JPH0652852A - Negative electrode plate for lead-acid battery and sealed thin lead-acid battery - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the thickness of a thin sealed lead-acid battery and enable high energy density. [Structure] An active material paste is filled in a paste filling concave portion formed in a retainer 1 to form an active material layer 2. A current collector 3 made of lead or lead alloy foil is bonded onto the active material layer 2 to form a cathode plate. By arranging this cathode plate on both sides of the anode plate 4 via the retainer 1, the electrode plate group 5 is constructed. The electrode plate group 5 is stored in the battery case 11 of the film pack.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin sealed lead acid battery and a cathode plate for lead acid battery suitable for use in this battery.

[0002]

2. Description of the Related Art A typical example of a thin sealed lead acid battery is a so-called film pack type sealed lead acid battery. This type of battery is superior in that it can provide a thin and lightweight lead storage battery as compared with a small sealed lead storage battery using a monoblock battery case that has been known for a long time. Typically, an electrode plate group including one anode plate, one retainer, and one cathode plate is housed in a battery case made of a film- or sheet-shaped synthetic resin body. However, even in this type of battery, in order to increase the capacity, it is necessary to adopt a configuration in which the cathode plate is a paste type electrode plate and two cathode plates are arranged on both sides of the anode plate. Become.

[0003]

The paste-type cathode plate which is widely used at present is prepared by applying a cathode paste to a collector such as a casting grid, an expanded grid, or a punched grid, and aging and drying the electrolytic solution. A cathode plate having an active material layer is obtained by reduction. However, the thickness of the cathode plate cannot be made thinner than about 1 mm as long as the structure in which the current collector supports the active material layer like the conventional cathode plate is taken, and this is the case when two cathode plates are used. This is a major obstacle to making batteries thinner. Further, in a conventional thin sealed lead-acid battery using a cathode plate, it is difficult to improve the weight energy density.

It is an object of the present invention to provide a cathode plate for a sealed lead-acid battery which is thin and which can achieve high energy density.

Another object of the present invention is to reduce the thickness of a storage battery even when using an electrode plate group in which two cathode plates are arranged on both sides of the anode plate in order to increase the utilization rate of the anode plate. Another object of the present invention is to provide a thin sealed lead-acid battery that can achieve high energy density.

[0006]

According to a first aspect of the present invention, there is provided a cathode plate for a lead storage battery, which is formed by a retainer provided with a paste filling recess and an active material paste filled in the paste filling recess. It is composed of a material layer and a current collector made of a foil of lead or a lead alloy bonded on the active material layer.

According to a second aspect of the present invention, an electrode plate group in which two cathode plates are arranged on both sides of the anode plate is formed by using the cathode plate of the first aspect, and the thin plate hermetically sealed by using the electrode plate group. Form a lead acid battery.

[0008]

In the cathode plate used in the first and second aspects of the present invention, since the retainer having the recess for filling the paste serves as the support for the active material layer, a thin lead or lead alloy foil is used as the current collector. Can be used, and it is possible to reduce the thickness and weight, and it is possible to significantly increase the weight energy density. In addition, since it is possible to increase the amount of the active material paste to be filled and to form the active material layer by filling the paste filling concave portion with the active material paste, it is possible to increase the capacity.

[0009]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 (A) is a partially cutaway perspective view showing the configuration of an embodiment of the cathode plate of the present invention, and FIG. 1 (B) is shown in FIG.
It is a BB line sectional view of (A). In these figures,
1 is a retainer having a paste filling recess 1a,
Reference numeral 2 is an active material layer, and 3 is a current collector made of lead or lead alloy foil. The retainer 1 is formed of glass non-woven fabric or the like as in the conventional case. In the illustrated example, the paste filling recess 1a is formed by forming an annular weir 1b projecting to one side surface (front surface) side. It is formed. An annular groove 1c formed on the other side surface (rear surface) side of the retainer 1 so as to face the dam portion 1b is formed by an annular convex portion formed around a metal mesh used when the retainer 1 is made into paper. It is a thing. When performing the paper making of the retainer using the metal mesh for paper making having the annular convex portion,
Retainer material fibers such as glass fibers are deposited on the annular convex portion in a state of being raised more than other portions. After the papermaking, the metal mesh is dried together with the metal mesh, and the retainer is peeled from the metal mesh after the drying, so that the retainer having the paste filling concave portion 1a can be obtained as illustrated. By the way, the thickness D1 of the base portion of the retainer 1 produced in the test was about 0.8 mm, and the height D2 of the dam portion 1b was about 0.6 mm.

The active material paste to be filled in the paste filling concave portion 1a of the retainer 1 has a viscosity lower than that of the paste used in the case of manufacturing an ordinary paste type cathode plate. This is to improve the filling property of the paste. Even if the viscosity is lowered, the viscosity is not so low that the filled paste easily leaks from the porous portion of the retainer. Before drying the active material paste,
A current collector 3 made of lead or lead alloy foil is pressed onto the undried active material paste layer, and then the conventional aging,
After drying, a target retainer-integrated cathode plate was obtained. The current collector used for the test was a punched lead foil having a thickness of 80 μm. In the test cathode plate thus manufactured, the thickness of the retainer was about 0.8 mm, and the thickness of the cathode portion, which was the total thickness of the active material layer 2 and the current collector 3, was about 0.65 mm.

FIG. 2 is a schematic sectional view of an embodiment of the thin sealed lead-acid battery of the present invention using the cathode plate shown in FIG.
In this storage battery, the cathode plates shown in FIG. 1 are stacked on both sides of a conventionally used paste type anode plate 4 having a thickness of about 1.0 mm so that the retainers 1 and 1 face the anode plate 4 side. The plate group 5 is configured. In this embodiment, in order to protect the electrode plate group, the electrode plate group is wrapped with a shrink film that shrinks when heat or the like is applied, and the film is shrunk (shrinked) to pack the electrode plate group. The pack applies a pressing force to the electrode plate group in the thickness direction. Note that, in FIG. 2, the cathode terminal 6 and the anode terminal 7 are schematically shown. The cathode terminal 6 may be connected to the current collectors 3, 3 by a conductive adhesive or spot welding, and the cathode terminal 6 is provided when punching the lead or lead alloy foil forming the current collector 3. Alternatively, the current collector 3 having the cathode terminal 6 integrally formed therein may be formed in advance by punching into a different shape. Reference numeral 8 is a terminal holder made of synthetic resin that can be heat-welded. The holder 8 to which the cathode terminal 6 and the anode terminal 7 are fixed and the electrode plate group 5 are wrapped with two film-shaped or sheet-shaped synthetic resin bodies 9 and 10,
The battery case 11 was formed by heat-welding the periphery of the synthetic resin bodies 9 and 10. Note that, in FIG. 2, the synthetic resin bodies 9 and 10 are not shown in thickness. The total thickness of the storage battery prepared under the same conditions as the conventional structure and manufacturing method except for the above-mentioned retainer-integrated cathode plate was 4.1 mm. At the same 4.1 mm, a similar storage battery was also prepared with a conventional anode plate and a cathode plate through a retainer, and a capacity test was performed to calculate the weight energy density. Each of the storage batteries used in the test was 13 in number, and a discharge test for 5 hours was performed. The weight energy density of the storage battery of the present invention was 49.2 wh / kg, whereas that of the conventional storage battery was 32.4 wh / kg. The storage battery of the present invention realizes about 1.5 times the weight energy density of the conventional storage battery.

The utilization rate of the anode plate of the battery of the present invention is about 50.
%, Which is the value for one conventional anode plate and one cathode plate.
It is a value that cannot be realized by the utilization rate of one anode plate. In the sealed lead-acid battery of the present embodiment, by integrating the retainer and the cathode plate, one sheet of positive electrode and two sheets of cathode plate in a thin sealed lead-acid battery with a thickness of about 4 mm, which could not be produced by the conventional technique. The configuration can be realized very easily. As a result, the weight energy density can be improved to about 1.5 times that of the conventional battery. Further, when the cathode plate of the present invention is used, since the retainer and the cathode plate are integrated, they have the advantages that they are easy to handle even when the thickness of the electrode plate is thin and the production time can be shortened. Further, since the retainer is provided with the weir, the weir prevents the short circuit with the anode plate. As described above, the present invention is of great industrial value in that a thin high energy density sealed lead acid battery can be easily realized.

[0013]

According to the present invention, since the retainer provided with the paste filling recess serves as the support for the active material layer, a thin lead or lead alloy foil can be used as the current collector, and the storage battery can be used. It has the advantages that it can be made thinner and lighter, and that the weight energy density of the sealed lead acid battery can be greatly increased.

[Brief description of drawings]

FIG. 1A is a partially cutaway perspective view illustrating a configuration of an embodiment of a cathode plate of the present invention, and FIG.
It is a BB line sectional view of (A).

FIG. 2 is a schematic vertical sectional view of a thin sealed lead-acid battery of the present invention.

[Explanation of symbols]

 1 Retainer 2 Active Material Layer 3 Current Collector 4 Anode Plate 5 Anode Plate Group 6 Cathode Terminal 7 Anode Terminal 8 Terminal Holder 9,10 Film- or Sheet-shaped Synthetic Resin Body 11 Battery Case

Claims (2)

[Claims] 1. A retainer having a recess for paste filling,
Lead acid battery comprising an active material layer formed by filling the paste filling recess with an active material paste, and a current collector made of a lead or lead alloy foil bonded on the active material layer. Cathode plate. 2. A thin hermetically sealed type in which an electrode plate group formed by superimposing two cathode plates with an anode plate sandwiched therebetween is housed in a battery case made of a film-like or sheet-like synthetic resin body. In a lead storage battery, the two cathode plates are a retainer having a paste filling recess, an active material layer formed by filling an active material paste in the paste filling recess, and the active material layer is formed on the active material layer. And a current collector made of a lead or lead alloy foil bonded together, wherein the electrode plate group is formed by superimposing the two cathode plates so as to bring the retainer into contact with the anode plate. Type sealed lead acid battery.