JPH0522342B2 - - Google Patents

Description

[Detailed description of the invention]

Industrial Application Field The present invention relates to a sealed lead-acid battery that is used while being charged by a constant voltage charging method such as long-term float charging or trickle charging, and in particular a method in which the negative electrode absorbs oxygen gas generated from the positive electrode (so-called negative electrode). absorption method)
This relates to lead-acid batteries. Structure of a conventional example and its problems A cross-sectional view of a conventional negative electrode absorption type lead-acid battery is shown in FIG. The electrode plate group consists of a negative electrode plate 3, a separator plate 7, and a positive electrode plate 4 stacked one after another, and each electrode plate is welded on a positive electrode welding shelf 6 or a negative electrode welding shelf 5. A pole pole serving as a current extraction section is welded to each shelf, and a terminal 8 is welded to the upper part of the pole pole. The lid 2 and the battery case 1 are bonded together, and the lid 2 is equipped with a safety valve 9. The separator used here is usually shorter than the inside width of the battery case and longer than the width of the electrode plate. A negative electrode absorption type lead-acid battery is one in which the required amount of electrolyte is impregnated into the electrode plate and separator to the extent that there is no free electrolyte.
Compared to the CS type, PS type, and HS type specified in 8704 (hereinafter referred to as liquid type), the amount of liquid is smaller, so the discharge capacity is controlled by the amount of electrolyte. This small amount of electrolyte causes the following problems. (1) Due to the small amount of electrolyte, the specific gravity of the electrolyte decreases significantly at the end of discharge, resulting in poor charge recovery after being left to discharge and a tendency toward sulfation. (2) The main mode of battery life is a decrease in capacity due to an increase in internal resistance as the amount of electrolyte decreases. (3) Due to differences in the amount of oxygen gas absorbed within the same cell, differences occur in the liquid content and electrolyte concentration for each separator. (4) Pure lead or a lead-calcium alloy is used for the grids, welding shelves, etc. to minimize self-discharge, so the mechanical strength is weak, and when strong vibrations are applied, the position of the electrode plate group may shift. . There has been a long-awaited desire to solve these problems (1) to (4) and to improve the reliability and extend the life of negative-electrode absorption lead-acid batteries. Purpose of the Invention The present invention solves the problems caused by the small amount of electrolyte compared to conventional liquid batteries, and solves the problems caused by the use of lead alloys with relatively weak mechanical strength such as pure lead and lead-calcium alloys. Solve the problems caused by using it,
The purpose is to improve the reliability and extend the lifespan of sealed lead-acid batteries. Structure of the Invention In order to achieve the above object, the lead-acid battery of the present invention comprises a plate group consisting of positive and negative plates and a separator placed between them, and a battery case that houses the plate group. The feature is that the width of the separator plate is longer than the depth dimension a of the battery case parallel to the main surface of the plate, and the excess portion protruding from the left and right ends of the plate is arbitrarily bent and inserted into the battery case. shall be. The appropriate dimension b of the surplus portion of the separator that protrudes from the left and right ends of the electrode plate is 2 to 5 times the difference between the depth dimension a of the battery case and the width dimension c of the electrode plate. It covers the left and right ends of the electrode plates and fills the space between the electrode plate group and the inner wall of the battery case. With this configuration, the reliability of the sealed lead-acid battery can be improved, and the battery life can be significantly extended. DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Note that the same reference numerals are given to the parts having the same configuration as in the conventional example, and the explanation thereof will be omitted. In Fig. 2, 7a is a separator plate, and the width dimension of this separator plate is longer than the depth dimension a of the battery case parallel to the main surface S of the negative electrode plate 3 and positive electrode plate 4 that constitute the electrode plate group. , the dimension b of the excess portion protruding outward from the left and right ends of the electrode plate is the depth dimension a of the battery case.
and the width dimension c of the electrode plate is set to three times the difference.
Further, the extra ends of the separator plate 7a protruding from the left and right sides of the electrode plate are bent so as to cover the left and right side edges of the electrode plate, as shown in FIGS. 2 and 3, and inserted into the battery case 1. be done. Here, the relationship between the depth dimension a of the battery case 1, the width dimension c of the electrode plates 3 and 4, and the dimension b of the surplus portion of the separator plate 7a protruding outward from the electrode plate side end portion was as follows. That is, in order to secure a large battery capacity, the depth dimension a of the battery case is kept constant, and the size c of the electrode plate that fits within this depth is varied, thereby increasing the space between the inner wall of the battery case and the left and right ends of the electrode plate. It was decided to fill it with the surplus part of the separator. 2b=(a-c)×(2~5) As a result, the width and thickness of the electrode plate and the space formed between the edge of the electrode plate and the inner wall of the battery case are determined by the extra portion b of the separator. Approximately three times the a-c dimension was good for filling and retaining more electrolyte without becoming liberated. Using such a separator, the 10 hour rate capacity
A negative electrode absorption lead-acid battery with a 50Ah output voltage of 12V (6-cell monoblock) was assembled, and the charge recovery after discharging, increase in internal resistance, electrolyte concentration distribution and liquid volume distribution, and earthquake resistance were investigated. First, regarding charge recovery after being discharged, the battery was left at a rate of 5A for 10 hours until the voltage reached 1.5V/cell, and after being left at 40°C for one month, it was charged at a voltage of 2.45V/cell for 12 hours, and again at 5A to 1.5V/cell. The cells were discharged and the capacity recovery status was investigated. The samples are the conventional product and this example product.
10 pieces were used. In addition, those that recovered to 90% or more of the initial capacity were considered good products, and those that recovered less than 30% were considered defective products, and the results are shown in Table 1.

[Table] As is clear from Table 1, it can be seen that the product of this example has better capacity recovery after being left to discharge compared to the conventional product. Further, the details of the increase in internal resistance are shown in FIG. Product A of this example had a smaller increase in internal resistance than conventional product B, and its lifespan was significantly extended. A 12V50Ah (10HR) battery was trickle charged at a charging voltage of 2.30V/cell and a temperature of 40°C. Capacity test conducted every 3 months, at 5A
It was decided to discharge to 1.8V/cell. Furthermore, regarding the distribution of electrolyte amount and electrolyte concentration, both this example product A and conventional product B were decomposed after being continuously overcharged for 100 days in a 40°C atmosphere at a constant current of 2.5A.
The liquid content and electrolyte specific gravity of each separator were investigated. The details are shown in Table 2, but in this example product, the space between the inner wall of the battery case and the electrode plate is filled with the excess portion of the separator plate, and the excess portions are in contact with each other. As a result, variations in liquid content and specific gravity values for each separator are significantly reduced. This suggests that the gas absorption reaction is also equalized for each electrode plate.

[Table] The charging conditions were: charging current 2.5A (constant current), ambient temperature 40°C, battery specification 12V50Ah, and 5 positive electrode plates and 6 negative electrode plates per cell. In terms of seismic resistance, when both the product of this example and the conventional product were subjected to continuous vibration for 2 hours at a gravitational acceleration of 2G, the pole pillars of the conventional product bent and the electrode plates shifted, but the product of this example did not have any problems. No abnormality was observed. Note that if the dimension b of the excess portion of the separator that protrudes from the left and right ends of the electrode plate is less than twice the difference between the depth dimension of the battery case and the width dimension of the battery case, the space between the electrode plate and the inner wall of the battery case is It is not possible to fill the space sufficiently, and the contact between the separators is insufficient, making it impossible to achieve the above effect. On the other hand, if the difference is 5 times or more, it becomes difficult to insert the battery into the battery case and the separator is more likely to be damaged, so it is desirable to set the difference to 2 times or more and 5 times or less. Effects of the Invention As described above, the present invention makes the width of the separator longer than the depth of the battery case so that the excess portion protrudes from the left and right ends of the electrode plate, and bends this excess portion to form the electrode plate. By covering the side edges of the battery and filling the space between the electrode plate group and the inner wall of the battery case, the movement of the electrode plate group is suppressed and the liquid holding capacity is increased, without creating free electrolyte. It is possible to increase the amount of electrolyte retained by 5 to 10% compared to before. As a result, it is possible to improve the charge recovery after discharging, suppress the increase in internal resistance, equalize the liquid content and electrolyte specific gravity for each separator, and suppress movement by reliably wrapping the electrode plate with the separator. Effects such as improved earthquake resistance were brought about, and it was possible to improve the reliability and extend the life of negative electrode absorption type lead-acid batteries.

[Brief explanation of the drawing]

Figure 1 is a partial cross-sectional view of a conventional sealed lead-acid battery.
Fig. 2 is a partial cross-sectional view of a sealed lead-acid battery according to an embodiment of the present invention, Fig. 3 is a perspective view showing the relationship between the electrode plates and the separator before insertion into the battery case, and Fig. 4 shows the period of use and the interior of the battery. FIG. 3 is a characteristic diagram showing the relationship between resistance change and capacitance change. 1...Battery container, 3...Negative electrode plate, 4...Positive electrode plate, 7
a... Separation plate, a... Depth dimension of battery case, b...
Extra dimension of separator, c... Width dimension of electrode plate.

Claims (1)

[Claims] 1.Equipped with a plate group consisting of positive and negative plates and a separator placed between them, and a battery case that houses this plate group, the depth of the battery case parallel to the main surface of the plate. The width dimension of the separator plate is longer than the dimension a, and the excess portion protruding from the left and right ends of the electrode plate has a dimension b.
is 2 to 5 times the difference between the depth dimension a of the battery case and the width dimension c of the electrode plate, and the surplus portion is bent to cover the left and right side ends of the electrode plate, and is bent to cover the electrode plate group and the inner wall of the battery case. A sealed lead-acid battery that fills the space between.