JP7037865B2 - Lead-acid battery - Google Patents

Description

The present invention relates to a lead storage battery.

There are two types of lead-acid batteries, liquid-type and control valve-type. In liquid-type lead-acid batteries, a group of electrode plates in which negative electrode plates and positive electrode plates are alternately arranged via a separator is an electric tank containing an electrolytic solution. It is stored in the cell room of.
Liquid lead-acid batteries used in conventional engine vehicles are often used in a sufficiently charged state (including a high charge rate state and an overcharged state). However, in recent years, charge control vehicles and idling stop vehicles are becoming mainstream. In addition, with the background of global environmental problems and the increase in accidents caused by elderly drivers, technologies such as eco-friendly vehicles, collision mitigation brakes, and automatic vehicle control are attracting attention, and the use of electrical components is increasing in vehicles equipped with these technologies. Under these circumstances, liquid lead-acid batteries mounted on vehicles in recent years are often used in a partially charged state (PSOC: Partial State Of Charge), which is an insufficiently charged state.

In the liquid lead-acid battery at the initial stage of charging, sulfate ions generated by the charging reaction are continuously released from the inside of the plate toward the electrolytic solution existing in the vicinity of the plate. Along with this, the sulfuric acid concentration of the electrolytic solution existing in the vicinity of the electrode plate increases. That is, concentrated sulfuric acid is continuously supplied from the inside of the plate to the outside (near the plate). Since this concentrated sulfuric acid has a higher specific gravity than the electrolytic solution (dilute sulfuric acid) existing in the portion away from the electrode plate, it descends according to gravity and accumulates in the lower part of the electric tank. As a result, the electrolytic solution in the electric tank has a specific gravity difference between the upper part and the lower part (stratification of the electrolytic solution).

In the initial stage of charging, most of the electric power supplied to the liquid lead-acid battery is used for the charging reaction, and the ratio of the electric power used for the electrolysis of the water constituting the electrolytic solution is small. However, as the charge rate increases, the ratio of the electric power supplied to the liquid lead-acid battery used for electrolysis of the water constituting the electrolytic solution increases. The gas generated by the electrolysis of water is released from the inside of the plate to the outside (in the electrolytic solution near the plate).
If power is continuously supplied to the liquid lead-acid battery (overcharged state) even after the charge rate reaches 100%, the supplied power is not used for the charging reaction, and the electricity of the water constituting the electrolytic solution is used. Since it is used only for decomposition, a large amount of gas is generated from the inside of the electrode plate. Then, this large amount of gas is released from the inside of the electrode plate into the electrolytic solution near the electrode plate, exerts an action of pushing up the concentrated sulfuric acid accumulated in the lower part, and the electrolytic solution is agitated in the electric tank. The stratification of the electrolytic solution is eliminated.

Therefore, when the liquid lead-acid battery is used in a sufficiently charged state, the stratification of the electrolytic solution is not a big problem, but when it is used in a state where the charge rate is low, the above-mentioned electrolysis by the gas is used. Elimination of liquid stratification cannot be expected. If the stratification of the electrolytic solution is not eliminated, sulfation at the lower part of the negative electrode plate progresses, and the life of the liquid lead-acid battery is shortened.
On the other hand, in Patent Document 1, a non-woven fabric composed of fibers of at least one material selected from the material group consisting of glass, pulp and polyolefin is brought into contact with the surface of the negative electrode plate during charging. It is described that the fall of sulfate ions eluted from lead sulfate is prevented to prevent stratification from occurring.

On the other hand, in Patent Document 2, in a lead storage battery using an expanded lattice as a positive electrode lattice, in order to improve the rapid discharge characteristics, the ratio of the expanded mesh volume to the apparent volume of the expanded mesh portion is increased. , It is described that the height of the rib provided on the surface of the bag-shaped separator (the surface facing the positive electrode plate) is lowered. Further, in this case, contact between the positive electrode plate and the bag-shaped separator and deterioration of the separator due to the contact are likely to occur, but in order to suppress this and provide a lead storage battery having excellent life characteristics and rapid discharge characteristics, the ribs are provided. It is described that the height is 0.6 mm or less, and the rib spacing is equal to or less than the grid width dimension of the expanded grid.

Patent Document 3 describes a separator for a liquid lead-acid battery, which has ribs (transverse ribs) extending along the width direction of the negative electrode plate on the surface facing the negative electrode plate and faces the positive electrode plate. It is described as having vertical ribs on the surface to be used. Further, there is a description that the rib height across is preferably about 0.02 to 0.30 mm, most preferably about 0.075 to 0.15 mm.
However, Patent Documents 1 to 3 do not describe the compressive force of the laminated body in the cell chamber.

Japanese Patent No. 5500315 Japanese Unexamined Patent Publication No. 2006-140034 Special Table 2013-541167 Gazette

An object of the present invention is to provide a novel lead-acid battery which can be expected to have a long life by suppressing stratification of an electrolytic solution when used in a partially charged state.

In order to solve the above problems, the lead storage battery according to one aspect of the present invention has the following configurations (1) to (6).
(1) A cell chamber and a group of electrode plates stored together with an electrolytic solution in the cell chamber are provided.
(2) The electrode plate group has a laminated body composed of positive electrode plates and negative electrode plates arranged alternately, and separators arranged between the positive electrode plates and the negative electrode plates.
(3) On the surface of the separator facing the positive electrode plate, vertical ribs, which are protrusions of streaky protrusions extending in the first direction corresponding to the vertical direction of the cell chamber, are formed in the second direction corresponding to the width direction of the positive electrode plate. Multiple pieces are formed at intervals.
(4) On the surface of the separator facing the negative electrode plate, the horizontal ribs, which are linear protrusions having a smaller protrusion height than the vertical ribs and extending in the second direction, are spaced smaller than the vertical ribs in the first direction. It is formed more than once by opening.
(5) The protruding height of the lateral rib is 0.05 mm or more and 0.5 mm or less.
(6) The compression force of the laminated body in the cell chamber is 2.5 kPa or more and 10.0 kPa or less.

According to the present invention, there is provided a novel lead-acid battery which can be expected to have a long life by suppressing stratification of an electrolytic solution when used in a partially charged state.

It is a top view which shows the outer surface (the surface which faces a positive electrode plate) of the bag-shaped separator which constitutes the electrode plate group of an embodiment. It is a partial cross-sectional view showing a bag-shaped separator, and corresponds to the AA cross-sectional view of FIG. It is a partial cross-sectional view which shows the laminated body which comprises the electrode plate group of an embodiment, and the bag-shaped separator corresponds to the BB sectional view of FIG. It is a front view which shows the grid-like substrate of the negative electrode plate which constitutes the electrode plate group of an embodiment. It is a figure which shows the relationship between the horizontal rib, and the hole of a grid-like substrate, and corresponds to the partially enlarged view of FIG. It is a graph which shows the relationship between the compression force of a laminated body and the degree of stratification obtained in the test of an Example. It is a graph which shows the relationship between the number of lateral ribs and the discharge duration obtained in the test of an Example.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the embodiments shown below. In the embodiments shown below, technically preferable limitations are made for carrying out the present invention, but these limitations are not essential requirements of the present invention.
[Explanation of the overall configuration]
The lead-acid battery of the embodiment has a conventionally known monoblock type battery case, a lid, and a group of six plates. The battery case is divided into six cell chambers by a partition wall. The six cell chambers are arranged along the longitudinal direction of the battery case. One electrode plate group is arranged in each cell chamber. Each electrode plate group has a laminate, a positive electrode strap, a negative electrode strap, a positive electrode intermediate pole column rising from the positive electrode strap, and a negative electrode intermediate pole pillar rising from the negative electrode strap. The laminate is composed of a plurality of positive electrode plates and a negative electrode plate, and a plurality of bag-shaped separators.

The positive electrode plate has a positive electrode substrate in which a mixture containing a positive electrode active material (positive electrode mixture) is held, and an ear portion protruding upward from the positive electrode substrate. The negative electrode plate has a negative electrode substrate in which a mixture containing a negative electrode active material (negative electrode mixture) is held, and an ear portion protruding upward from the negative electrode substrate. A plurality of positive electrode plates and negative electrode plates are alternately arranged via a separator. The number M _n of the negative electrode plates constituting the laminated body is one more than the number M _p of the positive electrode plates.
The negative electrode plate is housed in a bag-shaped separator. Then, by alternately stacking a plurality of bag-shaped separators containing a negative electrode plate and a plurality of positive electrode plates, the laminate is in a state where the separator is arranged between the positive electrode plate and the negative electrode plate. The compression force of this laminated body in each cell chamber is 2.5 kPa or more and 10.0 kPa or less.

[About the characteristic part of one aspect]
The characteristic portion will be described with reference to FIGS. 1 to 5. In these figures, the first direction corresponding to the vertical direction of the cell chamber is indicated by Z, the arrangement direction of the cell chamber is indicated by X, and the second direction corresponding to the width direction of the positive electrode plate is indicated by Y. Further, FIG. 3 shows a part of the laminated body 10 including the positive electrode plate 1, the negative electrode plate 2, and the separator 3.

[About the separator]
As shown in FIGS. 1 to 3, the bag-shaped separator 3 is composed of a base 31, a plurality of vertical ribs 32, a plurality of horizontal ribs 33, and a plurality of small protrusions 34. The vertical rib 32 is formed on the outer surface (the surface facing the positive electrode plate 1) 311 of the base portion 31 and extends in the Z direction (first direction). The plurality of vertical ribs 32 are arranged parallel to each other with a space in the Y direction (second direction). The arrangement interval Δ11 between the vertical rib 32 closest to the small protrusion 34 and the vertical rib 32 adjacent to the vertical rib 32 is larger than the arrangement interval Δ1 between the other vertical ribs 32.
The horizontal rib 33 is a protrusion having a protrusion height smaller than that of the vertical rib 32, is formed on the inner surface (the surface facing the negative electrode plate 2) 312 of the base 31, and extends in the Y direction with a gap in the Z direction. There is. The arrangement interval Δ2 of the horizontal ribs 33 is smaller than the arrangement interval Δ1 of the vertical ribs 32.
The arrangement interval is defined as the distance from the top of the adjacent ribs to the top as shown in FIG.

The thickness (dimension in the X direction) t of the base portion 331 is 0.1 mm or more and 0.3 mm or less. The protruding height (dimension in the X direction) T1 of the vertical rib 32 is 0.4 mm or more and 0.8 mm or less. The width (dimension in the Y direction) W1 of the vertical rib 32 is 0.4 mm or more and 0.7 mm or less. The arrangement interval Δ1 of the vertical ribs 32 is 8.0 mm. The protruding height (dimension in the X direction) T2 of the lateral rib 33 is 0.05 mm or more and 0.5 mm or less. The width (dimension in the Z direction) W2 of the lateral rib 33 is 0.2 mm or more and 0.6 mm or less. The arrangement interval Δ2 of the horizontal ribs 33 is 0.24 mm or more and 0.62 mm or less, with the width W2 or more of the horizontal ribs 33. The protrusion height (dimension in the X direction) of the small protrusion 334 is 0.05 mm or more and 0.5 mm or less.
The separator 3 has a bag shape, and both ends of the base 31 in the Y direction are sealing portions 311a. The small protrusion 334 is formed on the seal portion 331a at the time of gear sealing for forming the plate-shaped separator into a bag shape.

[Relationship between the negative electrode plate and the horizontal rib]
As shown in FIG. 4, the negative electrode plate 2 is composed of a negative electrode current collector 21 and a negative electrode mixture 22. The negative electrode current collector 21 is composed of a grid-like substrate 211 made of a rectangular expanded metal and a selvage portion 212 protruding upward from the grid-like substrate 211. The grid-like substrate 211 has a mesh-like hole 211a. The negative electrode current collector 21 is mainly made of an alloy containing lead. The negative electrode mixture 22 is held in all the holes 211a of the grid-like substrate 211 and in the entire front and back surfaces of the grid-like substrate 211. Note that FIG. 4 is a diagram in which the negative electrode mixture 22 is partially removed to expose a part of the negative electrode current collector 21.
As shown in FIG. 5, the maximum value K of the dimension in the Z direction of the holes 211a constituting the grid-like substrate 211 is in the range of 6 mm or more and 12 mm or less. Further, the number of lateral ribs 33 existing in the range of each hole 211a in the Z direction is 8 or more and 24 or less on average.

<Action, effect>
In the lead-acid battery of this embodiment, the presence of the horizontal rib 33 on the surface 312 of the separator 3 facing the negative electrode plate 2 suppresses the sedimentation of sulfate ions and stratifies the lead-acid battery as compared with the one without the horizontal rib 33. Sulfuric acid can be retained between the negative electrode mixture 22 and the lateral rib 33, so that the effect of improving the reactivity of the lead storage battery can be obtained.
Further, in the lead storage battery of this embodiment, the protruding height of the lateral rib 33 is 0.05 mm or more and 0.5 mm or less, and the compression force of the laminated body 10 in each cell chamber is 2.5 kPa or more and 10.0 kPa or less. It has become. Further, the maximum value K of the dimensions of the plurality of holes 211a constituting the grid-like substrate 211 in the Z direction is 6 mm or more and 12 mm or less, and the number of horizontal ribs 33 existing in the range of one hole 211a in the Z direction is determined. The average number is 8 or more and 24 or less. As a result, the lead-acid battery of this embodiment is highly effective in suppressing the stratification of the electrolytic solution when used in a partially charged state, and can be expected to have a long life.

On the other hand, if the protruding height of the lateral rib 33 is less than 0.05 mm, the effect of suppressing the sedimentation of sulfate ions cannot be substantially obtained, and the lateral rib 33 exists between the negative electrode plate 2 and the lateral rib 33. Since the amount of sulfuric acid to be added is significantly reduced, the effect of improving the reactivity cannot be substantially obtained.
The higher the protruding height of the lateral rib 33 (the larger the dimension in the X direction), the higher the action of suppressing the sedimentation of sulfate ions and the action of retaining sulfuric acid. However, if it exceeds 0.5 mm, the thickness of the laminated body 10 (dimension in the X direction) becomes too thick when a standard electric tank is used, and when the laminated body 10 is inserted into the cell chamber, the laminated body 10 becomes too thick. Insertion defects such as defects in the separator 3 and the positive electrode plate 1 are likely to occur.

Further, if the compression force of the laminated body 10 in each cell chamber is less than 2.5 kPa, the effect of suppressing the sedimentation of sulfate ions cannot be substantially obtained, and even if the value exceeds 10.0 kPa, sulfate ions can be obtained. The effect of suppressing sedimentation does not increase.
Further, if the maximum value K of the dimensions in the Z direction of the plurality of holes 211a constituting the lattice-shaped substrate 211 is less than 6 mm, it becomes difficult to fill the plurality of holes 211a with the negative electrode mixture 22, and the thickness exceeds 12 mm. Then, it is difficult for the negative electrode mixture 22 to be sufficiently filled in each hole 211a.

When a grid-like substrate 211 having holes 211a having a maximum value K of 6 mm or more and 12 mm or less in the Z direction is used as the grid-like substrate 211 of the negative electrode plate 2, it is within the range of one hole 211a in the Z direction. If the number of lateral ribs 33 present is less than 8 on average, the effect of suppressing the sedimentation of sulfate ions cannot be substantially obtained. If the number exceeds 24, the area where the holes 211a are closed by the horizontal ribs 33 becomes too large, and the amount of sulfuric acid that can be held between the negative electrode plate 2 and the horizontal ribs 33 becomes extremely small, so that the sulfate ions settle. The effect of suppressing is reduced.

<Manufacturing method>
The lead-acid battery of the embodiment can be manufactured by, for example, the following method by a conventionally known method.
First, the positive electrode plate 1 and the negative electrode plate 2 before chemical formation that form the electrode plate group are manufactured. The positive electrode plate 1 is the same as the conventional product. As the negative electrode plate 2, a negative electrode current collector 21 having a maximum value K (hereinafter, also referred to as “dimension K”) of the dimension of the hole 211a of the grid-like substrate 211 in the Z direction is 6 mm or more and 12 mm or less is prepared.
Next, obtain a bag-shaped separator having the above structure and dimensions, or obtain a plate-shaped separator having a vertical rib 32 formed on one surface and a horizontal rib 33 formed on the other surface, and obtain a bag-shaped separator. The separator 3 is manufactured. The dimension in the Z direction in the state of the plate-shaped separator is about twice that of the grid-like substrate 211 of the negative electrode plate 2. By bending the plate-shaped separator at the half position in the Z direction with the side on which the lateral rib 33 of the base 31 is formed inside, the bases 31 are overlapped with each other, and both ends of the base 31 in the Y direction are gear-sealed. , A bag-shaped separator 3 is obtained.

Then, the laminated body (strap-unformed electrode plate group) 10 is obtained by alternately laminating the negative electrode plate 2 before chemical conversion in the bag-shaped separator 3 and the positive electrode plate 1.
Next, using a COS (cast-on-strap) casting device for this laminated body, a positive electrode strap connecting the ears of the positive electrode plates, a negative electrode strap connecting the ears of the negative electrode plates, and a positive electrode intermediate rising from the positive electrode strap. A pole column, a positive electrode terminal pole pillar, a negative electrode intermediate pole pillar rising from a negative electrode strap, or a negative electrode terminal pole pillar are formed to form a electrode plate group. After producing six of these electrode plates, each electrode group is housed in each cell chamber of the electric tank.

Next, in a state where the electrode plates are housed in each cell chamber of the electric tank, resistance welding is performed to the adjacent positive electrode intermediate pole pillar and the negative electrode intermediate pole pillar via the partition wall between the cell chambers, and the plates are adjacent to each other. The cell chambers are electrically connected in series. Next, the upper surface of the electric tank and the lower surface of the lid are melted by heat, the lid is placed on the electric tank, and the lid is fixed to the electric tank by heat welding. When the lid is placed on the battery case, the negative electrode terminal pole pillar and the positive electrode terminal pole pillar are inserted into the through holes of the lead alloy bushing integrally formed on the lid by insert molding and welded together to integrate the terminals. And.
After that, the electrolytic solution (which contains aluminum ions by adding aluminum sulfate to the sulfuric acid aqueous solution) is injected into the cell chamber through the injection hole provided as a hole penetrating the lid. After that, a non-chemical lead-acid battery is assembled by performing a normal process such as closing the injection hole. After that, the electric tank is chemically formed under normal conditions to obtain a finished product.

[Test to investigate the effect of the difference in the protruding height of the lateral rib]
<Making test batteries>
As a lead-acid battery having the same structure as the lead-acid battery of the embodiment, the lead-acid batteries of Samples No. 1-1 to No. 1-7 were produced.
The lead-acid batteries of Samples No. 1-1 to No. 1-7 are D32 type liquid lead-acid batteries for idling stop, and as shown in Table 1, the protruding height T2 of the lateral rib 33 of the separator 3, respectively. Has different laminates. All other configurations are the same.
First, in the lead-acid batteries of Samples No. 1-2 to No. 1-7, as the separator 3, the thickness t of the base 31 is 0.2 mm, the width of the vertical rib 32 is 0.6 mm, and the protruding height of the vertical rib 32. The T1 is 0.6 mm, the arrangement interval of the vertical ribs 32 is 8.0 mm, the width of the horizontal ribs 33 is 0.3 mm, the arrangement intervals of the horizontal ribs 33 is 0.5 mm, and the protrusion height T2 of the horizontal ribs 33 is each sample. The values shown in Table 1 are prepared in. The protruding height of the horizontal rib can be changed by changing the depth of the groove for forming the horizontal rib when the separator is manufactured. For the lead-acid battery of sample No. 1-1, a separator without horizontal ribs was prepared.

Next, a JIS-D size punching substrate was prepared as a positive electrode current collector. Then, the lattice-shaped substrate of the positive electrode current collector was filled with a mixture (positive electrode mixture) containing a positive electrode active material prepared by a usual method, and aged and dried to obtain a positive electrode plate before chemical conversion.
As the negative electrode current collector 21, an expanded metal having a hole 211a of the lattice-shaped substrate 211 having a dimension K of 10 mm was prepared. Since the dimension K is 10 mm, the width of the horizontal ribs 33 is 0.3 mm, and the arrangement interval of the horizontal ribs 33 is 0.5 mm, the average value of the number of horizontal ribs 33 existing in one hole 221a in the Z direction. Will be 20. Then, the lattice-shaped substrate 211 was filled with a mixture (negative electrode mixture 22) containing a negative electrode active material prepared by a usual method, and aged and dried to obtain a negative electrode plate 2 before chemical conversion.

Next, after the negative electrode plate 2 was placed in the bag-shaped separator 3, seven positive electrode plates and eight separators containing the negative electrode plates were alternately laminated to obtain a laminated body 10. Six of these laminated bodies 10 are prepared, and a strap and an intermediate pole column, or a strap and a terminal pole pillar are attached to the positive electrode plate 1 and the negative electrode plate 2 of each laminated body 10 by using a COS (cast-on-strap) type casting device. By forming, a group of electrode plates for each cell was obtained. Each of the obtained electrode plates was housed in each cell chamber of the electric tank. Further, the compression force of the laminated body 10 in the cell chamber was set to 7.0 kPa.

When the electrode plates were housed in each cell chamber, the lead-acid batteries of Samples No. 1-1 to 1-6 did not have a defective insertion of the laminate, but the lead-acid batteries of Sample No. 1-7 did not have a defective insertion. A defective insertion of the laminated body 10 occurred.
Next, resistance welding between intermediate pole columns between adjacent cell chambers, heat welding of the battery case and lid, injection of electrolytic solution from the injection holes into each cell chamber, and closing the injection holes with a liquid spout, etc. A D23 type liquid lead-acid battery for idling stop was assembled by performing the usual process of. Then, by carrying out the electric tank chemical formation by a usual method, the specific density after the electric tank chemical formation was set to 1.285 (20 ° C. conversion value).

<Test and evaluation>
Each of the obtained lead-acid batteries was tested by the following method.
(High rate discharge characteristic test)
Battery Industry Association Standard SBA S 0101 8.4.3 According to the cold cranking current test, each lead-acid battery was allowed to stand for 24 hours in an atmosphere of -18 ° C, then discharged at a constant current of 610 A, and the voltage at the 30th second. Read the value. When this voltage value was higher than the voltage value of the lead-acid battery of sample No. 1-1, it was judged that the effect of improving the high rate discharge characteristics was obtained by providing the horizontal ribs, and Table 1 shows " If the voltage value of the lead-acid battery of sample No. 1-1 or less is displayed, it is judged that the effect of improving the high rate discharge characteristics could not be obtained by providing the horizontal ribs, and Table 1 shows. Displayed as "x".
Further, the result of the insertion performance of the above-mentioned laminated body 10 is also shown in Table 1 as "x" in the case of a defect and "◯" in the case of a good result.

As shown in Table 1, No. 1-3 to No. 1-6 using the separator 3 in which the protruding height T2 of the lateral rib 33 corresponding to the embodiment of the present invention is 0.05 mm or more and 0.50 mm or less. In the lead-acid battery of No. 1, the insertion performance of the laminated body 10 was good, and the effect of improving the high rate discharge characteristics was also obtained.
On the other hand, in the No. 1-2 lead-acid battery using the separator 3 in which the protruding height T2 of the horizontal rib 33 is 0.03 mm, the insertion performance of the laminated body 10 was good, but the high rate discharge was performed. No characteristic improvement effect was obtained. Further, in the No. 1-7 lead-acid battery using the separator 3 in which the protruding height T2 of the horizontal rib 33 is 0.07 mm, the effect of improving the high rate discharge characteristics was obtained, but the insertion performance of the laminated body 10 was improved. It was bad.

[Test to investigate the effect of the difference in the compression force of the laminated body]
<Making test batteries>
As a lead-acid battery having the same structure as the lead-acid battery of the embodiment, the lead-acid batteries of Samples No. 2-1 to No. 2-30 were produced. In addition, in order to make the compression force of the laminated body 10 different in the cell chamber, spacers having different thicknesses are provided between the cell chamber and the laminated body 10.
The lead-acid batteries of Samples No. 2-1 to No. 2-10 are D32 type liquid lead-acid batteries for idling stop, and use a separator having a horizontal rib 33 having a height T2 of 0.05 mm. Further, as shown in Table 2, the lead-acid batteries of Samples No. 2-1 to No. 2-10 have different compression forces of the laminated body 10, but all other configurations are the same.
The lead-acid batteries of Samples No. 2-11 to No. 2-20 are D32 type liquid lead-acid batteries for idling stop, and use a separator having a protruding height T2 of the lateral rib 33 of 0.50 mm. .. Further, as shown in Table 3, the lead-acid batteries of Samples No. 2-11 to No. 2-20 have different compression forces of the laminated body 10, but all other configurations are the same.
The lead-acid batteries of Samples No. 2-21 to No. 2-30 are D32 type liquid lead-acid batteries for idling stop, and use a separator without horizontal ribs. Further, as shown in Table 4, the lead-acid batteries of Samples No. 2-21 to No. 2-30 have different compression forces of the laminated body 10, but all other configurations are the same.

<Test and evaluation>
Each of the obtained lead-acid batteries was tested by the following method.
(PSOC cycle test)
After performing constant current discharge (CC discharge) at 10.4 A for 1 hour, constant current constant voltage charge (CC-CV charge) at 50 A and 14.3 V is performed for 30 minutes. With this as one step, a test was conducted in which this step was repeated 150 times.
After this test, the difference in the degree of stratification of each lead-acid battery was investigated. Specifically, first, in each cell chamber of each lead-acid battery, the specific densities of the electrolytic solution in the upper part and the lower part are measured, the specific gravity difference is calculated from both measured values, and the average value of the specific gravity difference in all the cell chambers is calculated. It was calculated and the value was taken as the degree of stratification. Next, using a separator without horizontal ribs, the relative value of the stratification degree of each lead storage battery was calculated with the stratification degree of No. 2-21 having a compression force of 0.0 kPa of the laminate 10 as 100. The results are also shown in Tables 2-4.

As shown in Table 4, when the separator without the horizontal ribs was used, the degree of stratification was the same at 100 regardless of the compression force of the laminated body 10 of 0.0 kPa to 14.0 kPa. Further, the lead-acid batteries of Samples No. 2-1 to No. 2-10 using the separator 3 having a protrusion height T2 of the horizontal rib 33 of 0.05 mm and the protrusion height T2 of the horizontal rib 33 of 0.50 mm. For the lead-acid batteries of Samples No. 2-11 to No. 2-20 using the separator 3, the relationship between the compression force of the laminated body 10 and the degree of stratification is shown in a graph in FIG.

As can be seen from the graph of FIG. 6, the present invention is carried out in the lead-acid batteries No. 2-1 to No. 2-20 using a separator having a lateral rib protrusion height of 0.05 mm or more and 0.50 mm or less. In the lead-acid battery having a compression force of 2.5 kPa or more and 10.0 kPa or less in the cell chamber of the laminated body 10 corresponding to the example, the effect of reducing the degree of stratification was high. If the compression force of the laminated body 10 in the cell chamber is less than 2.5 kPa, the effect of reducing the degree of stratification is hardly obtained, and even if it exceeds 10.0 kPa, the effect of reducing the degree of stratification is saturated. The compression force of the laminated body 10 in the cell chamber is preferably 5.5 kPa or more and 10.0 kPa or less.

[Test to investigate the effect of different dimensions K]
As a lead-acid battery having the same structure as the lead-acid battery of the embodiment, the lead-acid batteries of Samples No. 3-1 to No. 3-7 were produced.
As the negative electrode plate constituting the D32 type liquid lead-acid battery for idling stop, the negative electrode plate 2 having the shape shown in FIG. (See FIG. 5) different samples (Samples No. 3-1 to No. 3-6) were prepared, and a test was conducted to examine the filling property and the frame dropping property of the negative electrode mixture 22.
Specifically, regarding the filling property, when the negative electrode mixture 22 is filled in the lattice-shaped substrate 211 by a normal method, it is judged that it is good (○) if there is no unfilled hole 211a, and even one. If there is, it is judged to be defective (x). Regarding the frame drop property, a test was conducted in which the negative electrode plate 2 in which all the holes 211a were filled with the negative electrode mixture 22 was subjected to a test in which vibration was applied under conditions according to the vibration state during transportation of the lead storage battery, and the filling was performed. If there is even one hole 211a in which even a part of the negative electrode mixture 22 has fallen, it is judged to be defective (x), and the one in which the negative electrode mixture 22 does not fall at all is good (frames do not fall, ○) was judged.
Table 5 shows the dimensions K of each negative electrode plate and the test results.

As can be seen from Table 5, the negative electrode plates 2 of the samples No. 3-2 to No. 3-5 using the grid-like substrate 211 having the dimension K of 6 mm or more and 12 mm or less are excellent in the filling property of the negative electrode mixture 22. At the same time, the frames did not drop. On the other hand, the negative electrode plate 2 of sample No. 3-1 using the grid-like substrate 211 having a dimension K of 4 mm had poor filling property of the negative electrode mixture 22. Further, in the negative electrode plate 2 of sample No. 3-6 using the grid-like substrate 211 having a dimension K of 14 mm, the negative electrode mixture 22 dropped frames.

[Test to investigate the effect of the difference in the number of horizontal ribs]
As a lead-acid battery having the same structure as the lead-acid battery of the embodiment, the lead-acid batteries of Samples No. 4-1 to No. 4-16 were produced. For the lead-acid batteries of Samples No. 4-1 to No. 4-16, a separator 3 having a protruding height T2 of the horizontal rib 33 of 0.08 mm and a width of the horizontal rib 33 of 0.2 mm was used, and the cell of the laminated body 10 was used. The compression force in the room is 5 kPa.
The lead-acid batteries of Samples No. 4-1 to No. 4-8 are D32 type liquid lead-acid batteries for idling stop, and as shown in Table 6, the number of horizontal ribs 33 is different, but other than that. The configurations are all the same. The lead-acid batteries of Samples No. 4-1 to No. 4-8 have a dimension K of the grid-like substrate 211 constituting the negative electrode plate 2 of 6 mm.
The lead-acid batteries of Samples No. 4-9 to No. 4-16 are D32 type liquid lead-acid batteries for idling stop, and as shown in Table 6, the number of horizontal ribs 33 is different, but other than that. The configurations are all the same. The lead-acid batteries of Samples No. 4-9 to No. 4-16 have a dimension K of the grid-like substrate 211 constituting the negative electrode plate 2 of 12 mm.

<Test and evaluation>
Each of the obtained lead-acid batteries was tested by the following method.
First, as a PSOC cycle test, a step of performing constant current discharge (CC discharge) at 10.4 A for 1 hour and then performing constant current constant voltage charge (CC-CV charge) at 50 A and 14.3 V for 30 minutes is performed. , 150 times repeated. Next, as a high-rate discharge test, each lead-acid battery was allowed to stand for 24 hours in an atmosphere of -18 ° C according to the battery industry association standard SBA S 0101 8.4.3 cold cranking current test, and then a constant current of 610 A. Discharge was performed, and the time until the end of this discharge (high rate discharge duration) was investigated.
Then, in the lead-acid batteries of Samples No. 4-1 to No. 4-8, the high rate discharge duration of the lead-acid batteries of Sample No. 4-1 is set to 100, and Samples No. 4-9 to No. 4-16 are set. In the lead-acid battery of No. 4, the relative value of the high-rate discharge duration of each lead-acid battery was calculated, assuming that the high-rate discharge duration of the lead-acid battery of sample No. 4-9 was 100. The results are also shown in Table 6.

In addition, the number of horizontal ribs 33 and the discharge duration (relative values) for the lead-acid battery samples of samples No. 4-1 to No. 4-8 and the lead-acid batteries of samples No. 4-9 to No. 4-16, respectively. ) Is shown in a graph in FIG.
As can be seen from the graph of FIG. 7, the number of lateral ribs 33 of the separator 3 corresponding to the embodiment of the present invention is 8 regardless of whether the dimension K of the lattice-shaped substrate 211 constituting the negative electrode plate 2 is 6 mm or 12 mm. The lead-acid battery having a value of 24 or less has a high effect of improving the high rate discharge duration with respect to the lead-acid battery using the separator without the horizontal rib. Lead-acid batteries having less than 8 horizontal ribs on the separator have little effect on improving the high-rate discharge duration compared to lead-acid batteries using separators without horizontal ribs, and even if the number exceeds 24, the high-rate discharge duration is high. The improvement effect of is saturated. The number of lateral ribs 33 of the separator 3 is preferably 10 or more and 24 or less, and more preferably 16 or more and 24 or less.

1 Positive electrode plate 2 Negative electrode plate 21 Negative electrode current collector 211 Negative electrode plate grid-like substrate 211a Negative electrode plate lattice-like substrate hole 212 Negative electrode plate ear 22 Negative electrode mixture 3 Separator 31 Separator base 32 Separator vertical rib 33 Separator Horizontal ribs 34 Small protrusions on the separator 10 Laminated body

Claims (1)

A cell chamber and a group of electrode plates stored together with the electrolytic solution in the cell chamber are provided.
The electrode plate group has a laminate composed of positive electrode plates and negative electrode plates arranged alternately, and separators arranged between the positive electrode plates and the negative electrode plates.
On the surface of the separator facing the positive electrode plate, vertical ribs, which are streaky protrusions extending in the first direction corresponding to the vertical direction of the cell chamber, are spaced apart in the second direction corresponding to the width direction of the positive electrode plate. Opened and formed multiple
On the surface of the separator facing the negative electrode plate, horizontal ribs having a protrusion height smaller than that of the vertical ribs and extending in the second direction are linear protrusions extending in the second direction from the arrangement interval of the vertical ribs. Also formed multiple with small intervals,
The protruding height of the lateral rib is 0.05 mm or more and 0.5 mm or less.
The compression force of the laminated body in the cell chamber is 2.5 kPa or more and 10.0 kPa or less.
The negative electrode plate is a negative electrode mixture held on a grid-like substrate.
The maximum value of the dimensions of the plurality of holes constituting the grid-like substrate in the first direction is 6 mm or more and 12 mm or less.
A lead-acid battery having an average number of horizontal ribs of 8 or more and 24 or less in the range of one hole in the first direction .

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