JP2004119106A - Control valve lead storage battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a long life and very safe control valve lead storage battery suppressing corrosion of a connecting portion between a positive electrode shelf and an electrode pole part, which occurs when trickle charging is carried out on the control valve lead battery for a long period of time, and suppressing cracks caused by the corrosion. <P>SOLUTION: The battery has a group of electrode plates consisting of rectangular positive electrode plates and negative electrode plates which are arranged via retainers, wherein electrolyte is contained in the group of electrode plates. The control valve lead battery has a shelf portion 14 which is formed by welding current collection lugs 12 of positive electrode plates all together, and has connecting members 13 which are used for connecting electrically electrode poles or connectors welded to the shelf portion. A is ratio S<SB>1</SB>/S<SB>2</SB>, wherein S<SB>1</SB>is the area of the cross section of a boundary portion between the connecting member and the shelf portion, and S<SB>2</SB>is total summation of the area of the cross sections of the current collection lugs. d is the length of a side of the positive electrode plate, where the current collection lug 12 is disposed, h is the length of other side which is approximately orthogonal to above side, and B is ratio h/d. A≥1 when B≥1. A≥2.5B-1.5 when B≥0.8 and B is less than 1. A≥0.625B when B is less than 0.8. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a control valve type lead storage battery used for a backup power supply or the like.
[0002]
[Prior art]
The control valve type lead storage battery can be applied to a wide capacity range of several Ah to several thousand Ah. Further, since they are relatively inexpensive, they are widely used as backup power supplies such as uninterruptible power supplies for computers to emergency power supplies for buildings.
[0003]
In such a backup power supply, the control valve-type lead storage battery is always charged while the commercial power is normally supplied in preparation for the backup discharge. Such charging is called trickle charging, and is performed to compensate for the self-discharge of the battery. In order to suppress the performance degradation of the battery due to overcharge as trickle charging, constant voltage charging is generally performed so that the charging voltage of the battery does not exceed a predetermined value.
[0004]
On the other hand, such a control valve type lead storage battery used for backup needs to have a life of several years to several tens of years, and safety during such a long use period is required. Particularly, the trickle charging is performed over a long period of time, so that the positive electrode member continues to be corroded by oxidation. When the positive electrode member is corroded, there is a possibility that the cross-sectional area of the lattice bone or the current collecting ear is reduced, or the lattice is deformed and short-circuited with the negative electrode member.
[0005]
In particular, when the cross-sectional area of the current collecting ears and bones is reduced, these current collecting ears and bones may be blown when a battery is erroneously short-circuited during backup discharge or maintenance and inspection. Regarding the suppression of such melting of the current collecting ears and bones, it is known that the current collecting ear cross-sectional area and the bone cross-sectional area per theoretical capacity and active material amount of the battery are within a predetermined range (for example, see Patent Document 1). 1 and Patent Document 2).
[0006]
According to these patent documents, it is possible to suppress the fusing of the ear and the bone in the battery in the initial state. However, there is no description as to whether the fusion of the ear and bone can be suppressed over a long period of use such as several years to several decades. Therefore, the inventors of the present invention have studied the reliability of the ear and bone after a long use period.
[0007]
As a result, due to the configuration shown in each of the above-mentioned patent documents, although the reliability of the ears and bones is ensured, the corrosion progresses between the positive electrode shelf and the pole column parts, and this part is blown out. It turned out that there was a possibility. In particular, when trickle charging is performed in a high-temperature atmosphere such as 60 ° C., the positive electrode grid body is deformed, and stress is concentrated on the connection between the positive electrode shelf and the pole column component. As a result, there is a problem that as a result of corrosion progressing preferentially at the connection portion where the stress is concentrated, a crack is generated at this portion or the battery is disconnected due to disconnection.
[0008]
[Patent Document 1]
JP-A-64-19674 (page 3, lower left column, lines 3 to 8)
[Patent Document 2]
JP-A-2-281558 (page 3, upper left column, lines 15-20, lower left column, lines 1-4)
[0009]
[Problems to be solved by the invention]
The present invention suppresses the above-described phenomena such as corrosion of the connection portion between the positive electrode shelf and the pole column component and cracks caused by the trickle charge of the control valve type lead storage battery for a long period of time, and has a long life and excellent safety. A control valve type lead storage battery is provided.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 of the present invention provides an electrode plate group in which a rectangular positive electrode plate and a negative electrode plate are arranged via a retainer, by impregnating and holding an electrolytic solution, The present invention relates to a control valve type lead-acid battery including a shelf in which current collecting ears of a plate are collectively welded and a connecting member for electrical connection such as a pole or a connector welded to the shelf. A is the ratio (S ₁ / S ₂ ) of the cross-sectional area (S ₁ ) of the boundary portion to the total cross-sectional area (S ₂ ) of the current collecting ears, and the length of the side of the positive electrode plate where the current collecting ears are provided is d, when the length of the other side substantially orthogonal to this side is h, and the ratio (h / d) of these two sides is B, the ratio A is defined within the following range according to the ratio B: Is what you do.
[0011]
That is,
{Circle around (1)} When B ≧ 1, A ≧ 1.
[0012]
(2) If 0.8 ≦ B <1, A ≧ 2.5B−1.5.
[0013]
(3) When B <0.8, A ≧ 0.625B.
[0014]
According to a second aspect of the present invention, in the control valve type lead-acid battery of the first aspect, the positive electrode plate includes an expanded lattice body in which a lead alloy sheet is developed and elongated, and a direction in which the expanded lattice body is developed and current collection. The protruding direction of the ears is the same.
[0015]
Further, according to a third aspect of the present invention, in the control valve type lead-acid battery of the first or second aspect, the connecting member of the positive electrode and the shelf are made of lead or a lead alloy having different compositions.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
A control valve type lead storage battery (hereinafter, battery) according to an embodiment of the present invention will be described with reference to the drawings.
[0017]
As shown in FIG. 1, the electrode plate group 1 used in the battery of the present invention has a rectangular positive electrode plate 2 and a negative electrode plate 3 arranged via a retainer 4. As the conventional retainer 4, a nonwoven fabric of an acid-resistant fiber such as a glass fiber mat can be used. As shown in FIG. 2, the grid plate 10 is filled with the active material 11 in the positive electrode plate 2, and a current collecting lug 12 is formed on one side thereof. The negative electrode plate has the same structure as the positive electrode plate.
[0018]
The predetermined number of the positive electrode plates 2 and the negative electrode plates 3 are combined, and the ear portions of the same polarity, that is, the ear portions 12 and the connecting members 13 for electrical connection, such as pole members and connecting bodies, are integrated in the positive electrode. Is formed. As an example of a specific manufacturing method, a current collecting ear portion is arranged in a mold on a comb tooth, and is arranged at a position close to the ear portion 12, as conventionally called burning welding. Thereafter, molten lead is supplied to the periphery of the ear 12 and the space between the ear 12 and the connecting member 13, and the molten lead is solidified to form the shelf 14.
[0019]
In the present invention, the ratio (S ₁ / S ₂ ) of the cross-sectional area (S ₁ ) of the boundary between the connecting member 13 and the shelf 14 to the sum (S ₂ ) of the cross-sectional areas of the ears 12 is defined as the ratio of the positive electrode plate 2. It is defined in association with the aspect ratio. That is, the ratio (S ₁ / S ₂ ) is A, the length of the side 2a of the positive electrode plate 2 on which the ear 12 is provided is d, and the length of the other side 2b substantially orthogonal to the side 2a is h. When the ratio (h / d) of these two sides is B, A is defined according to the aspect ratio B of the dimension of the positive electrode plate 2.
[0020]
That is,
{Circle around (1)} When B ≧ 1, A ≧ 1.
[0021]
(2) If 0.8 ≦ B <1, A ≧ 2.5B−1.5.
[0022]
(3) When B <0.8, A ≧ 0.625B.
[0023]
When the positive electrode plate 2 expands due to oxidation and expands in size, the shelf 14 is pushed in the X direction in FIG. 1 by the ear 12, and a stress is applied in a direction in which the connecting member 13 and the shelf 14 bend at the boundary. Are concentrated, and corrosion tends to progress. In the present invention, by limiting the ratio (S ₁ / S ₂ ) of the cross-sectional area (S ₁ ) of the boundary portion to the total (S ₂ ) of the cross-sectional areas of the ear portions 12, stress concentration at the boundary portion and corrosion due to the stress concentration are caused. Of the process.
[0024]
Further, the stress applied to the shelf 14 by the ear 12 greatly changes depending on the shape of the positive electrode plate 2. This is because even if the electrode plate areas are the same, the dimensional change due to corrosion differs depending on the length-width ratio. For example, in the case of a vertically long electrode plate, extension in the vertical direction is performed with priority in the horizontal direction. In such an electrode plate, when the ears are arranged so as to protrude in the vertical direction, the stress applied to the shelf 14 increases even under the same corrosion condition as compared with the case where the ears are arranged so as to protrude in the horizontal direction. Therefore, it is necessary to determine the ratio (S ₁ / S ₂ ) according to the dimensional ratio (h / d) of the positive electrode plate.
[0025]
Further, in the present invention, in addition to the cast grid 17 as shown in FIG. 4 as a grid used for the positive electrode plate 2, the development direction especially at the time of expanding as shown in FIG. It is also suitable for the expanded lattice body 15 which is the same as the above. Such an expanded lattice body 15 is preferentially extended in the deployment direction, that is, the protruding direction of the ear 12 due to corrosion. Therefore, the stress on the shelf 14 and the connecting portion is increased. In the present invention, even if a lattice body which preferentially extends in the direction in which the ears 12 protrude is used, stress concentration at the joint between the connecting member 13 and the shelf 14 and corrosion due to this can be suppressed. Further, the configuration of the present invention can also be applied to a case where the lead portion 14 and the connection member use lead alloys having different compositions from each other.
[0026]
【Example】
In the electrode plate group shown in FIG. 1, the dimensional ratio (h / d) of the positive electrode plate, the cross-sectional area (S ₁ ) of the boundary between the connecting member 13 and the shelf 14, and the sum of the cross-sectional areas of the ears 12 (S ₂ ), the ratio (S ₁ / S ₂ ) was changed to produce a 2V65Ah control valve type lead-acid battery (hereinafter referred to as “battery.” As a grid used for the positive electrode plate, a cast grid 17 shown in FIG. 4 was used. The expanded lattice body 15 and the expanded lattice body 16 shown in Fig. 3 and Fig. 5 were used.The expanded lattice body 15 shown in Fig. 3 has the protruding direction of the ear 12 and the development direction at the time of the expansion processing as described above. On the other hand, the expanding lattice body 16 shown in Fig. 5 is configured such that the protruding direction of the ear 12 and the developing direction at the time of the expanding process are orthogonal to each other.
[0027]
In addition, Pb-0.07 mass% Ca-1.6 mass% Sn alloy was used for all of these lattice bodies. Pb-0.8% by mass Sn was used for the shelf 14 of the positive electrode, and Pb-2.0% by mass Sn alloy was used for the connection member.
[0028]
For each of these batteries, a durability test of the positive electrode shelf-connection member was performed. As a durability test, trickle charging was performed at a charging voltage of 2.275 V in an atmosphere of 60 ° C. for 420 days, and then each battery was disassembled to check the state of the junction between the positive electrode connecting member and the shelf. When a crack was generated in the joint, it was evaluated how much the cross-sectional area of the joint was reduced by the crack. The results are shown in FIGS.
[0029]
FIG. 6 shows the results of a durability test of a battery using an expanded grid body 15 in which the development direction shown in FIG. The symbol ○ indicates that there is no crack between the shelf of the positive electrode and the connecting member, the symbol × indicates that the shelf and the connecting member have broken due to the crack, and the junction between the shelf and the connecting member although a crack has occurred. Is maintained as a symbol ●, and the ratio of the cross-sectional area of the remaining shelf-connecting member is indicated in percentage with the symbol ●. For example, when the cross-sectional area of the shelf-connecting member was reduced to half of the initial value due to a crack, the value was shown as 50%.
[0030]
From the results shown in FIG. 6, d is the length of the side 2a of the positive electrode plate 2 on which the lugs 12 are provided, and h is the length of the other side 2b substantially orthogonal to the side 2a. When (= h / d) is 1 or more, the ratio A (= S ₁ / S ₂ ) to the total (S ₂ ) of the cross-sectional areas of the ears 12 is set to 1 or more, so that the crack between the shelf and the connecting member is formed. Can be suppressed. In order to suppress this crack, it is necessary to limit A by the value of B. When B is 0.8 ≦ B <1, the relationship between A and B is A ≧ 2.5B−1.5 A is limited within the range that satisfies. Further, when B is B <0.8, B is limited within a range where the relationship between A and B satisfies A ≧ 0.625B. By limiting A in accordance with B in this manner, corrosion due to stress concentration at the junction between the positive electrode connecting member and the shelf and the occurrence of cracks caused by the trickle charging, which may conventionally occur due to trickle charging, are remarkable. Can be suppressed.
[0031]
FIG. 7 shows the results of a durability test of a battery using the cast grid 17 shown in FIG. 4 as the positive grid. The results were shown in the same manner as in FIG. When the cast grid 17 was used as the positive grid, the same result as the battery using the expanded grid 15 was obtained. However, in the region where the crack occurs, the degree of the crack was reduced as compared with the case where the expanded lattice body 15 was used. Since the casting lattice 17 extends in the vertical direction (the direction in which the ears protrude) and also extends in the lateral direction, the extension in the direction in which the ears protrude is eased as compared with the expanded lattice which extends preferentially in the deployment direction. I can guess that.
[0032]
Further, a durability test result of a battery using the expanded grid body 16 of the comparative example shown in FIG. 5 as the positive grid body was performed, but no crack was generated between the shelf and the connection member. In these batteries after the durability test, unlike the batteries using the cast lattice 17 and the expanded lattice 15, the lateral extension of the electrode plate occurred in preference to the vertical extension of the electrode plate. Therefore, it can be assumed that there was no stress concentration leading to corrosion and cracks between the shelf and the connecting member.
[0033]
【The invention's effect】
As described above, according to the configuration of the present invention, even if the control valve-type lead-acid battery is trickle-charged for a long period of time, the above-described phenomena such as the corrosion of the connection portion between the positive electrode shelf and the pole column component and the cracks caused thereby. It is industrially extremely useful because it can provide a control valve type lead-acid battery with a long life and excellent safety.
[Brief description of the drawings]
FIG. 1 is a view showing an electrode group of a battery of the present invention. FIG. 2 is a view showing a positive electrode plate of a battery of the present invention. FIG. 3 is a view showing an expanded lattice used in the battery of the present invention. FIG. 5 is a view showing a cast grid used in the battery of the present invention. FIG. 5 is a view showing an expanded grid according to a comparative example. FIG. 6 is a view showing a durability test result of a positive electrode shelf-connecting member of batteries of the present invention and a comparative example. FIG. 7 is a diagram showing endurance test results of the shelf-connection member of the positive electrode of the batteries of the present invention example and the comparative example.
DESCRIPTION OF SYMBOLS 1 Electrode group 2 Positive electrode plate 2a Side 2b Side 3 Negative electrode plate 4 Retainer 10 Grid body 11 Active material 12 Ear part 13 Connecting member 14 Shelf 15 Expanded grid body 16 Expanded grid body 17 Cast grid body

Claims (3)

A control valve-type lead storage battery in which an electrolytic solution is impregnated and held in an electrode plate group in which a rectangular positive electrode plate and a negative electrode plate are arranged via a retainer,
A connecting member for electrical connection, such as a shelf where the current collecting ears of the positive electrode plate are collectively welded and a pole or a connecting body welded to the shelf,
A is a ratio (S ₁ / S ₂ ) of a cross-sectional area (S ₁ ) of a boundary portion between the connection member and the shelf to a total sum (S ₂ ) of cross-sectional areas of the current collecting ears;
When the length of the side of the positive electrode plate on which the current collecting ears are provided is d, the length of another side substantially orthogonal to the side is h, and the ratio (h / d) of these two sides is B. ,
When B is B ≧ 1, A is A ≧ 1;
When the B is 0.8 ≦ B <1, the A is A ≧ 2.5B−1.5,
A control valve type lead-acid battery characterized in that A is A ≧ 0.625B when B is B <0.8. 2. The control valve according to claim 1, wherein the positive electrode plate includes an expanded lattice body formed by expanding and expanding a lead alloy sheet, and a developing direction of the expanded lattice body and a protruding direction of the current collecting ear part are the same. 3. Type lead acid battery. 3. The control valve type lead-acid battery according to claim 1, wherein the connection member and the shelf are made of lead or a lead alloy having different compositions.

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