JP3191644B2 - Simple gas-absorption type lead-acid battery and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a simple gas absorption type lead-acid battery and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, a lead-acid battery employs a material such as pure lead or a lead-calcium alloy, which generates less hydrogen during charging, and a separator, such as a glass mat, which easily absorbs an electrolyte between the plates. In many cases, a so-called gas-absorbing sealed battery is used in which the amount of an electrolytic solution is limited so that an appropriate gas can be permeated and oxygen generated from a positive electrode is returned to water at a negative electrode. In these batteries, in order to complete the sealing function, the basic configuration is to provide a safety valve with a moderate valve opening pressure, and the others are usually completely sealed.

[0003]

However, in the above configuration, hydrogen is not generated at all, and hydrogen gas is stored inside the device because it has no function of ionizing hydrogen.

Originally, the purpose of sealing is to suppress the decrease of the liquid during charging and to prevent the contamination of peripheral equipment due to the splash of sulfuric acid, and minute hydrogen gas is extremely accumulated rather than accumulated inside. It is safer to spread it out of the battery system little by little. That is, in view of the above situation, a simple sealing system is desired in which hydrogen is appropriately permeated even if it is not a completely closed mechanism, and discharge of droplets is prevented.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a gas-absorption type lead-acid battery having a safe and simple structure by suppressing the accumulation of hydrogen gas, and a method for producing the same.

[0006]

In order to solve the above-mentioned problems, the present invention is to attach an acid-resistant synthetic resin film coated with an acid-resistant adhesive to an opening provided on the outer wall of a battery case. Having the following configuration.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The synthetic resin film used in the structure of the present invention is a continuous homogeneous film unlike a thin resin filter which is expected to be porous, such as a sintered body of fluororesin or a woven or nonwoven fabric. And so-called vinyl
They are commercially available as lute tapes, which are coated on one side with a tacky adhesive. These are apparently not uniform membranes, but molecular hydrogen, oxygen, nitrogen or water can permeate through the interstices of the crystals. Further, when a water-repellent material such as a fluororesin is present in either the film material itself or the adhesive, water permeation can be suppressed. However, when using these synthetic resin films for a lead storage battery, it is necessary that the film material and the tacky adhesive have acid resistance. On the other hand, it has been thought that the inside of the battery is basically decompressed because oxygen is absorbed by the negative electrode, and self-discharge is increased by sucking oxygen from the outside. Balance with. In addition, the gas pressure during overcharge is actually applied to a constant voltage charging system, so by appropriately selecting the thickness of the synthetic resin film or by using a safety valve together,
Danger such as rupture of the battery case can be avoided.

[0008]

FIG. 1 shows the features of a gas absorption type lead storage battery having a simple structure according to an embodiment of the present invention. 1 is a cylindrical resin container, 2 is a container cover, 3 is an electrode plate group including a positive electrode, a negative electrode and a glass mat separator. The positive electrode terminal 5 and the negative electrode terminal 6 are connected to the electrode plate by electrode conductors 7 and 8. In addition, the lid penetrating portions of the terminals of both electrodes are hermetically and liquid-tightly sealed with resin 9.

In this embodiment, a band-shaped recess 1 is formed on the outer periphery of the battery case.
0, and the concave portion is provided with one or more openings 11. Reference numeral 12 denotes an acid-resistant synthetic resin film which is an important part of the present invention, and a tacky and acid-resistant adhesive 1 inside the film.
3 is applied and adhered to the outside of the opening 11. At this time, it is important that the adhesive is exposed inside the film facing the opening.

In this embodiment, a fluororesin product manufactured by Nitto Denko; Nitoflon is used as an acid-resistant synthetic resin film. Reference numeral 14 denotes a ring-shaped band spring plate which is fitted in a concave portion.
The protection plate protects the gas permeable resin film.
The protective plate is preferably provided with a groove 15 serving as a gas passage on the side facing the film, or at least a portion corresponding to the opening is preferably made of a porous material.

Next, in order to confirm the effect of the present invention, FIG.
A cylindrical lead-acid storage battery having a nominal capacity of 1.2 Ah according to the embodiment of the present invention was manufactured with the configuration described above, and compared with a gas-absorption-type lead storage battery B having a conventional safety valve. In the case of the battery B of the conventional configuration during the formation charge, the amount of liquid required for formation cannot be ensured in the battery case. Therefore, the electrode group was formed in a spiral shape after separately forming an electrode plate. As a result, the active material was often peeled off and the capacity was insufficient. The present invention takes advantage of the fact that the battery case is provided with an opening through which an electrolytic solution can be supplied from the outside, and the spiral electrode group is formed without peeling and falling using a wet unformed plate, and this is formed with diluted sulfuric acid. Immersed in aging, stored in a battery case with an opening,
After completing the structure of the part other than the opening, the whole battery is immersed in another electrolytic solution tank for chemical conversion, and then the surface is washed with a shower and then has an adhesive adhesive. A non-porous synthetic resin film was attached to the opening to complete the configuration of the present invention. As described above, in addition to the resulting function, the possibility of adopting a new manufacturing method related to the merit that the shortage of the electrolyte during the formation can be easily avoided in the process of manufacturing the battery is expanded. In the test, constant voltage charging for 6. hours at 2.25 V at a maximum charging rate of 0.2 C per cell and discharging at an hourly rate were repeated.

FIG. 2 shows the result of examining the change in the hydrogen gas composition (converted to normal pressure) at the end of charging in a predetermined cycle, and FIG. 3 shows the result of examining the change in weight. As is apparent from these results, while the hydrogen gas was gradually accumulated in the conventional configuration, the present invention always started with a low hydrogen composition. The weight change was not inferior to the conventional valve structure.

[0013]

As described above, the present invention suppresses the accumulation of hydrogen inside the battery in a gas absorption type lead-acid battery with a simple structure in which a synthetic resin film coated with a tacky adhesive is attached to an opening. This has substantially the same effect as sealing, that is, prevents the electrolyte from being reduced and the sulfuric acid from being scattered.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of an embodiment of the present invention.

FIG. 2 is a diagram for explaining the effect of suppressing hydrogen accumulation according to the present invention.

FIG. 3 is a diagram for explaining the adaptability of the present invention to changes in weight.

[Explanation of symbols]

 1 battery case 2 lid 3 electrode plate group 4 positive electrode terminal 5 negative electrode terminal 6 electrolytic solution (not shown) 7 conductor 8 conductor 9 sealing resin 10 concave portion 11 opening 12 synthetic resin film 13 adhesive adhesive 14 belt-shaped protective spring plate 15 grooves

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01M 2/02-2/08 H01M 2/12 H01M 10/06-10/18

Claims (4)

(57) [Claims] 1. A gas-absorbing lead-acid battery, characterized in that an acid-resistant non-porous synthetic resin film coated with an acid-resistant adhesive is adhered to an opening provided on an outer wall of a battery case. 2. A battery case having a cylindrical shape, a band-shaped concave portion provided on a part of the outer periphery of the cylinder, an opening provided in the concave portion, a synthetic resin film disposed in the concave portion, and a protective plate provided above the concave portion. The gas-absorbing lead-acid battery according to claim 1, wherein: 3. The gas absorption type according to claim 1, wherein a protection plate is provided outside the acid-resistant synthetic resin film, and a groove serving as a gas passage is provided inside the protection plate. Lead storage battery. 4. A chemical forming step in which the electrode group is housed in a battery case having an opening in an outer wall, and then immersed in an electrolytic solution bath to perform initial charging.
A step of affixing an acid-resistant non-porous synthetic resin film coated with an acid-resistant tacky adhesive to an opening after washing the outer field, and closing the opening.