JPH08162148A - Sealed lead-acid battery and its charging method - Google Patents

Abstract

PURPOSE: To stabilize the discharging characteristic of a sealed lead-acid battery by filling a fine particle up to the upper part of a storage battery internal space in which an electrode plate group is housed, and making a flowing electrolyte present on the upper part of a porous body arranged on the upper part of the fine particle. CONSTITUTION: In a sealed lead-acid battery, a chemically stable fine particle 4 such as silica is used in the electrolyte holding part of an electrode plate group 3, and electrode plates are housed in a battery jar 1 with a constant electrode plate space. The fine particle 4 is filled up to the upper surface of a strap 12 in the storage battery internal space. A highly permeable porous body 5 is arranged as a pressing plate on the upper part of the fine particle 4. An electrolyte 7 is injected to the upper part of the porous body 5 until it is present as a flowing electrolyte. When a current is carried in this state, a generate gas pushes up the electrolyte 7 in the clearance part of the fine particle 4 to form a cavity part between the fine particles 4. The oxygen gas generated through the cavity part is absorbed by the negative electrode plate to cause a sealing reaction. Further, when the charging terminal current is limited to less than 0.05C, a higher sealing effect can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealed lead acid battery.

[0002]

2. Description of the Related Art In a sealed lead acid battery, a cathode plate absorbs oxygen gas generated from the anode side during charging,
Generation of hydrogen gas from the cathode side is suppressed to prevent a decrease in water content in the battery and an increase in battery internal pressure.

In order to carry out such a negative electrode absorption type oxygen cycle, a gap that serves as a passage for oxygen gas in addition to the electrolytic solution is required between both electrode plates. For this reason, the electrolytic solution is held to such an extent that it does not exude from the separator so as to leave a continuous void as a gas passage between the fibers inside the separator. Therefore, in the sealed lead acid battery, the amount of electrolytic solution existing between the electrode plates is 10 to 20% less than that of the liquid lead acid battery.

As a result, the discharge capacity of the lead-acid battery is proportional to the amount of electrolyte (sulfuric acid), and the discharge capacity of the sealed lead-acid battery is smaller than that of the liquid type.

Further, in the sealed lead-acid battery, the amount of electrolyte is smaller than that of the liquid type, and therefore the electrical resistance between the electrode plates changes significantly depending on the degree of contact between the separator and the electrode plate surface. Causing instability. For this reason, the sealed lead-acid battery requires sufficient pressure to stabilize the contact between the separator and the electrode plate surface, unlike the conventional lead-acid battery having a flowing electrolyte.

Since this pressure varies depending on the shape of the battery case and the position of the cell in the monoblock battery case, the battery characteristics naturally differ between the cells. In order to eliminate this difference, if the electrode plate group is inserted into the battery case with further pressure, the electrode plate group may be damaged or a short circuit may occur due to penetration of the active material into the separator. Moreover, since the pressure force between the electrodes is greatly reduced in the electrolyte-impregnated state and also decreases over time, it is very difficult to make the pressure levels on the electrodes of the sealed lead-acid battery uniform, and the characteristics such as the life This is a major cause of variation.

[0007] Therefore, in order to improve the contact with the separator which is the electrolytic solution holding portion, a sealed lead-acid battery has been developed which uses a resilient glass fiber retainer mat or a fine powder as a separator. ing.

[0008]

The retainer-type sealed lead-acid battery using the retainer mat requires a large amount of elasticity when inserting the electrode plate group into the battery case, and therefore has a large mass productivity. Chips and cost reduction are difficult. In addition, since the degree of pressure decreases significantly at the same time as the injection of the electrolytic solution, it has not yet reached the stable characteristics of the liquid lead acid battery.

In order to solve these problems, a granular type sealed lead-acid battery in which fine powder is filled between the electrode plates has been proposed. This method does not require pressure when inserting the electrode plate group, unlike the retainer type sealed lead-acid battery, only by filling powder between the electrode plates, the pressure gradually increases due to expansion of the electrode plates during use. Has become.

For this reason, in the granular type lead-acid battery, the adhesion between the electrode plate and the powder, which is the electrolyte holding portion, can be good for a long period of time, and the compression of the powder can prevent the electrode plate from expanding.
It has a life span of 2-3 times that of the retainer-type sealed lead-acid battery.

However, even if it is called a granular type sealed lead acid battery, the fact that the sealed reaction is utilized is the same as that of the retainer type sealed lead acid battery, and the oxygen generated at the positive electrode passes through the voids of the inter-electrode plate powder. Since it is absorbed by the negative electrode plate, the internal pressure of the storage battery may rise abnormally for some reason.
A valve section is required for the exhaust section.

In addition, since the negative electrode plate absorbs oxygen gas in the battery during standing and becomes a depressurized state close to a vacuum, if airtightness occurs in the bushing portion that is a pole column penetrating portion, the outside air is discharged from this gap to the battery. Will be sucked inside. For this reason, the sealed lead-acid battery is provided with a special shield design that is not available in the liquid lead-acid battery, which is one of the factors that make the cost higher than that of the liquid lead-acid battery.

On the other hand, lead-calcium alloy is used for the bipolar grid of the sealed lead-acid battery. This is because when an antimony alloy with a low hydrogen overvoltage is used, such as in a liquid lead acid battery, hydrogen gas is easily generated from the negative electrode plate at the end of charging, or hydrogen gas is generated by self-discharge due to antimony deposited on the negative electrode plate. This is because the sealed battery cannot be configured due to the occurrence of

However, most of the sealed lead-acid batteries are of the liquid type in which a lead antimony alloy is used for the bipolar or negative electrode grid, which has better castability of the grid than the calcium alloy and has a long service life. It has many features such as small elongation of the electrode plate in the inside, excellent adhesion with the active material, especially excellent alternate charge and discharge, long life expectancy, good recyclability, etc. is there. Speaking of its drawbacks, it is inferior to a sealed lead-acid battery using a lead-calcium alloy in that maintenance work is not required because a large amount of liquid reduction is required.

[0015]

Therefore, according to the present invention, a powder filled up to the upper surface of the strap in the internal space of the storage battery accommodating the electrode plate group, a porous body disposed on the upper side of the powder, and a porous body are provided. A sealed lead-acid battery, characterized in that it comprises an electrolytic solution injected so that a flowing electrolytic solution is present in the upper part of the
Furthermore, by setting the terminal current at the time of charging to 0.05 C or less, the valve section required for the sealed lead-acid battery is not required,
It is an object of the present invention to provide a sealed lead-acid battery that can obtain stable discharge characteristics regardless of pressure level, and that even if the lead-acid battery uses a lead antimony grid, replacement work is almost unnecessary. .

[0016]

The sealed lead acid battery according to the present invention has a constantly flowing electrolytic solution in the space behind the battery lid, so that the electrolytic solution completely shields the electrode plate group from the atmosphere and the valve required for the sealed lead acid battery. It can be configured by an ordinary liquid stopper having an exhaust part used for a liquid lead-acid battery without requiring a part.

Further, during discharge, the electrolytic solution in the space behind the storage battery lid is sucked by depressurizing the voids between the powder particles, so that the capacity can be increased by 10 to 20% as compared with the conventional sealed lead storage battery. Since the space between the powder particles is full of liquid, stable discharge characteristics can be obtained regardless of the degree of pressure between the electrode plate group and the powder material.

Further, in the sealed lead-acid battery of the present invention, since an excessive amount of electrolytic solution equivalent to that of the liquid lead-acid battery is stored in the space behind the battery lid in advance, moisture between the electrode plates can be easily maintained even with a slight overcharge. Since it does not decrease, the battery can be constructed with the electrode plate group using the lead antimony alloy grid.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The sealed lead acid battery according to the present invention will be specifically described below with reference to the suitable drawings.

FIG. 1 is a schematic sectional view of an embodiment of the sealed lead-acid battery according to the present invention.

In the figure, 1 is a battery case, 2 is a battery lid, and 3
Is a plate group. 4 is powder, and silica powder was used here. 5 is a porous body, 6 is a reinforcing plate, 10 is an exhaust part,
12 is a strap, 13 is a pole, and 14 is a glass fiber.

Here, the chemically stable powder 4 is also used in the electrolytic solution holding portion of the electrode plate group 3, the electrode plates are housed in the battery case 1 with a constant electrode plate interval, and the internal space of the storage battery is stored. The powder 4 is filled up to the upper surface of the strap 12. That is, the powder 4 is filled between the electrode plates, the space formed by the electrode plate group 3 and the inner wall of the battery case 1, and the upper portion of the strap 12 of the electrode plate group 3 above the upper surface.

Further, since the powder 4 is moved or blown up due to vibration or gas pressure during charging, the porous body 5 having good air permeability is arranged above the powder 4 as a holding plate. Here, the porous body 5 is formed by the plate-shaped glass fiber 14 and the porous resin-made reinforcing plate 6 having a pore diameter larger than the short diameter or the diameter of the powder. When only the porous body 5 having good air permeability is used, many of those having good air permeability generally have weak mechanical strength. Therefore, the reinforcing plate 6 is also used.

If a material having a high mechanical strength, such as a plate made of a resin, having a short diameter or a diameter smaller than the diameter of the powder is used as the porous body 5, the air permeability is good, so that the porous resin is used. It is not necessary to provide the reinforcing plate 6 and the plate-shaped glass fiber 14.

A hole slightly larger than the diameter of the pole was opened in the portion of the porous body 5 where the pole was inserted. Reference numeral 7 denotes an electrolytic solution, which is always injected into the upper portion of the porous body 5 regardless of the state of the storage battery until the electrolytic solution exists as a flowing electrolytic solution. Here, the upper end surface of the porous body 5, that is, the reinforcing plate 6
Was injected vertically upward from the top surface of the to a height of 1 to 2 cm.

Reference numeral 8 denotes a bushing portion through which the pole 13 penetrates, and is not specially sealed by filling a sealant or the like unlike the conventional sealed lead acid battery. This is because the atmosphere is shielded by the electrolytic solution 7 even if the inside of the storage battery is in a depressurized state during discharging or leaving, and oxygen in the atmosphere is not absorbed by the negative electrode.

Reference numeral 9 is a liquid stopper having an exhaust port 10, and any liquid stopper used in a normal liquid lead-acid battery is sufficient. This is also because the electrolytic solution completely blocks the electrode plate group and the atmosphere,
This is because the valve portion required for the conventional sealed lead acid battery is not required.

In the sealed lead-acid battery, the oxygen gas generated from the positive electrode plate is absorbed by the negative electrode plate, and a part of the surface of the negative electrode plate is always kept in an uncharged state to prevent the liquid reduction and the internal pressure rise. I am letting you.

When the oxygen gas moves from the positive electrode to the negative electrode, if the electrolytic solution exists between both electrode plates, the oxygen gas hardly reaches the negative electrode because it is hardly dissolved in the liquid, and bubbles are exhausted to the outside of the storage battery. To be done. Therefore, in the liquid storage battery, the liquid is reduced by electrolysis in proportion to the overcharge amount.

In any structure of the sealed lead-acid battery, in order to facilitate gas transfer, the amount of injected electrolyte is limited, and a void is formed in the pores of the separator, which is the electrolyte holding part between the electrode plates. It is common sense to leave it, but the sealed lead-acid battery of the present invention has the following characteristics.

That is, a state in which the electrolytic solution 7 is poured by vacuum impregnation so that the voids between the powder particles are completely filled, and the electrolytic solution 7 is present as a flowing electrolytic solution above the porous body 5. Fill up to.

When charging in this state, in the case of the granule system,
Since the powder is filled inside the battery, between the electrode plates, and the outer periphery of the electrode plate group, there is no escape area for the generated gas.
The electrolytic solution 7 in the gap portion is pushed up to form a gap portion between the powder particles.

Therefore, the oxygen gas generated through the voids is absorbed by the negative electrode plate and a closed reaction occurs.

Further, it was found that even higher sealing efficiency can be obtained by limiting the terminal charging current to 0.05 C or less.

On the other hand, during discharge, due to the pressure reduction in the voids between the powder particles, the electrolyte solution in the space behind the storage battery lid is sucked in, and the amount of electrolyte solution available for discharge increases. It is possible to increase the capacity by 20%. Moreover, since the voids between the powder particles are filled with liquid, stable discharge characteristics can be obtained without being affected by the degree of pressure between the electrode plate group and the powder particles.

[0036]

EFFECTS OF THE INVENTION The sealed lead-acid battery according to the present invention is a powder filled up to the upper surface of the strap in the storage battery internal space in which the electrode plate group is housed, a porous body arranged on the upper part of the powder, and a porous body. And an electrolytic solution injected so that a flowing electrolytic solution exists in the upper part of the.

As a result, although a calcium alloy grid is used in the conventional sealed lead acid battery, a good sealed lead acid battery can be obtained even if the bipolar lattice is the antimony alloy lattice or only the negative electrode lattice is the antimony alloy lattice. Can be provided. Further, at the time of discharging, since the electrolyte solution in the space behind the lid is absorbed between the electrode plates due to the pressure reduction in the inter-powder void portion, the capacity can be increased by about 10 to 20% as compared with the conventional sealed lead acid battery. At the same time, since the voids are filled with liquid, the contact between the electrolytic solution and the active material is improved, so that the voltage characteristics at the time of discharge can be significantly improved.

Further, in the conventional sealed lead-acid battery, the electrolyte holding portion (separator) must always be pressed. However, since the voids between the powders are in the same full-filled state as the liquid lead-acid battery during discharge, It is possible to provide a sealed lead-acid battery that has stable discharge characteristics regardless of the degree of pressure between the electrode plate group and the powder.

Further, the flowing electrolyte on the upper part of the porous body is
Since it plays the role of a seal for the pole penetration, it eliminates the need for a special seal design for the valve and pole penetration, unlike the conventional sealed lead-acid battery, which simplifies the storage battery configuration and is an inexpensive sealed lead-acid battery. A storage battery can be provided.

In addition, in charging the sealed type storage battery of the present invention, the efficiency of the sealed reaction can be further increased by setting the terminal current during charging to 0.05 C or less.

Therefore, the present invention has great industrial utility value.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an embodiment of a sealed lead acid battery according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery case 2 Storage lid 3 Electrode plate group 4 Powder 5 Porous body 6 Reinforcing plate 7 Electrolyte solution 8 Bushing 9 Liquid stopper 10 Exhaust part 12 Strap 13 Polar column 14 Plate glass fiber

Claims (2)

[Claims] 1. A powder filled up to the upper surface of a strap in an internal space of a storage battery accommodating an electrode plate group, a porous body arranged on the upper side of the powder, and a pouring liquid electrolyte is present on the upper side of the porous body. A sealed lead-acid battery, comprising: 2. The method for charging a sealed lead acid battery according to claim 1, wherein the terminal current at the time of charging is 0.05 C or less.