JPH04328272A - Sealed-type lead-acid battery - Google Patents

Abstract

PURPOSE:To prevent movement of the powder material from clearances generated around of poles to an upper part of a battery jar to prevent lowering of battery performance in a sealed lead-acid battery, in which the powder material is filled and the powder material is impregnated with the electrolyte practically. CONSTITUTION:In a sealed lead-acid battery, the powder material 5 having a high porosity and a large specific surface area is filled in a clearance between a positive electrode plate 2 and a negative electrode plate 3 and in the surroundings of plate group, and the powder material 5 is practically impregnated with the sulfuric electrolyte at a sufficient quantity required for charge and discharge of a battery. A porous thin sheet or a mat body 6 having acid resistance is placed on the powder material 5, and a hole drilled resin plate 14 having a hole for inserting a positive electrode pole 7 and a hole for inserting a negative electrode pole 8 and multiple holes 13 are placed thereon. A packing 12 having acid resistance and resiliency is attached to holes 9, 10 of the plate 14 and the periphery 11, and furthermore, the plate 14 is pressed by a container 16 provided inside of a cover 15. With this structure, blow-up of the powder material 5 is prevented to prevent lowering of battery performance.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvements in sealed lead-acid batteries.

0002

BACKGROUND OF THE INVENTION There are two types of sealed lead-acid batteries in which the negative electrode absorbs oxygen gas generated during charging of the battery: a retainer type and a gel type. In the retainer type, a matte separator (glass separator) mainly made of fine glass fibers is inserted between the positive and negative electrode plates, and this holds the sulfuric acid electrolyte necessary for discharge and isolates the two electrodes. In recent years, it has been widely used as a backup power source for portable devices and computers due to its characteristics such as no maintenance, no leakage, and no position.

[0003] However, glass separators are made of fine glass fibers with a diameter of around 1 micron manufactured using a special method into a mat shape, and are considerably more expensive than separators for lead-acid batteries that are generally used. In addition, in order to obtain stable battery performance, the electrode plates must be strongly compressed and assembled, which makes assembly of the battery difficult and inevitably increases the manufacturing cost of the battery.

[0004] Furthermore, only the glass separator inserted between the positive and negative electrode plates can hold the sulfuric acid electrolyte, and the electrolyte cannot be kept around the electrode plates as in an open type lead-acid battery. Since the battery cannot be placed anywhere in the battery, the battery reaction is limited by the amount of electrolyte, which has the disadvantage that the battery performance is inferior to that of a liquid type battery.

On the other hand, gel type batteries are cheaper than cage type batteries, but their battery performance is inferior to that of cage type sealed lead acid batteries.
The drawback was that the electrolyte separated from the sulfuric acid gel during use, resulting in poor longevity.

[0006] In order to eliminate these drawbacks, sealed lead-acid batteries have been proposed that are neither retainer type batteries using fine glass fiber nor gel type batteries using a gel electrolyte. That is, a powder having high porosity and a large specific surface area, such as silica powder, is used as an electrolyte holding material, and the above powder is filled in the gap between the positive electrode plate and the negative electrode plate and around the electrode plate group. This is a sealed lead-acid battery.

[0007] Silica powder is an inexpensive material that is produced and sold in large quantities, and has excellent acid resistance and electrolyte retention ability, so it is a powder used as an electrolyte retaining material for this type of sealed lead-acid battery. It can be said that it is an excellent material.

Furthermore, the volume of powder does not change even if it absorbs electrolyte, so if the powder is densely packed during battery manufacture, the element will continue to be strongly compressed while the battery is in use, extending its life. You can expect it.

However, in a sealed lead-acid battery that uses this powder as an electrolyte holder, this powder moves to the top of the battery together with the electrolyte and gas generated from the electrode plates during charging, and the positive and negative electrodes are separated. It has been found that voids may be formed between the battery and the plate, which may reduce battery performance.

Therefore, in order to suppress the movement of the powder, an acid-resistant, porous thin sheet or mat-like material is placed on top of the powder, and then a perforated resin plate having a plurality of holes is placed on top of the acid-resistant porous sheet or mat-like material. is forcibly inserted into the battery case, and furthermore, in order to fix the perforated resin plate thereon, the positive and negative poles, the perforated resin plate, and the inner wall of the battery case and the perforated resin plate are fixed with acid-resistant resin or the like. There was a need. However, such a method is complicated and time-consuming, and has the disadvantage that the perforated resin plate is required to have high dimensional accuracy in order to prevent the silica powder from being blown up from the gap by the generated gas.

[0011]

[Means for Solving the Problems] The present invention fills the gap between the positive electrode plate and the negative electrode plate and the periphery of the electrode plate group with powder having high porosity and large specific surface area.
The problem with sealed lead-acid batteries in which the powder is essentially impregnated with a sufficient amount of sulfuric acid electrolyte is that the powder moves to the top of the battery along with the electrolyte and gas generated from the electrode plates during charging. This is a relatively simple method to prevent a gap from forming between a positive electrode plate and a negative electrode plate, which would cause a decrease in battery performance. The gist of this is to place an acid-resistant, porous thin sheet or mat-like material on top of the powder, and then have a hole for passing the positive electrode pole, a hole for passing the negative pole, and multiple holes on top of the powder. A perforated resin plate is placed on the perforated resin plate, elastic packing is attached to the hole for the pole made in the perforated resin plate and the outer periphery, and the perforated resin plate is pressed by a protrusion provided on the inside of the lid. It is a sealed lead acid battery.

0012

EXAMPLES The present invention will be explained below based on examples. FIG. 1 is a sectional view of essential parts of a sealed lead-acid battery according to the present invention, in which a battery case 1 is inserted with a group of electrode plates consisting of a positive electrode plate 2, a negative electrode plate 3, and a separator 4. The gap between the plate 3 and the periphery of the electrode plate group is filled with powder 5 having high porosity and a large surface area. Since this powder 5 has high porosity and a large surface area, it can strongly hold a large amount of electrolyte. In this example, silica powder was used. A mat-like body 6 made of glass fibers having a diameter of about 1 micron is placed on top of the powder 5. This matte body 6 has acid resistance and allows gas and electrolyte to pass therethrough, but not powder.

A perforated resin plate 14 having a hole 9 through which the positive pole 7 passes, a hole 10 through which the negative pole 8 passes, and a plurality of holes 13 is placed on the mat-like body 6. The diameter of the hole 13 was approximately 5 mm. Acid-resistant and elastic rubber packing 12 is arranged in the holes 9 and 10 for the poles and the outer periphery 11 of the perforated resin plate. This perforated resin plate 1
4 is held down by a projection 16 provided inside the lid 15. Therefore, it is no longer necessary to fix the gaps between the perforated resin plate 14 and the poles 7, 8 or the battery case 1 with acid-resistant resin, which was conventionally done. Furthermore, this also eliminates the need for time for resin curing, improving battery assembly workability. Furthermore, even if the processing accuracy of the perforated resin plate 14 is somewhat poor, since the packing is elastic, there is no gap between the perforated resin plate 14 and the poles 7, 8 or the battery case 1.

FIG. 2 is a top view of the perforated resin plate used in this example (packing is not shown), and FIG. 3 is a top view of the perforated resin plate used in this example with packing provided through the positive pole. FIG. 3 is an enlarged cross-sectional view of the vicinity of the hole.

Next, in order to confirm the effects of the present invention, a battery with a nominal capacity of about 30 Ah was assembled and charged with a current of 10 A. Thereafter, the battery was inspected, but no powder was observed to be blown up.

In this embodiment, the positive and negative poles 7, 8
After drilling holes 9 and 10 for passing the electrolytic solution and gas through the resin plate, the packing 12 was set.
It is also possible to form the hole 13 in one piece and make the hole 13 at that time.

[0017]

As described in detail above, according to the present invention, blowing up of powder can be prevented by a relatively simple method, and its industrial value is extremely large.

[Brief explanation of drawings]

[Fig. 1] Cross-sectional view of essential parts of a sealed lead-acid battery according to the present invention

[Figure 2] Top view of the perforated resin plate used in the present invention (packing not shown)

[Fig. 3] An enlarged cross-sectional view of the vicinity of the hole for passing the positive pole of the perforated resin plate used in the present invention, which is provided with packing.

[Explanation of symbols]

1 Battery case 2　Positive electrode plate 3 Negative electrode plate 4 Isolator 5 Silica powder 6 Mat-like body 7 Positive pole 8 Negative pole 9 Hole for passing the positive pole 10 Hole for passing the negative pole 11. Outer circumference of resin plate 12 Packing 14 Perforated resin plate 15 Lid 16 Protrusion

Claims (1)

[Claims] Claim 1: The gap between the positive electrode plate (2) and the negative electrode plate (3) and the periphery of the electrode plate group are filled with powder (5) having high porosity and large specific surface area, which is necessary for charging and discharging the battery. This is a sealed lead-acid battery in which powder (5) is substantially impregnated with a sufficient amount of sulfuric acid electrolyte, and an acid-resistant porous thin sheet or mat-like material ( 6) and a hole (9) for passing the positive pole (7) thereon;
A perforated resin plate (14) having a hole (10) and a plurality of holes (13) for passing the negative electrode pole (8) is placed, and the holes (9), (10) and Outer circumference (1
1) is equipped with an acid-resistant and elastic packing (12), and a protrusion (16) provided inside the lid (15).
) is configured to press a perforated resin plate (14).