JPH0550809B2 - - Google Patents

Description

[Detailed description of the invention] Industrial applications The present invention relates to a sealed lead acid battery.

Conventional technology Conventionally, sealed lead-acid batteries have been made by stacking a certain number of positive electrode plates, negative electrode plates, and separators in a predetermined order to form an electrode plate group, which is then molded into a box-shaped synthetic resin electric cell made by injection molding. It was manufactured in storage.

Problems to be Solved by the Invention In recent years, devices using sealed lead-acid batteries have become smaller, and batteries are increasingly required to be lighter, smaller, and thinner. In order to meet these demands,
A battery having a structure as shown in FIG. 4, in which the electrode plate group is wrapped with a synthetic resin film or sheet 13, has been proposed (Japanese Patent Application Laid-Open No. 60-205958,
-230354).

However, in sealed lead-acid batteries, in order to prevent the electrolyte from leaking during use and to allow the negative electrode to absorb oxygen generated from the positive electrode during charging, the amount of electrolyte can be freely stored inside the battery by simply impregnating the electrode plates. It is strictly limited to the extent that no electrolyte exists, and therefore the adhesion between the electrode plate and the separator is extremely important. Fourth
In the proposal shown in the figure, the sheet or film 13 is made of a laminate containing a layer of synthetic resin that is difficult for water vapor and oxygen to pass through, so water in the electrolyte may be lost during use or may enter from the outside. Although the risk of significant deterioration of the negative electrode plate due to the oxygen produced by the oxygen has been reduced, the pressure necessary to always maintain sufficient contact between the electrode plate and the separator cannot be obtained, and as a result, the result is as shown in Figure 5. The battery must be housed in a more rigid container 15 made of synthetic resin or metal (Japanese Unexamined Patent Publication No. 195865/1986), which naturally limits the ability to make the battery thinner. Moreover, a complicated process of wrapping the electrode plate group in a laminate sheet or film 13 is required, which poses a major problem in that it is difficult to reduce the cost.

The present invention aims to solve the above-mentioned problems and provide a sealed lead-acid battery that applies good pressure to the electrode plate group, reduces the thickness of the battery, and is easy to manufacture.

Means for Solving the Problems In order to achieve this object, the sealed lead-acid battery of the present invention houses a group of electrode plates in a synthetic resin frame into which lead or lead alloy terminals are insert-molded. After the electrode plate ears are electrically connected to the terminals by a method such as arc welding, a laminate film or sheet having at least one surface layer made of a material similar to that of the frame is attached to the frame from both sides of the frame. This is a storage battery in which a layer of the same type of material is welded toward the frame using a method such as ultrasonic welding.

Effect: As a result, even if a laminate film or sheet with low rigidity is used, the rigidity of the frame compensates for this, and the electrode plate group can be kept in a good pressurized state.
Furthermore, since the assembly can be performed based on a frame of a fixed shape, manufacturing is much easier and costs can be reduced compared to the conventional method of wrapping only with a sheet or film.

Example An embodiment of the present invention will be described with reference to the drawings.

FIG. 4 shows a proposal for a conventional battery structure disclosed in Japanese Patent Application Laid-Open No. 60-230354. 2 electrode groups
It is wrapped in a sheet or film 13, and the terminals 14 are exposed on the welding surface.
A storage battery having such a structure must be housed in a rigid container 15 as shown in FIG. 5 in order to pressurize the electrode plate group, and there is a limit to how thin the battery can be made to be.

As shown in FIG. 2, the storage battery of the present invention is characterized by having a rectangular frame 1 made of synthetic resin into which terminals 2 made of lead or lead alloy are insert-molded. As shown in FIGS. 1 and 3, a group of electrode plates consisting of a positive electrode plate 5, a separator 6, and a negative electrode plate 7 is housed inside the frame 1, and the ears of the electrode plates are welded to the terminals 2 by a method such as spot welding. electrically connected.
Laminates 4 and 4' shown in FIGS. 1A and 1B are welded to both sides of the frame 1 by a method such as ultrasonic welding. Therefore, the layer 10 of the laminates 4, 4' in contact with the frame 1 is preferably made of the same material as the frame 1, and polypropylene resin, high-density polyethylene resin, etc. are suitable.

The frame 1 is provided with an exhaust hole 3, and when the internal pressure of the storage battery rises abnormally due to overcharging or the like, a safety valve 9 opens to release the internal pressure to the outside. Reference numeral 8 denotes a lid that prevents the safety valve 9 from falling off, and is attached to the frame 1 by a method such as ultrasonic welding.

The laminates 4, 4' have at least one polyvinylidene chloride layer 11 inside to prevent deterioration of battery performance due to permeation of water from inside the battery and intrusion of oxygen from outside the battery. The thickness of the polyvinylidene chloride layer 11 varies depending on the use of the storage battery, and is about 2 to 30 μm.

As the outermost layer 12 of the laminates 4, 4', polypropylene resin is sufficiently practical, but polyethylene terephthalate resin is selected if high-temperature strength is particularly required depending on the application. It was found that this allows for practically sufficient strength to be obtained even in an atmosphere of about 30°C.

If the strength of the synthetic resin frame 1 is still insufficient depending on the use or the size of the storage battery,
Laminate 4, 4' layer 10 in contact with frame 1
Use a metal or alloy such as aluminum or SUS316 for the other layer. The thickness of the metal or alloy layer is selected to be about 10 to 1000 μm depending on the required strength. This provides practically sufficient strength even in an atmosphere of about 120°C.

Effects of the Invention As described above, the present invention makes the storage battery thinner while maintaining sufficient pressure on the electrode plate group, and does not require processes such as forming the laminate into a complicated shape, making it easy to manufacture. A sealed lead acid battery is obtained.
In addition, by using polyethylene terephthalate resin for the outermost layer of the laminate, a sealed lead-acid battery that can withstand high temperatures of up to approximately 80°C can be obtained, and by using metal or alloy for one layer of the laminate, a sealed lead-acid battery that can withstand high temperatures of up to approximately 120°C can be obtained. The industrial value is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view in the thickness direction of the electrode plate group of a sealed lead-acid battery showing an embodiment of the present invention, FIG. 1A and FIG. 1B are enlarged views of the laminate used in the battery of FIG. 1, Figure 2 is a perspective view of the frame used in the battery shown in Figure 1, Figure 3 is a cross-sectional view of the battery shown in Figure 1 in the width direction of the electrode group, and Figure 4 is an example of a conventional sealed lead-acid battery. FIG. 5 is a sectional view showing another example. 1 is a frame, 2 is a terminal, 4 and 4' are laminates, 5 is a positive electrode plate, 6 is a separator, and 7 is a negative electrode plate.

Claims (1)

[Scope of Claims] 1. A sealed lead-acid battery in which a group of electrode plates is housed in a synthetic resin container, which has a synthetic resin frame into which lead or lead alloy terminals are insert-molded; A group of electrode plates is inserted into the frame, the electrode plate ears are electrically connected to the terminals, and a laminate film or sheet having at least one surface layer made of a material similar to that of the frame is inserted from both sides of the frame. A sealed lead-acid battery characterized by a layer of material similar to that of the frame welded toward the frame. 2. Claim 1, characterized in that the laminate that is welded from both sides of the frame is a laminate that has at least one layer of polyvinylidene chloride resin inside and has polyethylene terephthalate resin as the outermost layer. Sealed lead acid battery. 3 The laminate is welded from both sides of the frame.
At least one layer other than the layer directly in contact with the frame
The sealed lead-acid battery according to claim 1, characterized in that the layer is made of metal or alloy.