JPH07122292A - Sealed lead acid battery - Google Patents

Abstract

(57) [Summary] [Objective] To obtain a sealed lead acid battery capable of sufficiently suppressing the oxygen gas absorption reaction in the negative electrode plates located at both ends of the electrode plate group. [Structure] A positive electrode plate 4, a negative electrode plate 3, and a retainer 5 are stacked so that the negative electrode plates 3 and 3 are located at both ends to form an electrode plate group 2. The pressure spacers 6 are arranged between the negative electrode plates 3 on both ends of the electrode plate group 2 and the inner wall 1a of the battery case. The pressure spacer 6 is composed of an elastic body having an outer size larger than that of the negative electrode plate 3. The pressure spacers 6 are the outer end faces 3 of the negative electrode plates 3 on both ends in the stacking direction.
The outer end surface 3a, the upper end edge 3b, and both end edges of the negative electrode plate in the stacking direction are continuously covered so as to suppress the gas absorption reaction from the a side. An electrode plate fitting recess 6 a for fitting the negative electrode plate 3 is formed in the pressure spacer 6. A supplementary retainer is arranged between the pressure spacer 6 and the negative electrode plate 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved sealed lead acid battery.

[0002]

2. Description of the Related Art In a general sealed lead-acid battery, the number of negative electrode plates is increased by one with respect to the number of positive electrode plates, and a retainer is arranged between the positive electrode plate and the negative electrode plate so that both ends in the stacking direction are stacked. An electrode plate group configured to arrange the negative electrode plate is used.
In the electrode plate group having such a configuration, the negative electrode plates located at both ends of the electrode plate group are not much involved in the reaction as an electrode, but are much involved in the absorption reaction of oxygen gas generated from the positive electrode plate.
Oxygen gas generated in the positive electrode plate at the end of charging or during trickle charge reaches the negative electrode plate by directly passing through the retainer between the electrode plates to reach the negative electrode plate and the oxygen gas generated once There is a path to reach the negative electrode plate again after appearing in the peripheral portion. In the negative electrode plates located at both ends of the electrode plate group, particularly the latter route, that is, the amount of oxygen gas coming through the route in which the generated oxygen gas once exits the periphery of the electrode plate group and then reaches the negative electrode plate again, This causes many gas absorption reactions. Therefore, the amount of the negative electrode active material of the negative electrode plates located at both ends is reduced, or retainers are provided between the negative electrode plates located at both ends and the battery case to suppress the oxygen gas absorption reaction of the negative electrode plates located at both ends. The technology was proposed.

[0003]

However, in these prior arts, although the gas absorption reaction can be reduced to some extent, the oxygen gas entering from between the inner wall of the battery case and the outer end face of the negative electrode plate in the stacking direction can be reduced. The absorption reaction could not be significantly suppressed. The gas absorption reaction from the outer end face side of the negative electrode plate in the stacking direction increases as the gap or space in which the oxygen gas enters and stays between the inner wall of the battery case and the outer end face side of the negative electrode plate in the stacking direction increases. If this gas absorption reaction increases too much, a reaction locally occurs in the electrode plate group, and a temperature rise also easily causes a heat escape state, causing a problem that the charging current such as trickle charging increases. .

When a pressure spacer is arranged between the inner wall of the battery case and the negative electrode plates at both ends to apply pressure to the electrode plate group, the portion of the outer end face in the stacking direction of the negative electrode plate which is in close contact with the pressure spacer. The oxygen gas absorption reaction in can be partially suppressed. However, conventionally, since the pressurizing spacer has not been positively considered to suppress the oxygen gas absorption reaction, the conventionally proposed pressurizing spacer does not sufficiently absorb the oxygen gas on the outer end face side in the stacking direction of the negative electrode plate. The reaction could not be suppressed.

An object of the present invention is to provide a sealed lead acid battery capable of sufficiently suppressing the oxygen gas absorption reaction in the negative electrode plates located at both ends of the electrode plate group.

Another object of the present invention is to provide a sealed lead-acid battery which suppresses local absorption of oxygen gas in the electrode plate group, reduces the charging current of trickle, float, etc. and is thermally stable. That is.

Still another object of the present invention is to provide a sealed lead acid battery capable of sufficiently suppressing the oxygen gas absorption reaction in the negative electrode plates located at both ends of the electrode plate group and increasing the capacity. It is in.

[0008]

SUMMARY OF THE INVENTION According to the present invention, a positive electrode plate, a negative electrode plate and a retainer are laminated so that the negative electrode plates are located at both ends thereof. A sealed lead-acid battery in which a pressure spacer is arranged is targeted for improvement.

According to the first aspect of the present invention, as the pressure spacer, a negative electrode plate having a larger outer dimension than the negative electrode plate and adapted to suppress the gas absorption reaction from the outer end face side of the negative electrode plates at both ends in the stacking direction. An elastic body is used that continuously covers the outer end surface in the stacking direction and at least the upper end edge and both end edges of the negative electrode plate. Here, the elastic body in the present specification does not include a porous elastic body having a large number of holes or passages through which oxygen gas can freely pass, like a sponge. As the elastic body, an elastic body made of rubber having acid resistance is preferable, and for example, an elastic body made of foamed rubber made of chloroprene rubber can be used.

According to the second aspect of the present invention, the elastic body is provided with the electrode plate fitting recess for fitting the negative electrode plate so as to wrap at least the outer end face in the stacking direction, the upper end edge and both end edges of the negative electrode plate.

According to the third aspect of the invention, a supplementary retainer is arranged between the inner wall surface of the pressure spacer and the outer end surface of the negative electrode plate in the stacking direction. When forming the electrode plate fitting recess in the pressure spacer, a space for arranging the supplementary retainer may be formed inside the electrode plate fitting recess. A storage recess for storing the supplementary retainer may be formed in the pressure spacer.

According to the fourth aspect of the present invention, a passage for supplying the electrolytic solution to the supplementary retainer is formed in a portion of the pressure spacer made of an elastic body that faces the bottom surface of the battery case.

[0013]

According to the first aspect of the present invention, when the elastic body continuously covers the outer end face in the stacking direction of the negative electrode plates located at both ends of the electrode plate group and at least the upper end edge and both end edges of the negative electrode plate,
It is possible to substantially eliminate the gas passage that guides the oxygen gas emitted around the electrode plate group from the outside of the electrode plate group to the outer end faces in the stacking direction of the negative electrode plates located at both ends. Therefore, according to the present invention, it is possible to prevent the generation of gas absorption reaction from the outer end faces in the stacking direction of the negative electrode plates at both ends, suppress the oxygen gas absorption reaction at the negative electrode plates at both ends of the electrode plate group, and to conduct heat escape. Prevent the occurrence of the phenomenon. In addition, due to the presence of the elastic body, the pressing force inside the electrode plate group can be maintained within a predetermined range, and the battery performance can be improved. The elastic body may or may not cover the lower edge of the negative electrode plate. This is because the oxygen gas moves upward while the oxygen gas does not substantially enter from the lower end edge side of the negative electrode plate.

When the recess for electrode plate fitting is formed in the elastic body as in the second aspect of the present invention, movement of the elastic body can be prevented and at least the upper end edge and both side edges of the negative electrode plate are surely covered. be able to.

When the supplementary retainer is arranged between the inner wall surface of the pressure spacer and the outer end face of the negative electrode plate in the stacking direction as in the third aspect of the invention, the supplementary retainer is impregnated with the electrolytic solution, and therefore the electrode The negative electrode plates located at both ends of the plate group can be positively utilized as electrodes. Therefore, the capacity of the battery can be increased and the life of the battery can be extended.

According to the fourth aspect of the present invention, when the passage for supplying the electrolytic solution to the supplementary retainer is formed in the portion of the pressure spacer facing the bottom surface of the battery case, the passage is arranged between the pressure spacer and the negative electrode plate. The electrolyte solution can quickly penetrate into the supplementary retainer.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic partial cross-sectional view of the essential parts of an embodiment of the sealed lead-acid battery of the present invention. In this figure,
Reference numeral 1 is a battery case body that constitutes a part of the battery case, and 2 is a group of electrode plates housed in the battery case body 1. The electrode plate group 2 is formed by laminating six negative electrode plates 3, ..., Five positive electrode plates 4, ..., And ten retainers 5. This electrode group 2 is 2
It constitutes an electrode plate group of the V-40Ah storage battery. Electrode group 2
Between the negative electrode plates 3 and 3 located at both ends in the stacking direction and the wall portion 1a of the battery case body 1 (first pressure spacer).
6 and 6 are arranged. The pressure spacers 6 and 6 are
The negative electrode plates 3 and 3 are made of an elastic body having a larger outer dimension. Specifically, an elastic body made of chloroprene rubber foam rubber having a thickness of 5 mm is used.

The pressure spacers 6 and 6 used in this embodiment are
It has a structure as shown in FIG. The pressure spacer 6 has an electrode plate fitting recess 6a for fitting the negative electrode plate 3 so as to enclose the outer end surface 3a of the negative electrode plate 3 in the stacking direction, the upper end edge 3b, both side end edges 3c and the lower end edge 3d. is doing. The pressure spacer 6 also has a fitting portion into which the base portion of the ear portion 3e of the negative electrode plate 3 is fitted. This electrode plate fitting recess 6
a is the outer end face 3 in the stacking direction of the negative electrode plates 3 and 3 in which the oxygen gas discharged around the electrode plate group 2 is located at both ends from outside the electrode plate group 2.
It is formed so as to substantially eliminate the gas passages that enter the a and 3a and suppress the gas absorption reaction from the outer end face sides 3a and 3a of the negative electrode plates 3 and 3 at the both ends in the stacking direction. The bottom surface of the electrode plate fitting recess 6a has an outer end surface 3 in the stacking direction.
It is formed so as to come into contact with a, and the degree of adhesion of both surfaces is such that the compression force of the pressure spacer 6 that is compressed in the thickness direction between the electrode plate group 2 and the wall portion 1a of the battery case body 1 is strong. The higher it gets. With these configurations, it is possible to suppress the occurrence of gas absorption reaction from the outer end faces 3a, 3a in the stacking direction of the negative electrode plates 3, 3 at both ends.

FIG. 2B shows another example of the pressure spacer 6 '(second pressure spacer). This pressure spacer 6'is different from the pressure spacer 6 of FIG.
Since the electrode plate fitting recess is open to the bottom surface side of the battery case body, the lower end edge 3d of the negative electrode plate 3 is not covered by the pressure spacer 6 '. In this example, the lower end edge of the negative electrode plate 3 and the lower end surface of the pressure spacer are aligned with each other, but the lower end of the pressure spacer 6'may extend to a position beyond the lower edge of the negative electrode plate 3, as a matter of course. Is. Even if the lower end edge of the negative electrode plate 3 is not covered like the pressure spacer 6 ',
Since oxygen gas moves upward, oxygen gas does not substantially enter from the lower end edge side of the negative electrode plate, so that there is substantially no problem. However, in this case, it is preferable to increase the compressive force of the pressure spacer 6 ′ so that the degree of adhesion between the pressure spacer 6 ′ and the outer end surface of the negative electrode plate 3 in the stacking direction is as high as possible.

The pressure spacer 6, shown in FIGS.
Each of 6'has a pole plate fitting recess into which the negative electrode plate 3 is fitted. However, by appropriately selecting the elasticity of the elastic body forming the pressure spacer, 6'has a pole plate fitting recess. Even if it is a sheet-like pressure spacer (third pressure spacer), the negative electrode plate 3 bites into the pressure spacer, and therefore at least the outer end face 3a in the stacking direction, the upper end edge 3b, and the both end edges 3c of the negative electrode plate 3. And can be covered continuously. Even when the sheet-like pressure spacer is used, the positional relationship between the negative electrode plate 3 and the pressure spacer has the same positional relationship as the positional relationship between the negative electrode plate and the pressure spacer shown in FIGS. 2A and 2B. Can be taken.

Various sealed lead-acid batteries A to F using the above-mentioned first to third pressure spacers are prepared, and a conventional sealed lead-acid battery in which a retainer is arranged instead of the pressure spacers for comparison. G was prepared. The storage battery A is the first battery shown in FIG.
The storage battery B is a storage battery using the pressurizing spacer 6, and the storage battery B is a pressurizing device in which the end of the first pressurizing spacer 6 on the lower end side of the electrode plate fitting recess 6 a is extended to a position beyond the lower end edge of the negative electrode plate 3. It is a storage battery using a spacer. The storage battery C is shown in FIG.
The second pressure spacer 6'shown in (B) is a storage battery whose lower end edge is located above the lower end surface of the pressure spacer 6'as a negative electrode plate, and the storage battery D is shown in FIG. 2 (B). It is a storage battery in which the cathode plate is arranged in the relationship shown in FIG. The storage battery E is a storage battery in which a negative electrode plate is arranged in the center of the pressure spacer as shown in FIG. 2A using a sheet-shaped third pressure spacer having no electrode plate fitting recess. F is a sheet-like third
2B is a storage battery in which the negative electrode plate is arranged as shown in FIG. 2B. The storage battery G is a conventional storage battery in which a retainer is arranged instead of the pressure spacer. The external dimensions of each pressure spacer used are the same as those of the retainer.

The above storage batteries A to G were left in an atmosphere of 45 ° C. and the trickle current value at 2.275 V was measured. The result is shown in FIG. This result is a result of one month after being left, but the storage batteries A to F of the embodiment of the present invention have a current value about half that of the conventional storage battery G. However, if the degree of compression of the pressure spacer made of an elastic material is reduced to reduce the degree of adhesion or the biting degree between the negative electrode plate and each pressure spacer, the result shown by the broken line in FIG. 3 is obtained. It was As can be seen from this result, when the compression force of the pressure spacer made of an elastic body or the pressure applied by the pressure spacer is reduced, the effect is recognized but the effect is small.

Next, the results of comparison of discharge performance are shown in FIG.
Shown in. In FIG. 4, as described above, the storage battery G uses a retainer in place of the pressure spacer. As for the product of the present invention, as a representative, the storage battery A [the first pressure spacer 6 and the negative electrode of FIG. Battery Using Plate] and Battery E
The measurement result about (a storage battery using a sheet-shaped third pressure spacer) is shown. The storage battery A'is the first
A space for arranging a supplementary retainer is formed inside the electrode plate fitting recess 6a of the pressure spacer 6, and the supplementary space is provided between the inner wall surface of the electrode plate fitting recess 6a and the outer end face 3a of the negative electrode plate 3 in the stacking direction. A storage battery in which a retainer for the vehicle is arranged.

The discharge test conditions are 1 CA discharge and a final voltage of 1.6V. As can be seen from FIG. 4, the storage batteries A, E and A'of the embodiment of the present invention have a long discharge duration. In particular, the discharge duration of the storage battery A ′ in which the supplementary retainer is arranged between the inner wall surface of the electrode plate fitting recess 6a and the outer end surface 3a of the negative electrode plate 3 in the stacking direction is about 20 times that of the conventional storage battery G. % Longer. It is considered that this is because the pressurization of the electrode plate group is sufficient and the electrolytic solution is sufficiently supplied to the negative electrode plates located at both ends of the electrode plate group.

Next, the liquid absorption properties of a storage battery (a storage battery of the aforementioned storage battery A'type) in which a supplementary retainer is arranged between the inner wall surface of the pressure spacer and the outer end surface 3a of the negative electrode plate 3 in the stacking direction were compared. FIGS. 5A and 5B are two types of pressure spacers 1 in which sheet-like elastic bodies made of elastic body are formed with storage recesses 16a and 16'a for storing supplementary retainers.
It is the figure which showed roughly the relationship between 6,16 ', the negative electrode plate 3, and the retainer 5'for a supplement. In FIG. 5A, a storage recess 16a is formed in the center of the sheet-shaped elastic body so as to completely surround the outer circumference of the supplementary retainer 5 '. FIG. 5B shows a storage recess 16 ′ for storing the supplementary retainer 5 ′ such that the outer peripheral lower end surface is exposed.
The sheet a is a sheet-like elastic body. FIG. 6 shows the time until the electrolytic solution permeates into the retainer 5 ′ housed in the housing recesses of the two types of pressure spacers 16 and 16 ′. The pressure applied during the measurement was 20 kg / cm ² . The electrolyte had a specific gravity of 1.320 and was colored with methyl red. As is clear from FIG. 6, the permeability of the electrolytic solution into the retainer is stored in a shape in which the lower end is open and communicates with the space inside the battery case, as in the pressure spacer 16 shown in FIG. 5B. The use of the recessed portion 16'a allows the electrolytic solution to permeate in 1/3 of the time. Even in the pressure spacer 16 of FIG. 5A, if the communication passage communicating with the storage recess 16a and the space inside the battery case is provided at the lower end, the permeation time of the electrolytic solution can be shortened. When using a pressure spacer having a recess 6a for accommodating an electrode plate, such as the pressure spacers 6 and 6'shown in FIGS. 2A and 2B,
A space for accommodating the supplementary retainer may be provided in the electrode plate accommodating recess 6a.

In a storage battery in which a supplementary retainer is arranged between the pressure spacer and the negative electrode plates located at both ends of the electrode plate group, the discharge capacity increases. To further increase the capacity, see FIG.
As shown in (B), it is better to use one that opens at the lower end of the storage recess 16'a and communicates with the space inside the battery case. Therefore, a storage battery F using the structure shown in FIG.
′ Was examined for cycle life characteristics of the storage battery. The result is shown in FIG. 7. For comparison, the cycle life characteristics of the storage battery G using a retainer instead of the pressure spacer were also examined. As can be seen from FIG. 7, the cycle life characteristic of the storage battery F ′ is good. It is considered that this is because the pressure was uniformly maintained by the insertion of the pressure spacer made of an elastic material, and the drop of the active material and the elongation of the lattice were suppressed.

As described above, in the sealed lead-acid battery of the embodiment of the present invention, the pressure spacers made of an elastic body are provided between the negative electrode plates located at both ends of the electrode plate group and the inner wall of the battery case to apply pressure. The spacer is configured so that each edge of the negative electrode plate penetrates, and the retainer for supplement is arranged between the pressure spacer and the negative electrode plate, so it is positioned at both ends of the electrode plate group compared to the conventional sealed lead acid battery. By suppressing the absorption of oxygen gas by the negative electrode plate, the trickle charge and float charge current values are reduced. Therefore, thermal characteristics such as heat escape are improved. Further, by inserting a pressure spacer made of an elastic body, the pressure applied to the electrode plate group is always constant, which is excellent in that the cycle life characteristic of the battery is significantly improved.

[0028]

According to the first aspect of the present invention, the pressure spacers made of an elastic material are used to separate the outer end faces of the negative electrode plates in the stacking direction, which are located at both ends of the electrode plate group, and at least the upper end edge and both end edges of the negative electrode plate. Since the electrodes are continuously covered, it is possible to substantially eliminate the gas passage through which the oxygen gas discharged around the electrode plate group enters from the outside of the electrode plate group to the outer end faces in the stacking direction of the negative electrode plates located at both ends. Therefore, according to the present invention, it is possible to prevent the occurrence of gas absorption reaction from the outer end faces in the stacking direction of the negative electrode plates at both ends, suppress the oxygen gas absorption reaction in the negative electrode plates at both ends of the electrode plate group, and to perform heat escape. There is an advantage that the occurrence of the phenomenon can be prevented. In addition, due to the presence of the elastic body, the pressing force inside the electrode plate group can be maintained within a predetermined range, and the battery performance can be improved.

According to the second aspect of the invention, since the recess for fitting the electrode plate is formed in the elastic body, it is possible to prevent the elastic body from moving, and at least the upper end edge and both side edges of the negative electrode plate are surely secured. There is an advantage that it can be covered.

According to the third aspect of the present invention, since the supplementary retainer is arranged between the inner wall surface of the pressure spacer and the outer end surface of the negative electrode plate in the stacking direction, the electrode plate is formed by the electrolytic solution impregnated in the supplementary retainer. The negative electrode plates located at both ends of the group can be positively utilized as electrodes, and the battery capacity can be increased, and the battery life can be extended.

According to the fourth aspect of the invention, since the passage for supplying the electrolytic solution to the supplementary retainer is formed in the portion of the elastic body facing the bottom surface of the battery case, it is arranged between the pressure spacer and the negative electrode plate. The electrolyte solution can quickly penetrate into the supplementary retainer.

[Brief description of drawings]

FIG. 1 is a schematic partial cross-sectional view of a main part of an embodiment of a sealed lead-acid battery of the present invention.

FIGS. 2A and 2B are diagrams showing a state in which a pressure spacer and a negative electrode plate that can be used in the present invention are combined.

FIG. 3 is a graph showing trickle charge current values at 45 ° C. of the product of the present invention and the conventional product.

FIG. 4 is a diagram showing discharge durations of three types of storage batteries of the present invention and a conventional product.

5 (A) and 5 (B) respectively show a sheet-shaped elastic body having a storage recess for storing a supplementary retainer.
It is the figure which showed roughly the relationship of the kind of pressurization spacer, the negative electrode plate, and the retainer for a supplement.

FIG. 6 is a diagram for comparing the electrolyte permeability of the supplementary retainer when the pressure spacers of FIGS. 5A and 5B are used.

FIG. 7 is a diagram showing cycle life characteristics of a storage battery of the present invention and a conventional storage battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery case 2 Electrode plate group 3 Negative electrode plate 4 Positive electrode plate 5 Retainer 5'Retainer for supplementation 6, 6 ', 16, 16' Pressure spacer

Claims (4)

[Claims] 1. A positive electrode plate so that negative electrode plates are positioned at both ends,
A sealed lead-acid battery in which a pressure spacer is disposed between the negative electrode plates at both ends of the electrode plate group formed by laminating a negative electrode plate and a retainer and the inner wall of the battery case, wherein the negative electrode is the negative electrode. The outer end face of the negative electrode plate in the stacking direction and at least the upper end edge of the negative electrode plate having outer dimensions larger than those of the plates and corresponding to suppress gas absorption reaction from the outer end face side of the negative electrode plate in the stacking direction. A sealed lead-acid battery using an elastic body that continuously covers both side edges. 2. The elastic body has an electrode plate fitting recess for fitting the negative electrode plate so as to enclose at least the outer end surface of the negative electrode plate in the stacking direction, the upper end edge and the both end edges. Item 1. The sealed lead acid battery according to Item 1. 3. The sealed lead-acid battery according to claim 2, wherein a supplementary retainer is arranged between the inner wall surface of the pressure spacer and the outer end surface of the negative electrode plate in the stacking direction. 4. The sealed lead-acid battery according to claim 3, wherein the elastic body has a passage for supplying an electrolytic solution to the supplementary retainer at a portion facing the bottom surface of the battery case.