JPH0521088A - Sealed lead-acid battery - Google Patents

Abstract

PURPOSE:To achieve long life of a battery by forming an active material supporting body in which a dotted or linear lead material is diffused, on a lead thin film provided on a substrate, in an integrated manner, and by forming an active material layer so that the supporting body is embedded therein. CONSTITUTION:An active material supporting body 10 is formed on a thin film 2 provided on a substrate 1 of plastic film, in an integrated manner, while an active material layer 3 is formed on the thin film 2 in such a way that the supporting body 10 is embedded in the layer. The supporting body 10 is formed by diffusing a fiber material 11 into a network form. The fiber material 11 is formed by providing a coating layer 13 of lead or lead alloy on a base material 12 comprising glass, carbon and the like that are not corroded by an electrolyte. The active material layer 3 is adhered to the thin film 2 through the supporting body in a three-dimensional way. The active material layer 3 is thus not easily peeled off from the thin film 2, and the life of a battery is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a lead-based thin film made of lead or a lead alloy formed on a plastic film substrate.
The present invention relates to a sealed lead storage battery having a structure in which an active material layer is formed on the thin film.

[0002]

2. Description of the Related Art In recent years, the demand for inexpensive, thin and high energy density sealed lead acid batteries has increased, and the demand for further thin and high energy density has become stronger. As a sealed lead-acid battery having a thickness of 5 mm or less, for example, JP-A-2-199771 is available.
There is something shown in the issue. This storage battery is sealed with a plastic film and has a structure in which an active material layer (electrode member) is formed on a plastic film substrate via a lead-based thin film. The lead-based thin film and the active material layer have the same planar shape. The positive electrode active material layer (positive electrode member) and the negative electrode active material layer (negative electrode member) in the active material layer are formed so as to be flush with each other, and the opposite end faces of both active material layers alternately project to the other side and are equally spaced from each other. This structure protects the current collector located at the center of the electrode surface from deterioration because the direction of the field of the battery reaction accompanying charging and discharging is parallel to the electrode surface. It is possible to apply electrode members.

[0003]

However, in the above structure, since the lead-based thin film is flat, the lead-based thin film and the active material layer are in a flat contact. Therefore, due to the volume change of the active material layer during repeated charge and discharge, stress stress occurs between the active material particles of the active material layer and at the interface between the active material layer and the lead-based thin film, and particularly the positive electrode active material layer. However, there is a problem in that it is easily peeled off from the lead-based thin film, which makes the life relatively short.

An object of the present invention is to provide a sealed lead acid battery capable of preventing the active material layer from peeling off from the lead-based thin film without impairing the feature of being thin and having high energy density. .

[0005]

The sealed lead-acid battery of the present invention has a structure in which a lead-based thin film made of lead or a lead alloy is formed on a plastic film substrate, and an active material layer is formed on the thin film. In a sealed lead-acid battery having, an active material support is integrally formed on a lead-based thin film, and an active material layer is formed on the lead-based thin film so that the active material support is embedded therein,
The active material support is characterized in that at least the surface of the support is dispersed in a dot or linear shape made of lead or a lead alloy.

Further, the following configuration may be adopted. The active material support is formed by coating lead or lead alloy on the surface of a base material that is not corroded by the electrolyte. The active material support has a mesh shape.

Therefore, the present invention is greatly different from the conventional example in that the active material support is integrally formed on the lead-based thin film,
The active material layer is formed on the lead-based thin film so that the active material support is embedded therein, and the active material support has at least a surface in the form of dots or lines made of lead or lead alloy. The point is that they are configured by being scattered.

[0008]

In the structure according to the first aspect, the active material layer is three-dimensionally adhered to the lead-based thin film via the active material support. In the structure according to the second aspect, even if the corrosion of the active material support proceeds, the base material remains, and the function of the active material support is exhibited unchanged. In the structure according to the third aspect, the active material support is more strongly supported by the active material support, and the flexibility of the active material layer is improved.

[0009]

1 is a plan view showing the inside of a sealed lead acid battery of the present invention, and FIG. 2 is a vertical sectional view of the sealed lead acid battery of the present invention. FIG. 2 corresponds to the II-II cross section of FIG. In the figure,
Reference numeral 1 is a plastic film forming a closed case of this battery, and 2 is a lead-based (lead or lead alloy) thin film formed on a plastic film (substrate) 1 in the closed case. The thin film 2 is formed by, for example, a resistance heating type vacuum deposition method via an adhesive layer, or a method of superposing the substrate 1 via the adhesive layer and hot-pressing to laminate. Reference numeral 3 denotes an active material layer formed on the thin film 2, which is composed of a positive electrode active material layer 3a and a negative electrode active material layer 3b.
The positive electrode active material layer 3a and the negative electrode active material layer 3b are formed on the same plane, and the opposite end faces of the both active material layers 3a and 3b alternately project to the other side and are equally spaced. The thin film 2 and the active material layer 3 have the same planar shape. The active material layer 3 is formed by applying the active material by screen printing,
It is formed by performing ordinary chemical conversion treatment. Reference numeral 5 is an electrolyte provided between the end faces of the positive electrode active material layer 3a and the thin film 2 below it, and the negative electrode active material layer 3b and the thin film 2 below it. 6 is a safety valve.

In the present invention, the active material support 10 is integrally formed on the thin film 2, and the active material layer 3 is formed on the thin film 2 so that the active material support 10 is embedded therein. ing. As shown in FIG. 3, which is a partially enlarged view of the active material support 10 in which the active material layer 3 is not formed, the fibrous materials 11 are scattered in a mesh shape. Has been done. FIG. 4 is a view on arrow IV in FIG. As shown in FIG. 5, the fibrous material 11 is formed by forming a coating layer 13 made of lead or a lead alloy on a base material 12 made of a substance that is not corroded by the electrolyte 5, for example, glass, synthetic fiber, carbon or the like. . Examples of such a mesh-like active material support 10 include a woven cloth, a non-woven cloth, a net, and a foam made of the fibrous material 11.

In the lead-acid battery having such a structure, the active material layer 3 is formed on the thin film 2 so that the active material support 10 integrated with the thin film 2 is embedded therein. The material layer 3 has thin films 2 and 3 via the active material support 10.
It is dimensionally closely attached. Therefore, even if the volume of the active material layer 3 changes when charging and discharging are repeated, the active material layer 3 is formed into the thin film 2.
It is difficult to peel it off. Moreover, since the active material support 10 is in the form of a mesh, the active material layer 3 is more firmly supported and the flexibility of the active material layer 3 is improved, and the active material layer 3 is further peeled from the thin film 2. It's getting harder. This prevents the active material layer 3 from peeling off from the thin film 2 and exhausting the battery life, thereby improving the life performance.

Moreover, the active material support 10 has a coating layer 1 of lead or lead alloy on the surface of a base material 12 which is not corroded by the electrolyte 5.
Since it is composed of the fibrous material 11 in which 3 is formed, the base material 12 is surely left even if the corrosion progresses, and the function of the active material support 10 is exhibited unchanged. Therefore, the active material layer 3 is supported for a long time, and the life performance is surely improved.

When the base material 12 is carbon,
The conductivity of the active material support 10 is improved, and the decrease in reactivity in the active material layer 3 is prevented.

As the active material support 10, it is also possible to use a support composed of fibrous substances 11 scattered without being entangled as shown in FIG. Also, as shown in FIG.
You may use what was comprised by scattering the dot-shaped thing (for example, spherical object) 11a. The dot-shaped material 11a is made of lead or a lead alloy, or the surface of a dot-shaped base material is coated with lead or a lead alloy.

The fibrous material 11 may be made of lead or lead alloy as shown in FIG. 8 or may be hollow as shown in FIG. 9 made of lead or lead alloy.

Further, as shown in FIG. 10, the active material support 1
If a part of 0 is covered with the acid-resistant resin 14, corrosion of the covered part is prevented, so that the sustainability of the function of the active material support 10 is improved.

Further, as shown in FIG. 11, the mesh-like active material support 10 may be provided so as to exist also in the portion where the electrolyte 5 exists. In this case, it is assumed that the fibrous material 11 existing in the portion where the electrolyte 5 is present is made of only the base material 12, and the base material 12 is made of non-conductive glass, synthetic resin or the like. According to this, the fibrous material 11 existing in the portion where the electrolyte 5 is present exerts functions such as retention of the electrolyte 5 and good contact between the active material layer 3 and the electrolyte 5, and thus the life of the battery. Performance is improved.

It is needless to say that the shape and density of the active material support 10 are determined in consideration of the ease of forming the active material layer 3, the battery capacity and the like.

Next, examples of the present invention will be compared with comparative examples. (Example) An active material support 10 made of a lead-based nonwoven fabric having a basis weight of 300 g / m ² and a thickness of 100 μm was integrated on a lead-based thin film 2 made of a lead alloy and having a thickness of 200 μm.
An integrated film of μm was formed. Then, the integrated film and the polyolefin-based plastic film substrate 1 were overlapped with each other with an adhesive layer interposed therebetween, and this was heated and pressed by a hot press machine to be laminated to form an integrated film on the substrate 1. Next, a lead paste, which is an active material, is applied onto the thin film 2 by a screen printing method so as to have a thickness of 300 μm, and is left at a temperature higher than room temperature for several days to leave the lead paste and the thin film 2
And the active material support 10 was bonded. After that, the lead paste layer was made into an active material layer 3 composed of a positive electrode active material layer 3a and a negative electrode active material layer 3b by an ordinary chemical conversion treatment method.

The dimensions of the battery thus produced are
The thickness was 0.65 mm, the length was 50 mm, the width was 78 mm, the weight was 4.9 g, and the volume was 2.5 cc. In terms of battery performance, the battery capacity at a 20-hour rate is 48 mAh, the energy density is 20 Wh / kg, 38 Wh / liter,
It had practically sufficient characteristics. Furthermore, the depth of discharge is 75%,
A charge / discharge cycle test was carried out at a temperature of 25 ° C., and it was found that the battery had a life of about 380 cycles and had excellent durability.

Comparative Example A battery was manufactured in the same manner as in Example except that the active material support 10 was not used. The size and volume of this battery are the same as in the above example, but the weight is 4.7.
It was g. The battery performance is such that the battery capacity at the 20-hour rate is 50 mAh, the energy density is 21 Wh / kg,
It was Wh / liter and had practically sufficient characteristics. Further, a charge / discharge cycle test was carried out under the same conditions as in the example, and the life was about 200 cycles, which was sufficient durability.

As can be seen from the above, the life performance of the example is about two times better than that of the comparative example. It is considered that this is because the active material layer 3 and the thin film 2 are firmly adhered to each other via the active material support 10 and the active material layer 3 is less likely to be separated from the thin film 2.

[0023]

Since the present invention is constructed as described above, it has the following effects.

According to the sealed lead-acid battery of claim 1,
Since the active material layer 3 is three-dimensionally adhered to the thin film 2 via the active material support 10, the active material layer 3 can be hardly peeled from the thin film 2, and the active material layer 3 is peeled from the thin film 2. It is possible to prevent the battery life from running out and improve the life performance. Moreover, since the active material support 10 on the thin film 2 is embedded in the active material layer 3, the thickness of the battery size is not increased and the energy density is not reduced. Therefore, the thin and high energy density sealed lead-acid battery does not impair the thin and high energy density feature.

According to the sealed lead-acid battery of claim 2,
Even if the corrosion of the active material support 10 progresses, the function of the active material support 10 is exerted by the base material 12 without change.
The active material layer 3 can be supported for a long time, and the life performance can be surely improved.

According to the sealed lead-acid battery of claim 3,
Since the active material support 10 is in the form of a mesh, the active material layer 3 can be more firmly supported, the flexibility of the active material layer 3 can be improved, and the active material layer 3 can be more hardly peeled from the thin film 2. . Therefore, the life performance can be further improved.

[Brief description of drawings]

FIG. 1 is a plan view showing the inside of a sealed lead-acid battery of the present invention.

FIG. 2 is a vertical cross-sectional view of the sealed lead-acid battery of the present invention,
It is a figure corresponding to the II-II cross section of FIG.

FIG. 3 shows the state of FIG. 1 in a state where no active material layer is formed.
FIG.

FIG. 4 is a view on arrow IV in FIG.

FIG. 5 is a cross-sectional view of a fibrous material.

FIG. 6 is a plan view showing another example of the active material support.

FIG. 7 is a plan view showing still another example of an active material support.

FIG. 8 is a cross-sectional view showing another example of a fibrous material.

FIG. 9 is a cross-sectional view showing still another example of a fibrous material.

FIG. 10 is a plan view showing still another example of an active material support.

FIG. 11 is a cross-sectional view showing another example of how to provide an active material support.

[Explanation of symbols]

1 plastic film substrate 2 Lead-based thin film 3 Active material layer 10 Active material support 11 Fibrous material 12 Base material 13 Coating layer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroto Nakajima             6-6 Josaimachi, Takatsuki City, Osaka Prefecture Yuasa Battery Co., Ltd.             Inside the company (72) Inventor Satoru Okada             6-6 Josaimachi, Takatsuki City, Osaka Prefecture Yuasa Battery Co., Ltd.             Inside the company (72) Inventor Toshio Horie             1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo             Inside Telegraph and Telephone Corporation

Claims (3)

[Claims] 1. A sealed lead-acid battery having a structure in which a lead-based thin film made of lead or a lead alloy is formed on a plastic film substrate, and an active material layer is formed on the thin film.
An active material support is integrally formed on a lead-based thin film, and an active material layer is formed on the lead-based thin film so that the active material support is embedded in the active material support. A sealed lead-acid battery, characterized in that it is configured by scattering dot-shaped or linear-shaped lead alloys. 2. The sealed lead acid battery according to claim 1, wherein the active material support is constituted by coating a surface of a base material which is not corroded by an electrolyte with lead or a lead alloy. 3. The sealed lead-acid battery according to claim 1, wherein the active material support has a mesh shape.