JPS5942761A - Lead-acid battery - Google Patents

Abstract

PURPOSE:To suppress mud generation at high temperature and eliminate insufficient charging at low temperature to keep good life performance by installing a belt-shaped strip which warps inside or outside a container side wall according to temperature. CONSTITUTION:A cross-shaped plate strip 2 is embedded on the surface, parallel to an electrode group, of a container 1 while the container is made by for example, injection molding. The plate strip 2 is formed with a bimetal or a shape memory alloy which warps outside a container side wall at low temperature and inside it at high temperature. By this function, since an electrode group is compressed at high temperature, generation of mud is suppressed, and since gas generating in charging at low temperature is exhausted outside, increase of apparent resistance of electrolyte is minimized and insufficient charging is prevented. Therefore, good life performance is obtained over wide environments.

Description

[Detailed description of the invention] The present invention relates to lead acid batteries.

Lead-acid batteries are used in a variety of environments, and even if we look only at lead-acid batteries for automobiles, they must maintain the ability to start the engine reliably for a long period of time under all conditions, from midsummer to the depths of winter. In order to conserve resources and energy, automobile lead-acid batteries are forced to become smaller and lighter, and the required performance is becoming more and more severe.

Previously, lead-acid battery containers were made using ebonite, but now they are made from polypropylene resins, such as acrylonitrile butadiene styrene resin, and their walls are becoming thinner and thinner to reduce weight.

Lead Mj? One of the factors that governs the lifespan of a Ci pond is a phenomenon called sludge formation of the anode plate active material, and it is effective to pressurize the electrode plate group in suppressing this phenomenon. It is well known that when assembling a battery, the electrode plates are applied and inserted into the battery case, but as lead-acid batteries are used at high temperatures, the thermoplastic polypropylene resin-based battery case
There seems to be a tendency for it to gradually swell and the pressure to be applied to it to become smaller.

As a result, the period of use was long (as it turns out, the anode active material became muddy at a faster rate, resulting in a shortened lifespan).

In order to prevent this phenomenon, if the pressure when inserting the plate group is too high, the gas generated during charging during use at low temperatures will not be smoothly discharged from the plate group, and electrolysis will occur. The apparent resistance of the electrolyte increases as the solution contains many air bubbles, which impedes the progress of the charging reaction and shortens the lifespan due to insufficient charging.It also poses various manufacturing difficulties. Therefore, it is not preferable to make the initial addition too high.

An object of the present invention is to provide a lead-acid battery that suppresses sludge formation even at high temperatures, does not become insufficiently charged even at low temperatures, and exhibits good life performance under all environments.

An embodiment of the present invention will be described. In FIG. 1, a cross-shaped plate piece 2 is embedded in a surface parallel to the electrode plate group (not shown) of the electrode 61 during injection molding. As shown in Figure 2, this plate #Jr2 pushes out the side wall of the battery case toward the outside of the battery as shown by the broken line a under low temperatures, and pushes the side wall toward the inside of the battery as shown by the solid line under high temperatures. Bimetals are examples of materials that provide this kind of action, and any material that warps depending on the temperature can be used. The resulting shape memory alloy exhibits good effects.

In a lead-acid battery constructed in this way, the side walls warp inward at high temperatures, and even in a thin-walled battery case made of thermoplastic resin, the electrode plates are subjected to 1111 pressure, which prevents the progress of sludge formation. As the side walls warp outward at low temperatures, the gas generated during charging is smoothly discharged to the outside of the electrode plate group, so the apparent resistance of the electrolyte does not increase much, leading to insufficient charging. As a result, it can exhibit an excellent lifespan under a wide range of environments.

Figure 3 shows the relationship between temperature and life.

While the lifespan of conventional products is significantly shortened at low or high temperatures, the product of the present invention has good service life over a wide range of temperatures from low to high temperatures. So-called sealed lead-acid batteries, which have virtually no free electrolyte, have been attracting attention, and the present invention is particularly effective in this sealed lead-acid battery.

Sealed lead-acid batteries are charged and discharged using an electrolytic solution impregnated in the electrode plates or separators or sulfuric acid contained in gelled colloidal silica, so the electrode plate surface and the separator or the electrode plate surface and the gelled electrolyte are connected. Is the quality of adhesion between lead acid? Because it largely controls the performance of the battery, it has the disadvantage that when the battery case loses its pressurizing ability, especially at high temperatures, the charging and discharging performance deteriorates rapidly.

) However, the sealed lead-acid battery adopting the container structure according to the present invention maintains good adhesion between the electrode plate surface and the separator or between the electrode plate surface and the gel electrolyte even at high temperatures.
l. It can prevent sudden deterioration of charging and discharging performance, and it can extend the performance as a portable power supply and power supply device in the cordless era for a long time.
It becomes possible to maintain the temperature stably for 1 hour.

As described above, the lead-acid battery of the present invention has excellent life performance and charging/discharging performance in all environments from high to low temperatures, and has enormous industrial value.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a battery case used in one embodiment of the present invention;
The figure is an explanatory diagram showing the deformation state of the side wall of the battery case at low temperature and high temperature in the battery case in Figure 1, and Figure 3 is a comparative curve diagram showing the relationship between temperature and life of the product of the present invention and the conventional product. . ■ is the battery case, 2 is the plate-like piece, a is the position of the side wall of the battery case at low temperature,
b is the position of the side wall of the battery case at high temperatures Patent applicant Shin-Kobe Electric Co., Ltd. Representative Director Stone 9;

Claims (4)

[Claims] (1) On the side wall of the battery case parallel to the electrode plate, there is a strip or plate-like piece that pushes the side wall toward the outside of the battery at low temperatures and pushes the side wall into the interior of the battery at high temperatures. A lead-acid battery characterized by: (2) Lead Wf according to claim 1, characterized in that a bimetal is used as the band-like or plate-like W.
7r1 pond. (3) The lead-acid battery according to claim 1, characterized in that a shape memory alloy is used as the strip or plate-like piece. (4) The lead-acid battery according to any one of claims 1 to 3, characterized in that the battery is a so-called sealed lead-acid battery having substantially no free electrolyte. .