JPH0752641B2 - Sealed lead acid battery - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a sealed lead acid battery having an extended life.

(Prior Art) Conventionally, a plurality of electrode plate groups in which a fine fiber mat having a density of 0.15 g / cm ³ is interposed between positive and negative electrode plates are fixedly housed in a battery case under an appropriate pressure, and A sealed lead-acid battery, in which a mat is impregnated with an ordinary electrolytic solution or a colloidal electrolytic solution and held, is known.

(Problems to be Solved by the Invention) In the conventional storage battery described above, the thickness of the glass fine fiber mat shrinks during use, resulting in poor adhesion to the electrode plate, resulting in a gap between the electrode plate and the mat. It is unavoidable that the battery capacity is rapidly reduced and the life is shortened. In order to prevent this, when assembling the electrode plate group, the electrode plate group is assembled in a state in which the mat is remarkably compressed by applying extremely large pressure, and in this state, it is immovably housed in the battery case. But,
Not only the workability of assembling but also the housing is deteriorated, but the liquid absorption amount of the mat is lowered, and the electrolyte holding amount is remarkably reduced, so that the capacity may be insufficient. Particularly in the case of a large battery having a high height, the rise of the liquid is reduced in the upper part of the electrode plate group, and the amount of the electrolytic solution is particularly insufficient in the upper part, and the characteristics are deteriorated.

(Means for Solving Problems) The present invention is good even when the height is large without decreasing the thickness due to the impregnation of the electrolytic solution, and the adhesion with the positive and negative electrode plate surfaces is deteriorated. In addition, sufficient electrolyte was retained for a long period of time to extend battery life. Furthermore, it provides a sealed lead-acid battery that does not require large pressurization as in the past when assembling the electrode plate group and is easy to assemble and install in the battery case. A composite mat consisting of a thick fiber mat having a density of 0.1 g / cm ³ or less and having a thin fiber mat polymerized on both sides of the core as a core, and a positive and negative electrode plate facing each other with a composite mat interposed between the positive and negative electrode plates. A desired group of electrode plates assembled by closely adhering the fine fiber mats on both sides to the surface is immovably accommodated in a battery case under appropriate pressure and the colloidal electrolyte is impregnated and held in the composite mat.

(Embodiment) Next, an embodiment of the present invention will be described with reference to the accompanying drawings.

The drawing shows a cutaway side view of the sealed lead-acid battery of the present invention,
(1) is a positive electrode plate, (2) is a negative electrode plate, and (3) is a composite mat which is an essential part of the present invention interposed between each positive electrode plate (1) and the negative electrode plate (2). The composite mat (3) comprises a thick fiber mat (3a) having a fiber diameter in the range of about 15 to 50 μ and a density of 0.1 g / cm ³ or less as a core, and a fine fiber mat (3) on both sides thereof.
b) Polymerized from (3b). The composite mat (3) is a thick fiber mat (3a) and both fine fiber mats (3b).
The (3b) may be formed by polymerizing separately prepared ones, or may be preliminarily polymerized into one body by paper making or the like. In the illustrated case, two positive electrode plates (1) and three negative electrode plates (2) are used, and each positive electrode plate (1) and negative electrode plate (2) are used.
The composite mat (3) is interposed between the two and the assembly is assembled into a plurality of electrode plates, and the assembly is fixedly housed in the battery case (4) under an appropriate pressure. Thus, each composite mat (3) has a fine fiber mat (3b) (3
In b), the positive and negative electrode plates are interposed between the positive and negative electrode plates (1) and (2) facing each other on both sides of the positive and negative electrode plates in good contact with each other.

A desired amount of colloidal electrolyte is injected and held in the whole of each composite mat (3) of this battery. Thus, in particular, the core thick fiber mat (3a) has a fiber diameter of 15 to 50 μ and a density of 0.1 g / c.
Since it is less than m ³ and is not compressed, it serves as a storage container for the gelled electrolyte, and can supply the electrolytic solution to the fine fiber mats (3b) (3b) for a long period of time, as well as the conventional method. Since there is no contraction of the composite mat (3) over time, the fine fiber mats (3
In b) and (3b), the good contact state with the facing positive and negative electrode plates (1) and (2) is maintained, and the battery life is extended. Even when the electrode plate of the battery is particularly tall, the impregnation and holding of the colloidal electrolyte is evenly distributed over the entire composite mat (3). Thick fiber mat (3a) and fine fiber mat (3b)
Generally, it is a non-woven fabric made by the origami method, etc., and the thick fiber mat (3a) must have the above fiber diameter and low density in order to withstand the compressive force and to sufficiently retain the colloidal electrolyte. However, it is preferable to use fibers having a fiber diameter of 20 to 40 μ, alone or in combination, and having a density of 0.05 g / cm ³ or less. As the fine fiber mat (3b), from the viewpoint of adhesion and contractibility with the electrode plate surface, use fine fibers having an average fiber diameter of about 0.1 to 5 μ, and particularly 1 mm or less, preferably 0.3 to 0.6 mm. Due to
Adhesion does not decrease due to contraction when the electrolyte is reduced, and good adhesion to the electrode plate surface can be maintained for a long period of time. As the colloidal electrolyte, use is made of a mixture of silicic acid sol, alumina sol, and other sol-like substances alone or a mixture with a required amount of dilute sulfuric acid electrolyte, and this is mixed in a battery to form a composite mat (3).
Inject and impregnate into a gel or thick fiber mat (3a)
A powder of a gelling substance such as a fine silicic acid powder that gels with dilute sulfuric acid is dispersed and mixed therein, and dilute sulfuric acid is injected into the powder to form a composite mat (3) containing a gelling electrolyte of a colloidal electrolyte. Obtainable.

The battery case with a built-in battery shown in the figure is a sealed lead-acid battery with a battery lid provided by a conventional method. Next, further specific examples will be described by way of comparative test examples with conventional batteries. The specifications of the common battery used in the comparative examples are shown in Table 1 below.

The thick fiber mat of the composite mat used in the battery of the present invention is 20
Acrylic binder is sprayed on glass fiber of μ and density is 0.
It is a non-woven fabric made into paper with a thickness of 4 mm so that it will be 01 g / cm ³ .
The fine fiber mat is a non-woven fabric formed into an average fiber diameter of 1 μ and a thickness of 0.4 mm. This was impregnated with the amount of colloidal electrolyte shown in Table 1 above to prepare a sealed lead-acid battery A of the present invention shown in the figure and used for the test. For comparison, average fiber diameter 1μ, thickness 4.8m
A fine fiber mat of m was prepared and impregnated with the same amount of the same colloidal electrolyte to prepare a sealed lead acid battery B. A 5 hour rate discharge capacity test and a constant voltage overcharge life test were performed for each of the storage batteries A and B. The results are shown in Table 2 below.

As is clear from Table 2 above, it is considered that the difference in the supply of the electrolytic solution to the upper electrode appears as a difference in capacity, especially in a battery having a relatively high height such as a test battery, and a constant voltage is considered. In overcharge, shows the result that the difference in adhesion between the electrode plate and the electrolyte appears over time, whereas in the battery of the present invention, the thickness of the mat does not change with the decrease of the electrolytic solution over time. However, in the comparative battery, the life of the battery is varied due to the decrease in the thickness of the mat as the electrolyte decreases.

(Effect of the invention) As described above, according to the present invention, a thick fiber mat having a density of 0.1 g / cm ³ or less selected from the range of the fiber diameter of about 15 to 50 μ between the positive and negative electrode plates is used as the core. In a state where a composite mat formed by polymerizing thin thin fiber mats is interposed on both sides and the thin fiber mats on both sides are in close contact with the positive and negative electrode plates,
Since a sealed lead-acid battery was constructed in which the colloidal electrolyte was impregnated and held in the battery case immovably, the thickness of the compound mat was prevented from decreasing during its use, and The fine fiber mats on both sides impregnated with the electrolytic solution can be held in good contact with the opposite electrode plate surface, and the core thick fiber mat can be uniformly stored and held with a large amount of colloidal electrolytic solution without being compressed. It acts as a supply source of the electrolytic solution to the fiber mat and has the effect of providing a storage battery with a long life.

[Brief description of drawings]

The drawings show a cut-away side view of the essential parts of a sealed lead-acid battery according to an embodiment of the present invention. (1) …… positive electrode plate, (2) …… negative electrode plate, (3) …… composite mat (3a) …… thick fiber mat, (3b) (3b) …… thin fiber mat (4) …… battery case , A ... Storage battery of the present invention

Claims (3)

[Claims] 1. A fiber diameter ranging from about 15 to 50 μm and having a density
A composite mat composed of a thick fiber mat of 0.1 g / cm ³ or less as a core and thin thin fiber mats superposed on both sides of the mat is inserted between the positive and negative electrode plates, and the positive and negative electrodes are opposite to each other. A sealed lead acid battery in which a desired number of electrode plates assembled by closely adhering fine fiber mats are immovably accommodated in a battery case under appropriate pressure and a composite mat is impregnated and protected. 2. A fine fiber mat having an average fiber diameter of 0.1 to 5 μm and a thickness of 1 mm or less.
Lead acid battery described in. 3. The thick fiber mat preferably has a fiber diameter of 20 to
The lead acid battery according to claim (1), which has a density of 0.05 g / cm ³ and a thickness of about 4 mm at 40 μm.