JP7660024B2 - Lead-acid battery and method for manufacturing the same - Google Patents

Description

The present invention relates to a lead-acid battery.

A flooded lead-acid battery includes a cell chamber and a plate group housed in the cell chamber together with an electrolyte. The plate group has a laminate consisting of alternatingly arranged positive and negative plates and a separator arranged between the positive and negative plates. The positive and negative plates each have a current collector having a rectangular lattice substrate and ears protruding upward from the lattice substrate, and an active material mixture (positive electrode mixture, negative electrode mixture) held by the lattice substrate.

In recent years, lead-acid batteries have come to be used more frequently in high-temperature (tropical) regions, such as Southeast Asia. When lead-acid batteries are used in such high-temperature regions, the batteries deteriorate more quickly than when they are used at room temperature, resulting in a shorter battery life.
One of the reasons for the short life is that oxygen gas generated from the positive plate during overcharging can cause the separator to oxidize and deteriorate, causing the positive and negative plates to come into contact with each other and cause a short circuit. In particular, high temperature conditions are an environment in which such oxidation and deterioration of the separator is likely to progress. In addition, lead-acid batteries used in high temperature environments are in an environment in which the growth occurring in the lattice substrate of the positive plate becomes significant, causing the positive plate to curve, and the separator is likely to be pressed by the positive plate.

As an example of a conventional technique for improving the lifespan of a lead-acid battery by improving the separator, Patent Document 1 discloses a technique in which a bag-shaped separator that houses a positive plate has a surface that abuts against the positive plate, and the surface is provided with a plurality of rib-like protrusions that are parallel to the vertical direction of the positive plate and have narrower spacing at the parts that abut against the ends of the positive plate than at other parts, thereby suppressing oxidation deterioration and hole formation in the separator and suppressing short circuits.
Furthermore, Patent Document 2 discloses that a plurality of linear ribs are formed parallel to one another on the surface of the separator facing the positive electrode plate, and the cross-sectional shape of the rib is configured with a trapezoidal lower rib portion and an upper rib portion, thereby suppressing the falling off of active material from the positive electrode and shortening the life of the lead-acid battery when used in high-temperature regions and under high vibration.

Japanese Patent Application Publication No. 9-231995 Patent No. 4590813

However, the lead-acid batteries described in Patent Documents 1 and 2 have room for improvement in terms of suppressing the progress of oxidative deterioration of the separator when used in high-temperature regions.
An object of the present invention is to provide a lead-acid battery in which the progress of oxidative deterioration of a separator is suppressed and a long life can be achieved even when the battery is used in a high-temperature region.

In order to solve the above problems, a lead-acid battery according to a first aspect of the present invention has the following configurations (1) to (3).
(1) A battery comprising a cell chamber, a plate group housed in the cell chamber, and an electrolyte injected into the cell chamber, the plate group having a laminated body made up of alternatingly arranged positive and negative plate plates and a separator arranged between the positive and negative plate plates. The separator is composed of a plate-shaped base and a number of ribs protruding from the surface of the base facing the positive plate. The ribs are stripe-like protrusions extending in one direction, and the multiple ribs are arranged in parallel.
(2) The height _H0 of the rib when no pressure is applied is 0.25 mm or more and 1.15 mm or less.
(3) Before assembly, the separator is placed on a horizontal table with the ribs facing up, and a pressure plate is placed on the ribs. When a pressure of 9 kPa is applied from above to the pressure plate, the height H of the rib is between 0.70 and 0.90 times the height H0 of _{the rib} when no pressure is applied.

A second aspect of the present invention is a method for producing a lead-acid battery having the above configuration (1), and has the following configuration (11).
(11) A separator is used in which the height _H0 of the rib when no pressure is applied is 0.25 mm or more and 1.15 mm or less, and when, before assembly, the separator is placed on a horizontal table with the rib facing up and a pressure plate is placed on the rib, and a pressure of 9 kPa is applied from above to the pressure plate, the height H of _{the rib} is 0.70 to 0.90 times the height H0 when no pressure is applied.

The lead-acid battery of the present invention is expected to have a long life even when used in high-temperature regions, as the oxidation degradation of the separator is suppressed.

FIG. 2 is a plan view showing a part of a laminate constituting the lead-acid battery of the embodiment. 4 is a plan view showing the outer surface (the surface facing the positive electrode plate) of a pouch-shaped separator that constitutes the laminate. FIG. 3 is a partial cross-sectional view showing the bag-shaped separator, and corresponds to the cross-sectional view taken along line AA in FIG. 2.

The following describes embodiments of the present invention, but the present invention is not limited to the embodiments described below. In the embodiments described below, technically preferable limitations are imposed for implementing the present invention, but these limitations are not essential requirements for the present invention.

[Explanation of overall configuration]
The lead-acid battery of this embodiment has a monoblock-type battery case, a lid, and six plate groups. The battery case is divided into six cell chambers by partitions. The six cell chambers are arranged along the longitudinal direction of the battery case. Each cell chamber contains one plate group and is filled with an electrolyte. Each plate group has a laminate consisting of multiple positive and negative plates arranged alternately and a separator arranged between the positive and negative plates.

The positive electrode plate is composed of a positive electrode current collector and a positive electrode mixture (a mixture containing a positive electrode active material), and the positive electrode current collector has a rectangular lattice substrate and an ear portion protruding upward from the lattice substrate, and the positive electrode mixture is held by the lattice substrate. The negative electrode plate is composed of a negative electrode current collector and a negative electrode mixture (a mixture containing a negative electrode active material), and the negative electrode current collector has a rectangular lattice substrate and an ear portion protruding upward from the lattice substrate, and the negative electrode mixture is held by the lattice substrate. The multiple positive and negative electrode plates are alternately arranged with separators between them.
The negative electrode plate is housed in a pouch-shaped separator. The pouch-shaped separator containing the negative electrode plate and the positive electrode plate are alternately stacked, with the separator disposed between the positive and negative electrode plates. Note that the positive electrode plate may be housed in the pouch-shaped separator instead of the negative electrode plate.

Each plate group also has positive and negative straps that connect the positive and negative plates of the stack at different positions in the width direction, and positive and negative intermediate poles that rise from the positive and negative straps, respectively. The positive and negative straps connect the ears of the positive and negative plates, respectively. The positive and negative straps are arranged in the cell chambers at both ends in the cell arrangement direction, and the positive and negative poles are formed with small pieces, respectively, and are connected to the positive and negative poles that serve as external terminals.

[About the separator]
Fig. 1 shows a laminate consisting of a positive electrode plate 1, a negative electrode plate 4, and a pouch-shaped separator 5. Fig. 2 shows the outer surface of the separator 5 (the surface facing the positive electrode plate 1). Fig. 3 shows a cross section taken along line A-A in Fig. 2. In these figures, X indicates the lamination direction of the laminate, Y indicates the width direction of the laminate, and Z indicates the up-down direction of the cell chamber.

As shown in Fig. 1, the positive electrode plate 1 is composed of a positive electrode collector 2 and a positive electrode mixture 3. The positive electrode collector 2 is composed of a rectangular lattice-shaped substrate 21 and tabs 22 protruding upward from the lattice-shaped substrate 21. The negative electrode plate 4 is housed in a bag-shaped separator 5.
As shown in Fig. 2, the separator 5 is composed of a plate-shaped base 51 and a number of ribs 52 protruding in the X direction from an outer surface 511 (the surface facing the positive electrode plate 1) of the base 51. The ribs 52 are stripe-like projections extending in the vertical direction Z of the cell chamber. A number of ribs 52 having the same shape and dimensions are formed in parallel at equal intervals in the Y direction (the width direction of the positive electrode plate). Both ends in the Y direction form seal portions 511a.

As shown in FIG. 3, the cross-sectional shape of the rib 52 in the Y direction is an isosceles trapezoid, and the width (lower base) W1 on the outer surface 511 side of the base 51 is larger than the width (upper base) W2 of the tip. In addition, small protrusions 54 with a height lower than the rib 52 are provided on the inner side of the seal portions 511a at both ends in the Y direction. Providing these small protrusions 54 improves the strength of both ends of the separator 5 in the Y direction. The height (dimension in the X direction) of the small protrusions 54 is preferably 0.05 mm or more and 0.3 mm or less, and the width (dimension in the Y direction) is preferably 0.1 mm or more and 0.4 mm or less. The separator 5 may also have small protrusions 54 on the inner surface of the base 51 (the surface facing the negative electrode plate 4).

The height (dimension in the X direction) H ₀ of the rib 52 when no pressure is applied is 0.25 mm or more and 1.15 mm or less.
When the separator 5 is placed on a horizontal table with the unassembled ribs 52 facing up and a pressure plate is placed on the ribs 52, and a pressure of 9 kPa is applied from above to the pressure plate, the height H of the rib is 0.70 to 0.90 times the unpressurized height _H0 . In other words, the ratio (H/ _H0 ) of the height H of the rib 52 in a pressurized state to the unpressurized height _H0 is 0.70 to 0.90.
The thickness (dimension in the X direction) T of the base 51 is not less than 0.15 mm and not more than 0.3 mm.
When the positive electrode plate 1 is housed in the pouch-shaped separator 5 , a rib 52 is provided on the inner surface of the base 51 of the separator 5 (the surface facing the positive electrode plate 1 ).

[About the electrolyte]
The electrolyte is dilute sulfuric acid containing aluminum ions at a concentration of 0.01 mol/L to 0.3 mol/L, or dilute sulfuric acid containing sodium ions at a concentration of 0.002 mol/L to 0.05 mol/L.

[Functions and Effects of the Embodiments]
In a lead-acid battery used in a high-temperature environment, the growth occurring in the lattice-shaped substrate of the positive plate becomes significant, causing the positive plate to bend, and the separator is easily pressurized by the positive plate. In the lead-acid battery of this embodiment, the height H ₀ of the rib 52 of the separator 5 when no pressure is applied is 0.25 mm or more and 1.15 mm or less, and the ratio (H/H 0 ) indicating the elastic force exerted by all ribs when the rib side of the separator is pressed by a plate-shaped object (hereinafter referred to as the "elastic force by all ribs _" ) is 0.70 or more and 0.90 or less. Therefore, when used in a high-temperature environment, the durability of the separator and the positive plate is ensured, and a necessary space is secured between the base 51 of the separator 5 and the lattice-shaped substrate 21 of the positive plate 1, and the progress of oxidation deterioration of the base of the separator due to oxygen gas generated from the positive plate during overcharging can be suppressed. As a result, the life can be extended when used in a high-temperature region.

Even if the height _H0 of the rib when no pressure is applied is 0.25 mm or more and 1.15 mm or less, if the ratio (H/ _H0 ) is less than 0.70, the necessary space cannot be secured during use in a high-temperature environment, and the effect of suppressing oxidation deterioration of the separator base due to oxygen gas generated from the positive electrode plate during overcharge cannot be obtained. On the other hand, if the ratio (H/ _H0 ) exceeds 0.90, the elastic force of all the ribs becomes insufficient, and when the separator is pressurized due to the bending of the positive electrode plate in a high-temperature environment, the ribs are more likely to damage the abutting positive electrode plate.

Even if the ratio (H/H ₀ ) indicating the elastic force of all ribs is 0.70 or more and 0.90 or less, if the height H ₀ of the ribs when no pressure is applied is less than 0.25 mm, the distance between the positive electrode plate and the base of the separator in the laminate becomes extremely short, making it impossible to ensure the necessary space when used in a high-temperature environment, and significantly increasing the risk of the base of the separator being oxidized and deteriorated by oxygen gas generated from the positive electrode plate during overcharge. From this viewpoint, the height H ₀ of the ribs when no pressure is applied is preferably 0.30 mm or more, and more preferably 0.40 mm or more.

The higher the height H ₀ of the rib when no pressure is applied, the greater the effect of suppressing oxidation deterioration of the separator base due to oxygen gas generated from the positive plate during overcharge in a high-temperature environment. However, if the height H ₀ exceeds 1.15 mm, the distance between the positive plate and the base of the separator in the laminate becomes extremely long, and the amount of deflection of the rib caused by the separator being pressurized due to the curvature of the positive plate in a high-temperature environment becomes extremely large, so that cracks are likely to occur at the boundary between the rib and the base, and the durability of the separator cannot be ensured. From this viewpoint, the height H ₀ of the rib when no pressure is applied is preferably 0.80 mm or less, more preferably 0.60 mm or less.

In addition, the lead-acid battery of this embodiment has excellent charge acceptance by using dilute sulfuric acid containing aluminum ions at a concentration of 0.01 mol/L to 0.3 mol/L or dilute sulfuric acid containing sodium ions at a concentration of 0.002 mol/L to 0.05 mol/L as an electrolyte. If the concentration of aluminum ions contained in the dilute sulfuric acid in the electrolyte is less than 0.01 mol/L, the effect of improving charge acceptance cannot be obtained, and if it exceeds 0.3 mol/L, gas generated inside the electrode plate group is difficult to discharge to the outside.
As described above, the lead-acid battery of this embodiment can extend its life when used in high-temperature regions, and also has excellent charge acceptance.

In addition, since the cross-sectional shape of the rib 52 along the Y direction is an isosceles trapezoid with W1>W2, the rib is less likely to bend, collapse, or deform even under pressure, and the separator itself is less likely to be damaged. The rib dimension W1 is preferably 0.3 mm or more and 0.8 mm or less, and the rib dimension W2 is preferably 0.1 mm or more and 0.4 mm or less. In addition, from the viewpoint of the shape retention characteristics of the rib and the oxidation resistance of the separator, W2/W1 is preferably 0.25 or more and 0.85 or less.
Furthermore, since the thickness T of the base 51 is 0.15 mm or more and 0.3 mm or less, the oxidation resistance is superior to a thickness less than 0.15 mm, and the internal resistance of the battery can be reduced more than a thickness exceeding 0.3 mm.

〔others〕
Methods for adjusting the ratio (H/ _H0 ) to be 0.70 or more and 0.90 or less include appropriately selecting the area of the tip face of the rib (the tip width W2 in the above embodiment), the formation density of the rib, and the material of the rib (the entire separator).

[Preparation of test battery]
As the lead-acid batteries of Samples No. 1 to 60, D23 size lead-acid batteries having the same structure as the lead-acid battery of the embodiment were manufactured.
<Preparation of Positive and Negative Electrode Plates before Chemical Formation>
First, a positive electrode collector made of a lead alloy was produced by a book mold casting method. A negative electrode collector made of a lead alloy was produced by a continuous casting method. Next, a paste of a mixture (positive electrode mixture) containing a positive electrode active material produced by a normal method was filled into the lattice-shaped substrate of the positive electrode collector, and the mixture was aged and dried to obtain a positive electrode plate (positive electrode filled plate) before chemical formation. A paste of a mixture (negative electrode mixture) containing a negative electrode active material produced by a normal method was filled into the lattice-shaped substrate of the negative electrode collector, and the mixture was aged and dried to obtain a negative electrode plate (negative electrode filled plate) before chemical formation.

<Preparation of separator>
The pouch-shaped separators were prepared by the following method. First, a porous synthetic resin separator with a base thickness of 0.25 mm and a width of 152 mm was prepared as a strip with ribs of different dimensions for each sample, wound into a roll (separator roll). In each separator roll for each sample, 18 ribs were formed at intervals of 7 mm. Separators cut out to a length of 240 mm from each separator roll were folded with the rib side facing outward, and the edges were gear-sealed to obtain pouch-shaped separators with a Z direction of 120 mm and a Y direction of 152 mm.
The lower base W1, upper base W2, and heights H ₀ and H of the isosceles trapezoidal cross-sectional shape of the rib are shown in Tables 1 and 2 for each sample.

<Measurement of H ₀ and H before assembly>
The heights H ₀ and H of the ribs before assembly were measured by the following method using a test piece cut to a length of 240 mm from a separator roll.
For the height _H0 without pressure, first, the separator was placed on a horizontal table with the rib facing up, and the sum of the rib height and base thickness (" _H0 + T" in Fig. 3) was measured by sandwiching the top surface of the rib and the bottom surface of the base using a micrometer. Next, the base thickness T was measured by sandwiching only the base, and the value obtained by subtracting this value from the total was determined as the height _H0 of the rib without pressure.
The height H in the pressurized state is the value when the separator is placed on a horizontal table with the ribs facing up, the pressing plate is placed on the ribs, and a pressure of 9 kPa (more precisely, 8.889 kPa) is applied from above to the pressing plate. This height H was measured using a Minebea tensile compression tester in the following manner.

First, the separator was placed on the main base of the tensile compression tester with the ribs facing up, and a metal plate with a length of 150 mm, width of 150 mm, and thickness of 9 mm was placed on top of it as a pressing plate, and a 5 kN load cell was placed so that it was just in contact with the plate. The 5 kN load cell was then lowered at a speed of 0.01 mm/min, and the movement of the load cell was stopped when a pressure of 0.2 kN was applied to the pressing plate. From the movement distance of the load cell at this time, the total value (H+T) of the height H of the separator's ribs in the pressurized state and the thickness T of the base was calculated. In addition, since no pressure is applied to the base in this state, the height H in the pressurized state is calculated by subtracting the thickness T of the base measured when the height H ₀ without pressure is measured from the calculated "H+T".
A pressing plate that is 150 mm long and 150 mm wide has a pressing area of 0.0225 m ² (=0.15 m×0.15 m), so applying a pressure of 0.2 kN to this pressing plate means applying a pressure of 0.2 kN/0.0225 ^{m 2} =8.889 kPa.

<Production of electrode plates and subsequent processes>
Five positive electrode packed plates and six negative electrode packed plates were prepared by the above-mentioned method. Next, the six negative electrode packed plates were each housed in a pouch-shaped separator, and the separators containing the negative electrode packed plates and the positive electrode packed plates were alternately stacked to obtain six stacks each having five positive electrode packed plates and six negative electrode packed plates. The stacking was performed so that the ribs of the pouch-shaped separators were in contact with the positive electrode packed plates.

Next, using a COS (cast-on-strap) casting device, straps, intermediate poles, and terminal poles were formed on the positive and negative electrode filled plates of the six resulting stacks, respectively, to obtain six electrode plate groups. Next, the six resulting electrode plate groups were placed into six cell chambers of a polypropylene monoblock-type battery case. The protruding dimension of the guide rib on the inner wall of the battery case was adjusted so that the compression force in each cell chamber of the stack was constant, within the range of 5 kPa to 10 kPa.

Then, resistance welding of the intermediate poles between adjacent cell chambers and heat welding of the battery case and the lid were performed in a normal manner. Next, aluminum sulfate was added to dilute sulfuric acid with a specific gravity of 1.245 to obtain an electrolyte with an aluminum ion concentration of 0.1 mol/L (specific gravity of 1.255), and this electrolyte was injected into each cell chamber through the injection hole in the lid. Next, the injection hole was blocked to assemble an unformed lead-acid battery, and then the battery case was formed in a normal manner to turn the positive and negative electrode filled plates into positive and negative plates.
In this manner, two each of lead-acid batteries No. 1 to No. 60 were obtained.

<Measurement of H ₀ and H after chemical formation>
One of the two lead-acid batteries No. 1 to No. 60 obtained was disassembled to measure the rib heights H ₀ and H after chemical formation. Specifically, the plate group was first removed from the cell chamber (third cell chamber) two cells away from the cell chamber (first cell chamber) in which the plate group having the positive terminal pole was housed, and disassembled. The negative plate was removed from the bag-shaped separator arranged on the fourth cell chamber side, and the gear seal portion of the bag-shaped separator was cut and stretched to prepare a battery. Next, the rib heights H ₀ and H were measured using the same method as that used before assembly.

[Evaluation test]
The remaining one of the two lead-acid batteries No. 1 to No. 60 obtained was used to carry out a high-temperature durability cycle life test without being disassembled.
Specifically, the light load life test specified in "JIS D5301:2019 Lead-acid starting batteries" was performed at 75°C instead of 40°C. In other words, each lead-acid battery was placed in a water tank maintained at 75°C ± 2°C, and the test was performed under the conditions specified in the above standard except for the test temperature, and the number of cycles until the battery reached the end of its life was examined. In addition, rehydration with purified water was performed once a week.
In addition, after this life test, each lead-acid battery was disassembled and visually inspected to see whether there were any cracks in the connection between the separator rib and the base, and whether there was any damage on the surface of the positive plate where the rib was in contact.
The results of these tests are also shown in Tables 1 and 2.

These results reveal the following:
The height H ₀ of the separator ribs when no pressure is applied did not change before and after assembly and disassembly, but the height H when pressure is applied became lower after disassembly than before assembly.
Lead-acid batteries No. 1 to No. 6, in which the separator rib height _H0 without pressure was 0.20 mm and the ratio (H/ _H0 ) before assembly was 0.60 to 0.95, did not develop cracks in the ribs, but the high-temperature life cycle count was 1500 to 1990, which did not reach the required number of cycles of 2300. Furthermore, lead-acid battery No. 6, in which the ratio (H/ _H0 ) before assembly was 0.95, had damage to the positive plate.

The lead-acid batteries No. 55 to No. 60, in which the separator rib height _H0 without pressure was 1.30 mm and the ratio (H/ _H0 ) before assembly was 0.60 to 0.95, had high-temperature life cycles of 1400 to 1970 and had cracks in the ribs. Also, the lead-acid battery No. 60, in which the ratio (H/ _H0 ) before assembly was 0.95, had damage to the positive plate.
In the lead-acid batteries No. 7 to No. 54 in which the separator rib height _H0 when no pressure was applied was 0.25 mm or more and 1.15 mm or less, no cracks were generated in the ribs.

Among the lead-acid batteries No. 7 to No. 54 in which the height _H0 of the separator rib when no pressure is applied is 0.25 mm or more and _1.15 mm or less, the lead-acid batteries No. 8 to No. 12, No. 14 to No. 18, No. 20 to No. 24, No. 26 to No. 30, No. 32 to No. 36, No. 38 to No. 42, No. 44 to No. 48, and No. 50 to No. 54 in which the ratio (H/H0) before assembly is 0.70 or more had a high-temperature life cycle number of 2,370 or more, whereas the lead-acid batteries No. 7, No. 13, No. 19, No. 25, No. 31, No. 37, No. 43, and No. 49 in which the ratio (H/ _H0 ) before assembly is 0.60 had a high-temperature life cycle number of 1,900 or less.

Among the lead-acid batteries No. 7 to No. 54 in which the height _H0 of the separator rib when no pressure is applied is 0.25 mm or more and _1.15 mm or less, the positive plates of the lead-acid batteries No. 8 to No. 11, No. 14 to No. 17, No. 20 to No. 23, No. 26 to No. 29, No. 32 to No. 35, No. 38 to No. 41, No. 44 to No. 47, and No. 50 to No. 53 in which the ratio (H/H0) before assembly is 0.70 or more and 0.90 or less, were not damaged. In contrast, the positive plates of the lead-acid batteries No. 12, No. 18, No. 24, No. 30, No. 36, No. 42, No. 48, and No. 54 in which the ratio (H/ _H0 ) before assembly is 0.95 were damaged.

The lead-acid batteries No. 14 to No. 18, No. 20 to No. 24, No. 26 to No. 30, No. 32 to No. 36, No. 38 to No. 42, and No. 44 to No. 48, in which the unpressurized height _H0 of the separator rib was 0.30 mm or more and 0.80 mm or less and the ratio (H/ _H0 ) before assembly was 0.70 or more, had a high-temperature life cycle count of 2,500 or more.
The lead-acid batteries Nos. 20 to 24, 26 to 30, and 32 to 36, in which the separator rib height _H0 without pressure was 0.40 mm or more and 0.60 mm or less and the ratio (H/ _H0 ) before assembly was 0.70 or more, had a high-temperature life cycle count of 2,860 or more.

In other words, in a lead-acid battery having a ratio (H/ _H0 ) before assembly of 0.70 or more, if the height _H0 of the separator rib when no pressure is applied is 0.25 mm or more and 1.15 mm or less, the occurrence of cracks in the rib during use in a high temperature environment is prevented and excellent high temperature life performance is obtained, if this height _H0 is 0.30 mm or more and 0.80 mm or less, even better high temperature life performance is obtained, and if this height _H0 is 0.40 mm or more and 0.60 mm or less, even better high temperature life performance is obtained.

In addition, a lead-acid battery in which the height _H0 of the separator rib when no pressure is applied is 0.25 mm or more and 1.15 mm or less and the ratio (H/ _H0 ) before assembly is 0.70 or more and 0.90 or less prevents the occurrence of cracks in the ribs when used in a high-temperature environment, and in addition to achieving excellent high-temperature life performance, it also prevents damage to the positive plate when used in a high-temperature environment.

REFERENCE SIGNS LIST 1 Positive electrode plate 2 Positive electrode current collector 21 Grid-shaped substrate 22 Ear portion of positive electrode plate 3 Positive electrode mixture 4 Negative electrode plate 5 Separator 51 Base portion of separator 511 Outer surface of base portion (surface facing positive electrode plate)
511a Seal portion 52 Separator rib 54 Small projection of separator

Claims (6)

The battery includes a cell chamber, a plate group housed in the cell chamber, and an electrolyte injected into the cell chamber;
the electrode plate group has a laminate including positive electrode plates and negative electrode plates arranged alternately and a separator arranged between the positive electrode plates and the negative electrode plates;
the separator is composed of a plate-shaped base and a plurality of ribs protruding from a surface of the base facing the positive electrode plate, the ribs being stripe-like protrusions extending in one direction, and the plurality of ribs being arranged in parallel;
The height H ₀ of the rib when no pressure is applied is 0.25 mm or more and 1.15 mm or less,
a lead-acid battery in which, before assembly, the separator is placed on a horizontal table with the rib facing up, and a pressing plate is placed on the rib, and a pressure of 9 kPa is applied from above to the pressing plate, the height H of the rib being 0.70 to 0.90 times the height H0 of the _rib when no pressure is applied. 2. The lead-acid battery according to claim 1, wherein a height _H0 of the rib when no pressure is applied is 0.30 mm or more and 0.80 mm or less. 2. The lead-acid battery according to claim 1, wherein a height _H0 of the rib when no pressure is applied is 0.40 mm or more and 0.60 mm or less. The electrolyte is dilute sulfuric acid containing aluminum ions,
The lead acid battery according to any one of claims 1 to 3, wherein the concentration of the aluminum ions is 0.01 mol/L or more and 0.3 mol/L or less. The electrolyte is dilute sulfuric acid containing sodium ions,
The lead acid battery according to any one of claims 1 to 4, wherein the concentration of the sodium ions is 0.002 mol/L or more and 0.05 mol/L or less. The battery includes a cell chamber, a plate group housed in the cell chamber, and an electrolyte injected into the cell chamber;
the electrode plate group has a laminate including positive electrode plates and negative electrode plates arranged alternately and a separator arranged between the positive electrode plates and the negative electrode plates;
The separator is composed of a plate-shaped base and a plurality of ribs protruding from a surface of the base facing the positive electrode plate, the ribs being stripe-shaped protrusions extending in one direction, and the plurality of ribs being arranged in parallel.
The separator may include
The height H ₀ of the rib when no pressure is applied is 0.25 mm or more and 1.15 mm or less,
A manufacturing method for a lead-acid battery using the separator, the separator being placed on a horizontal table with the rib facing up before assembly, a pressing plate being placed on the rib, and a pressure of 9 kPa being applied from above to the pressing plate, the height H of the rib being 0.70 to 0.90 times the height H0 of the _rib when no pressure is applied.

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