 is also referred to as a negative electrode active material.

  The lattice body 31 is formed in a lattice shape to hold the active material 33 to be filled. The lattice body 31 may be the same as or different from the lattice body 21 of the positive electrode plate 12. When the lattice body 31 is an expanded lattice body similar to the lattice body 21 of the positive electrode plate 12, the lattice body 31 includes a lattice-shaped bone portion 31a and an upper frame bone that is positioned above the bone portion 31a and extends linearly. 31b. In this case, the active material 33 is filled in the bone portion 31a. The width W1 of the lattice body 31 can be set to, for example, 145 mm. The height H1 of the lattice body 31 can be set to 115 mm, for example. The thickness of the lattice body 31 can be set to 1.3 mm, for example.

  The active material 33 is composed of porous spongy lead. Although the production method of the active material 33 is not particularly limited, for example, it can be produced by the following method. First, carbon powder, lignin powder and barium compound powder are added and mixed as additives to lead powder having a degree of oxidation of 70% produced by the ball mill method. Subsequently, water and dilute sulfuric acid are added and kneaded to prepare an active material paste. Subsequently, the produced active material paste is filled in the lattice 31, and is aged and dried by a conventional method. As a result, an unformed active material 33 filled in the lattice 31 is obtained.

  And the part filled with the active material 33 among the negative electrode plates 13 becomes a filling part 34 (stipled part (part hatched in sand) in FIG. 4). The definition of the filling portion 34 is the same as that of the filling portion 24 of the positive electrode plate 12.

(Bag separator)
As shown in FIGS. 2 and 3, the bag separator 14 has a function of separating the positive electrode plate 12 and the negative electrode plate 13. Moreover, the bag separator 14 has microporosity so that electrolyte solution (dilute sulfuric acid) can pass through. The bag separator 14 is made of a microporous resin sheet. Examples of the resin used for the bag separator 14 include polyethylene.

  FIG. 7 is a front view showing a separator used for producing a bag separator. FIG. 8 is a view showing a state in which the negative electrode plate is put into the bag separator. As shown in FIG. 7, the separator 41 used for producing the bag separator 14 is formed in a long sheet shape. The bag separator 14 is obtained by cutting the separator 41 into an appropriate length, folding the separator 41 in the longitudinal direction of the separator 41 and superimposing them, and mechanically sealing, press-bonding, or heat-welding both sides. Thereby, the bag separator 14 shown in FIG. 8 is obtained.

  In addition, eight ribs 42 extending in the longitudinal direction of the separator 41 are formed at the center of the separator 41 in the width direction. A large number of mini-ribs 43 extending in the longitudinal direction of the separator 41 are formed on both sides of the rib 42 in the width direction of the separator 41. After processing into the bag separator 14, mechanical seal portions 45 extending in the longitudinal direction of the separator 41 are formed at both ends in the width direction of the separator 41, which are both sides of the mini-rib 43 in the width direction of the separator 41 (see FIG. 8). . A portion of the separator 41 where the rib 42, the mini-rib 43, and the mechanical seal portion 45 are not formed is referred to as a base portion 44. The rib 42 has a function of opening a gap between the adjacent positive electrode plates 12. The mini-rib 43 has a function of improving the strength of the separator 41 in order to prevent the lead 41 from breaking through the separator 41 at the corner of the positive electrode plate 12 and short-circuiting when the lead storage battery 1 vibrates in the lateral direction. In place of or in addition to the mechanical seal portion 45, a crimping portion for crimping both sides of the folded separator 41 or a thermal welding portion for thermally welding both sides of the folded separator 41 may be provided. Good. Note that the height, width, and interval of the mini-ribs 43 are all smaller than that of the ribs 42. The thickness of the base part 44 can be 0.2 mm, for example. The thickness of the rib 42 can be 0.6 mm, for example. The thickness of the bag separator 14 where the ribs 42 are formed can be set to 0.8 mm, for example.

(Plate group)
As shown in FIGS. 3 and 8, the negative electrode plate 13 is inserted into the bag separator 14. As shown in FIGS. 2 and 3, the electrode plate group 11 includes seven positive electrode plates 12 and eight negative electrode plates 13 through the separator 41 in a state where the negative electrode plate 13 is inserted into the bag separator 14. Are stacked alternately. The number of positive plates 12 and negative plates 13 constituting the electrode plate group 11 may be changed as appropriate. The current collectors 22 of the seven positive plates 12 are collectively welded to the positive side strap 15, and the current collectors 32 of the eight negative plates 13 are collectively welded to the negative side strap 16. That is, the current collector 22 of the positive electrode plate 12 and the current collector 32 of the negative electrode plate 13 are collectively welded to the positive side strap 15 and the negative side strap 16 for each polarity. An inter-cell connecting portion 17 or a pole column 18 is connected to the positive side strap 15 and the negative side strap 16, respectively. When the electrode plate group 11 is stored in the battery case 2, the positive electrode side strap 15 of the electrode plate group 11 arranged closest to the positive electrode side and the negative electrode side strap 16 of the electrode plate group 11 arranged closest to the negative electrode side. Further, the pole column 18 is connected, and the inter-cell connecting portion 17 is connected to the other positive side strap 15 and negative side strap 16. The positive side strap 15 and the negative side strap 16 are required to have weldability, strength and acid resistance with the current collector 22 or current collector 32. As a material of the positive side strap 15 and the negative side strap 16, for example, a lead-antimony alloy or a lead-tin alloy is used.

(Battery case)
FIG. 9 is a perspective view showing the battery case. As shown in FIG. 9, the inside of the battery case 2 is divided into six sections by five partition walls 51 to form six cell chambers 52. The cell chamber 52 is a space into which the electrode plate group 11 is inserted. The electrode plate group 11 is also called a single cell, and the electromotive force is 2V. Since the electrical equipment for automobiles is driven by stepping up or down the DC voltage 12V, the six electrode plate groups 11 are connected in series to make 2V × 6 = 12V. Therefore, when the lead storage battery 1 is used as an electrical component for automobiles, six cell chambers 52 are required. In addition, when using the lead storage battery 1 for another use, the cell chamber 52 is not limited to six pieces.

  Ribs 53 extending in the height direction of the battery case 2 are provided on both side surfaces of the partition wall 51 and a pair of inner wall surfaces facing the partition wall 51 of the battery case 2. The rib 53 has a function of appropriately pressing (compressing) the electrode plate group 11 inserted into the cell chamber 52 in the stacking direction of the positive electrode plate 12 and the negative electrode plate 13.

(Production of battery)
The electrode plate group 11 is inserted into each cell chamber 52 of the battery case 2. At this time, the electrode plate group 11 is appropriately pressed (compressed) in the stacking direction of the positive electrode plate 12 and the negative electrode plate 13 by the ribs 53 provided in the partition wall 51 and the battery case 2. Then, the inter-cell connection part 17 of the positive electrode side strap 15 of the adjacent electrode plate group 11 and the inter-cell connection part 17 of the negative electrode side strap 16 are connected to each other through a through hole (not shown) provided in the partition wall 51. Weld by. In addition, welding the connection part 17 between cells by a partition wall penetration welding method in this way is called connection between cells.

  Subsequently, the lid 3 is thermally welded to the battery case 2. Thereby, the pole 18 connected to the positive side strap 15 of the electrode plate group 11 arranged on the most positive electrode side is connected to the positive electrode terminal 4, and the negative electrode side strap 16 of the electrode plate group 11 arranged on the most negative electrode side. The pole 18 connected to is connected to the negative terminal 5.

  Subsequently, each liquid port plug 6 is opened, and dilute sulfuric acid, which is an electrolytic solution, is injected into each cell chamber 52 from each liquid injection port provided in the lid 3 to form a battery case. The battery case formation is performed, for example, by energizing for 20 hours at an ambient temperature of 40 ° C. and a current of 25 A. After battery case formation, the lead acid battery 1 is obtained by adjusting the liquid level of electrolyte solution.

(Total surface area of the filling part of the positive electrode plate / apparent volume of the filling part)
When the total surface area of the filling portion 24 of the positive electrode plate 12 is S and the apparent volume of the filling portion 24 of the positive electrode plate 12 and the filling portion 34 of the negative electrode plate 13 is V, S / V is 3.95 cm ⁻¹ or more. ing. In this case, it is preferable that S / V is 4.20 cm ⁻¹ or more.

  The total surface area S of the filling portion 24 of the positive electrode plate 12 is a unit cell that is the minimum unit of the lead storage battery 1, that is, a portion that contributes to power generation of the positive electrode plate 12 in the electrode plate group 11 inserted into one cell chamber 52. Total surface area. That is, the total surface area S is a value obtained by multiplying the total surface area of the front and back surfaces of the filling portion 24 by the number of positive electrode plates 12 constituting the electrode plate group 11. More specifically, as shown in FIG. 4, the width of the filling portion 24 is the filling portion width W, the height of the filling portion 24 is the filling portion height H, and the number of the positive electrode plates 12 in the electrode plate group 11 is When the number of positive electrode plates is N, the total surface area S is expressed by the following equation (1).

Total surface area S = (filling part width W × filling part height H) × 2 × number of positive electrode plates N (1)
The apparent volume V of the filling portion 24 of the positive electrode plate 12 and the filling portion 34 of the negative electrode plate 13 is a unit cell that is the smallest unit of the lead storage battery 1, that is, the electrode plate group 11 inserted into one cell chamber 52. It is the apparent volume of the part that contributes to. That is, the apparent volume is a volume of an area surrounded by the filling portion 24 of the positive electrode plate 12 and the filling portion 34 of the negative electrode plate 13, and is an apparent volume including a gap between adjacent filling portions 24. is there. Between the adjacent positive electrode plate 12 and negative electrode plate 13, there is a space without the filling portion 24, and the volume of the region including the space without the filling portion is an apparent volume V. Specifically, as shown in FIGS. 3 and 4, when the thickness of the electrode plate group 11 in the stacking direction of the positive electrode plate 12 and the negative electrode plate 13 is the electrode plate group thickness D, the apparent volume V is It is represented by the following formula (2).

Apparent volume V = filled portion width W × filled portion height H × electrode group thickness D (2)
The upper limit value of S / V is not particularly limited, but for practical use of lead-acid batteries, the upper limit value of S / V is preferably 5.2 cm ⁻¹ , more preferably 4.9 cm ⁻¹ , and even more preferably 4.5 cm ^−1. .

  In addition, the thickness of the positive electrode plate 12 and the negative electrode plate 13 can be changed by adjusting the filling amount of the active material 23 of the positive electrode plate 12 and the active material 33 of the negative electrode plate 13. That is, when the filling amount of the active material paste is increased, the thickness of the electrode plate is increased, and when the filling amount of the active material paste is decreased, the thickness of the electrode plate is reduced. For this reason, S / V can be changed by changing the filling amount of the active material 23 of the positive electrode plate 12 and the filling amount of the active material 33 of the negative electrode plate 13. The S / V can also be changed by changing the thickness of the grid body 21 and the grid body 31, the thickness of the separator 41, the height of the rib 42, and the like.

Here, by setting S / V to 3.95 cm ⁻¹ or more, the S / V of the active material 23 of the positive electrode plate 12 in the charge / discharge cycle of the lead storage battery 1 is compared with the case where S / V is less than 3.95 cm ⁻¹ . It is considered that the progress of softening is suppressed. For this reason, according to the lead storage battery 1 which concerns on this embodiment, since the short circuit in the upper part of the electrode group 11 by the dropped active material 23 is suppressed compared with the case where S / V is less than 3.95 cm < ^-1 >. Thus, the number of times that charge / discharge can be increased, and the life of the lead storage battery 1 can be extended.

Moreover, since it is thought that progress of softening of the active material 23 of the positive electrode plate 12 is further suppressed in the charge / discharge cycle of the lead storage battery 1 by setting S / V to 4.20 cm ⁻¹ or more, the lead storage battery is further increased. 1 can be extended in service life.

  The preferred embodiments of one aspect of the present invention have been described above, but the present invention is not limited to the above embodiments.

  Next, examples of the present invention will be described. However, the present invention is not limited to the following examples.

Example 1
As the grid body 21 of the positive electrode plate 12, an expanded grid body was used in which a slit was formed in a lead-calcium-tin alloy sheet and the slit was widened. The grid body 21 of the positive electrode plate 12 had a width W1 of 145 mm, a height H1 of 115 mm, and a thickness of 1.5 mm. Then, an active material paste was prepared by adding slurry and water and diluted sulfuric acid, which was previously mixed with dilute sulfuric acid to lead powder of 70% oxidation degree produced by the ball mill method, and kneaded. . Subsequently, the produced active material paste was filled in the lattice body 21, and aged and dried by a conventional method. Thereby, the positive electrode plate 12 in which the lattice body 21 was filled with the unformed active material 23 was obtained.

  As the grid 31 of the negative electrode plate 13, an expanded grid was used in which a cut was made in a lead-calcium-tin alloy sheet and the cut was expanded. The grid 31 of the negative electrode plate 13 had a width W1 of 145 mm, a height H1 of 115 mm, and a thickness of 1.3 mm. Then, carbon powder, lignin powder and barium compound powder were added and mixed as additives to lead powder having a degree of oxidation of 70% produced by the ball mill method. Subsequently, water and dilute sulfuric acid were added and kneaded to prepare an active material paste. Subsequently, the prepared active material paste was filled in the lattice 31, and aged and dried by a conventional method. As a result, the negative electrode plate 13 in which the lattice body 31 was filled with the unformed active material 33 was obtained.

  In the separator 41 constituting the bag separator 14, the thickness of the base portion 44 is set to 0.2 mm, the thickness of the rib 42 is set to 0.6 mm, and the thickness of the bag separator 14 in the portion where the rib 42 is formed is set to 0. It was 8 mm.

  As the positive electrode side strap 15 and the negative electrode side strap 16, a lead-antimony alloy having an alloy composition of Pb-3 mass% Sb was used.

  Then, the negative electrode plate 13 is inserted into the bag separator 14, and the seven positive electrode plates 12 and the eight negative electrode plates 13 are alternately stacked via the separator 41, and the current collector 22 and the negative electrode plate 13 of the positive electrode plate 12. The current collector 32 was collectively welded to the positive side strap 15 and the negative side strap 16 for each polarity to obtain the electrode plate group 11.

  The electrode plate group 11 was inserted into each of the six cell chambers 52 of the battery case 2 and connected between the cells, and the lid 3 was thermally welded to the battery case 2. Thereafter, each liquid stopper 6 is opened, diluted sulfuric acid is injected into each cell from each liquid inlet provided in the lid 3, and energized for 20 hours at an ambient temperature of 40 ° C. and a current of 25 A. The 85D23 type battery of JISD5301 regulation was produced.

  In Example 1, by adjusting the filling amount of the active material 23 of the positive electrode plate 12 and the active material 33 of the negative electrode plate 13, the filling part width W is 14.5 cm, the filling part height H is 11 cm, and the electrode plate The group thickness D was 3.35 cm, and the total surface area S and the apparent volume V were as follows.

Total surface area S = (14.5 × 11) × 2 × 7 = 2233 [cm ² ]
Apparent volume V = 14.5 × 11 × 3.55≈566 [cm ³ ]
Therefore, in Example 1, S / V was 3.95 cm ⁻¹ .

(Example 2)
A battery was prepared in the same manner as in Example 1 except that the S / V was 4.00 cm ⁻¹ by adjusting the filling amount of the active material 23 in the positive electrode plate 12 and the filling amount of the active material 33 in the negative electrode plate 13. Produced.

(Example 3)
A battery was fabricated in the same manner as in Example 1 except that the S / V was changed to 4.10 cm ⁻¹ by adjusting the filling amount of the active material 23 in the positive electrode plate 12 and the filling amount of the active material 33 in the negative electrode plate 13. Produced.

Example 4
A battery was prepared in the same manner as in Example 1 except that the S / V was changed to 4.20 cm ⁻¹ by adjusting the filling amount of the active material 23 in the positive electrode plate 12 and the filling amount of the active material 33 in the negative electrode plate 13. Produced.

(Example 5)
The battery was fabricated in the same manner as in Example 1 except that the S / V was changed to 4.30 cm ⁻¹ by adjusting the filling amount of the active material 23 in the positive electrode plate 12 and the filling amount of the active material 33 in the negative electrode plate 13. Produced.

(Example 6)
As the positive side strap 15 and the negative side strap 16, a lead-tin alloy having an alloy composition of Pb-3 mass% Sn is used, and the filling amount of the active material 23 of the positive plate 12 and the filling of the active material 33 of the negative plate 13 are used. A battery was fabricated in the same manner as in Example 1 except that the S / V was adjusted to 4.10 cm ⁻¹ by adjusting the amount.

(Comparative Example 1)
The battery was fabricated in the same manner as in Example 1 except that the S / V was set to 3.85 cm ⁻¹ by adjusting the filling amount of the active material 23 in the positive electrode plate 12 and the filling amount of the active material 33 in the negative electrode plate 13. Produced.

(Comparative Example 2)
The battery was fabricated in the same manner as in Example 1 except that the S / V was 3.90 cm ⁻¹ by adjusting the filling amount of the active material 23 in the positive electrode plate 12 and the filling amount of the active material 33 in the negative electrode plate 13. Produced.

(Evaluation test for life performance)
The batteries of Examples 1 to 6 and Comparative Examples 1 and 2 were subjected to a light load life test specified in JIS D5301. In the light load life test, at an ambient temperature of 75 ° C., (1) discharge at a current of 25 A for 4 minutes, (2) charge at a constant voltage of 14.8 V and a limit current of 25 A for 10 minutes, and (1) and (2) Is a test in which charging and discharging are repeated in one cycle. Although the JIS standard is an ambient temperature of 40 ° C., the temperature conditions have been made stricter in consideration of the high temperature environment of the battery due to the overcrowding of engine rooms of automobiles in recent years.

  During the test, the sample was left for 56 hours every 480 cycles, and then discharged for 30 seconds at the rated cold cranking current, and the voltage at 30 seconds was recorded. The battery life cycle number is the number of cycles when the voltage at 30 seconds is 7.2 V or less, and it is confirmed that the voltage does not exceed 7.2 V again by rated cold cranking current discharge after 480 cycles. did.

(Charge performance evaluation test)
The batteries of Examples 1 to 6 and Comparative Examples 1 and 2 were discharged at a 5-hour rate current (10.4 A) for 30 minutes at an ambient temperature of 25 ° C. Thereafter, a current value at 5 seconds after the start of charging when charging was performed with a constant voltage of 14 V and a limiting current of 100 A was measured, and the charging performance was evaluated based on the measured values.

The test results of Examples 1-6 and Comparative Examples 1-2 are shown in Table 1, and the test results of Examples 1-5 and Comparative Examples 1-2 are shown in FIG. The life cycle number and charging performance evaluation shown in Table 1 and FIG. 10 were relative evaluations when Example 1 was set to 100. In FIG. 10, the horizontal axis represents S / V (cm ⁻¹ ), and the vertical axis represents the number of life cycles.

As shown in Table 1 and Figure 10, Examples 1 to 5 S / V is 3.95Cm ^-1 or more, compared to Comparative Examples 1-2 to S / V is less than 3.95Cm ^-1, The life performance has been greatly improved. Further, among the examples, Examples 4 to 5 in which S / V is 4.20 cm ⁻¹ or more have a life performance that is higher than those in Examples 1 to 3 in which S / V is less than 4.20 cm ^−1. Improved.

  Further, in Examples 1 to 5, the charging performance was improved as compared with Example 6 by using a lead-antimony alloy (Pb-3 mass% Sb) as an alloy constituting the strap.

DESCRIPTION OF SYMBOLS 1 ... Lead acid battery, 11 ... Electrode plate group, 12 ... Positive electrode plate, 13 ... Negative electrode plate, 14 ... Bag separator, 41 ... Separator, 15 ... Positive electrode side strap (strap), 16 ... Negative electrode side strap (strap), 22 ... Current collecting part, 23 ... active material, 24 ... filling part, 32 ... current collecting part, 33 ... active material, 34 ... filling part, 45 ... mechanical seal part.

Claims (1)

A lead-acid battery comprising an electrode plate group in which positive and negative electrode plates are alternately stacked via a separator, and the current collectors of the positive electrode plate and the negative electrode plate are collectively welded to a strap for each polarity,
The positive electrode plate and the negative electrode plate each have a filling part filled with an active material,
The alloy composition of the strap is a lead-antimony system,
S / V is 3.95 cm ⁻¹ or more, where S is the total surface area of the filling portion of the positive electrode plate and V is the apparent volume of the filling portion of the positive electrode plate and the filling portion of the negative electrode plate. 00 cm ⁻¹ or less,
Lead acid battery.