JPS5927450A - Lead storage battery - Google Patents

Abstract

PURPOSE:To obtain a maintenance-free lead storage battery by contacting a separator material impregnated with synthetic resin in fine hole having maximum diameter smaller than 100mu against positive plate and negative plate while placing glass fiber sheet having fiber diameter of 9-20mu between the separator members. CONSTITUTION:Positive plate 1 is made by utilizing a grid made of Pb-Ca alloy while negative plate 2 is made similarly. First separator member 3 has maximum hole diameter smaller than 100mu while epoxy resin is flowed linearly to material 4 composed of 80wt% of glass fiber having average fiber diameter of 0.5mu and 20wt% of glass fiber having average fiber diameter of 13mu to form a partition 5. Second separator member 6 is mainly composed of glass fiber having fiber diameter of 9-20mu and formed into a sheet. The separator 3 is contacted against the plates 1, 2 by inclining the partition 5 while a separator member 6 is placed between the separator members 3. In such a manner, the lead storage battery has sufficiently fluid electrolyte while oxygen absorbing function can be provided to the negative plate.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a non-maintainable lead-acid battery that is capable of absorbing oxygen scum generated at the positive electrode plate by the negative electrode plate, even though it has a sufficient amount of flowing electrolyte. The purpose is to provide a high-performance, long-life, extremely low-cost, maintenance-free lead-acid battery without adding any special expensive parts.

There have been many proposals regarding maintenance-free lead-acid batteries. A typical example is the use of the so-called oxygen cycle, in which the electrolyte volume is made to be the same as or less than the pore volume of the electrode group to make it non-fluid, and the oxygen gas generated from the positive electrode plate is recombined with the negative electrode plate at the end of charging. There are some that have been made airtight by doing so. A similar technique is one in which the electrolyte is made into a colloid and hermetically sealed. These sealed lead-acid batteries do not have a flowing electrolyte, so there is no electrolyte leakage, so lead-acid batteries can be used in any position, and their waste absorption efficiency is high, making them completely maintenance-free lead-acid batteries. It can be said that there is. However, in these types of lead-acid batteries, the amount of liquid injected is set so that the flowing electrolyte runs out, so the amount of electrolyte is small compared to the amount of active material in the positive and negative electrode plates, and this electrolyte is The drawback is that the battery capacity is limited by the amount of sulfuric acid in the solution. It also prevents the electrolyte from evaporating during use, prevents the oxygen gas generated at the end of charging from being released, and prevents air from entering the battery from outside and causing the oxygen scum in the air to react with the negative electrode plate. Therefore, a valve is required to prevent the negative electrode plate from self-discharging, and special measures are required for the terminal section to improve leakage resistance. At the same time, the battery case is required to have sufficient internal pressure resistance to withstand the opening pressure of the valve, so the material used for the battery case is limited and the wall thickness of the case is thick. Application of this method to high-capacity lead-acid batteries is extremely difficult.

By the way, as a result of research on the application method of a separator formed into a sheet shape mainly made of glass fibers with an average fiber diameter of 1μ or less, as shown in Japanese Patent Publication No. 55-5816, it was found that this separator can make the conventional electrolyte non-fluid. Even in lead-acid batteries that have a sufficient amount of flowing electrolyte under certain conditions, oxygen scum generated from the positive electrode plate can escape to the top of the electrode group. It has been found that the particles can move through the separator toward the negative electrode plate and be recombined by the negative electrode plate. This is because the separator is flexible and has a lot of fluff, so it adheres very closely to the surface of the electrode plate, and the pores on it are small, so there is a large resistance for oxygen gas to escape to the top of the electrode group. Rather, it is thought that this is because it moves obliquely in the thickness direction and reaches the negative electrode plate.

After researching the gas absorption properties of various separators in the presence of a flowing electrolyte, it became clear that such gas absorption occurs when the following conditions are met.

a. The separator must have enough flexibility and compressibility to come into close contact with the positive and negative electrode plates without leaving large gaps between the separator itself and the irregularities of the active material on the surfaces of the positive and negative electrode plates.

b. The substantial maximum pore diameter of the separator itself is larger than the substantial maximum pore diameter of the gap at the surface in close contact with the positive and negative electrode plates.

C. The pore size of the separator itself is small. That is, the maximum pore diameter of the material is 100μ or less, more preferably 40μ
Must be less than μ.

By meeting the above conditions, the oxygen scum generated on the positive electrode plate is moved in the thickness direction of the separator and reaches the negative electrode plate, rather than escaping from the interface between the separator and the positive electrode plate to the upper part of the electrode group. I can do it.

However, there are few separators that meet these conditions. For example, a conventional fiber-reinforced separator is inflexible and too rigid, so that oxygen gas escapes from the gap between the positive electrode plate and the separator to the outside of the electrode group, and the gas is not absorbed. This is a microporous rubber separator or Daramic (product name: W,
The same result can be obtained even if a separator such as R, manufactured by Brace Co., Ltd. is used.

On the other hand, when a sheet made of glass fiber with an average fiber diameter of 19μ, which has been conventionally used as a glass mat for lead-acid batteries, is used as a separator, the maximum pore diameter becomes 500μ, which is too coarse and Even if it can be brought into close contact with the surface of the negative electrode plate, oxygen scum will escape to the upper part of the electrode group through the large pores, so scum absorption will not take place. Furthermore, if the pore size is large, the oxygen gas bubbles themselves become large, which causes electrical resistance, and the discharge characteristics of the battery are also unfavorable.

As a separator that meets these conditions,
5-5816, the fiber diameter is 1
A sheet formed mainly of glass fibers with a diameter of less than μ is extremely suitable. In addition, U.S. Patent No. 425
As described in the specification of No. 6679, the filter is composed of 0 to 80% pearlite and 20 to 70% glass fiber, the particle size of the pearlite is 6 to 100μ, and the fiber diameter of the glass fiber is 0.6 to 100μ. 1.0μ, special publication 1984-50
As shown in Publication No. 0040, it consists of 15 to 75% pearlite, 20 to 70% glass fiber, and 5 to 20% acid-insoluble thermoplastic fiber, and the particle size of pearlite is 6 to 1 LIOμ, Glass fiber with a fiber diameter of 6-03 to 1.0μ, JP-A-56-99968
As shown in the publication, fibrillar synthetic fibers with a hydrostatic degree of 550 CC or less were mixed at a ratio of about 1096 or less to glass fibers having a specific surface area of substantially +Jrd/y or more (fiber diameter of about 2 μ or less). things, even PCT
As shown in Publication No. WO81105397, it has a diameter of 0.1 to 5.5μ and a specific gravity of 2.46y.
Acicular acid-resistant inorganic substance larger than /cc 10-9096
A material made of glass fiber with a fiber diameter of 10 μm or less and a synthetic fiber binder of 25% or less can be used.

The present invention further improves the gas absorption performance of such a lead-acid battery, and provides a lead-acid battery with a sufficiently flowing electrolyte and a negative electrode plate with an oxygen gas absorption function, which has a maximum pore diameter of 100/l. The first part is made of a flexible material and has a horizontal or inclined partition formed by infiltrating a synthetic resin into the fine pores of the material and making this part substantially non-porous. A second separator material having a separator material, the first separator material being brought into contact with the positive electrode plate and the negative electrode plate, and a second separator material mainly made of glass fibers having a fiber diameter of 9 to 2 μm formed in a net shape between the first separator material. It is characterized by interposing a separator material.

Hereinafter, the present invention will be explained with reference to the drawings showing one embodiment thereof. That is, in FIGS. 1 and 2 showing a schematic side sectional view and a schematic partially broken front sectional view, respectively, of an embodiment of the present invention, 1 uses a lattice body made of a P b -Ca alloy, and is different from the conventional one. A positive electrode plate was prepared according to the procedure, and 2 is a negative electrode plate prepared in the same manner.

Also, the glass fiber with an average fiber diameter of 05μ is 80% by weight.
The first separator material 4 is made of 20 weight 96 glass fibers with an average fiber diameter of 16 μm, and the partitions 5 are formed by pouring epoxy resin in a linear manner. 6 is a sheet □ mainly made of glass fibers with a fiber diameter of 9 to 20 μm. and the negative electrode plate 2, and a second separator material 6 is interposed between the first separator materials 6.

A strap 7 connecting the ears of the positive electrode plate 1 and negative electrode plate 2 and a pole pillar 8 rising from the strap 7 are formed on the stacked electrode group in this way, and this is placed in a battery case 9 made of polyolefin for 20 minutes. ~40Kg/cd
After storing the battery case lid 10 under the pressure of An electrolytic solution 11 made of sulfuric acid having a specific gravity of 00 d was injected to a height where the electrode group was sufficiently immersed, and an exhaust plug 16 having an exhaust port 12 was tightened to obtain a lead-acid battery according to the present invention.

In the lead-acid battery according to the present invention, the amount of electrolyte needs to be added to the extent that the electrode group is sufficiently immersed. This is because when the electrolyte level becomes too low, unlike in conventional sealed lead-acid batteries, there is no flowing electrolyte and the negative electrode plate is exposed. This is because it absorbs even oxygen from the air and self-discharge progresses.

Therefore, in the lead-acid battery of the present invention, it is necessary to have a flowing electrolytic solution that sufficiently wets the negative electrode plate, rather than an amount that leaves the negative electrode plate half dry.

−9= However, a flowing electrolyte is not needed in excess.

In other words, in conventional non-maintenance automotive lead-acid batteries, about 200 buttons of electrolyte were provided on the electrode group in order to extend the water replenishment period, or because the lead-acid battery according to the present invention has scum absorption performance, this electrolyte % or less, it is possible to make the battery smaller and lighter, and it is also possible to improve the weight efficiency and volumetric efficiency of maintenance-free lead-acid batteries.

Furthermore, the lead-acid battery according to the present invention does not necessarily require a valve, and even if the electrolyte decreases due to causes other than water electrolysis, water can be easily replenished if necessary.

In addition, in the case of a lead-acid battery having such a sufficiently flowing electrolyte and having a negative electrode plate having an oxygen sludge absorption function, it is necessary to prevent oxygen gas from escaping upward. Therefore, in the present invention, horizontal or inclined partitions are provided in the first separator material so that the oxygen gas moves horizontally and is more easily absorbed by the negative electrode plate, rather than escaping upward.

10- By the way, when the amount of oxygen gas generated exceeds the oxygen sludge absorption capacity of the negative electrode plate, the oxygen sludge remains in the first separator phase, increasing the resistance between the electrode plates, and this causes the capacity characteristics to change. There is a problem that voltage characteristics deteriorate. In the present invention, in order to improve this problem, a first separator layer mainly made of glass fibers having a thick fiber diameter of 9 to 20μ is formed in a sorted shape between the first separator phase that is in contact with the positive electrode plate and the negative electrode plate. A separator material is interposed. By interposing this second separator material, oxygen gas that cannot be completely absorbed can be released to one side. However, while the oxygen scum is being absorbed, the path to the second separator is relatively short, so it does not escape to the first separator 4.
It is absorbed by the negative electrode plate through the particles.

In addition, the second separator material, which is mainly made of glass fibers with a large fiber diameter, has a smaller capillary effect than the first separator material, so it has the ability to diffuse the electrolyte inside the electrode group well into the electrolyte outside the electrode group. Therefore, the specific gravity of the electrolyte within the electrode group is no longer unevenly distributed. Further, glass fibers having a fiber diameter of 9 to 20 μm are inexpensive, and therefore, by using such glass fibers as the second separator material, it is possible to reduce the manufacturing cost of lead-acid batteries.

Although the present invention has been described above with reference to one embodiment thereof, various embodiments of the present invention can be considered without departing from the spirit thereof. For example, each has a maximum pore diameter of 100μ or less,
And belonging to Category 1, which uses a flexible material and has a horizontal or inclined partition formed by infiltrating the fine pores of the material with synthetic resin to make this part substantially non-porous. In that case, the first separator material that contacts the positive electrode plate and the first separator material that contacts the negative electrode plate may be different materials.

As described above, the lead-acid battery according to the present invention can easily have a gas absorption function, has high performance, has a long life, is inexpensive, and does not require a sealed structure, so its industrial value is high.

[Brief explanation of the drawing]

FIGS. 1 and 2 are a schematic partially broken front sectional view and a schematic side sectional view, respectively, of an embodiment of the present invention. ] ・Positive electrode plate 2 ・Negative electrode plate 1st separator hole 4 ・Material 5 .. Lift 6 .. 2nd separator hole 7
Strap 8...Pole Pillar 9...Battery container
10...Battery container lid 1]...Electrolyte solution 12
...Exhaust port 15/Exhaust plug Applicant: Yuasa Battery Co., Ltd. 16- Figure 1 Figure 2

Claims (1)

[Claims] 1) By using a flexible material with a maximum pore diameter of 100 μm or less and infiltrating a synthetic resin into the pores of the material to make this part substantially non-porous. , has a first separator material provided with a horizontal or inclined partition formed thereon, the first separator material is brought into contact with the positive electrode plate and the negative electrode plate, and the fiber diameter between the first separator materials is 9 to 2.
It is characterized by having a second separator material formed into a sheet mainly made of 0 μ glass fiber interposed therebetween, which has a sufficiently flowing electrolyte, and has an oxygen sludge absorption function in the negative electrode plate. Lead acid battery. 2) The lead-acid battery according to claim 1, wherein the first separator material is formed into a sheet shape mainly made of glass fibers with a fiber diameter of 1 μm or less.