JPH04328267A - Sealed type lead-acid battery - Google Patents

Abstract

PURPOSE:To prevent lowering of battery performance by providing cylindrical projections in the periphery of insertion ports of current outputting poles, and making the tip thereof to abut or to be embedded on/in a foaming resin plate near the periphery of the current outputting poles. CONSTITUTION:When a foaming resin plate 10 having acid resistance and the continuous foam, which passes electrolyte and gas but not the powder material 3, is pushed by the pressure more than a constant pressure, it is deformed and is not returned. This plate 10 at an area larger than that of the top surface of a battery jar 1 is pushed from the upper part of the battery jar 1, inserting current outputting poles 6, 7 through the plate 10, to be inserted into the battery jar 1 without clearance between the plate 10 and the inner wall of the battery jar 1, and is inserted till it closely contacts the top surface of the powder material 3. Cylindrical projections 8 are provided in the periphery of insertion ports 11 of the poles 6, 7, and the tip thereof are pushed to be buried in the plate 10 near the periphery of the poles 6, 7. Blow-up of the powder material 3 during the charge is thereby prevented, and a battery having the excellent discharge capacity can be provided.

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. but,
In sealed lead-acid batteries that use this powder as an electrolyte holder, this powder moves to the top of the battery along with the electrolyte and gas generated from the electrode plates during charging, and is deposited between the positive and negative plates. It has been found that voids may occur, which may reduce battery performance.

Therefore, in order to suppress the movement of the powder, a porous thin sheet is placed on top of the powder, and a perforated resin plate with a plurality of holes is then forcibly inserted into the battery case. ,
Alternatively, foam the phenolic resin on top of the powder,
The silica powder was fixed. However, the method of using a thin porous sheet and a perforated resin plate in combination is complicated, and has the disadvantage that the perforated resin plate requires high dimensional accuracy because it is forced into the battery case.

On the other hand, the inside of foamed phenolic resin has open cells and has high porosity and excellent acid resistance, but a film called a skin layer is formed on the surface of foamed phenolic resin, which inhibits the permeation of gas and liquid. Therefore, it was necessary to devise a way to break this skin layer.

[0010] Therefore, a method was found for fixing the powder by pressing a foamed resin plate larger than the top surface of the battery case and having open cells from the top surface of the battery case and inserting it into the battery case. This method has a simple structure, good workability, and can solve the drawbacks of the above two methods. However, a new problem has emerged.

[0011] That is, when the foamed resin plate is pressed from the top surface of the battery case and inserted into the battery case, a gap may be created around the current extraction pole, and powder may blow through this gap while the battery is being charged. It was found that a void may be formed between the positive electrode plate and the negative electrode plate, and sufficient performance may not be obtained. This is caused by a slight misalignment when inserting the electrode plate group into the battery case, a slight misalignment of the pole in the vertical direction, and also due to misalignment when inserting the foamed resin plate into the battery case. It is extremely difficult to correct this deviation during the manufacturing process.

0012

[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 a large specific surface area, which is larger than the top surface of the battery case.
A foamed resin plate with open cells is pressed from the top of the battery case and inserted into the battery case to fix the powder, and a sufficient amount of sulfuric acid electrolyte is applied to substantially the powder. The problem with sealed lead-acid batteries impregnated in the body is to prevent the movement of powder from the gaps that occur around the poles mentioned above. The present invention is characterized in that a cylindrical protrusion is provided on the foamed resin plate, the tip of which is in contact with or embedded in the vicinity of the outer periphery of the current extraction pole of the foamed resin plate.

[0013]

EXAMPLES The present invention will be explained below based on examples. FIG. 1 is a cross-sectional view of the main parts of a sealed lead-acid battery according to the present invention.A battery case 1 includes a battery pack 2 consisting of a positive electrode plate, a negative electrode plate, and a ribbed separator for keeping the distance between the electrode plates constant. It is buried in 3. This electrode plate group is embedded in powder 3 to such an extent that its positive and negative electrode straps 4 and 5 are just hidden, and the powder 3 densely fills the area between the positive and negative electrode plates and around the electrode plate group 2.

The powder used here may be any powder having high porosity and large specific surface area, such as white carbon (fine powder of hydrated silicon dioxide), diatomaceous earth, fluorite (silica-rich calcium silicate powder), etc. ), all of which have a porosity of 80-90% and a specific surface area of 10-30%.
It is in the range of 0m2 /g, and 1 to 2 of the glass separator
It has a considerably larger specific surface area than m2/g. Current extraction poles 6 and 7 are formed above the positive and negative electrode straps 4 and 5 of the electrode plate group embedded in the powder 3.

Reference numeral 10 denotes a foamed resin plate having open cells for fixing the powder 3 densely packed in the battery case 1, and prevents movement of the powder 3 by the electrolytic solution and generated gas discharged from the electrode plate during charging. It has the role of preventing This foamed resin board 10 is
Not only is it acid resistant, but it also has open cells that allow electrolyte and gas to pass through, but not powder 3. It deforms when pressed above a certain pressure, and has the property that it almost never returns to its original shape. have. In this example, foamed phenolic resin was used.

This foamed resin plate 10 is larger than the top surface of the battery case 1, and is inserted into the battery case 1 by pressing it from above the battery case 1 and inserting the current extraction poles 6 and 7 into the battery case 1 so that it is in contact with the inner wall of the battery case 1. It is inserted without any gap between the powders 3 until it comes into close contact with the upper surface of the powder 3. At this time, the inner wall of the battery case 1 and the foamed resin board 1
0 means that the foamed resin plate 10 larger than the top surface of the battery case 1 is pressed and inserted, so the foamed resin plate 10 is deformed and brought into close contact with the current extraction poles 6 and 7 and the foamed resin plate 10. There may be a gap between them.

For example, when the current extraction pole 6 (7) is not formed vertically as shown in FIG. occurs. If a gap 12 is created between the foamed resin plate 1 and the current extraction pole 6 (7) in this way, the electrolyte and generated gas discharged during charging will cause the powder 3 to fall between the foamed resin plate 10 and the current extraction pole. 6 (7), and a gap is created between the positive electrode plate and the negative electrode plate, resulting in insufficient performance.

However, in this embodiment, as shown in FIG. 2, a cylindrical projection 8 is provided at the bottom of the lid 14 and on the outer periphery of the insertion opening 11 of the current extraction poles 6 and 7. Since the powder 3 is embedded near the outer periphery of the current extraction poles 6 and 7 of the foamed resin board 10 to which the powder 3 is fixed, the foamed resin board 1 shown in FIG.
Even if a gap 12 is created between the current extraction pole 6 (7) and the powder 3 blows out from this gap, the blowing up of the powder will cause the current extraction pole 6 and 7 to , is limited to only a small space 9 formed by the foamed resin plate 10 and the cylindrical protrusion 8 provided at the bottom of the lid 14, and can substantially prevent the powder 3 from blowing up during charging. .

[0019] Then, the nominal capacity according to the present invention is about 30Ah.
We assembled a sealed lead-acid battery and investigated its effectiveness in preventing powder from blowing up. For comparison, a conventional battery was also tested in which the powder was fixed by pressing a foamed phenolic resin plate larger than the top of the battery case. In the test, the battery was first charged with a current of 10 A to see the effect of preventing the powder from blowing up, and then subjected to 5-hour rate discharge and low-temperature high-rate discharge. A battery charged with a small current of 2A was also added to the conventional battery.

[0020] When assembling the batteries, parts from the same lot are used to press and insert a foamed resin plate into the tank, and then 30 batteries each are selected at random and placed into the three types mentioned above. Assembled the battery. The results are shown in Table 1. In Table 1, the numbers in parentheses are test results for batteries in which powder was blown up.

[0021]

[Table 1]

In conventional battery A, which was charged at 2A, there were 5 batteries in which powder was blown up, and in battery B, which was charged at 10A, powder was blown up in 18 batteries. This powder was blown up from between the current extraction pole and the foamed resin board, and it started to be blown up immediately after gas generation became active during charging. In conventional battery A, which was charged at 2A, the degree of gas generation was gradual, so powder was blown up in only 5 batteries, and the amount of powder blown up was small, but when charged at 2A, the amount of powder blown up was small. In conventional battery B, which was charged with 18 batteries, powder was blown up, and in some cases there was so much powder that it clogged the exhaust valve.

[0023] Table 1 shows the capacities of batteries with and without powder blowing up separately, and the capacity of the battery with powder blowing up was significantly lower than that of the battery with no powder blowing up. There was a tendency that the larger the amount of powder blown out, the greater the decrease in capacity. On the other hand, in the batteries C of the present invention, there were no batteries in which the powder was blown up, and all of them had excellent discharge performance.

In the sealed lead acid battery of the present invention, at the bottom of the lid,
Also, a cylindrical protrusion is provided on the outer periphery of the insertion opening of the current extraction pole, and the tip thereof is brought into contact with or buried near the outer periphery of the current extraction pole inserted into the foamed resin plate to which the powder is fixed. However, the diameter of this cylindrical protrusion varies depending on the size in the production line or the degree of variation in pole position, so the tip of the cylindrical protrusion is attached to a foamed resin plate inserted into the battery case. It shall be designed so that it can be abutted or buried.

[0025]

As explained above, the sealed lead-acid battery according to the present invention has a cylindrical projection at the bottom of the lid and on the outer periphery of the insertion hole of the current extraction pole. By simply contacting or burying the foamed resin plate near the outer periphery of the current extraction pole inserted through it, the powder can be densely packed around the positive and negative electrode plates and the electrode group, effectively charging the powder. It is possible to provide a sealed lead-acid battery having a structure in which a sufficient amount of electrolyte is retained, which can prevent powder from blowing up during charging, and which has an excellent discharge capacity; The industrial value is enormous.

[Brief explanation of the drawing]

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

[Fig. 2] An explanatory diagram of a battery using a lid having the structure of the present invention.

[Figure 3] Explanatory diagram showing problems with conventional batteries

[Explanation of symbols]

1 Battery case 2 Pole group 3 Powder 6 Paul 7 Paul 8. Cylindrical projection 9 Space 10 Foamed resin board 12 Gap 14 Lid

Claims (1)

[Claims] Claim 1: Filling the gap between the positive electrode plate and the negative electrode plate and around the electrode plate group with powder having high porosity and large specific surface area, and forming a foamed resin plate larger than the top surface of the battery case and having open cells. The sealed lead is pressed from the top of the battery case and inserted into the battery case to fix the powder, and the powder is substantially impregnated with a sufficient amount of sulfuric acid electrolyte necessary for charging and discharging the battery. A storage battery in which a cylindrical protrusion is provided at the bottom of the lid and on the outer periphery of the insertion hole of the current extraction pole, and the tip thereof is in contact with or buried near the outer periphery of the current extraction pole of the foamed resin plate. Characteristics of sealed lead acid batteries.