JP2005197145A - Separator with rib for lead acid storage battery, and lead acid storage battery using that separator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a separator with a rib capable of suppressing stratification phenomenon and a lead acid storage battery having a long life and a high performance using the separator. <P>SOLUTION: In the separator with the rib for the lead acid storage battery having the rib 3 on the base surface 2a of a sheet 2, the rib 3 is installed crossing the base 2a surface with its length direction oriented in horizontal direction, and the upper face 3a of the end part of the rib 3 is located at a higher position than that of the upper face 3b of the inner portion 3b, and as for the lower face of the rib 3, the center part lower face 3c in the length direction of the rib 3 is located at the lowest position, and the rib 3 is formed in an upward slope from the center part lower face 3c toward the end part low face 3c of the rib 3. In the lead acid storage battery, a group of electrode plates in which a positive electrode plate and a negative electrode plate are alternately laminated interposing the above separator is inserted in a battery case, and the degree of pressure at the time of inserting the above group of electrodes into the battery case is 5-30 kPa. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an improvement in a ribbed separator for a lead storage battery, and a lead storage battery using the separator. The lead storage battery of the present invention is particularly useful for starting automobiles, auxiliary machines, cycle use of industrial equipment, standby use, and the like.

  As shown in FIG. 5 (a), the conventional lead-acid battery rib-attached separator has a kink-folded rib 11 for reinforcing the sheet 2 on the base surface 2a of the flexible synthetic resin thin sheet 2 and its length. A gas discharge path 13 that is continuous in the vertical direction is provided in such a manner that the vertical direction is provided, or V-shaped ribs 12 are provided in a vertical and horizontal lattice shape as shown in FIG. (For example, Patent Document 1).

JP-A-9-97601

In recent years, new systems such as an idle stop system or an overcharge prevention system have been introduced into automobiles for the purpose of saving fuel and reducing exhaust gas.
The idle stop system is a system that stops an engine when a vehicle stops due to a signal or the like, a lead storage battery supplies necessary power during that time, and quickly starts the engine when starting, the overcharge prevention system is It is a system that terminates charging before overcharging where intense gas is generated. It aims to reduce the load on the generator, reduce the electrolyte accompanying overcharging, and prevent corrosion of the positive grid.

  However, the idle stop system has a problem that the stratification phenomenon is likely to occur because the deep discharge and the charge are repeated, as compared with the conventional SLI (starting / lighting / ignition) application. The prevention system has a problem that the stratification phenomenon is difficult to be solved because the electrolytic solution is not stirred by a large amount of gas generated during overcharging.

  The stratification phenomenon is a phenomenon in which sulfuric acid generated during charging settles in the lower part of the battery cell, and the electrolytic solution in the battery cell becomes thicker in the lower part and thinner at the upper part. The efficiency decreases and sulfation in which lead sulfate accumulates at the lower part of the electrode plate proceeds, and a concentration cell is formed, and self-discharge proceeds rapidly. As a result, the life of the lead storage battery is significantly shortened.

  Under such circumstances, the lead acid battery using the conventional separator causes a stratification phenomenon because concentrated sulfuric acid generated during charging settles in a large amount under the electrode plate through the gas discharge path of the separator. It was easy and difficult to apply to automobiles incorporating the new system.

  An object of the present invention is to provide a ribbed separator capable of suppressing the stratification phenomenon and a long-life, high-performance lead-acid battery using the separator.

  The invention according to claim 1 is a separator with a rib for a lead storage battery in which a rib is provided on a base surface of a sheet, wherein the rib is provided across the base surface with its length direction set in a horizontal direction. The upper surface of both end portions of the rib is at a position higher than the upper surface of the inner portion, and the lower surface of the rib is at the lowest position in the central portion in the length direction of the rib, and is inclined upward from the central portion toward both ends. It is the separator with a rib for lead acid batteries characterized by being formed.

  According to a second aspect of the present invention, in the separator with a lead-acid battery rib in which a plurality of short ribs are provided on the base surface of the sheet, the required number of the plurality of short ribs is a predetermined interval with the length direction set in the horizontal direction. A rib group is formed which opens and continues and crosses the base surface, and the rib group is formed by a vertically adjacent rib group and an end portion overlapping each other to form a rib pair, and the short rib The upper surfaces of both ends of the short ribs are positioned higher than the upper surface of the inner portion, and the lower surfaces of the short ribs are located at the lowest central portion in the length direction of the short ribs and are formed in an upward slope from the central portion toward both ends. It is the separator with a rib for lead acid batteries characterized by being made.

  A third aspect of the invention is a lead-acid battery in which the ribbed separator according to the first or second aspect is used.

  The invention according to claim 4 is a lead storage battery in which a group of electrode plates in which a positive electrode plate and a negative electrode plate are alternately laminated with the ribbed separator according to claim 1 or 2 interposed therebetween is inserted into a battery cell, The lead storage battery is characterized in that the degree of compression when the electrode plate group is inserted into the battery cell is 5 to 30 kPa.

  In the separator according to the first aspect of the present invention, the rib provided on the base surface of the sheet is provided across the base surface with its length direction oriented in the horizontal direction, and the upper surfaces of both ends of the rib are Since it exists in a position higher than the upper surface of an inner part, the concentrated sulfuric acid produced | generated at the time of charge is trapped on the said rib, and generation | occurrence | production of a stratification phenomenon is suppressed. Further, the lower surface of the rib has the lowest central portion in the length direction of the rib, and is formed in an upward slope from the central portion toward both ends. , And escapes upward from the end of the rib. Therefore, there is no problem that the gas is interposed between the electrode plate and the electrolytic solution, the contact area between the two is reduced, and the current density is increased.

According to a second aspect of the present invention, the required number of the plurality of short ribs provided on the base surface of the sheet crosses the base surface by connecting the length direction in the horizontal direction at a predetermined interval. A plurality of rib groups are formed, and the rib groups are vertically adjacent to each other and end portions overlapping each other in the vertical direction to form a pair of ribs, and the upper surfaces of both ends of the short ribs are inner portions. Therefore, concentrated sulfuric acid generated during charging is trapped on the short ribs constituting the rib pair, and the occurrence of stratification is suppressed. Further, the lower surface of the short rib is formed such that the central portion in the length direction of the short rib is at the lowest position and is formed in an upward slope from the central portion toward both ends. Rises along the lower surface of the electrode plate, and comes out from the end of the short rib to the upper side of the electrode plate. Therefore, there is no problem that the gas is interposed between the electrode plate and the electrolyte, the contact area between the two decreases, and the current density increases.
Therefore, according to the present invention, a long-life and high-performance lead-acid battery can be obtained, and it can be suitably used for an automobile incorporating the new system.

  A lead storage battery according to a fourth aspect of the present invention is a pressure degree when inserting an electrode plate group in which a positive electrode plate and a negative electrode plate are alternately laminated with the ribbed separator according to the first or second aspect interposed therebetween in a battery cell. Is defined as 5 to 30 kPa, and a gap is hardly formed between the rib and the electrode plate, and concentrated sulfuric acid is trapped well on the rib.

Hereinafter, the best embodiment of the present invention will be specifically described with reference to the drawings.
FIG. 1 is an explanatory front view showing a first embodiment of the separator of the present invention.
In the separator 1 according to the present invention, a large number of ribs 3 are provided on the base surface 2a of the thin sheet 2 so as to cross the base surface with their length directions oriented in the horizontal direction. The top surface 3a is higher than the top surface 3b of the inner portion, and the bottom surface of the rib 3 is at the lowest position in the center bottom surface 3c in the length direction of the rib, from the center bottom surface 3c of the rib 3 to the end bottom surface 3d. It is formed in an upward slope. The ribs 3 are also provided in the same arrangement pattern on the base surface 2b on the back side of the thin sheet 2.
Note that the upper surface 3b of the inner portion refers to an upper surface other than the upper surfaces 3a at both ends. Moreover, the center part lower surface 3c used as the lowest position of the lower surface of the rib 3 does not need to be in the middle of the length direction of a rib, and may be offset in the edge part direction.

  FIG. 2 shows a structure in which a positive electrode plate 4 and a negative electrode plate 5 are alternately stacked with the separator 1 of the present invention shown in FIG. 1 interposed therebetween to form an electrode plate group 6. It is side explanatory drawing which shows the state inserted in (not shown). Here, the sheet 2 is processed into a bag shape, and the positive electrode plate 4 is accommodated in the bag 2c. In FIG. 2, reference numeral 7 denotes a current collecting ear. Although not shown, the ears having the same polarity are welded to each other by a strap.

  In the separator 1, the rib 3 is in close contact with the positive electrode plate 4 and the negative electrode plate 5, and concentrated sulfuric acid generated at the time of charging is trapped on the rib 3 and is prevented from being settled below the positive and negative electrode plates 4 and 5. . Since concentrated sulfuric acid trapped on the rib 3 is relatively small, it easily diffuses into the surrounding electrolyte.

  Since the lower surface of the rib 3 has the lowest central lower surface 3c in the length direction of the rib 3 and is inclined upwardly toward the lower end surface 3d, the gas generated during charging and discharging is the central portion of the rib 3. It rises from the lower surface 3 c along the end lower surface 3 d and is discharged from the end of the rib 3 to above the electrode plates 4 and 5. For this reason, the problem that a gas stagnates between the electrode plates 4 and 5 and the electrolyte and the current density increases does not occur.

  It is desirable that the ribs be provided at equal intervals, because concentrated sulfuric acid traps or settles equally on the upper surface of each rib and the lower part of the electrode plate, and concentrated sulfuric acid is likely to diffuse.

FIG. 3 is an explanatory front view showing a second embodiment of the separator of the present invention.
In this ribbed separator 1 ′, a plurality of short ribs 8 are formed in a multi-stage manner in which a plurality of short ribs 8 are arranged in a horizontal direction with a predetermined interval therebetween to cross the base surface 2a. The other rib groups 8g ′ adjacent to each other in the vertical direction are arranged on a zigzag with the end portions of the short ribs 8 overlapping each other in the vertical direction to form a rib pair 8t. Further, the short rib 8 is located at a position where the upper surface 8a at both ends thereof is higher than the upper surface 8b of the inner portion, and the lower surface of the short rib 8 is located at the position where the center portion lower surface 8c in the length direction of the short rib 8 is lowest. An upward slope is formed from the center lower surface 8c toward the end lower surface 8d.

  In this ribbed separator 1 ′, the rib group 8 g forms a rib pair 8 t by overlapping the adjacent rib group 8 g ′ with the end portion in the vertical direction so that the concentrated sulfuric acid generated during charging is electrolyzed. While descending the liquid, it is trapped in any short rib 8 without any leakage. In addition, the short ribs 8 are formed in an upward slope from the center lower surface 8c toward the end lower surface 8d, and the gaps 8e are opened between the short ribs 8 that are continuous in the horizontal direction. The gas rises from the lower surface 8c of the central portion of the short rib 8 along the lower surface 8d of the end portion and is released upward of the electrode plate.

  In this case, it is preferable that all the rib groups form a pair as shown in the figure, but there may be some rib groups that do not form a pair, as shown in FIG. A single rib that crosses over the entire width may be mixed as appropriate.

  In the present invention, when a soft material is used for the ribs or short ribs, the adhesion between the ribs or short ribs and the electrode plate is increased, and concentrated sulfuric acid is trapped better. Even if a rib or a short rib is used as a hollow material and elastically deformed, good adhesion can be obtained. The cross-sectional shape of the rib or short rib may be any shape as long as it is in close contact with the electrode plate, such as a square or a circle. The front shape of the rib is arbitrary as long as it can trap concentrated sulfuric acid and discharge gas, such as a V shape or an arc shape.

  In the present invention, the arrangement pattern of the ribs on the base surface may be different on both the front and back surfaces. For example, when the pitches of the grid substrates of the positive electrode plate and the negative electrode plate are different, the ribs are arranged according to the pitches. It is preferable to optimize the arrangement pattern. By doing so, the stratification phenomenon can be suppressed and the gas can be released without deteriorating the battery performance.

  In the present invention, if the degree of compression when the electrode plate group is inserted into the cell is less than 5 kPa, the degree of compression is too low, and if it exceeds 30 kPa, the compression is too strong and the rib collapses. There may be a gap between the plates, and concentrated sulfuric acid may flow out from there. Accordingly, it is desirable that the degree of compression when the electrode plate group is inserted into the cell is 5 to 30 kPa.

  Hereinafter, the present invention will be specifically described by way of examples.

The ribbed separator of the present invention was produced by the following method.
That is, mineral oil (paraffinic oil) is added to high-density polyethylene resin powder and inorganic powder (silica powder having an average particle diameter of 5 μm), and this is mixed with a mixer. 1. Extruded into the rib arrangement pattern shown in FIG. 1 on both base surfaces of a 3 mm polyethylene resin sheet, pressure-molded with a molding roll, and then immersed in a solvent to remove some mineral oil and ribs A separator with a gap was manufactured.
The cross-sectional shape of the rib 3 is a square having a width of 0.4 mm and a height of 0.5 mm, and the maximum height difference H (see FIG. 1) between the end portion upper surface 3 a and the inner portion upper surface 3 b is 4 mm. The vertical interval D (see FIG. 1) was 10 mm.

An unformed positive electrode plate and negative electrode plate manufactured by a conventional method are alternately stacked with the separator obtained in Example 1 interposed therebetween to assemble an electrode plate group, which is inserted into a battery cell, and has a specific gravity. An electrolytic solution of 1.20 was injected to form a battery case, and a D23 size, 50 Ah liquid lead acid battery was manufactured. The degree of compression at the time of inserting the electrode plate group was variously changed in the range of 4 to 35 kPa.
About each obtained liquid type lead acid battery, the charge / discharge cycle test which charges only for the amount of discharge electricity with DOD10% was done at the temperature of 40 degreeC, and the life cycle number was investigated. Three batteries were used for the test.

A separator with ribs was manufactured by the same method as in Example 1 except that the mixture was extruded into the rib arrangement pattern shown in FIG.
The cross-sectional shape of the short rib 8 is a square having a width of 0.4 mm and a height of 0.5 mm, the maximum height difference H ′ (see FIG. 3) between the end upper surface 8a and the inner partial upper surface 8b of the short rib 8 is 3 mm, and the rib group The vertical distance D ′ between 8 g (see FIG. 3) was 6 mm.

(Comparative Example 1)
A ribbed separator is produced in the same manner as in Example 1 except that the mixture is extruded into a rib arrangement pattern shown in FIG. 4 (in which the linear ribs 10 are arranged in the horizontal direction with the length direction oriented in the horizontal direction). And the number of life cycles was examined.

(Comparative Example 2)
A ribbed separator was manufactured by the same method as in Example 1 except that the mixture was extruded into the rib arrangement pattern shown in FIG. 5 (a), and the number of life cycles was examined.

(Comparative Example 3)
A ribbed separator was manufactured by the same method as in Example 1 except that the mixture was extruded into the rib arrangement pattern shown in FIG.
The survey results are shown in Table 1.

  As is clear from Table 1, the lead-acid batteries of the present invention examples (Examples 1 and 2) had a life cycle number of 450 times or more. This is because concentrated sulfuric acid generated during charging is trapped on the ribs or short ribs to suppress the stratification phenomenon, and the gas generated during charging and discharging is released well so that the contact area between the electrode plate and the electrolyte is sufficiently maintained. This is because. In particular, those having a compression degree of 5 to 30 kPa (No. 2 to 5, No. 8 to 11) have excellent adhesion between the rib and the electrode plate, and the concentrated sulfuric acid is trapped well, so the number of life cycles exceeds 500 times. It was.

  On the other hand, since the comparative example 1 is provided with the straight ribs horizontally, the comparative examples 2 and 3 have the gas discharge path in the vertical direction. A large amount of sedimentation caused a stratification phenomenon and the cycle life was shortened. In particular, the lead storage battery of Comparative Example 1 had the shortest cycle life because it was difficult for gas to be released.

  The lead storage battery of the present invention (Examples 1 and 2) and the conventional lead storage battery (Comparative Examples 2 and 3) were mounted on an automobile incorporating an idle stop system and an overcharge prevention system, and the battery performance was investigated. As a result, all of the lead storage batteries of the present invention showed remarkably superior battery performance compared to conventional lead storage batteries, and were proved to be applicable to automobiles incorporating a new system.

It is front explanatory drawing which shows 1st Embodiment of the separator with a rib of this invention. It is side surface explanatory drawing of the electrode group which integrated the separator with a rib shown in FIG. It is front explanatory drawing which shows 2nd Embodiment of the separator with a rib of this invention. It is front explanatory drawing of the separator with which the rib was provided linearly in the horizontal direction. (A), (b) is a front explanatory view of a conventional ribbed separator.

Explanation of symbols

1, 1 'Ribbed separator 2 of the present invention Thin sheet 2a Thin sheet base surface 2b Thin sheet back base surface 3 Rib 3a Rib end upper surface 3b Rib inner portion upper surface 3c Rib center lower surface 3d End lower surface 4 Positive electrode plate 5 Negative electrode plate 6 Electrode plate group 8 Short rib 8a Short rib end surface 8b Short rib inner portion upper surface 8c Short rib central portion lower surface 8d Short rib end lower surface 8g, 8g 'Short rib Group 8t short rib pair

Claims (4)

  In the lead-acid battery separator with ribs provided on the base surface of the sheet, the ribs are provided across the base surface with the length direction thereof set in the horizontal direction, and upper surfaces of both end portions of the ribs. Is located at a position higher than the upper surface of the inner portion, and the lower surface of the rib is formed such that the central portion in the longitudinal direction of the rib is at the lowest position and is inclined upward from the central portion toward both ends. Rib separator for lead storage battery.   The separator with a lead-acid battery rib having a plurality of short ribs provided on the base surface of the sheet, wherein the required number of the short ribs are continuous with a predetermined interval in the length direction in the horizontal direction. A rib group crossing each other, and the rib group is vertically adjacent to each other to form a rib pair, and the upper surface of both ends of the short rib is an inner portion. The lower surface of the short rib is formed in an ascending slope from the central portion toward both ends. Rib separator for lead storage battery.   A lead-acid battery using the ribbed separator according to claim 1 or 2.   A lead storage battery in which an electrode plate group in which positive electrode plates and negative electrode plates are alternately stacked with the ribbed separators interposed therebetween is inserted in a battery cell, the electrode plate group being a battery case. A lead-acid battery characterized by having a compression degree of 5 to 30 kPa when inserted into a cell.

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