JPH08315849A - Sealed lead-acid battery - Google Patents

Abstract

PURPOSE: To provide a sealed lead-acid battery in which an internal short circuit is hardly caused and which has the long service life by arranging rib-shaped projections contacting with upper surfaces of the whole positive electrode plates on an inside surface of an intermediate cover, and arranging a positive electrode support body of a sulfuric acid corrosive resin material in a bottom part in a battery jar. CONSTITUTION: Plate groups composed of positive electrode plates 1, negative electrode plates 2 and a glass mat-like separator 3 are housed in a plurality in a battery jar 4 made of ABS or the like, and are sealed by an intermediate cover 5 and an upper cover 7. In this sealed lead acid battery, rib-shaped projections 6 contacting with upper surfaces of at least the whole positive electrode plates in a cell chamber are arranged on an inside surface of the intermediate cover 5. A support body 8 composed of a sulfuric acid corrosive resin material, for example, urea resin, ethyl cellulose or the like is arranged in a bottom part in the battery jar 4 so as to be opposed to lower parts of the positive electrode plates. Therefore, the support body is corroded and dissipated in response to elongation by corrosion of a positive electrode plate lattice, and the occurrence of a short circuit between the positive electrode plates and the negative electrode plates can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery container mainly composed of a battery case and an inner lid of a sealed lead acid battery.

[0002]

2. Description of the Related Art With the development of computers and the like, uninterruptible power supply (hereinafter referred to as U
The need to install PS) is widely recognized, and the number of UPS units sold tends to increase year by year.

In order to contribute to the improvement of reliability including safety as a measure against the Manufacturer's Responsibility Law, in addition to downsizing, weight reduction, and maintenance-free of such UPS, this UP is
There is also an urgent need for improvements in sealed lead acid batteries that support S.

By the way, the method of using the sealed lead-acid battery is roughly classified into a cycle method and a trickle method.
Is used in the latter scheme. The deterioration mode that determines the battery life in the trickle system is that the amount of electrolytic solution decreases due to the dissipation of water vapor through the battery wall made of resin material, for example, ABS, and the accompanying increase in internal resistance, or the corrosion of the positive electrode grid. Growth is mainly cited. As a means to improve these deteriorations, each manufacturer is trying to change the constituent materials of the separator, the battery case, etc. and the alloy composition of the positive electrode grid, and to develop an optimal trickle charging method, but this is still being tried. The results have not been satisfactory.

[0005]

The sealed lead-acid battery used as a backup power source for UPS or the like is usually trickle charged, that is, continuously charged by a minute current.
Therefore, the deterioration of the battery is large as compared with the use in the so-called cycle application. One of the deterioration modes in use in trickle applications is the problem of corrosion and elongation of the grid of the positive electrode plate. As the positive electrode plate lattice extends, the extended portion comes into contact with the negative electrode plate connecting body in the cell, causing a short circuit. Due to the internal short circuit, not only the battery performance such as voltage and current satisfying the purpose of use cannot be obtained, but in the worst case, a large current flows inside the battery, which may cause ignition. Since a solution to the problem caused by the elongation of the positive electrode plate lattice is not yet sufficient, improvement is strongly required.

[0006]

In order to solve the above-mentioned problems, the present invention covers a battery case in a sealed lead acid battery provided with an electrode plate group composed of a positive electrode plate, a negative electrode plate and a glass mat-like separator. Provided on the inner surface of the lid (middle lid) is a rib-shaped protrusion that comes into contact with at least all positive electrode plate upper surfaces in the cell chamber,
A resin material having a sulfuric acid corrosive property is arranged in a portion of the bottom of the battery case facing the lower portion of the positive electrode plate.

[0007]

With the above-described structure, the present invention provides a sealed lead-acid battery having a long life and excellent reliability. That is, a plate group composed of a positive electrode plate, a negative electrode plate, and a glass mat-like separator is inserted into the cell chamber of the battery case, and a rib for contacting at least the upper surface of the positive electrode plate in all the cell chambers is provided in the inner lid that covers the battery case. Since the resinous material having a sulfuric acid corrosive property is disposed at the bottom of the battery case facing the lower part of the positive electrode plate, the resinous material is corroded and decomposed by sulfuric acid as it is used. On the other hand, since the upper surface of the positive electrode plate is regulated by the rib-shaped protrusions, even if the grid is corroded and stretched as a trickle is used, the elongation is reduced in the downward direction, that is, in the direction of the negative electrode plate connected body, that is, in the direction of the negative electrode plate connected body. It is possible to face the inner bottom of the tank. In that case,
It is preferable to adjust the volume into which the resin material enters according to the height size of the electrode plate. That is, according to the amount of expansion of the electrode plate, the electrode plate having a high electrode plate thickness is made thicker, and the electrode plate having a lower electrode plate thickness is made thinner. If the resin material is not present, the electrode plate will excessively enter the battery cell chamber during assembly of the battery, which will hinder the production of the electrode plate connection body and the shelf.

As a result of investigations, the present inventors have found that it is desirable that the thickness of this resin material having sulfuric acid corrosiveness is 5 to 15% of the electrode plate height. If it is thinner than this,
After the positive electrode plate extends downward and reaches the inner bottom of the battery case, it further extends upward and comes into contact with the negative electrode plate connecting body to short-circuit,
Do not play that role. If it is thicker than this, contact with the negative electrode plate connecting body can be avoided, but the volume of the battery becomes too large, and miniaturization cannot be achieved.

[0009]

EXAMPLES The present invention will be described below with reference to examples.

The battery has a nominal voltage and capacity of 12V 6.5A.
The one equivalent to h (20 hr) was used. The positive electrode plate 1 has a width of 40
mm, height 65 mm, thickness 3.5 mm, negative electrode plate 2 having width 42 mm, height 65 mm, thickness 2.0 mm, and length 280 mm bent into an M shape. A positive electrode plate 1 was arranged in the upper open space of the glass fiber separator 3 having a width of 45 mm and a thickness of 1.0 mm to form one battery from the six electrode plate groups configured as shown in FIG. 1 in FIG.
Is a battery case, and 5 is an inner lid, and rib-shaped projections 6 that come into contact with the upper surface of the positive electrode plate are provided on the inner surface thereof. 7 is an upper lid, 8
Is a support made of a resin material having a sulfuric acid corrosive property, which is provided at the bottom of the battery case corresponding to the lower part of the positive electrode plate.

The resin material having a sulfuric acid corrosive property as the support 8 used in the present invention is not particularly limited, and urea resin, formaldehyde resin, ethyl cellulose, cellulose acetate, cellulose propionate, and cellulose nitrate are preferably used. . The shape of the material for the positive electrode plate support is also not particularly limited, and it can be used in the form of lumps, particles, or the like.

Specific examples of the present invention will be described in detail below. Example 1 As the support 8, a 4.5 mm thick lumped ethyl cellulose resin having a sulfuric acid corrosive property is located at the inner bottom of the battery case 4 made of ABS, and the inner lid 5 is in contact with the upper surface of the positive electrode plate 1. A battery was manufactured by using two projections 6 in a shape of a circle.

(Comparative Example 1) As the support 8, an ethyl cellulose resin having a thickness of 2.0 mm and having a sulfuric acid corrosive property is used.
A battery was produced in the same manner as in Example 1 except for the above.

(Comparative Example 2) As the support 8, a resin material having a sulfuric acid corrosive property was replaced with the same ABS material as that of the battery case, and the inner lid 5 having no rib-like projection 6 for pressing the electrode plate was used. A battery was prototyped in the same manner as in Example 1 except for the above.

For each of the five batteries produced, 40 ° C.
In the above, trickle charging was performed at a voltage of 2.3 V / cell. The capacity is checked every 3 months in an atmosphere of 25 ° C.
The battery was discharged at 4.0 CA, the time when the voltage dropped to 1.60 V / cell was measured, and the time was taken as the battery capacity. The result is shown in FIG.

From FIG. 2, the batteries of Example 1 are superior in capacity to Comparative Examples 1 and 2. This is because due to the corrosion dissipation of the support 8, the elongation of the lattice with the use of the positive electrode plate 1 can be sufficiently allowed in the downward direction.

[0017]

As described in detail above, according to the present invention,
In a sealed lead-acid battery having an electrode plate group composed of a positive electrode plate, a negative electrode plate, and a glass mat-shaped separator, a rib-shaped projection that comes into contact with at least all the upper surfaces of the positive electrode plates in the cell is provided in the inner lid, and in a battery case. By arranging a resin material having sulfuric acid corrosiveness in the bottom portion opposite to the lower portion of the positive electrode plate, it is possible to produce a battery in which the positive electrode plate lattice extended with use does not come into contact with the connection body of the negative electrode plate, It is possible to manufacture a battery that has a long life and is unlikely to cause an internal short circuit.

[Brief description of drawings]

FIG. 1 is a schematic view of a battery used in an example of the present invention.

FIG. 2 is a trickle charge period and 4.0C of the embodiment of the present invention.
Relationship diagram with discharge time (capacity) at A current

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Positive electrode plate 2 Negative electrode plate 3 Separator 4 Battery case 5 Inner lid 6 Rib-like protrusions 7 Upper lid 8 Sulfuric acid corrosive support

Claims (1)

[Claims] 1. A sealed lead acid battery comprising a positive electrode plate, a negative electrode plate, and an electrode plate group composed of a glass mat-shaped separator, wherein at least all positive electrodes in a cell chamber are provided on an inner surface of an inner lid for covering a battery case. A seal-type lead-acid battery, characterized in that a rib-shaped projection that comes into contact with the upper surface of the plate is provided, and a resin material having a sulfuric acid corrosive property is arranged at the inner bottom of the battery case facing the lower part of the positive electrode plate.